Layout of centerlines

I'm faced w/ laying out some centerlines on my x axis. This normally wouldn't be a huge issue on a smaller machine, however in my case the centerline is 240" long and must be pefectly straight. I'm laying out the center line for mounting my linear rails and I've found that these rails aren't nesc. perfectly straight right out of the box. Mine have ever so slight a curve to them. This isn't really an issue as they are bolted down every 60mm and this can be taken out of them. But how do I get their mounting holes [in the sub structure] straight before the install? I'm not going to D&T their mount holes but rather just drill oversize mount holes and then add a nut to the bottom of the mnt bolt. I've got holes in the side of the mnt structure to reach through and put the nut on. This will allow me some lattitude to get things parrellel and sqr w/ the opposite rail [ which is 10' away]. However I do need to start w/ a master rail which is perfectly straight, and the second rail will then be slaved/matched to it. I thought about using fishing line and feeler gauges, any other suggestions?? I don't think a heavy pc of CRS would be straight enough would it?? Is there some trade secret out there that someone could pass on?? My sub-structure [ which the rails mount to] is composed of welded HSS, its very straight, but there are no garrentee's that there isn't a 1/32" [its small if there is any] bow in them [side to side] so measuring off the side of them isn't an option. I'm potting the rails down w/ Moglice so the elevation isn't an issue [ if there is slight warpage from welding]. I've purchased a master precision level [ 0.0005" level accuracy over 10"] which when used in conjuction w/ jig blocks that fit the rail and two set screws per jig block, I can get the rail as flat and level as it needs to be, I just don't know how to get the mount holes laid out perfectly straight. And once the rails are mounted there is still going to be the need to bolt them down straight w/out and curves in them.
Suggestions and opinions welcome as always.
Jerry

I'm faced w/ laying out some centerlines on my x axis. I thought about using fishing line and feeler gauges, any other suggestions??
Jerry

Hello Jerry,
You could try using a laser level and use the beam as a reference, but, from my experience, the laser dot is always too big and it is hard to detect where the edge (or centre) of it is.
Your idea of fishing line and feeler gauges would be hard to use IMHO. It would be hard to detect when the gauge is touching........hence this mad idea...
Don't use fishing line, use thin solid copper wire (not insulated) , and get it really tight. Connect one end of the wire to a small battery's positive terminal. Connect the negative terminal to one side of a small bulb or buzzer. Connect the other side of the buzzer/bulb to a flying lead which goes to your metal feeler gauge. Make sure your copper wire and feeler gauge are completely free of grease and oxide. Bingo!
It should work.
Regards
Martin

Steel Music Wire tie off one end and hang a weight on the other end
http://www.shopaid.com/music.htm

You are probably correct that a length of CRS would not be straight enough for what you need; but it would be stable so what you need to do is get a piece and calibrate it. If you know the deviation from straight every 100 mm that would be good enough. Use the piano wire idea; I have uploaded a picture showing how you would stretch the wire along the length of cold rolled with identical size insulated spacers each end (glass rod maybe?). You are not worried about the exact distance between the wire and the bar just the difference from one point to another so rather than feeler gauges use the tapered wedge I show in the second picture. You hold this flat against the edge of the bar and slide it in until your electric circuit is completed. If the length is around 10 inches and the taper is something like .040 over the full length then 1/4" of movement of the wedge corresponds to 0.001.
Just mark which end of the bar you start your calibration table from.

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Dear Geof,
Brilliant!
Best wishes,
Martin

Wow, you guys really think outside the box! Some good idea's here.. I was thinking about when I layout the centerline to drill the mount holes [ this stuff usually comes to me when I'm trying to sleep.. i was having a nap this afternoon ] I currently use blue-layout paint.. And If I was to string the fishing line down the top of the frame and then spray w/ blue-layout the string would block someof the paint from getting on the structure and there-by put a line on it right?? Or.. Coat the fishline in oil, and then use it like a chalk line, the blue-layout won't stick to any oil so when it dries you can just wipe to top surface and you'd have a perfect line that way too. I know the layout won't stick to oily area's because there was some oil residue left on the tube from my last drill proceedure and the layout didn't stick in those area's.
Geof, on your CRS idea your thinking to just mark the corrected value/deviation at each location as you move along?? What about any sag in the copper line?? The CRS will only come in 12 [ or is it 10??] foot lengths so its to short to do it in 1 complete shot, you'd have to move it along, say 1/3 of the way and then continue for the next third then move it again, this way you'd have 2/3 of the crs clamped to a known straight edge and then the last 1/3 would be used to align the un-mounted part of the rail??
I'm wondering if I can't use the fish line idea's above and eliminate any of these issues, drill the holes to the proper size for a tight bolt fit [ possibly reamed holes] and be straight enough.. I'm gonna have to think on this a bit more.. maybe even test some ideas..I haven't decided what is an acceptable tolerance for this. I think though, if I had w/in 10thou over the length I'd be happy.. is that to huge or to tight??
Thanks for the idea's guys.. feel free to post more if you think of them!
Jerry

There's some info on this page about using highly tensioned wire to align linear rails. It starts by the 4th picture.
http://oneoceankayaks.com/madvac/machine_frame.htm

Thanks Gerry, I've read that before.. of course it was one of those " I won't ever forget that" kind of things.. which I promptly forgot about. I've emailed that gentleman to find out what multiplication value he used. Also I've been thinking more about this, I wonder if I couldn't use the same wire.. and mount a video camera to the carriage/truck and zoom in on the wire, it wouldn't matter to much how much zoom I got. then connect a screen of some sort [small tv or whatever] overlay it w/ a clear plastic overlay. Draw to lines which locate the edge of the rail and the wire and then adjust the rail as I slide the cammera assembly down the rail.. crazy idea??
I could do the same thing just w/ a microscope mounted to the truck??
Boy this is a long ways away from the route I was thinking of taking.. I gotta say that the "ZONE" is a great place.. filled w/ GREAT people!!
Jerry

Thanks Gerry, I've read that before.. of course it was one of those " I won't ever forget that" kind of things.. which I promptly forgot about. I've emailed that gentleman to find out what multiplication value he used. Also I've been thinking more about this, I wonder if I couldn't use the same wire.. and mount a video camera to the carriage/truck and zoom in on the wire, it wouldn't matter to much how much zoom I got. then connect a screen of some sort [small tv or whatever] overlay it w/ a clear plastic overlay. Draw to lines which locate the edge of the rail and the wire and then adjust the rail as I slide the cammera assembly down the rail.. crazy idea??
I could do the same thing just w/ a microscope mounted to the truck??
Jerry

I have had to do this on an OEM router that never would run without a periodic servo current fault with the trucks bolted tight to the gantry. I used .025 music wire around some bolts fashioned similar to an instrument tuning peg. I first set the top straight, then from the side. Then of course used that rail as the master to re-align the other rail. The problem is where the rails actually have a slight tilt. The bearing trucks have specific class of fit. On our router, the truck specs are around .0015 rail to rail mis-alignment across the width of the truck. As ours does a rapid, you can still hear a minor change in servo load along different areas of the run. The machine runs within spec and no longer faults, but I am still suspicious of why the OEM couldn't do better.
What I do like about the link posted above is using 2 wire lines for each rail bed. If you did this for both rails, then strung another wire across all 4 wires at each end. You should end up with a decent reference plane. If it were tight enough, you could just use a light touch indicator under the wire.
Most rail manufacturers suggest the rail be set against at least 2 machines surfaces. That not always being possible, it is left up to the user to resolve mounting them aligned and free running. Then do it again after a crash.
DC

After re-reading One of Many's post. I went back and re-read the link. I dunno what I was on or smoking but it read totally different this time.. weird. Anyway what I've done.. or am going to try is using a metalurgist microscope to measure the gap between the wire and rail. I will still do the fine wire down the side of the rail and then mount this microscope to the top of the truck and focus it down the side to where the wire is. I figure w/ 10x magnification I should be able to measure the gap down to about 1/10 or less of a mm using the graduations inside the microscope. I'll let ya know if it works.
Jerry

JerryFlyGuy Or you could spend some money on an Ingersoll tight wire alignment kit complete with battery operated sound sensor / headset, micrometer/light indicator etc. Then find some Federal electronic levels for more big bucks. Then, rent them to the rest of us who can't afford them. JUST KIDDING

See picture attached. These are for shafts instead of rails but maybe it will give you some ideas.....
We used something like piano wire yes, attached to a boat winch. We made a notch on one end and the same for the other end. We made sure the notches were accurate to 1/32 of an inch (just use tape measure). We then put the piano wire over the notches, secured it at one end and then used the winch to make it real tight. We then put a tape measure across and marked the hoels respectfully. We then drilled the holes 9/16 (we had a special rotenbrauch bit that could fit on a portamag sooo we went with this route). The bolts for the linear rails are only 1/4" so we have ordered large washers.
Our gantry on the other hand is fully machined. Everything is VERY accurate so the placement of the pillow blocks are ACCURATE. So we will be aligning our shafts with the pillow block. What i mean is move the gantry back and forth and back and forth and tighten it while we do this.
Hope this helps? I am a believer in fine tuning
Also a pic of the shafts mounted on rails on the same surface as the attached pic. http://www.ubcustom.com/cnc/index.php?img=51
Erik

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JerryFlyGuy Or you could spend some money on an Ingersoll tight wire alignment kit complete with battery operated sound sensor / headset, micrometer/light indicator etc. Then find some Federal electronic levels for more big bucks. Then, rent them to the rest of us who can't afford them. JUST KIDDING

RICHARD!!! did your ma' ever yell at ya like that Tell ya what.. you tell me what they cost and where I can get them.. and then I'll rent them for 50% of the original cost w/ a 200% deposit before shipping to you Can you tell me how these choice item's are operated and their proposed alignement tolerance when "used as recommended"??
Jerry [anyone ever used a microscope like I just bought - but don't have it yet]

We then drilled the holes 9/16 (we had a special rotenbrauch bit that could fit on a portamag sooo we went with this route). The bolts for the linear rails are only 1/4" so we have ordered large washers.
Our gantry on the other hand is fully machined. Everything is VERY accurate so the placement of the pillow blocks are ACCURATE. So we will be aligning our shafts with the pillow block. What i mean is move the gantry back and forth and back and forth and tighten it while we do this.
Hope this helps? I am a believer in fine tuning
Erik

Erik, great minds think alike.. I too am using a MAGDRILL and Rotorbrauch bits, I love this thing.. 1.5" hole through 1/4" pl in under 30seconds.. which is a good thing as I have LOTS of these holes to put in. [ I pays to work for a steel fab shop which has all the tools

So, I take it you are planning on floating the Moglice to find it's own level?
Per my previous post. The first thing I did was level the 4 corners and center with our master precision level. When I had one rail straight on 2 planes. I used 2 trucks on that rail as the master. Our old router is only 56 inches rail to rail, 126" long. I made a make shift fixture that bolted the 2 trucks common to a section of angle iron about 12-14" apart. I then made that the base of a right triangle from more of the same angle iron that straddled both rails. A few brackets later, I had this right triangle riding on 3 trucks, bolted only to 2 on the master rail. The slave rail truck just supported the fixture, floating under it, but more importantly the fixture had a 1" travel indicator attached to it. Thereby indicating on the trucks side which helped me set the 2 rails parallel to each other within .001.
Parallel, may be a bit of an over statement, but they do follow each other fairly close regardless of the slight error in the master being copied to the secondary rail.
As I stated before, our rails do not have a decent mounting surface and therefore lean inward. rather than rework the whole mount under each rail, I elected to put shims under the gantry to allow the trucks to run free at a slight tilt. I think the total of the shims was in the .002-.007 range. I hated to do it, but it has been going well now for quite a few years. I just dread a crash since it throws everything off. Then I have to start the swearing all over again!
DC

Well, floating might be a bit to broad of a term. I'm going to jig this rail in space above the main structure, the rail is held down via its mounting bolts, yet held up [every 12"] w/ my little jig's. W/ the two screws on the jig I can tilt as well as elevate [ to level along the length] the rail. this gets me level in two planes, then I have to do the get straight part where the microscope comes into play. I'm 3/4 the way through welding one of my side structures [ which the x-axis rails sit on] and it has a slight [ no suprise really] curl to it of about 1/16" in the center. I'm going to try to pull as much as I can of that out but regardless it won't be perfectly straight, hence the question of how to lay out the centerline of my rail. I need to drill holes for all the mnt locations and while they will be oversize, I'd like them as "in-line" as I can get. Measuring off the side of the tube [structure] isn't going to be good enough. Using a tensioned wire gets me a straight line, then I need to locate my rail in ref to this straight line. I could in theory just move along the rail, clamping it and then using a hole center punch and center punch the hole centers as I move along, use lots of clamps and then take the rail back off and drill them. It might work, but is this measuring w/ a caliper, marking w/ a pc of chalk and cutting w/ a hand axe?? I've got 6mm holes in my rail so an 8 or 9 mm hole would give alot of room for alignment, maybe just mark it out w/ a tight wire and scribe that would get me w/in 0.5mm. Probably close enough. I like your idea for matching the second rail, I think I'll probably use some type of similar system to do mine.
any other idea's on how to get the master rail perfectly straight using the simple tool's I've listed already. Any flaw's you can see in what I plan to do?
Jerry [ I gotta get some Moglice on order]
Ps, the image below show's the rail jig, the red lines are the D&T'd bolts the blue line is the split line of the jig. The notches on the underside of the jig [against the rail] are for sqr keystock mat'l. This is the dam for the moglice.

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Hmmm... If I had to do a low tech layout for a ref line that long, I'd go with the tight bare wire method and use an indicator led to display contact point. Then I'd make up a drill guide jig that could clamp to the side of the base rail and be screw adjusted until the guide bushing came in contact with the wire. Then it's just lock down all adjustments and drill the hole for that location then move on to the next.
Dunno if that made any sense, but it's as clear as I can describe offhand and atm I'm too lazy to draw up any clarifying illustrations
Tiger

Hmmm... If I had to do a low tech layout for a ref line that long, I'd go with the tight bare wire method and use an indicator led to display contact point.
Tiger

Dear Jerry,
If you go the tight wire electrical route, you will need to limit the current to prevent arcing. Arcing will jump the air gap and give bogus contact data. Put a series resistor in the circuit to limit the current to the LED to ,say, 4mA.
Best wishes,
Martin

......any other idea's on how to get the master rail perfectly straight using the simple tool's I've listed already......

Yes but you rejected it about five million posts back and I have been sitting in the corner sulking ever since.

Yes but you rejected it about five million posts back and I have been sitting in the corner sulking ever since.

Dear Geof,
Cheer up old bean!
Best wishes
Martin

Geof, I believe you.. almost.. Your too happy a fella to sulk. I may still end up trying your electrical idea, that is if my microscope doesn't do the trick. It may take some playing around before I get a working solution.
Jerry

Geof, I believe you.. almost.. Your too happy a fella to sulk. I may still end up trying your electrical idea, that is if my microscope doesn't do the trick. It may take some playing around before I get a working solution.
Jerry

If you need the key stock as the moglice dam. Will the rail be in the middle or side supported by the key stock?
As previously stated. If the rail OEM recommends 2 surface mounting from the side and bottom as many do. I would concentrate on getting one edge(inside) of the key stock aligned to the tight wire, offset from the rail centerline. Then you will have something solid to clamp the rail to while marking the hole locations.
Moglice is normally used in similar applications as trucite(way repair coating). I know trucite is very close to teflon as far as durometer. The difference of course being one is resin and the other is sold as sheet. I can't help but wonder if this is a stable enough material for such a small surface area verses the loads it may be exposed to.
The continuity tight wire system has been around for a long time. I don't think all of them use solid wire. Some use stranded wire which has a damping effect instead of a sustained ring of solid. IIRC some used a mic spindle to measure the deviation?
DC

The keystock will be resting on top of the substructure, the rail will be sandwiched between the two keystock's.
I talked to their tech guy in Florida [I think] and he was of the opinion this was the best way to do it. Apparently he does this for a living and said this should work fine. I'm going to use the DWL310 [ thats from memory] which is for static app's and is recommended for use from 1/32 to 1/8" [again from memory]. Moglice produces many types of compounds, some are way repair and some are static potting compounds with high density and rockwell, similar to mild steel.
I haven't read anywhere that the side of the rail should be supported also. However this doesn't mean its not recommended, can you point me to a website where it talks about this? Come to think of it, I haven't seen a rail supported on two sides either.
The bottom of these rails has a groove in it, which the moglice should mold to, this groove will maintain the alignment more than the bolts will. The moglice is pumped into the cavity under the rail via a caulking gun, there won't be a whole pile of pressure but they tell me its enough to get a perfect fit, w/ little or no voids to speak of. The rail and the dam's are coated w/ wax to stop the moglice from sticking to them so they are removable and replacable if need be.
when you talk about the tight wire system your talking about Geof's post there w/ the wedge and electrical current??
Thanks for bringing this to light, I appreciate the comments..
Jerry [ used up one 20lb spool of weld wire last night.. gotta buy more today..]

The keystock will be resting on top of the substructure, the rail will be sandwiched between the two keystock's.
I talked to their tech guy in Florida [I think] and he was of the opinion this was the best way to do it. Apparently he does this for a living and said this should work fine. I'm going to use the DWL310 [ thats from memory] which is for static app's and is recommended for use from 1/32 to 1/8" [again from memory]. Moglice produces many types of compounds, some are way repair and some are static potting compounds with high density and rockwell, similar to mild steel.
I haven't read anywhere that the side of the rail should be supported also. However this doesn't mean its not recommended, can you point me to a website where it talks about this? Come to think of it, I haven't seen a rail supported on two sides either.
The bottom of these rails has a groove in it, which the moglice should mold to, this groove will maintain the alignment more than the bolts will. The moglice is pumped into the cavity under the rail via a caulking gun, there won't be a whole pile of pressure but they tell me its enough to get a perfect fit, w/ little or no voids to speak of. The rail and the dam's are coated w/ wax to stop the moglice from sticking to them so they are removable and replacable if need be.
when you talk about the tight wire system your talking about Geof's post there w/ the wedge and electrical current??
Thanks for bringing this to light, I appreciate the comments..
Jerry [ used up one 20lb spool of weld wire last night.. gotta buy more today..]

Jerry,
Here is one example of linear rail mounting. Point being.... side support will limit the rails motion if the gantry tries to crab walk on you for any reason. Not neccesarliy 2 sides, but 2 surfaces. The bottom and one side as a minimum, but I have seen them just mounted to a flat surface in light duty applications. The bottom groove you mention is typically only about .010 deep. Although some may be deeper.
Bosch/Rexroth
Yes, I was talking about Geof's and a few others with a similar suggestion. Even Radio Shack or other suppliers would have simple beepers, buzzers or LED's that could be connected for a low voltage continuity circuit. Either the wire or the reference block will need to be insulated from the frame of course.

DC

Jerry; I forgot to respond earlier to your comment about welder's sunburn. Is this the first time you have done so much welding and the first time you have had welder's sunburn? You should cover up; it can be more serious than regular sunburn because you are getting not only a higher UV intensity but also more of the higher energy UV. Welder's sunburn penetrates deeper and can do more long term damage.
Incidentally I confused you because I was confused. My flippant comment about being hurt that you don't take notice of my posts was not referring to the one about the tight wire. It was referring to one from another thread when I was describing an idea for mounting the rails on alignment blocks. It is post #54 in your thread about DIY Linear Rails.
I quoted part of this comment from you; "any other idea's on how to get the master rail perfectly straight using the simple tool's I've listed already. Any flaw's you can see in what I plan to do?" I deleted the bit about flaws but I DO see flaws in what you are doing. When you have something that is bent and are trying to align it in two planes you need to be able to push or pull at all the points of adjust. Your wedge idea pushes but cannot pull, yes you have bolts pulling but they are not at exactly the same location and that is what is important. Also you need to be able to control twist which will be difficult with your wedge idea. All this control is inherent in the sketch I uploaded and the only thing I missed was sideways adjustment but this could be very easily added.

One of Many, thanks for that link, It's printing right now so I'll be able to sit down and read it later. I'm goinh to have lots of reading later as I think my CAM program is showing up today as well.
Geof, I had to go back and read some of that history in the DIY thread. After looking at your picture and then my reply it all came back to me. I think your idea is a good one, however far from a simple one. In this instance I think it's complicating things more than simplifying them. I know that this issue isn't nesc. a simple one, however w/ twice as many bolts to drill and tap there is a large probability of error [ at least on my part] I'd have to not only mark out (VERY accuratly I might add) two row's of bolts, but drill them as accuratly and then tap them, There is no allowance for horizontal movement of the members [ there isn't w/ the moglice either but I can grind it off and re-apply it] I think that the setup I'm planning on using will do the job just as well. It should [ in theory] work just like a tripod does, you have only three contact points so by tightening up any one you can move the rail which ever way you want. If I need to move it horizontally, I'm going to use a J shaped pl that fits under the structure [ around to the other side] w/ a D&T'd hole in the 'T' part of the J, the bolt will push against the rail and move it over incrimentally, I then tighten it down w/ the mounting and jig bolts and move to the next position.
Maybe we should get a second opinion, for those who aren't familar with the post that Geof is talking about its right HERE (DIY Linear Rails)
Btw, thank for the advice on the Welders sunburn, I'm not much of a welder, but I do work for a welding shop [drive a computer all day] and I knew about welders flash and burns. I had been drilling holes and my gloves got all overed in drill coolant [ rapid tap] and I was getting oil from my soggy gloves everywhere so I took them off, just gritted my teeth when spatter was hitting my hand, and being Mr tough guy [or at least trying to be ].. just kept welding.. Later while taking a shower I realized how bad it was when the warm water hit it.. and it stung like the dickens.. It's now swollen up and is nice and puffy. On my other hand/arm [not burned] you can see some of the tendons and the outline of veins and what not, but no this hand.. Lesson learned.. I went and bought new coveral's and gloves.. even when welding last night, the hand started to sting while it was inside my glove, just from being near the heat.. ahh well.. some lesson's you just have to learn the hard way.
Thanks for the help and advice, don't take my difference of opinion on the rails personally
Jerry

Moglice is normally used in similar applications as trucite(way repair coating). I know trucite is very close to teflon as far as durometer. The difference of course being one is resin and the other is sold as sheet. I can't help but wonder if this is a stable enough material for such a small surface area verses the loads it may be exposed to.
DC

Dear Jerry,
I don't know anything about Moglice, but I have used Devcon Liquid Steel, a metal-loaded epoxy which is pourable. I used it to fill the space between a solid steel guide rod 1 1/2" diameter and a 1 1/2" by 4" steel box section. The assembly was ten foot long and was a linear rail to carry a cross-cut table for a table saw. I drilled and tapped the steel rod every 10", drilled oversize holes in the box section and used a 1/2" bolt and four nuts per fixing point to push and pull the rod into line. I then built a dam of MDF below the lower surface of the rod and sealed it with duct tape. Then I poured in the Devcon . The final cross-section of Devcon was about 1 1/2" by 1 1/2". It is still rock solid after 18 years. It is tough stuff.
Regards
Martin

Thanks for the help and advice, don't take my difference of opinion on the rails personally Jerry

Speaking only for myself I can say I won't. If you (I suppose I should be generous and say "When you") make your approach work I can be magnanimous and say you did a very good job against serious odds and I am impressed. If you find it gives you all sorts of problems I could just sit back and smirk saying "I told you so". Of course being a magnanimous fellow I will never do that.

Thanks Martin, Its good to hear success stories like that. I have heard, however, that Devcon stuff can be kinda brittle, have you noticed this? It's definatly cheaper than Moglice.
Geof, you haven't met my stubborn streak yet , however if I can't get it to work MY WAY, then there is always your way to try, but what happens if it doesn't work either?? Just so you know, the 'WHEN YOU' part is looming above me, I got two sample rail jig parts today from the lazer cutter I'm off to see if I can make them work.
Jerry [recovering weld burn victim

[quote]I have heard, however, that Devcon stuff can be kinda brittle, have you noticed this? It's definatly cheaper than Moglice.
Jerry [recovering weld burn victim

Dear Jerry,
The set-up was for my Powermatic 66 DIY cross-cut table. The guide rail is 10ft long. The cross-cut table is about 4ft front to back and about 5ft wide and sticks out to the left of the cast iron surface of the saw. The far edge of the cross-cut table is supported by a swinging triangular strut gizmo fixed to the saw base. The table runs on 3 cast iron pallet truck rollers turned out to a 90 degree angle
That saw has been abused, and I have often dropped 3/4" sheets of MDF onto the flying edge of cross-cut table when trying to get them into position in my limited workshop space.
The Devcon Liquid Steel, in my case, acts pretty much as a packing material (in compression) between my steel box section and the 1 1/2" guide rod . It also helps reinforce the 1/2" bolts which connect the rod to the box and helps the bolts from bending under a vertical load (bending).
Now comes a confession...
I have used the steel box section on the saw as a medium-duty anvil right next to the Devcon dam. No problems so far as regards brittleness.
I really rate Devcon Liquid Steel. Oh yes!
Regards
Martin

Hey good to know martin, thanks for taking the time to pass that on. I could probably buy all the devcon I need for about 1/2 the price of Moglice, plus I can get it shipped directly to me w/out any hassel as it can be purchased in Canada a big plus.
Jerry [All 50 feet of rack and my copy of OneCnc Xr2 came today, the garage is starting to get packed and I'm just getting started!]

Dear Jerry,
Thank-you. Glad to be of help.
Get some sun-tan lotion.
Best wishes
Martin

I guess I consider 10ga as sheet metal, not plate. Oh, well........I cannot say I was following all that close, so the terminology may have confused me.
DC

Your right.. It's the border line between the two.. sorry for the confusion. I had been talking about putting a 3/8" facing plate and then having it stress relieved and milled on a large boring mill, I'm not sure that I'm going that route now.. and if I don't then the thickness will go back down to 10ga.
Jerry

JerryFlyGuy Shipping is relative to where in Canada you are. Google Brute machine bases. If they look like what you want done give them a call. I have been designing machines for ** years and have discovered the people who do this grinding are very clever about supporting and holding workpieces. By the way Sullivan's e-mail address is [email protected]

Richard, I've no doubt that they could do it, and do it well. Setting up work fixtures to do the grinding is only 1/2 the problem, and its the easy half. They have a machine which can be measured off of and used to set my parts in place. The real tough part comes when I get these fancy ground pc's back to my shop and need to install them on the floor. It took me about a week of work to get these two substructures where I wanted them and had them leveled and straight. As I stated before, the substructure is flimsy and is easily flexed side to side by just tightening down the floor bolts. I designed it this way so that I could take any weld warp out of the weldment. You can imagine the extra effort required to place a structure of this type so that its level w/ its neighbour 10ft away. It's parrallel as well as level from end to end, and is straight. All this has to be done in one step. W/ precision ground surfaces there is no room of error or adjustment.
In reality, it makes far more sense to use these Subplates to get a trued base to mount the rails. The cost will be less, I don't have to remove and then re-install the existing structure, and if the machine shifts or moves in the future due to the floor cracking,weld stress relaxing or my moving to a different location, the process can easily be repeated to get it all back to "true". Not to mention that I only need to get my substructure 'close' before installing the plates. The plates are also designed specifically to assist while getting them in their proper position, they won't be fighting me the whole way.. or at least I hope not!
I'm not saying the grinding won't work, or is the improper way to do the job, it just doesn't fit the bill in my case and current situation. I'm sure there are places where they would be just what the 'doc' ordered. I think my Gantry would be a very good place to try this. There isn't any alignment that needs to be or can be done between the rails as they are mounted on a common structure.
One of these days I'll post some pic's that show my machine in it's entirety.. [sp] then it will become a bit more clear to understand the needed "how's and why's "..
Thanks again..
Jerry

Anywhere there is large machinery being built you will probably find a grinder that can do this. There are at least four in my area but I am next to Long Beach Harbour and we have allot of machiner manufacturing in the area. So maybe I am just spoiled.
just a suggestion.

Mr FlyGuy;
Except for this comment all my comments will be in uppercase. But I am not shouting I am just too lazy to fuss with the html stuff to get italics or bold and anyway you have confused things by doing your post using italics.
I AM NOW HAPPY WITH THE FORM OF ADDRESS.
WITH RESPECT TO THE WINDY STAKES IN MY HUMBLE (NOW THERE'S A LAFF) OPINION YOU WIN. IT IS NECESSARY TO DO ANY AGE CORRECTION; BY THE TIME YOU GET TO MY AGE IT IS OBVIOUS YOU WILL GREATLY SURPASS ME.
I've attached a PDF showing what I Had planned to do w/ the plates but I don't think its anywhere close to what you have in mind. You can scope that out and see how bass-ackwards I do things
YOUR PICTURE CONFUSED ME BUT I WILL NOT DWELL ON IT OTHER THAN TO COMMENT YOU SEEM TO SHOW THE Position Locking Bolt HOLDING DOWN THE 'HAP' BUT ALSO SEEM TO DESIGNATE THIS BOLT AS 10-24???
The Subplate is the plates we are trying to design. These plates are going to help adjust for any warpage or out-of-level condition that exists in my pre-fabricated Sub Frame. They will provide a perfectly level surface on which the rails will be clamped/bolted down. They will be potted in/onto the existing structure once all the leveling and installing proceedures have been accomplished.
YES
The Elevation bolts are the bolts which have a clearance hole through the middle. The Head is resting on my existing substructure. The bolt is threaded into a Tapped hole in the Sub Plate. The Hex head of this bolt will fit up into a recessed pocket on the underside of the Sub plate. The center drilled hole in these bolts will be significantly sloppy. If the bolt is a 1/2" bolt it would have a 3/8" Hole to allow for some mis-alignment when D&T-ing the Position Locking Bolts- tapped holes
YES. THESE WILL BE 9/16-18 SO THE THREAD PITCH IS THE SAME AS THE Position Locking Bolts MENTIONED BELOW. iNCIDENTALLY THE HEAD CAN BE FACED DOWN TO AROUND 1/8 THICK, MAYBE LESS BECAUSE YOU ARE NOT GOING TO BE APPLYING A LARGE TORQUE TO THESE BOLTS.
The Position Locking Bolts are passed down through the center of the Elevation bolts and are D&T'd into the existing substructure. They impart a clamping effect to tighten the Subplate down to the existing sub0structure.
YES. THESE ARE 5/16-18 GRADE 8.
The Rail bolts are the Cap Screws which are used to hold the rail in place to the Sub-plate.
YES
Ok.. so I'll just do a quick re-cap of what you propose to make sure I'm clear.
Your thinking a specially made plate for the rail joint, w/ the needed Rail Bolts threaded holes in it. These bolts would run down a groove in the Subplate. This plate should be at least 180mm long [ two 60mm c-c holes and then ~60mm across the joint].
YES
[Is there any reason not to make this Subplate the same 600mm long? Should all the SubPlates have this grouve in them that captures the rail and holds it straight? I don't think just having it bolted every hole into a tapped hole [ which is cnc tapped in a straight line] will garrentee a straight rail.. It needs some type of reference edge? Should the Subplates have machined ends to hold each plate sqr to its neighbour, there-by ensuring the rail is straight w/out ever having to measure it?
600mm LONG?? YOU NEED ENOUGH LENGTH TO SPAN TO Rail Bolt HOLES ON EACH RAIL SO IF 600 IS ENOUGH YES.
THE GROOVE IN THIS PLATE IS A PRECISE FIT ON THE TWO RAIL ENDS TO HOLD THEM IN ALIGNMENT ON THIS THE JOINING PLATE
GROOVES IN ALL PLATES?? NO ... THIS WOULD MEAN ALL THE SUBPLATES WOULD HAVE TO BE PERFECTLY LINED UP AND PARALLEL; THIS WOULD MEAN YOU ARE TRYING TO ADJUST FOUR PARAMETERS AT ONE GO; INDIVIDUALLY LEVEL, LEVEL WITH ADJACET SUBPLATE, INLINE WITH ADJACENT SUBPLATE, PARALLEL TO ADJACENT SUBPLATE. I THINK FOCUS ON GETTING LEVEL IN ONE OPERATION THEN INLINE IN AN INDEPENDENT OPERATION.
MACHINED ENDS ON SUBPLATES?? NO, OBVIOUSLY FROM ABOVE REPLY. ACTUALLY YOU WANT A SMALL GAP BETWEEN SUBPLATES SO THAT IS SLIGHT MISALIGNMENT OF THE DRILLED AND TAPPED HOLES FOR THESE MEANS THEY ARE NOT PARALLEL THEY DO NOT TOUCH.
I was a bit concerned about getting the C-C distance correct across the joint. I guess I could lay the rails out on a pc of steel, center punch the holes and measure the marks. Then get the c-c dim about 1mm shorter and file the ends of the rails until they line up?]
THESE HOLES WILL BE DRILLED IN THE CNC WHEN THE PLATES ARE MACHINED BUT YOU DO HAVE A GOOD POINT!! ARE THE HOLES A SPECIFIC DISTANCE FROM THE RAIL END? ARE THE RAIL ENDS PERFECTLY SQUARE WITHOUT ANY CHAMFER? YOU DO NEED A SQUARE END WITH SQUARE CORNERS (NO CHAMFER) SO WHEN THEY ARE ALIGNED AND BUTTED THERE IS NO GAP FOR BALLS TO CATCH IN. IT WOULD BE NICE TO HAVE SOME METHOD OF ACTUALLY PULLING THE RAIL ENDS TOGETHER ... HOW TO DO THAT ELUDES ME AT THE MOMENT.
When I have all my Sub Plates, I'm to bolt them to the rails so they are basically one large assembly. Then I'm to lay this on top of my existing sub structure and thread in the Elevation bolts [from the top] just temporarily while I center punch all the hole locations [its easier to center punch thru the thru-hole in the center of the bolt]. Then I take all of this back off the existing structure and start drilling and tapping these Position Locking Bolt holes.
YES
[Question at this point. How do I get the rail straight and hold it in place so that I know the holes I'm D&T-ing into the existing sub structure are going to keep the rail straight? I haven't done any step's to make sure it is straight.. is this taken care of by the groove in the Subplate? Or do I do some type of step's like w/ my old Horiz. Alignment jig?]
I MENTIONED CENTERING THE RAIL ON THE SUBPLATE HOLES BY USING COUNTERSUNK BOLTS. THIS JUST LINES UP THE SUBPLATE ON THE RAIL SO THE CLEARANCE BETWEEN THE RAIL AND THE RAIL BOLT IS EVEN ALL ROUND. YES YOU WOULD THEN USE YOU OLD HORIZONTAL ALIGNMENT JIGS TO LINE EVERYTHING UP BEFORE CENTER PUNCHING THE MAIN FRAME FOR THE SUBPLATE HOLD DOWN BOLT HOLES. I THINK I DID MENTION THAT THIS ALIGNMENT HAS ONLY GOT TO BE A LITTLE BETTER THAN THE RADIAL CLEARANCE BETWEEN THE RAIL HOLES AND RAIL BOLTS.
Because the Elevation Bolts aren't center drilled w/ a very tight hole there is some forgivness as to how close the Tapped holes in the existing sub-structure are located.
So when I've got all these holes Tapped into the Existing Sub-structure, I'm to re-install the rail/Subplate assembly. The Subplates will have all the Elevation Bolts inserted from the underside now and the assembly will rest on top of the existing sub-structure, by sitting on the heads of the Elevation Bolts
[Question. At this point how do I accurately aligne and ensure that the rail stays straight as there is some movement in the Position Locking Bolts [thru the Elevation Bolts] as well as the Rail Bolts which to are undersized to the holes currently in the rails?]
AT THIS STAGE YOU DO NOT WORRY ABOUT STRAIGHT. SEE COMMENTS ABOVE.
From there on is the leveling proceedure which I'll leave for now.
I'll give you a quick note as to why I did this the way I did and the step's I had been thinking of to get it accomplished.
I could D&T the Subplates like you said before installing the rails. I would start at the center under the joint and install all the Subplates the same. I would center punch the Position Locking Bolts D&T locations the same way. Then I would install the Subplates assembly on top of the Existing Substructure and get it perfectly level & locked down into place. I would then use the tight wire to get the reference edge of the HAP's [Horizontal adjustment plate] straight and Bolt them down tight. I would then set on the rails they would have their bolts just loosely started into the holes but not tight. I would use small clamps to clamp the rail to the HAP [ one side of the clamp on the rail, one side on the outside face of the HAP so it doesn't get moved] As I moved along the rail, clamping it tight to the HAP I would bolt it down tight to the Subplate. After the rail had been bolted down I'd install the opposite side HAP's and clamp them tight to the rail and bolt them down tight.
YES THIS IS AN ACCURATE PRECIS OF THE PROCEDURE; LEVEL IS ONE OPERATION ALIGNMENT IS ANOTHER.
In hind-sight it might work just fine to only use HAP plates on only 1 side of the rail [ the outside] as it should limit where it can move.
NO, I THINK YOU NEED SOMETHING TO GRIP THE RAIL BETWEEN TO HOLD THE ALIGNMENT INDEPENDENT OF THE RAIL MOUNTING BOLTS. IF THE RAIL IS TRYING SPRING AWAY FROM THE PREVIOUSLY ALIGNED hap AND YOU DO NOT HAVE ONE ON THE OPPOSITE SIDE TO CINCH IT IN IT MIGHT GET FRUSTRATING.
so hopefully that makes some sense.. and we/I can get this settled and make some headway.. before the winter is over .
IT MAKES A LOT OF SENSE, HEADWAY IS BEING MADE AND AN EIGHT MONTH DEADLINE (THAT IS ABOUT HOW LONG WINTER LASTS ISN'T IT?) IS JUST FINE.

Mr Geof;
I don?t mind if your lazy, just as long as you answer my questions
If you prefer this form of address.. then so be it.. [whatever floats you boat ]
I?ll skip the ?windy? commentary as I feel it?s a loosing battle, I?ll never win. [A? La ?fight the battles you can win? etc..]
Sorry my PDF is confusing? The Position locking bolts were planned to be ΒΌ-20 the HAP lock down bolts were planned to have been 10-24. The section view detail should clarify which is depicting which.

Ok, so I think we?ve got the definitions down to we are talking apples to apples.
I?ll adjust my design to allow for the 9/16? Elevation Bolts w/ 5/16? Position lock down bolts. I?ll also allow for the facing off of the bolt heads. I hope I can find some Grd 8 Socket Head Cap Screws [SHCS] for these 5/16? Position Lock down bolts. I have a suspicion they only come in Grd.5 [w/out some special order].
I think we?re on the same page for the complete process except for 1 point. I?m not really to excited to be putting a groove in the center plate. I understand why your doing it, but I don?t like it . The reason I don?t like it is because of the issue it creates while trying to align that center plate. The plates are going to be 360mm long, I took the time to sit down and figure out what works best. 360mm is the magic number [they will be 4mm shorter than this o/a but for general conversation 360 is close enough]. So here we have this 360mm plate, which has a groove in it. This plate now becomes super critical when placing it into alignment. I have to locate this plate on my substructure just ?so? or the rail will wander off the substructure at one end or the other [or both]. This could be pretty tough to get set up. I would then have to align my ?tight wire? to match this edge [instead of aligning the edge to the wire] that?s a pretty? tricky proposition.
I?m not sure I see any ?lack? in the way I propose to do this all w/ the HAP?s. In my thinking, if I clamp the rail joint to the HAP on either side of the joint, I should have the same thing in effect as a machined groove.


THESE HOLES WILL BE DRILLED IN THE CNC WHEN THE PLATES ARE MACHINED BUT YOU DO HAVE A GOOD POINT!! ARE THE HOLES A SPECIFIC DISTANCE FROM THE RAIL END? ARE THE RAIL ENDS PERFECTLY SQUARE WITHOUT ANY CHAMFER? YOU DO NEED A SQUARE END WITH SQUARE CORNERS (NO CHAMFER) SO WHEN THEY ARE ALIGNED AND BUTTED THERE IS NO GAP FOR BALLS TO CATCH IN. IT WOULD BE NICE TO HAVE SOME METHOD OF ACTUALLY PULLING THE RAIL ENDS TOGETHER ... HOW TO DO THAT ELUDES ME AT THE MOMENT.

No the holes at the ends of the rails are not at a specific length [that I could measure anyway]. They are about 28-30mm from each end [respectively]. The ends are ground sqr. and chamfered from the supplier , I was under the impression this was ok to a certain extent. I?ve run the carriage over the joint and didn?t notice anything but then it was just sitting static and not all bolted down. I?m afraid I might have to use some type of grinding or filing to get them flat and true [ye-uck ].

I now understand your counter-sunk-head bolts and their use? good idea.


IT MAKES A LOT OF SENSE, HEADWAY IS BEING MADE AND AN EIGHT MONTH DEADLINE (THAT IS ABOUT HOW LONG WINTER LASTS ISN'T IT?) IS JUST FINE.

um.. well I do have some projects lined up and people wanting stuff done on this thing already.. I'm willing to make sure its done right from the start.. but its gotta get done [preferably sooner rather than later] and start paying it's keep or ... well. I dunno what the recourse to that 'or' is.. but I'll figure it out..
Jerry [got my gantry beam welded/tacked together over the weekend. Currently making haste... slowly... ]

......I hope I can find some Grd 8 Socket Head Cap Screws [SHCS] for these 5/16? Position Lock down bolts. I have a suspicion they only come in Grd.5 [w/out some special order].

It would be more better if I didn't do typos or read things wrong; substitute 5 for 8. These bolts need to have good strength but some ductility because you are going to be getting them fairly tight in the final stages of levelling but might want to actually adjust the plate upwards a thou or so putting even more stress on the 5/16" bolt. You want it to be able to stretch a little not just have the head fly off.

....I think we?re on the same page for the complete process except for 1 point. I?m not really to excited to be putting a groove in the center plate. I understand why your doing it, but I don?t like it ...... This could be pretty tough to get set up. I would then have to align my ?tight wire? to match this edge [instead of aligning the edge to the wire] that?s a pretty? tricky proposition......

Yes you do have a good point here. And do you realise that the 'tricky proposition' is what you would have been faced with if all the plates had a reference edge machined in them. And I pointed out it would be very difficult to level and also align sideways at the same time. So now we have both switched sides of the issue which I think conclusively proves either we are both totally out to lunch or great minds think alike.
The HAP's should be more than adequate if the rail is clamped between them.
Regarding your rail joint and the chamfers and letting the carriage just ride over it. This gives me an uncomfortable feeling but maybe it is not justified; there are many balls carrying the load, only one is going to be over the gap at any one time and they are not going to be moving fast like a ballrace running at a few thousand rpm. Your 'ok to a certain extent' is probably quite okay at the feed rates and loads you will be working with.

substitute 5 for 8.

Done.

Yes you do have a good point here. And do you realise that the 'tricky proposition' is what you would have been faced with if all the plates had a reference edge machined in them. And I pointed out it would be very difficult to level and also align sideways at the same time. So now we have both switched sides of the issue which I think conclusively proves either we are both totally out to lunch or great minds think alike.

I figured you couldn't possibly want me to put those grooves down the length, but figured I'd better ask. That would have been a nightmare. I had this same 'tricky proposition' w/ my stupid jig's. Btw.. I'm sure it wouldn't take a whole lot of convincing for ppl to think we're both out to lunch..

The HAP's should be more than adequate if the rail is clamped between them.

Awesome!!

Regarding your rail joint and the chamfers and letting the carriage just ride over it. This gives me an uncomfortable feeling but maybe it is not justified; there are many balls carrying the load, only one is going to be over the gap at any one time and they are not going to be moving fast like a ballrace running at a few thousand rpm. Your 'ok to a certain extent' is probably quite okay at the feed rates and loads you will be working with.

Hear Hear.. I agree totaly.. I will look at that again when I do the center punch test to see what the C-C dim is [ run a carriage over the joint] and see if my dial indicator show's anything.
I'll draw up the drawings and send em' to ya to review.. see if I've got it all correct.
Jerry [ anyone want to buy some really nice Rail installation jig's? 1 complete kit w/ all the needed jig's and fixtures for any 25 size linear rail. Selling for only the time and mat'l cost's. $13,436.00 for a complete set! won't last long at this price... email me now!]

Well, I got my sample plate from the machinist today.. I love when the test fit goes as well as it did today! Bolted it up.. and everything works just as hoped. I was a bit concerned about some of my clearance's, things had gotten pretty tight. I'd actually had to step back and re-design things a bit but it was worth it! I'm sure the fella doing my machining was a bit tired of all my changes and delay's, in the end however, I got a working solution! I can't wait to get all the rest of the parts now.. I can finally get moving forward again!
I'll get some pic's posted once I get my camera from work..
Jerry [now I've just gotta be patient and wait the couple weeks until the parts get here.. oh well.. there's lots more to do while I wait .. isn't there always?]

And the fuzzy pictures..
Jerry

Attached


IMAGE(http://factorydaily.com/fdattachs/fdattachs6/112616351310875.jpg)


IMAGE(http://factorydaily.com/fdattachs/fdattachs6/112616351410876.jpg)

So Geof... I'm starting to think over my Gantry [Y axis] rail mounting... wondering what you think would be the best route.. The gantry is 12" sqr, w/ 2" sqr tubes in each corner.. 120" long.. and use's 1" sqr 'trussing' between all the 2 x 2 tubes. I'd been thinking about getting it stress relieved and then having the rail beds milled into a heavy facing plate [ 3/8" m.s. plate welded to the front face of the beam/structure] finding a shop that has a big enough oven and mill has been tough.. any good idea's on how to align the rails there? I've sketched up some subplates like the side rails, however.. they'd be 7" x 12" X 1/2" mat'l... 17 pc's to do the job.. and lots of extra weight... also the rail's would have to be mounted in ~ 1.75" from the edge of the plate to leave room for the elevation bolts outside of the rail.. Better idea's? the upside of going this route is, this time I can put a milled slot into the plate which the rail sits down into.. no Horizontal alignment plates needed..
Stewing..
Jerry..

...I'd been thinking about getting it stress relieved and then having the rail beds milled into a heavy facing plate [ 3/8" m.s. plate welded to the front face of the beam/structure] finding a shop that has a big enough oven and mill has been tough.. any good idea's on how to align the rails there? ......Stewing..Jerry..

Stewing is unnecessary; this is the 'proper' way to do things. When the machining is done get a reference edge machined and all the mounting holes drilled and tapped. Also remember I mentioned in a post much earlier that I had looked at one of my machines and found that the rail seems to be held against the step machined in the casting by some eccentric head screws. You need to find out something about these.

I know its the proper way.. the problem is I haven't found a shop that can do it.. at least not in any type of decent lead time.. and I don't want to ship this thing all the way to hell and back.. The fella machining my Subplates said he'd be interested in doing the milling.. but he'd have to do it in 3 setups.. not a really good 'option' if I can find a place that can do it all in 1 go..
Jerry [more stewin..]

Sorry, I interpreted your other post to mean you had found a shop.
Did I mention at any point a really crazy idea I had; machine your own gantry rail beds.
Once you have the base rails mounted you have the means to travel a grinder back and forth with a fairly good precision. So you fabricate a bridge structure and mount it on the trucks, have a small slide mechanism to mount a grinder on, bolt your gantry to the garage floor and grind away back and forth.
If my explanation is a bit terse read it a few times and use your imagination.

Hey.. no need to say sorry... I might have come across as a bit curt... i was tired.. I do know of a shop that could do it, about 4 hr's drive away.. however their lead time is in yrs.. Or was basically, the last time I talked to them on another project for work. I like your grinder idea.. It would take a fair amount of setup.. but it could be done w/ some level of precision.. most likely not as accuratly as a properly milled job.. but close.. I'll have to look at that possibility a bit closer.. I've still got to get it stress relieved somehow before I can take that step. It had been suggested that I do the relieving myself.. but thats a bit of a scary proposition.. I'd like to see the mounting face clamped straight before the heat is applied.. and I haven't got a snip of an idea.. how to do that and keep the heat in all at the same time..while heating the entire thing evenly.. I'm sure some old millright-coggers could do it w/ their eye's closed... I'm not that old yet.. nor am I a millright.. But then again.. I'm not qualified to build this thing either..
I gotta make a few phone calls.. I'll think on this a bit more..
Jerry [no-one said it was going to be easy right!? ]

It's a given that you can't expect a complex weldment like this gantry to remain true after machining without stress relieving it beforehand. So, you have two choices--stress relief before machining, or don't machine it.
Wait a minute. We just said we had to machine it!
Let's consider the no machining option. You get this gantry all welded up, you let it sit for days or weeks so it gets done warping. You do no further machining on it, and you know that it's surfaces are out of true. What do you do? How do you properly align the gantry to the table rails? How do you properly align the cutting head to the table? How do you accomplish this without precision machinework which can't be done without stress relief?
Well, I'd of thought you of all people would have had the answer!
Drum roll please...
You can use the same Moglice-style approach to your Y, and Z axis rail mounting that you used for the X surface. Precision alignment is achieved through fasteners, leveling screws, and Moglice injected as the interface between the precision rail mounting plates and your (potentially) warped gantry.
I would be tempted to bolt the thing up in place on the table and inject the resin in situ. I would be concerned that if you try to do it piecemeal, with the gantry laying flat on your garage floor for example, flexure and other gremlins would foil the plan. Assemble the gantry on it's x-rails. Assemble the precision plates for the Y-axis and install the rails. Put the Z plate onto the blocks. Now you can use a dial indicator and the reference of you choice to get that Y-mounting plate properly aligned with the leveling screws. Inject the resin once that's done. You will need some sort of o-ring style arrangement to keep it in place in this orientation, but you can likely even do that with a ring of silicone cement before you inject the epoxy.
If necessary, follow a similar path with a Moglice interface between the cutting head and the Z-plate mounted on the Z-blocks.
BTW, why not just use the same style plates you've already got being made? Get some more made for the Y-Axis, or something very similar.
Best,
BW
Best,
BW

Your right Bob, I'd to come to the conclusion either I thermal stress relieve it.. or don't touch it at all..[ machining wise]
I've taken the time to design some more 'SubPlates' for the y axis.. and they would work w/out a doubt. They are in a way.. simpler than the last design for the X axis. As they won't need to have any type of horizontal alignment plates, I'd just mill a shallow groove in the plate ~ 10-15thou wider than the rails, then get all the mounting holes D&T'd into the plate. Each plate would have two grooves in it [ 1 @ the top, 1 @ the btm]. The down side? Well to properly install this plate[s] you have to have elevation bolts located on the outside of the rail [ so they are accessable under the plate..] and so this means the rail can't be mounted right to the outside of the plate, but rather it has to be moved inwards ~ 1 1/4" [ memory] , thats 2 1/2" overall narrower across both rails.. They would then be 8 1/2" c-c instead of the 11" I'd planned for originally... thats 22.7% decrease in width.. and about a 45% decrease in stiffness of the structure due to a smaller lever/arm. Not something I'm terribly excited about.. If I was to put the Elevation bolts inside the rails [ instead of outside] then I could space the rails out to the edge's of the plate and have the original rail width again.. but how to adjust the elevation bolts is a bit tough.. [ milled access holes into the plate w/ a special made wrench to turn them] as well as having the rails cantilevered outside the bolts.. not a really exciting design..
W/out a doubt the stress relieving and maching is the best route.. I just need to figure out a way to do it.. w/out the huge lead time..
Just for kick's I called my contact at this machine shop again.. he told me that there wouldn't be a hope of getting it done in less than 3 months... I don't want to have to wait that long.
I was prepared to do this step as you'd noted, w/ my handy dandy jig's, but I'm starting to think that.. that isn't the proper route... it'd be to much "Fighting" the rail, beating it into submission.. and I think that will just cause issues down the road. I really like how simple the rail mounts to the subplates for the X axis.. it was amazing how simple it was.. I'm confident that I could place and mount that rail in a morning, aligned and done.. ready for the potting. The best part is.. no fighting.. Every time I torqed down a screw w/ my old jig's I was twisting and warping.. and I'm pretty sure "undoing" the work I'd just got done on either side of the point where I was working.. going in circles..
In reality.. a "Bolt it up" solution is best.. and possibly absolutly nesc.
There's a solution out there.. I just haven't decided what it is..
Jerry

Jerry have you fully welded your gantry? I cannot recall whether you posted an sketches but I am guessing you are being conventional in placing bothe the Y rails on what will be the front face. If you still have welding to do might I suggest holding back a little. If you do find a place to get it stress relieved and machined then having both rail beds available in a single setup is certainly the best. However, if you are going to use levelling plates and there will be no machining there is no great advantage to having them on the same face. You comment that you are squeezed for space and in order to make room for the levelling plate bolts you would have to move the rails closer which you do not want to do. Consider this; Put one rail on top and one on the face at the bottom. This means you can set the bottom one up a little to have bolts clearance and set the top one back for the same purpose. I don't see that it is necessary to have the rails on the same face and I don't think they have much difference in their load carrying capacity in the vertical or horizontal directions. After all I have a machine with two rails placed on a horizontal surface for the X, two rails running across a vertical face for the Y and two running up a vertical face for the Z. I doubt that it matters what the orientation of the rails is.

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