[Mountaincraft]

I spent part of the afternoon and most of the evening aligning the X axis rails and shimming the mounting bolts to get the rails equidistant and parallel to each other. I used 1/2" wide strips of 0.008" thick aluminum roof flashing for the shims. They are placed on each side of the bolts to put equal pressure on the rails at each side of the bolts.

I wouldn't mind seeing pictures of that process (if you're so inclined.. )... as I'm not really understanding exactly what you're shimming and how you're measuring the results...

When I build my steel table base and reassemble everything in the shop, I'm going to need all the tips, tricks and insight I can get..
:cheers:

[.xXACEXx.]

i hope you are making some really good plans of your build. ill bet you could sell em! i for one really like the design so far ((i still stubbornly want to use one motor per axis on my machine)) but other than that i really like how darn solid that thing looks!

like it could fall off the table and still not be hurt any ,as for my build i have been pricing parts more lately originally (years ago) had a budget of $500 but if i go with a G540 kit that pretty much blows my budget, unless i can get some free material from a sponsor (like the shop owner where i work)

[CarveOne]

I wouldn't mind seeing pictures of that process (if you're so inclined.. )... as I'm not really understanding exactly what you're shimming and how you're measuring the results...

When I build my steel table base and reassemble everything in the shop, I'm going to need all the tips, tricks and insight I can get..
:cheers:

I'm sitting here in the computer chair dead-to-the-world-asleep for an hour and just now woke up. I must have heard you guys talking about me....

The process is a lot less scientific than you might think. You just need a good reference surface to start with. Everything is measured upwards from there. Very similar to using a "waterline" mark or grid in a CAD drawing.

When I started this build I checked the work table top with an 6' aluminum rule for flatness and made some adjustments to the sheet of birch veneer plywood top to make it as flat as I could get it. The table top is also very close to level using a 4' carpenters bubble level. This is my reference surface for everything.

I have a simple height indicator that is a ground block of steel for the base, a chromed vertical shaft, and it just has an adjustable horizontal pointer. I put the frame on the table top and used the pointer at the corners of the frame to adjust the feet on the frame's legs to get the top corners of the frame to the same distance from the table top surface. The frame will not rock if the feet are adjusted correctly.

The X axis rails were installed and I used two machinist's 1/4" thick parallel bars stacked together to use as a gauge block to make the top edge of the rail (remember that mine are vertically oriented, not horizontal like Ahren does his rails) exactly 1/2" above the top of the frame. The parallel bars just sit on top of the frame at the corners and the rail is raised up flush to the top of the bars and the mounting screw is tightened. This had to be done a couple of times to get it right at each end of the rail. Ditto for the other rail.

I am at this point concerned that the top edges of the rails are parallel to each other, and that the rails are equidistant apart from each other. Mine are exactly 36-1/8" apart at any point along the rails when measured with a tape measure.

When I cut the box tubes for making the frame I made the box tubes exactly square by grinding with my 12" disk sander and a bit of careful grinding and checking the ends with a machinist's square. The frame would have been perfectly square if I had not tightened the pipe clamps a little too much, and there was not a center box tube that prevented the longer side tubes from pulling inward during welding the corners. That mistake is why I had to use the aluminum shims to align the rails. They make up for the 0.030" or so of bow at mid-span of the side tubes and I can tighten the rail mounting bolts without pulling the rails out of alignment. The rails are straight and will stay that way. I was originally thinking about using JB Weld or Bondo to make this a more solid connection, but I may not want to do this all over again later as long as it works ok as it is now.

I should now be able to use the height indicator pointer to see if all corners and points along the rails are all the same height from the table top surface. I haven't checked it yet but I will.

CarveOne

[CarveOne]

i hope you are making some really good plans of your build. ill bet you could sell em! i for one really like the design so far ((i still stubbornly want to use one motor per axis on my machine)) but other than that i really like how darn solid that thing looks!

like it could fall off the table and still not be hurt any ,as for my build i have been pricing parts more lately originally (years ago) had a budget of $500 but if i go with a G540 kit that pretty much blows my budget, unless i can get some free material from a sponsor (like the shop owner where i work)

I drew some preliminary plans just to show what it was supposed to look like, but as with all my builds so far, things get changed as I go. The steel channel seemed to be a good idea, but my implementation of it really sucked, and they were bowed even before I welded it together, so I started over with heavier wall box tubes. It is my intent to draw some plans after the fact and post them here if this machine works as well I am hoping for. They will be parts drawings mostly, and free. It is not for those with minimal machinery and welding capabilities though, and it is a going to be a lot of work to build.

CarveOne

[CarveOne]

Here is a photo of the height indicator I mentioned. It is not precision, but it gives an idea of how far off something is. It's used for comparisons to a reference measurement.

A dial or digital height indicator costs more and can't reach into as many places as this one can, but they are much more precise.

CarveOne

[Mountaincraft]

So you are pretty comfortable with the flatness of the workbench it's all sitting on?

I like you how you've painted the unused portion of the CRS rails.. I may have to do that when I move everything onto the permanent steel base... maybe that copper flaked black with an overlay of tri-color flames... Let's make this baby 'Hot-Rod!.. LOL

[CarveOne]

So you are pretty comfortable with the flatness of the workbench it's all sitting on?

I like you how you've painted the unused portion of the CRS rails.. I may have to do that when I move everything onto the permanent steel base... maybe that copper flaked black with an overlay of tri-color flames... Let's make this baby 'Hot-Rod!.. LOL

Basically, it's built from from the work table top surface upwards. Do what you can to make the surface it will be sitting on as flat as you can. There may be some deflection of the work table surface now that the total machine weight is right at 200 pounds.

Yes, it is as flat as I could expect a work table top to be, though it's certainly not as good as a granite surface table.

I used the height indicator to make the top of the frame equal all around each of the corners by adjusting the 1/2" bolts that are the feet of the machine. To adjust the rails square with the machine frame I used the machinist parallel bars to set the top edge of the X axis rails to 1/2" above the top of the frame. When I checked the top edge of the rails with the height indicator I was happy with the results. The 1/2" measurement sets the rails so that the bolt heads on the CNCRP carriages have equal clearances to the frame box tubes. If I had a digital height gauge I could get more accurate results - but it would still only be as good as the work table top "reference plane". The rails must be true relative to the MDF table top that is mounted in the frame, not necessarily to the work table top. The Y axis rail will be adjusted square relative to the X axis rails. The MDF table top in the machine will eventually be surface planed to correct for any minor differences that remain. Then the Z axis will be final adjusted to the surface planed MDF top.

I paint them to minimize rusting. I finish the unpainted parts of the rails with pure carnuba automotive paste wax. Any rust that appears can be cleaned off with with a green scouring pad and re-coated with carnuba wax.

I like your color idea, but the textured black will show dust readily. The hammered silver and textured silver I have been using doesn't. Take lots of good photos of the finished paint job before you start serious cutting efforts.

CarveOne

[Mountaincraft]

My Initial steel base construction will just be the business end of things... A bic 'C' channel on it's back... Basically, the support for the material bed itself and the sides up to the X rails...

Then I'm going to cut the uprights off of this existing table, adding some more structural support (and more wheels) and set the new base on top of it.. That should be fine until it's time to add plasma.. At that time I'll build a new steel structure underneath to replace the wood 'cart' it's all sitting on (with a place for a shallow water tub to catch slag)..

For flatness, I was thinking of bringing the steel home (all 2x2 x 1/4" box tubing), cutting it to length, and drilling all the holes.. Then taking it back to the steel place along with a drawing, and having them weld it for me on their assembly tables.. They can get it much flatter and squarer than I can...

The main cost of labor is in the cutting and drilling anyways... If I could afford it, I'd have them put the finished product in their mill (which is the size of a small house.. LOL) and surface the rails perfect to each other... who knows, maybe that's a possibility before it's all over...

They will load the beast on a trailer for me, but when I get home, I'll have to offer a few neighbors and friends a beer or two help me carry it into the shop...

I'm going to make up some jigs to hold the 80/20 rails in place as I mount them... probably three or four jigs... Cut them all at the same time, so that they are all the same...

I'll also have to build an 'insert' to go into the new bed.. This insert will bolt to the new material bed support, and basically be a raised box made from 1.5" x 1.5" x .1875" square tube... It will raise the sacrifice board(s) up to within 4-6" of the bottom of the gantry where accuracy will be best.. and like you said, I can use the router to surface it... Most all sheet work will be done on that...

Later I can build a low profile version of the same for larger work, another with an indexer installed, and another with slats for plasma... A separate cart will hold the replaceable inserts, that can roll them right up to the table and have adjuster screws on the legs to lift the insert to be used right up parallel with the table for sliding it in or pulling one out..

That's all gonna take time and money.. So in the beginning, just the big 'C' and the first insert is the goal...

[Mountaincraft]

PS.. Thanx for the tip on the wax... I was wondering how to best deal with the maintenance of these rails... I imagine this will also help the bearing surfaces stay clean and gunk free too..

[CarveOne]

PS.. Thanx for the tip on the wax... I was wondering how to best deal with the maintenance of these rails... I imagine this will also help the bearing surfaces stay clean and gunk free too..

There are other products that work well also. Something that doesn't leave an oily film that creates a surface that dust sticks is usable. Boeshield is a popular coating for woodworking equipment. Dupont Dry Teflon Multiuse in a spray can works well. Garage door track spray lube works fine. Spraying it will get all over other things, so spray a piece of T-shirt material and then wipe it on the unpainted metal. What I am using is a can of Eagle One pure carnuba automobile wax. It is a yellowish paste that I wipe on and buff off with a clean rag. I use it on my table saw, wood band saw, spindle sander, and scroll saw. Wood slides more easily after coating the bare metal and buffing.

CarveOne

[louieatienza]

There are other products that work well also. Something that doesn't leave an oily film that creates a surface that dust sticks is usable. Boeshield is a popular coating for woodworking equipment. Dupont Dry Teflon Multiuse in a spray can works well. Garage door track spray lube works fine. Spraying it will get all over other things, so spray a piece of T-shirt material and then wipe it on the unpainted metal. What I am using is a can of Eagle One pure carnuba automobile wax. It is a yellowish paste that I wipe on and buff off with a clean rag. I use it on my table saw, wood band saw, spindle sander, and scroll saw. Wood slides more easily after coating the bare metal and buffing.

CarveOne

I've used LamiLube (used for trimming laminate with self-piloted bits) and DriCote (used for coating machine surfaces and tool edges) both with success. I spray it on and lightly wipe it off. a hit with the air nozzle here and there to blow the dust off...

[diyengineer]

I've used LamiLube (used for trimming laminate with self-piloted bits) and DriCote (used for coating machine surfaces and tool edges) both with success. I spray it on and lightly wipe it off. a hit with the air nozzle here and there to blow the dust off...

I've used boeshield but it leaves a waxy residue. Sure works well though.

[jyotti]

Thanks Mike, we'll just have a good old-time steel frame CNC revival then. Mine will top 200 pounds. Are you going to beat that?

Go with at least 3/16" wall steel to get the corners more rigid. Welding has it's drawbacks if it isn't done right, but I prefer it over bolts because nothing moves or flexes in the frame. Also, there are no bolts and nuts in the way of mounting other parts to the frame after the weld beads are ground flat.

CarveOne

Got me beat there, C1. I finally got down to B&B and got the bed steel .. theorhetical weight will be 185.22 lbs. That is 2 ea 1/4" x 3 1/2" crs by 108", 2 ea 2" x 1 1/2" .120 rectangular tubing by 108", and seven pieces of 2" x 1 1/2" by .120 wall rectangular tubing by 54". 24' of the 1/4" and 60' of the tubing cost $282.52 fob ukiah .. plus cut charge and tax.

All your grief with bowing in yur channel build was not lost on me C1. Seven ribs .. precision machined to length, 14 new Kant-twists, and 7 new Pony clamps, should keep this puppy locked solidly in place for tacking and welding .. one would hope. Yeah .. the darn clamps cost more than the steel .. but .. you can never have too may clamps in the shop, right? Once inspired to build in steel, I am comitted to embrace every advantage, and welding up the bed is certainly most critical.

Umm .. seven ribs may be overkill, but my neighbor .. EX as well, asked me if it could do marble, so I went back to the seven rib design. The mass of 85 square feet of 3/4" mdf glued to a seven rib bed should be pretty darn stable, as far as the bed is concerned.

The bed will be gimbled for welding .. two pieces of like 3/4" crs round through the end ribs, and one wall of ribs 2 and 6. I am not a welder .. get by with 6013 or 7018 for tractor stuff. Got some .030 and tips for the Millermatic 180. Probably mount indicators to compensate for sag in the vertical position.

I am using .120 wall here, and while I acknowledge your admonishments regarding welding the rails onto the bed, I am still inclined to follow that plan, dependant on the accuracy of the bed upon welding completion.

As to your new 3/16" wall construction, I do suggest you use "Rollers" for the threading .. roll forming taps. The metal is actually roll-formed into threads, swaging the grain of the material to conform to the thread form, rather than inturupting the material grain. Also .. use class 3 taps and hardware .. closer tolerance. A slight 120 degree c-sink helps the lead .. the drill size is more critcal for rolling threads, and moly type tapping fluid is about as good as it gets. I've rolled 0-80 threads in 304 .. it works .. and no damn chips ... hehehe. The slight extrusion created, depending on your depth of c-sink (keep at a minimum) can be easily flatened with a mill file. Have Fun .. Be Safe :-)

[CarveOne]

I've used boeshield but it leaves a waxy residue. Sure works well though.

The carnuba wax leaves some waxy build-up on the carriage bearings also. I clean it off before each cutting session. Which hasn't happened very much lately due to too many other things interfering with my CNC fun.

CarveOne

[CarveOne]

Got me beat there, C1. I finally got down to B&B and got the bed steel .. theorhetical weight will be 185.22 lbs. That is 2 ea 1/4" x 3 1/2" crs by 108", 2 ea 2" x 1 1/2" .120 rectangular tubing by 108", and seven pieces of 2" x 1 1/2" by .120 wall rectangular tubing by 54". 24' of the 1/4" and 60' of the tubing cost $282.52 fob ukiah .. plus cut charge and tax.

My 200 lbs for this smaller 3' x 4' machine includes the Z axis weight without the router, so we're probably running about the same at the moment, though it sounds like you are building a larger machine. My 12' long machine used 1x2x.120" box tubing. I didn't keep track of the component part weight during that frame build. The third revision of the gantry has been weighed at 185 pounds with M12VC router.

All your grief with bowing in yur channel build was not lost on me C1. Seven ribs .. precision machined to length, 14 new Kant-twists, and 7 new Pony clamps, should keep this puppy locked solidly in place for tacking and welding .. one would hope. Yeah .. the darn clamps cost more than the steel .. but .. you can never have too may clamps in the shop, right? Once inspired to build in steel, I am comitted to embrace every advantage, and welding up the bed is certainly most critical.

Not having at least one rib in the middle and overtightening the bar clamps was probably causing my problem with bowing. Just bad procedure on my part.

Umm .. seven ribs may be overkill, but my neighbor .. EX as well, asked me if it could do marble, so I went back to the seven rib design. The mass of 85 square feet of 3/4" mdf glued to a seven rib bed should be pretty darn stable, as far as the bed is concerned.

Do I hear CNC gravestone/monument carving? Will have to look that up to see if it's commonly done. The dust would be nasty stuff to deal with.

The bed will be gimbled for welding .. two pieces of like 3/4" crs round through the end ribs, and one wall of ribs 2 and 6. I am not a welder .. get by with 6013 or 7018 for tractor stuff. Got some .030 and tips for the Millermatic 180. Probably mount indicators to compensate for sag in the vertical position.

I have an 10 year old Miller 175. Does everything I ever needed.

I am using .120 wall here, and while I acknowledge your admonishments regarding welding the rails onto the bed, I am still inclined to follow that plan, dependant on the accuracy of the bed upon welding completion.

As to your new 3/16" wall construction, I do suggest you use "Rollers" for the threading .. roll forming taps. The metal is actually roll-formed into threads, swaging the grain of the material to conform to the thread form, rather than inturupting the material grain. Also .. use class 3 taps and hardware .. closer tolerance. A slight 120 degree c-sink helps the lead .. the drill size is more critcal for rolling threads, and moly type tapping fluid is about as good as it gets. I've rolled 0-80 threads in 304 .. it works .. and no damn chips ... hehehe. The slight extrusion created, depending on your depth of c-sink (keep at a minimum) can be easily flatened with a mill file.

I haven't tried those taps yet. Will see about getting some of the common sizes I use. If they will also break, I'm up to the job.

Have Fun .. Be Safe :-)

CarveOne

[CarveOne]

With some luck I'll be working on the Y axis lead screw installation today.

The height indicator thingie I showed is really called a surface gauge. Grizzy sells them as H 2712 ($12.95) AND H2713 ($14.95)

CarveOne

[Mountaincraft]

I've never even heard of rolled taps.. Now there's something else I have to look into...
:cheers:

[louieatienza]

I've never even heard of rolled taps.. Now there's something else I have to look into...
:cheers:

I think they're also called thread forming taps, I guess it's almost like forging the threads, though I wonder if the displacement of metal would cause stresses and cause the metla to warp?

"Do I hear CNC gravestone/monument carving? Will have to look that up to see if it's commonly done. The dust would be nasty stuff to deal with."

It's the way it's done more and more, whether laser etched, water jet, or carving. Really, you could cut soapstone with regular woodworking router bits. For hard stone, I think they use PCD which is pretty expensive, and definitely water/mist...

[Mountaincraft]

I think they're also called thread forming taps, I guess it's almost like forging the threads, though I wonder if the displacement of metal would cause stresses and cause the metla to warp?

"Do I hear CNC gravestone/monument carving? Will have to look that up to see if it's commonly done. The dust would be nasty stuff to deal with."

It's the way it's done more and more, whether laser etched, water jet, or carving. Really, you could cut soapstone with regular woodworking router bits. For hard stone, I think they use PCD which is pretty expensive, and definitely water/mist...

There are guys using mechmates to cut and polish granite countertops... I plan on using mine to make forms for concrete countertops fairly soon after it's in the shop and the bugs are worked out..

Who knows, maybe granite is in my future..

Granite routers are not cheap though.. Would cost almost as much as the upgrade to plasma will...

[CarveOne]

I suppose that if the machine is well painted (powder coat) and moving parts are protected from rusting (or if the sight of rust doesn't bother you so much as it does me) then it wouldn't be so bad with a water mist system. Doing the work in a blocked off containment area of the table top would also help.

I cut 12" square concrete pavers for my walkways a few years back with my angle grinder and a diamond impregnated cutting disk and was thinking of all the dust that made.

CarveOne