80/20 mill build

[LeeWay]

I have been cutting a pretty good batch of parts. I did get the larger motor installed and installed it using the belt drive kit. I had to tap through the face plate on the motor in order to mount it to the belt kit's mount. I had to drill holes for it. I had to cut a little of the motors head to make room to install the brackets bolts. I had to do away with the ratchet handle from the kit though. I will have some pictures of this soon.

Rather than cast iron, I ordered some Mic-6 cast tooling plate from Yarde Metals Drop Zone. I bought a piece for the table and one for the saddle. I am seroiusly considering building this part like Arie made his. The X rails mounted fast to a lower long table and let the blocks hold the shorter milling table. I have been using this with a long table travel. If I cut parts that need near the 14" travel, then the end of my table would hit the sides I will eventually put on my drain pan. Arie's type machine is a lot smaller footprint than what I have now. I ordered 1" x 7" x 25" and a 1" x 8" x 15" plates. These will allow me to spread the X rails out just a little as well.
Since the mill is running now, I will be able to use it to mill cavities in the new parts for blocks, rails and and nut clearance. I should be able to take my time with it and get it right the second go around. Right for a mostly aluminum mill, that is.
Right now, I am not taking cuts any greater than .04" in either aluminum or steel. 60IPM for the most part at about 2000 RPM guesstimate. Since it is not bolted down yet and is just sitting on my aluminum drain pan, when I cut deeper, I get resonance in the pan. I will adjust the size and shape of this pan too, once I get the smaller X footprint. It mills and drills fine though, even without being beefed up more.
I will simply use the hydraulic cement I bought along with the birdshot to fill both large cavities in both 80/20 extrusions. I would like to shoot for a .1" DOC in mild steel, but I think the spindle will be the limiting factor here. Being a cnc though, there is really no need to cut that deep. Just cut shallower and faster more times.

It is cutting okay now though, so the mod's will have to come after I get a little stock built up. A week or two's worth anyway. Just guessing here, but I think this machine right now can cut parts out that would take me about 4 days, in a day and a half.
This while I am working on other parts. Very cool. It's like a helper that don't talk back. It can, however be a little stubborn at times.

[LeeWay]

No pics yet. I will take a few today. Just more rambling for now.

I have ordered some larger motors. 495 oz nema 23's. I will sell the 269 oz motors. They worked okay on my router, but I need more torque. I will try the 495's on here and if they are not good enough, I will have to step up to a Nema 34. I wanted to avoid that if possible since the mounts are built already. I think they should do fine though. I just noticed some movement when I was manually cutting with the machine in jog mode with a 3/4" end mill. That really shows possible problem spots. In this case, I noticed the Y axis move slightly when the end mill engaged. I think more holding torque would lessen this.

I bought a new power supply as well. This one is 72 VDC @ 12A. I ordered these from Keling.

This means I will have two power supplies and three motors to sell. The first supply is a 24VDC 6A regulated linear PS made by Condor.

The second is the same PS that Keling offers for $60. Its a couple weeks old now. 48VDC 7.3A This is what the website says.

1: High Efficiency, Low Temperature, Small Size.
2: Over Load and Short Circuit Protection.
3: Over Voltage Protection.
4: Input: 120VAC or 220V

I did turn this up to about 54VDC and down to about 36VDC, so there is a range of voltage you can use.

The Steppers are 269OZ 8 wire, so they can be configured three ways. They still work as good as new, just not strong enough for me now. Would make great starter motors for a Newbie.

I will accept offers on these. If no takers, I'll list them on Ebay.


What I am looking for is $25 for each motor. $35 for the small supply and $45 for the larger one. Plus shipping of course. Everything sold as used, but guaranteed not DOA. If interested, just email me. leesty@gulftel.com
Thanks.

[LeeWay]

Here are a few images I took this am.

[LeeWay]

I did make a video of this machine cutting out some of my parts. This is still with the 269 oz motors running 3 gecko 203V's @48 VDC. The mill is sitting on a wooden plant stand right now and is not bolted down at all. I have a steel bench that I will sit this on when I get ready to rebuilt this with a new table design, feet, gussets, filled extrusions, bigger PS and larger steppers. I am also going to have to run the spindle motor on 220 v to get full power and speed out of it. The smaller controller I bought from Surplus center doesn't get it. It semi stalls and goes into a slower speed at times. This is a nice motor and I have it mounted well, I just need the bigger driver. More power. :rainfro:

Here is the link to this video on You Tube. My first try, so if you like to watch paint dry, you'll love this video.

[LeeWay]

I was able to get the mill moved in my shop to a better location and on a steel base. I installed the sides of the semi enclosure. It is 1/4" polycarbonate. The front just slips in some aluminum channel. I was able to get the new PS hooked up. Haven't done much else to it though. Production has taken the front seat.
More to come soon, probably after Christmas.

[LeeWay]

Oh! I forgot to share a little info with you guys about the mill. Take a look at the rear of the mill in this photo. See anything missing there?




Well, it is hard to see, but there are 4 holes in the angle plate. The 5/16" bolts aren't in there yet. All that is holding the column, cast iron Z axis slide, stepper, treadmill motor and spindle is just the 4 1/4"-20 threaded rods down through the column extrusion. That's right. How the heck was I able to run a couple weeks worth of parts and that was all that was holding the Z in place? I feel like an idiot somewhat, but I do think it preformed rather well, especially given this. Gussets on each side and actual bolts and nuts into the angle plate might even let me start hogging off more material than I ever expected from this.
I rewatched the video with this knowledge and I am just in awe of those amazing 1/4"-20 rods. Those are some bad boys.

[LeeWay]

I have had a chance to get more done on this machine that past few evenings.
Here is a link to a thread about the spindle motor.
http://www.cnczone.com/forums/showthread.php?t=48755

I have a few more photo's to share.
I still haven't got the table redone, but that will be next when I get a little time. After securing the column and getting more speed and torque from the motor by going 220 with a different drive, I am pretty impressed with it so far. I won't yet try hogging off hunks of steel, but when I get the table done and the filler in the extrusions, it should be able to handle some decent cuts. I made several cuts @ .07 DOC @ 120 IPM @ 3740 RPM with a 1/4" HSS two flute. It wasn't bothered at all by it. It can do more.
The machine on it's new base is rock solid. I may eventually have to weld some angle brackets to the legs so I can bolt the table down to the concrete, but have to see how it works out. I will install angle brackets on both sides of the Z slide on the column to help me tram it for side to side. I think it is very close now, but haven't put a dial on it yet.

[ckm]

Congrats on getting this done. Lots of good info, looks awesome. I bookmarked it.

Thanks for sharing this.

Chris.

[LeeWay]

Thanks Chris. I checked out your X1 build. Nice work there too.

I have been wondering about something. I intend to add a high speed cutter on this head. It's just a HF die grinder. I only want to use it for drilling very small holes and things like that. Run out should not be too much of a problem as the hole tolerances aren't that critical for what I have in mind.

I am hoping that this would help with the tool change in some of my parts. The part I am making in the video earlier needs 3 3/32" holes drilled. I do them by hand now, but if I had the DG installed, perhaps it could drill them right along in the toolpath with the main spindle. Assuming I zero both the endmill in the spindle and the drill bit in the DG at the same height, would it be possible to somehow use an offset or something to get the DG to drill these little holes? Is this something I set in Mach or Sheetcam or both? Would a relay start spindle two when it is needed and shut it off after the drilling?
I know I would have to raise my work holding in the vise, but I intend to make some taller stepped steel jaws for it. The DG would mount on the front of the head rather than on one side or the other. I have more travel in the Y than I actually can use with the spindle and the DG would make use of that extra.
I have many parts that would really benefit from being able to drill small holes in.
Thanks.

[LeeWay]

I am in the process of redesigning the table on this. It will be a similar design to Arie's. Long saddle and shorter table. I now have 14" of X travel. This plus the motor being direct drive on the end of the axis takes up a lot of real estate. My enclosure is 4' wide, but this isn't enough for it setup this way. I only get around 12" of travel.
I have made a determination about the travel. I think 12" will be fine for this. Arie's design uses less overall space for the same amount of travel. My parts should all fit in the 9.5 x 12" span. I will include some dowel holes and register longer parts. Work around the size so to speak. I think it will be much easier doing this with the wider table @ just over 8" than it was on the X2. Though it can be done on it as well. I bought 10 of these HSR25HB blocks on Ebay for around $200. All brand new still in the package. I think I will add a third block to each rail. Put them on there box car style. This will take just over 12" of the rail. The rails are 24". That should give me close to 12" of travel in the X.
Doing it like this, there will be 12" of blocks. This will aways place part of a block under the cutter unless cutting on the extremes of Y. That should be pretty solid.
It is a compromise between rigidity and travel. Since I have the blocks, I might as well use them. It may prove to be an even better mill with them on there. If later I find that the travel is too limiting, I can always add longer rails. I will have to optimize ball nut placement with this in mind. The screw is around 18", so it can handle the travel.
The rails will be a little wider spaced as well. I will also have to redesign the motor mounting block for the X.

I milled out the holes and cap screws in the saddle last night. I noticed that the part actually scrubbed up against my gas spring. I will need to make a plate that mounts where the spring is mounted now to move it more vertical and back out of the travel area.

I had every intention of doing some drawings for this, but have never got anything but little bits and pieces done, so there won't be any plans. There will be more pics though.

[ckm]

You could turn the motors around using a belt drive. That's what I did. Attached is are pictures of the two piece mount I designed for this. The pulleys will be from SDP-SI with a 1-1 ratio. Note that this is for a mini-lathe cross-slide, not a mill, but the same principle applies.

Also, you can mount the Y-axis drive on the back of the column, also reducing space.

Chris.

[LeeWay]

Thanks Chris. It's no longer possible to put the Y motor at the rear of the column. Way too much stuff back there. I actually initially had the Y motor tucked under with a roller chain drive. It worked okay, but the chain was noisy and I had the motor laying in the bottom of the coolant tray. Everything fits perfectly in the enclosure on the Y direction with the motor inline.
I initially had what appeared to be backdriving on the Y, but have since upped the motor and PS size. I haven't seen that happen anymore. The X an Y are happy jogging @ 300 IPM. I have them set for 150 though. More torque that way.

I may eventually tuck the X motor, but with the newer long saddle design, I am no longer strapped for space in the enclosure. The saddle and X motor won't travel in the X direction like it does now. It will be stationary and only the ball nut and table will travel. Currently the ball nut is fastened to the saddle and is stationary.

I know it isn't good practice, but the balls don't fall out of these blocks. If I actually needed to run with the 14" travel for one job, I could run the end blocks off the rails by about an inch on each end. This would still put 2.5 blocks on each rail.

I will also be building or converting a lathe soon. These rails would work well on that. I still have 4 other new blocks. I could get some 28 or 30" rails to increase the travel to the full travel of the screw. Pictures should help clear things up. Hope to get this done soon. So far, it is cutting nicely even with the fiberglas saddle. I am anticipating even better performance.

[LeeWay]

I got this to actually cut some parts. Some of the pics show drilling and slotting the new saddle for mounting. Some show pocketing for the ball screws. Not quite done with that yet. Need to move the plate and finish the shallow screw slot. While milling these things, I nudged up against the gas spring, so I had to relocate it farther back behind the front plane of the column. I actually like that position better.
I was using a 1/2" 2 flute cutting @ 3740 rpm @ 15 IPM. DOC was .05. I could have went a little faster and even taken deeper cuts. It had no trouble even with the fiberglass saddle and 1/2" plate table. It should really do well with the new table and extra bearing blocks.
I was really impressed with the spindle and the motor performance now. It did not bog what so ever. Full power through all the cutting. Spindle head and motor were both cool to the touch. Pretty much ambient temp in the shop. I think I'm going to like this thing.

More to come sometime soon.

[LeeWay]

Well, my cpu bit the dust on my last remaining shop computer. That's three all with differnt issues. I may be able to make one good one later on out of the parts. I went to office depot and found one on sale with an LCD monitor. It also had a couple rebates. I hate those, but ultimately this will cost around $300 with the OD advantage card.
It is similar to my office desktop, but smaller in speed, ram, accesories and came with Vista Home Basic. It is still plenty big enough to run these machines though. I was installing all the updated drivers and getting Mach setup and noticed that this had no printer port. My desktop didn't either. I also could not just swap the older HD into these machines and let them run XP. I tried two. One 8.4 Gig and the other is a 140 Gig. I kept getting HD error. I saw no way to set up for this type HD in the bios either. Thats okay I guess. When I did try to load XP in the first machine as a second OS, XP was not able to drive most of the newer hardware.

At any rate, the new computer is running fine. I had a PCI card with two ports on it. I installed those and Vista found the drivers automatically. Back in business. I was able to drill some more holes in the table for mounting the blocks. I used the Cad drawing from THK and they are perfect with regard to hole placement. I was a bit leary, so measured first. Everything was in the bubble as it should be.

I added some side to side tramming aids to the column. Total of four. They work very well. It was out of tram by just a bit. Kinda tilted the spindle left. a turn or two fixed it right up. These were very easy to make and add to the 80/20. It would have been more involved with a different type column. I know it was a bear to tram my little X2 with tilting column.

[Jay C]

I saw no way to set up for this type HD in the bios either. Thats okay I guess. When I did try to load XP in the first machine as a second OS, XP was not able to drive most of the newer hardware.

I can agree with you that the BIOS on that PC may not support PATA (parallel ATA hard drives) any more, but I disagree that XP can't run newer hardware. If the hardware doesn't meet Windows PNP then yes you will need to install SP2 and download the XP drivers from the manufacturer's website. I have nothing but distaste for Vista

FWIW,
Jay

[LeeWay]

There was a list of the hardware that XP would not run, but I upgraded to Vista Ultimate just so I could load up Virtual machine with XP. I was having several problems with my different software in Vista even after doing all the special crap.
XP seems to have no trouble with any of my older software or any of the new hardware when running in Virtual PC. That is where I have to run Turbocad. In Vista, it is missing stuiff like Join polyline and a few other tools that I like to use. The rest of it runs flakey too under Vista.
I really dislike this as an OS, but hopefully when and if they come out with an SP, some of the issues will go away.
This should be a lightning fast machine and it is slower than many of my older computers. All but maybe the 386 and 3.11 Windows.

[LeeWay]

A few more pics of the new saddle and table going in. I can still get that 14" of travel I had, but runs the outside bearing half off the rail. I'll only use that when in dire need. As it is, I get 5" to the right of center on the table and easy 7" to the left. That's from exact center of the table. Most of what I will be milling is in the 8" long range, so still suits my needs.
I cleaned up the coolant mount. I removed all the grease fittings in the blocks and installed set screws in the ends instead. This let me slide the blocks together. I drilled and tapped through holes in the table with set screws too. I remove a set screw and install a grease fitting to lube each block, then replace with set screws. That works nicely.

I need to shorten my old way covers and design a skirt for the new saddle. I want to install aluminum covers on the X and Y motors. I have only just started drilling the table for mounting holes. I will either be using a vise or sacrificial tooling plates for most of my milling, so the table should stay in pretty fair shape even though it's cast aluminum.
I wanted to cut T-slots into it, but I just didn't trust the other fiberglass saddle I had on it before, however it did a real nice job of cutting the screw bearing holder / motor mount. I initially was having some trouble with circles coming out round, but that must have cleared up when I got this new computer. This one came out a perfect slip fit around the bearing housing.

I still want to install the lazy end bearing holder on the screw. That will at least prevent me from running the ball nut off the end.
Limit switches and things will have to come later. Soft limits are working for now.


PS. I meant to mention that at some later date, possibly if I install longer rails, I would want to shift the saddle to the right some more. An inch now would center the table on the rails. This screw is 21.5" long not including the bearing. If I had designed it a little better, I could have gotten about 14.5" travel. Live and learn.

[ckm]

How did you align the X rails?

Chris.

[LeeWay]

I basically relied mostly on the previous rail alignment to cut the slot pockets for the new rails. I registered the saddle on several bolts holes from the lower table. These had been previously squared to the column with a quilter's block. It's about an 18" square piece of plastic with multiple square lines on it. It is perfectly square. I know this because I have used it to make chess boards and it helped me align my sliding miter table on my saw to produce perfectly square cuts.
I checked, double checked, rechecked and checked some more during the whole process. That is something that you have to get right. It really helped that the MIC-6 plate was cut very nice and square as well.
It took a lot of time, but the rail pockets came out great. I could not have done any better of a job aligning the cuts. I could have done them in two passes, but using three and starting in the center helped to eliminate error.
I was able to get the rails to about .0005" parallel to each other over the 24" on X. Y was already that close.
I have to say that this thing moves incredibly smooth. I thought my router moved smoothly on skate bearings. No comparison really to big linear rails.

I did get a chance to check out the balls in the nuts too. They are staggered arrangement. This means they are preloaded for anti backlash. I only removed a few that were in the tube and then replaced in the exact order.
The sizes were 3.14 mm and 3.09 mm. Now I know what size balls to order should these ever start wearing.
I have seen worn balls before from a small THK rail that I had bought off Ebay. The worn balls look football shaped. I made sure I tested these at several points around each ball and they show no sign of wear. This tells me that I got an even better score on these screws off Ebay than I had ever hoped for.
You also can't see it, but I redid the ball nut mounts. They are now steel angle iron. You can see the top of the four cap screws in the table top now.
I must have lucked up and got them extremely close as well because the lazy end of the screw doesn't wiggle or wobble, it just spins. I really wouldn't need to put the bearing mount on there, but as I said earlier, it scares me that the nut would run off the end.

Somehow I also gained another .2" of travel in the Y. Now I have 9.7". I have to say that I am finally very pleased with this build. I will make a video of it cutting soon, just to show the difference between it now and what it initially started life as. I have to say though that I have certainly had my fill of visits from Murphy and many head scratching moments during this rebuild. I am certainly glad that this is nearing the end of it's incubation. I am going to have to make it skip college and go straight to work.

[LeeWay]

Now does anyone have any ideas on how to fab a skirt for this type table? I want to cover the motors separately. I have some more of this roofing rubber, but it has it's drawbacks. It bunches. I had considered getting some of these.
http://www.littlemachineshop.com/pro...431&category=6
I didn't care for them on the mini mill though. I imagine my thoughts would be the same here.

I like the looks of these at Mcmaster Carr.


That's another couple hundred though. One good thing is that all my screws and rail blocks have wipers on them, but on the rails in this configuration, crud gets into the bolt holes and then into the blocks. Once in there it can migrate to in between the balls. This can lock up some balls and then you have hardened balls grinding on the rails because they can't roll. That's imminent failure and destruction of precision.

I am also considering fabbing my own. I am thinking that a nice heavy canvas covered on both sides with some elastomeric roof coating would work pretty well. That is sounding like more work though and not all that cheap either. I may just buckle and go for the real thing. If anyone has any other thoughts or suggestions, I would like to hear or see them. Thanks.