80/20 mill build

[Jay C]

I found this and prototyped a z-way cover for my mill out of copy paper.

BTW, My sister was gifted a PC with Vista this Christmas. It ran so slow, no one would use it so she asked me to load XP. The drivers weren't easy to find, but they are out there The reason Vista (home/basic) was so slow ... out of the 1GB of RAM it was idling and using 890MB and 90% CPU.

Jay

[LeeWay]

Thanks for that link, Jay. Now that looks doable there. I may go that route. Get the LOML to help out.
She is real good at folding things. Clothes, cash.....

Both my desktop and the new machine are the dual core cpu's. Desktop is an AMD and the new shop puter is Intel. I got some really strange driver test outputs in Mach 3 on the shop computer. Almost a thick solid line on top and bottom about 1/4" in total with no spikes at all. Every now and then it would thin out enough to see the slashes, then back to solid. That is strange.
Now I am getting inadvertent Estops. I set the debounce up to 20,000 and it does it a lot less, but still there. Not sure how to correct that.
I have removed most of the bulk of stuff from the shop vista. I will continue to hone it down over time to get it to the bare necessities.

I took a couple more pics. I installed a couple motor covers and finished drilling and tapping the table for now.

[LeeWay]

I thought I would drop this image in here for a wild idea.
This might actually be doable. I have an extra head that I bought for this project, but dismantled the X2 instead.
I knew I left that extra slab of aluminum out to the left for something.

This new motor seems to have plenty of torque now. Doesn't even flinch when cutting .035 in aluminum with a 2 flute 1/2" end mill. The motor still stays cold as well. Even after long cutting times. That is good.

Anyway, I make some parts that are 5" long. A spindle mounted like this would let me mount two vises and cut two parts at once. I would have to run an idler pulley for the belt to make it adjustable, but the idea is interesting. Not going to be doing it anytime soon. Just would like some feedback or thoughts about the idea.
Thanks as always.

[Jay C]

Thanks for that link, Jay. Now that looks doable there. I may go that route. Get the LOML to help out.
She is real good at folding things. Clothes, cash.....

Not trying to hijack Lee, but here is the mock up of the one I folded yesterday. The paper I used was 8x14". I folded each side 1.5" so the middle coverage is about 5". Next step is to find a flexible paint or else something as a scrapbooking store that is more burable like maybe vellum or spray plasti-dip.

Also, LOML (edit: Love of my life) is a new one for me ... what's that mean?

Jay

[LeeWay]

No problem at all. LOML means just what you edited.
Some guys write SWMBO (she who must be obeyed), but I ain't all that kind of whipped. Plus, she ain't here right now, so I can say what I want! (he typed looking over his shoulder)

That pleating looks pretty darn cool. It's also adjustable for length depending on material size.
I think I will have to check out Michael's or Hobby Lobby. They should have the perfect type and size plastic we are looking for. I will let you know what I find when I get a chance to get over to one of these in Pensacola.

[LeeWay]

I did get a little more done. I bought a magnetic chuck from Grizzly. This one is 6" by 12". It works very well. I cut a lot of steel with this now until my plasma cutter gets finished and the magnet really saves wasted material and time. Pulls the sheets down flat too. Not only that, but I came up with a way to mount my vice solid using some 1/8" steel plate and a piece of angle iron. Nice and square and solid.
I used steel pins through the sheet and used a bolt into the mill side of the vise into the angle along with a couple more pins. The mill drilled it's own holes in the chuck and the table. I aligned it using the holes that were there to start with. Easy job.
I made new jaws for the vise out of some CRS bar. Milled a step on both sides for small parts.
I love how the magnet works too. I thought the chips might stay in the cut too much when I am milling steels, but it actually aligns most of the chips along the magnetic lines in the magnet. Quite cool actually. I take most of the chips with me when I take parts off.
I have another iron T-slot table that I will mount similar to the vise. That should take care of bigger things that aren't steel and won't fit the vise.
My rubber way cover on the X is actually under the chuck and bolted down too.
Before I put that in there, I would get a little vibration in the aluminum coolant tray at times. Not anymore. The only noise it makes now is cutting.
I thought the rubber might make it wiggle or chatter, but didn't happen. It is smooth and solid and strong for what it is. I'll post another video sometime when I get a chance.

[LeeWay]

Well, a little more progress. I installed a locking mechanism on this side of the vise. It wasn't moving, but a mechanical clamp is extra protection and easy enough to lock. I am really liking that mag chuck.
I managed to turn my gas spring over into the recommended orientation. I made another video. If you watch the coolant on the vise, you can see how smoothly this thing is cutting. I haven't given it any real tests yet of strength and endurance, but I will when I get some time.
Still have quite a bit left to do.
Limits and homes. I have some relay cards for the coolant to connect. I have the motor speed controller to install as well. Still need to install the X end bearing carrier on the ball screw that will also act as a hard stop.
I may mount my second spindle head on this or possibly just the high speed die grinder I have. Maybe both.

At any rate, I am really pleased with this project so far. The 80/20 extrusions are still unfilled. So far, no resonance problems at all.








"http://www.youtube.com/watch?v=7jRaXnqlxKQ"]http://www.youtube.com/watch?v=7jRaXnqlxKQ

[LeeWay]

I did get a chance to push the motor some when I was setting up to do some drilling with a pointed drill mill. 1/4" cobalt 2 flute. I was drilling some 1/4" holes in this 3/8" 6061 aluminum. I was taking a .05 peck depth @ 60 IPM plunge rate. I knew this was a little much. About halfway through, I started hearing some bogging. Well it wasn't the motor that was slowing down, it was the spindle. The belt was starting to slip. I stopped it and tightened the little V belt up as much as I thought it cold take without trying to stretch it any. It drilled the second hole and it only stuttered once. Again it was a belt slip. To be fair, the two pulleys I am using are nearly the same size when in high speed. Just the standard Steele belt conversion pulleys. This doesn't really give the belt enough of a wrap around to give it good gription. I am thinking that I will eventually go with a timing belt drive since this motor has so much torque. No need to limit this thing by using the wrong kind of drive setup.
I backed off the plunge rate to 30IPM and it runs fine without a hitch.
I was initially disappointed with this motor and the original driver I bought for it, but since getting the right driver and wiring it 220, I am pleased a punch.

[axis_control]

wow!....great going..i am looking forward to this thread.

[LeeWay]

Thanks. I still have quite a bit more I want to do to this and will post as progress is made. It is running very nicely though. Just doing some production work with it now. It's earning it's spot on my cnc wall.

[sergizmo]

Great thread Lee! Pretty impressive build and results from simple tools and materials. Do you have any more updates? Timing pullies for the steppers? High speed spindle? Have you cut any steel on this thing?

Building your own machine over buying/converting an X2 was the way to go. It is faster, more precise and probably more rigid. Plus if it goes down you can fix it immediately. Not to mention building your own mill is just plain cool. The only really nice table top CNC mills for metalworking (At least that I know of) are the Wabeco, and they are $$$$$$$.

I want to thank you for the angle plate idea. That looks like a very cost effective way to both align and strengthen the column. I will be using one in my small mill build for sure.

Serge

[LeeWay]

Thanks a bunch, Serge.
This has been very satisfying. It is a fairly impressive machine in person as well. I still have more to do on the to do list. As of yet, no good Estop. Need to implement one. Limits and homes aren't there either. Spindle control and higher speed is still lacking. Timing belt spindle drive still to come. I have the gears and belts to add to the Z axis motor for more torque, but not yet installed.
I just peck shallow in the meantime.
This machine easily runs all day 4 days a week and it is cutting mostly steel. About half a day on aluminum. The stuff it is doing now will soon be done by plasma in a couple hours.
Cutting thin material on a mill has its own short comings. You have to be careful not to lift the material with too much of a cut. I do use the mag chuck with outstanding results. I have two fixtures for it. One holds my little vise and the other holds aluminum sheet. I will take some more video and pictures when I can as well as report back with progress. I sure do like the way this thing wound up working. It surpassed my hopes. That is the second time on as many machines that this has happened. Over building in some areas sure can have an effect on the outcome and capabilities of an otherwise sup pro machine.

[sergizmo]

Wow. So it's a full production machine cutting steel. Raking in the cash Lee?:rainfro: Very, very impressive for a low buget home build. Honestly, very impressive period for a machine of this size.

Yes, an e-stop is a major priority. If you run big steppers and fast rapids, then limit switches would be good too. But homing switches? It takes a couple minutes to edge find and establish zero. Doesn't really seem worth it.

I'm surprised the spindle has held up. You boosted the power big time and are cutting a lot of steel. Don't these spindles just have deep groove bearings? Any plans to upgrade this in the future? How are you contolling the spindle speed now?

Got to get back to CAD drawing my machine. Reading these build threads is really inspiring.

[LeeWay]

You are correct about the homing switches. It takes very little time to mark center on my stock and the tell Mach 3 that is home. All my drawing for the mill have center as home. It makes little difference if you are off by a hair. It still cuts the prts out to the correct size if you allow that in the stock.
This machine is so predictable with the Gecko's though, that an estop is not a priority.
Any failures and I can hit the mouse or the AC PS switch.I leave the mouse hovered over the stop button, so effectively it acts as an estop unless the comp locks up. Then the AC PS switch is there and easy to get to.
As for the spindle, this one works great. It's a little slow, but I'll fix that with a timing belt drive.
I have been into this particulat head and it went back together flawlessly. It has no discernable run out. I did get lucky with it. I may also upgrade in the future. For now though, it stays nice and cool @ 3800 RPM.

[sergizmo]

Lee, sorry to bug you again. First off, any updates on the machine?

Just a little info required in regards to the spindle.

Originally I had planned to make my own spindle. But, time, money and tooling considerations made this less appealing.

So, I went looking for small spindles. Not a lot out there that isn't some super high RPM water cooled dealie that costs $3,000. The Sherline ER16 spindle is nice but not beefy enough. The Finley ER20 one looks great but is priced at $1,300 just for the spindle. Then there is the X2 spindle that you use with great success. Being Chinese made and having deep groove bearings made me a little weary at first but it appears as though these spindles seem to be pretty solid and not have too much runout. The problems with the Chinese mills seem to be in other areas.

Anyways...

If I wanted to get started with the stock motor and contol I could get this:
http://www.littlemachineshop.com/pro...ory=-269978449
And this because I don't want to deal with plastic gears:
http://www.littlemachineshop.com/pro...gory=879658189
Maybe this:
http://www.littlemachineshop.com/pro...638&category=2

Can the column dovetail part on the back be removed to obtain a flat surface that can be screwed on to a plate? Almost certain it's yes but I just want to make sure.

If I wanted to use an upgraded motor right away I would start with this:
http://www.littlemachineshop.com/pro...ory=-269978449
Then get the belt drive and drawbar as above.
Then get DC motor and appropriate speed control. Don't need a ton of power. Say a 3/4 horse with this:
http://www.surpluscenter.com/item.as...tname=electric

Do both these scenarios sound about right?

Also, have you looked into the Tormach tooling system for use with this spindle?

Thanks to Lee or anyone else who can give me some advice.

Serge

[pzzamakr1980]

Hey Serg, depending on what you are doing, the mini mill motor is generally adequate. Unless you are really trying to punish the motor by going way too deep with a big endmill. The gears have to be replaced immediately, that is without a doubt the first thing you should do with the head. Other than that, machine the dovetails off or unscrew the head from the connector and you would be good to go.

Any oh yes, I use the tormach system with my x3 and I love it. Its a great tool system.

[LeeWay]

I found that the motor that comes with the head is just too weak unless you program to cut very shallow and not peck very deep when drilling. It will get the job done, but very slow.

Going with the bigger motor and 220 volts I was able to run parts about 6 times faster than with the original motor. Bigger steppers and power supply contributed to that though.

The belt drive is very good if you choose to use the original motor.
The belt is too undersized for a stronger motor though. It starts to slip when under torque because there is not enough difference in the two high speed pulleys for the little belt to grip well.

I am going to go the timing pulley route on the spindle. I really have to program slower drilling cycles than the machine is capable of because of belt slippage.

The one update I do have is that I installed a timing pulley setup on the Z motor. No more lost steps on the Z when I get too fast with it. Just the spindle belt slipping now. These little machines are only as strong as the weakest link allows. Fixing the weaker links is kinda fun and interesting and worth it in the long run. At least for me. I would say another couple months production and this machine will have paid for itself.

[sergizmo]

Guys, thanks a lot for the help.

Lee, your machine continues to impress me. You are taking some pretty beffy cuts with a tabletop mill. I think using such large rails and making sure the column is solid plays a big part in this. Can you give us the lowdown on what speeds, feeds, and DOC you are running for both aluminum and steel?

Looking at the stock motor again it may not be adequate. It's .47HP, but that's input power, not power delivered. It's probably more like 1/3 or less output. Looking for more like 3/4 HP output. So the spindle box, drawbar, belt drive kit can be purchased. The belt drive should be fine for 3/4 HP. You were pecking at 60IPM, not gonna try anything like that!

[LeeWay]

On steel sheet, I have been running .025" doc @ 25 IPM 3800 RPM with a 3/16" chinese 4 flute EM. I could go deeper and a little faster with this as well, but I am using a magnetic chuck to hold the sheets. It would move the sheet if I got too much more aggressive with it.

On 6061 aluminum in a small vice, I run about .045" doc @ 80 IPM with a Chinese 1/8" EM 3 flute 3800 RPM.

I also run a mill drill for some ops. It is 1/4" and I run it @ 120 IPM when engraving both steel and aluminum @ about .008 to .01" doc. I run it the same as the 1/8" on aluminum.

I have started doing some aluminum sheet on a tooling plate now. .063" 5052 aluminum in two passes @ 25 IPM and 3800 RPM.

All these feeds and speeds are just trouble free use. They produce the least amount of broken EM's. I am sure if I used some nicer EM's, I could get this up. Spindle speed will be increased soon as well.

The column rigidity has a lot to do with this little mill. Even though it is aluminum, it is very stout.
I am noticing on hard pecks that I do get very minor movement, not in the column itself, but in the cast iron slide. I never took that appart, but I bought it used. It may well have some worn balls in it. I now have a supply of replacement balls for the preloaded ball screws. Got them on Ebay.
Next time I break it down some I will check out those balls in the Z slide.

That should be pretty soon. I just ordered the timing pulleys and belt for the splindle. I'll check it out then.
Thanks.

[LeeWay]

Here are a couple images of the Z timing belt install. Initially the motor was direct drive and mounted on the slide itself. The slide came with a Nema 23 mount designed into it.
Problems with missed steps during heavy pecks with anything other than a brand new mill drill caused me to do this mod. I think it worked pretty well. I added 1/2" pillow block bearing to carry the load on the screw extension for the pulley.
I got the pulleys and belt from SDPI. Nice stuff at a great price I think. 1/2" wide belt. 10 tooth pulley on the motor and 20 on the screw.

I need to raise the pulley just a bit to get the belt tracking more in center, but this really works nice and smooth even though there are mulitple parts. I had to mill 1/8" off the base of the pillow block and clip the ends off to get it to mount on the existing bolts on the column. I used aluminum shims to get it to just the right height.

Next up will be the spindle motor pulley redo.