New Machine Build- My Mini VMC

[CPK_Jim]

I built a cnc plasma table last fall and have been using the heck out of it ever since and now I think I have been bitten by the cnc bug cause I really want to build a mill!!!!!! Espiecially since I have collected most of the parts that i needed to find. I have some zero backlash ballscrews and some nice thk linear rails to use.




I have some heavy 48" long rails and 4 blocks to go with also.

I also have some yaskawa servos and drives to use for the mill, but I may just dump em and get a stepper setup idk yet. I'lll decide when i get a chance to play with the servos a little. They are 200v 100w. what do you guys think, will they do ok?

I think the travel I will end with will be something like X30" Y11" Z11". I only have a 16" travel screw for the x so it will start off with that unless i find a longer one before I get to it. Table will be about 12" x 36"

Spindle??? Im not sure which route I will go with but im thinking something like a dc treadmill motor.

What do ya think? I cant wait to get started on the build but I know this will be a fairly long build maybe 6mo. or more.


Jim

[hesham morsy]

pick your poison


http://www.cnczone.com/forums/showthread.php?t=30262

http://www.5bears.com/cnc.htm

http://www.gimbal.com.au/content.aspx?name=cnc-mill

[CPK_Jim]

thank you those are some good links. I remember reading some of that stuff last yr when I was building my plasma table. Now I can go through them with this project in mind and see if I can drum up some cool ideas.

[Starleper1]

you can check out my mini VMC I'm building under the bench top section.

[CPK_Jim]

Well, I didnt want to build this thing out of junk but....... Ive been wanting to build this thing for so long I just couldnt wait any longer. It is actually turning out to be very solid and accurate, so far im happy with the results from the first tests. Now I cant wait to get the rest of it done!!!!!

Here is the first axis, not totally complete, needs a few tweeks and limit switches and whatnot. It only travels about 18 inches becuz that is the longest screw I have been able to get a hold of. It will travel 30 inches when I find the correct screw. This thing is solid, no slop and as of now 180 inches per min rapid and accuracy of .0003 not bad for a bunch of junk



Heres a little video of me riding on the it. LOL

YouTube- Mill Ride.MPG

YouTube- Mill Ride.MPG

Heres another vid. In this one i programed it to rapid 1 inch and then back a few times to do a quick repeatability test.

YouTube- mill test.MPG

YouTube- mill test.MPG

Jim

[CPK_Jim]

More progress, I got the columns mocked up as well as the Y and Z axis. Still need to fabricate column braces and mount y screw. Also still need to fabricate Y and Z motor mnts and install them. Everything seems pretty tight and stiff at this point but the real test will come when I start cutting with it. As far as straightness, in case you guys were wondering. After I get everything mocked in place, I am going to disassemble it and have the necessary parts blanchard ground, to help straighten everything out.

Heres a few pics





Jim

[will gilmore]

looking good. how about adding some additional bracing to the legs of the bridge? with the moving table you could make those things massive without loosing any travel. maybe more difficult to load...

Will

[CPK_Jim]

Thats actually what I was refering to when I said I still need to add column bracing. I dont think they will be in the way to much. They will def stiffin things up.

Jim

[RotarySMP]

What is it going to be bolted down onto? A granite surface table?

[CPK_Jim]

I havent totally decided on the stand for it. The base plate is 1" thick hrs plate that has been blanchard ground on both sides. I figure I may be able to get away with just fabricating some sort of heavy duty stand for it. I figure if it needs more mass to absorb vibration, I can get another one or 2 of those plates I used for the base, and bolt em to the base. I have a good hookup on those plates and there almost free.


Jim

[RotarySMP]

This is a pretty big machine. What will roughly end up weighing.

You are making fast progress.

[CPK_Jim]

I figure with the stand and the machine it will way in somewhere between 1000 and 1500 lbs. Big is the name of the game here, Im after as big of travels as I can afford. After i find a long screw for the X I will hopefully end up at 30 in X, 17 in Y, and 11 in Z. I figure its a decent size to Justify the build costs. I am trying to build this almost completely with stuff I have collect of the last cpl yrs. Either by getting it cheap or free. All the steel so far has cost me $0. And I still figure I'll have about $2000 into it. Which isnt bad if it works as well as what I think its going to.


Jim