Enjoy watching every one elses projects grow so much thought i would share mine. This will be the second machine i built, first is a rock cliff which i am still happy with, just wanted bigger and to be able to try it with my plasma cutter also.
This machine was designed from scratch, ideas taken from umm every other build i have ever seen :) Everything was bought new except the two linear rails used for the z downfeed (dont have enough time to bargin hunt): Total cost was 2k. not everything is on yet, but do have all the parts.
Used the vbxbearings.com 20mm rods and slides for the x and y. Y seems ok but the x with the narrow spacing and moderate cross slide does have to much torsional flex at teh moment. I think i may add a piece of barstock behind the x rails, and then a bearing follower from the cross slide to help eliminate it, or bolt in another plate behind it and swap in some linear rails.
it was designed as a light duty machine to run a laminate trimmer or plasma so the follower bearings will probably do the trick. its fun anyway :)
I also made it for easy disassembly so I could move it around and into the
basement. Top rails are held on with 4 1/2 bolts, cross braces are bolted on
too, rest welded. Right now has some resonance when you tap the frame, but bolting on the table should finish sturdying it up. For drive on the Y axis I went with a rack and pinion to drive both sides, 1/2 shaft will drive both with flange/pillow block bearings to be mounted on gantry. gearing is 1:1 on the rack gears and 4:1 on the belt drive off the stepper to the shaft.
ballscrew on the x axis, you can see a cheesy ball end mount. collar with 2 set screw on ballscrew then a roll pin to threaded ended going through bushings to mount to stepper. I will probably redo this a bit better want a little more length on the thread endand probably want to lightly weld steel collar to ballscrew. my lathe is not up to turning down the ballscrew even with carbide bit take to long :( on teh other end ballscrew is cupped by another aluminum sleave just to keep it from whipping i will add a grease fitting to that end and call it a day. lost one tiny ball bearing from ballnut..scared to try to get it back in there not sure if one missing matters.
ballnut is welded onto another piece of steel then bolted to cross slide. didnt have a tap on hand to mount it proper but will be fine.
down feed is acme screw, i did make an antibacklash nut block for it, but it runs kinda tight will see what i use in the end. all steppers are 469oz xyolex with xyolex board. will be using mach3 to drive it. guess thats all i can think of for now..will post updates as i finish her up. :)