Newbie- Milling Machine Build Experience Needed!

[jacobbiljo]

Well i've started to design and aquire parts for a scratch built vertical milling machine that I plan on getting the basics hammered out in my last 2 months of school this summer. Ive already gotten 2 14inch ball screws and one 20 inch as well as a 600 watt 180vdc motor.
Ive attached a preliminary Solidworks drawings and i am hesitant to go forward until i hear some opinion about whether my frame will be rigid enough. I have easy access to lots of 2" square tubing with 1/4" wall and was planning on using that for my frame with a 1x1/2" piece of flat bar welded ontop of each piece of tubing so that it can be machined and ground level then tapped to mount roller guides on.
My question is would this size spindle motor be as capable as something along the lines of a Sieg Model X3 because thats all I am looking for power wise and are my X and Y axis tables rigid enough or do i need to go more along the lines of solid bar stock because I dont think i'll be able to scrounge that up for free like the square tubing.
Thanks for any help

Jacob

[The Tin Man]

Hi jacobbiljo, Good to see a bit of enginuity I am just wondering what tools you have at your disposal? Sounds like you have access to a mill but it is possible to build a milling machine from scratch even without machine tools as described in the books, Build Your Own Metal Working Shop From Scrap series written by David J. Gingery. Looking at your preliminary drawing I could only imagine that you intend to do light machining, the base needs depth. As far as your spindle goes I would suggest taper roller bearings to take the load. "Precision" taper roller bearings are expensive so I would use just a generic off the shelf taper bearing unless you really need it. Your motor has plenty of power but don't use the motor shaft as the spindle output unless you only want to do light work. The motor bearings are not meant for it. I work as a structural fabricator and machinist. It would be easy to pick up some nice big bits of Parallel flange channel for your bed from your local industrial area as any offcuts of beam gets tossed anyway. The roller guide idea is a good one as far as precision goes and for a small mill it could be quite serviceable. Your design might be ok as is for "light" work but vibration will be your biggest enemy. Have fun and I look forward to seeing this thing when it is done.

[hesham morsy]

http://www.diy600.net/

http://www.netikka.net/saulij/cnc/Versio2.jpg
http://www.netikka.net/saulij/cnc/Versio4.jpg
http://www.netikka.net/saulij/cnc/Versio5.jpg

http://www.usbcnc.com/index_machine2.html
http://www.usbcnc.com/images/machine...2/machine2.jpg

http://www.cnczone.com/forums/showth...979#post324979

[jacobbiljo]

Yes for the next two months as well as saturdays for the next year i'll have access to a well equiped shop with a heat treat oven, surface grinders, milling machines and lathes. I was planning on mounting the motor and spindle seperately so that i could use stepped pulleys to change the torque/speed. To make the spindle simple to make i was planning on not machining a taper for the work holder but simply grinding a 3/4" holder in the end and using a ER 32 collet system to adapt it for smaller sizes. And yes i managed to get some nice tapered roller bearings from timken through a project i worked on.

Jacob

[hedgehog23]

you could always fill the tube with that sand/stone/resin that seems so popular on here. would cut down the vibrations for you.