I have recently moved and have my shop to the point I can think about working on my SX2 again. I have the Micromark version along with most of the raw stock, motors, and parts to get it CNCed. I have been running the mill manual for the last couple of years so I can get god enough to build the parts I need. The plan is to use the stock lead screws with belt drive steppers and a Z system modeled after hoss's.
My first thought is to stiffen up the colum. I also need a mout about 4 to 6" above the top so the Z drive can clear the spindle motor. My plan is to bolt the machine to 2 long square tubes that extend out the back 12". At the back I would weld another tube perpindicular. This would create sort of a large T with the top of the T at the back wall of the bench. On each side of the colum I would add some long square stock that extended up high enouhg to support the Z axis stepper. For added stiffness and tram adjustment I would run some 1/2" or 5/8" fine threaded rod from the top of the original colum out to the ends of my base. This would form 2 diagonal braces about 45 deg out from the top to the back.
What are your thoughts on bracing and adjusting the tram of the colum that way? To me it would appear to be stronger than trying to bolt or shim the base to the colum directly.
I have made great progress. X axis is all done. Moving on to Y next. I had a thread about timing belts vs couplers here: http://www.cnczone.com/forums/bencht...ml#post1402454 I have copied some pics and a video of a test here as well.
Great progress. The vertical belt drive is interesting, tidy arrangement and looks like it only needed about 1.5" of vertical lift on the base to get the needed clearance. --md
It actually could be made to clear the bench. I did have to cut out a notch to clear the mounting bolts. It also blocks the Y axis lock. I plan on replacing it with a bolt and just adjusting the jibs for CNC. If I had to do it again I would go to the back or back and down if I felt like making a bunch of angle cuts. I have mine on wood to give me some room to work. I also plan on putting the whole mill on a steel frame with bracing to the column so I am not too worried about clearance.
Started on my Z axis. First step was drilling and tapping the lead screw after grinding is square. This will connect it to a bracket on the head. I don't have a drill press so I made a drilling jig out of a chunk of steel I had laying around. It was drilled for the tap drill size. Then I drilled and bored about 1/2 through to the size of the screw. This held it all together strait so I could drill it with a hand drill. Then I drilled the guide out to support the tap. Drilling and tapping the lead screw was hard. It is partly hardened but still workable. Very small chips that had to be cleared more often than normal.
Wow, I have made so much progress since this post! Since I hate to find 1/2 done build threads I thought I would at least post a follow up. The machine is fully CNC now. Just need to clean up the wire routing. I did a variation of HOSS's z access. The most interesting is the counter weight system. I ended up using a garage door spring as counterbalance for the head. I will post a video when I have time.
SX2 build starting back up. Some questions.
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