Part 1 ) Spindle , Gear train and Motor "upgrade"
I used quotes around the word "upgrade" because I have yet know if its an vertical move, or lateral !
For instance, the Motor probably doesn't produce more HP but it appears to be better quality and also has an encoder for better speed control with an appropriate VFD. Depending on the speed control ( VFD ) the encoder can be used as feedback for the VFD to help maintain speed more consistently, and also should maintain better torque. I believe the Delta VFD-E that comes with the PM940 CNC VS has this capability with an optional card, but I am not sure. I also bought , but have yet to use, a Durapulse VFD with a feedback card. So far, its collecting dust due to time constraints mostly. The Delta seems to be working pretty well after someone on this forum suggested settings that match this particular motor better than the default settings that the VFD comes with.
april 15 2017 edit
[ So, I should go into more detail about the spindle bearing upgrade. You need a large press to remove the spindle bearings and put it all back together with the new AC bearings, Also, you need a bearing puller to remove the standard bearing race(s) (this is a tricky step because there isn't much lip for the puller to access).
The AC bearings do not have a separate bearing race like the standard bearings, so when you assemble it, it has to be pressed into each part in a logical order or it will put stress / harm the new ball bearing and/or races. The upper bearing on the inner bearing surface (of the spindle itself) can either be cooled and the bearing warmed to allow the bearing to be seated, OR you can do what I did which was create a slip fit for the inside of the upper bearing by turning the spindle on a lathe with a bit of sandpaper to buff it down a small amount. The problem with this approach is you could introduce some runout by creating too much of a slip fit. Also if you aren't consistent you may make your spindle "seat" out of round. My greatest worry is that I'd take too much off and certainly this would result in increased runout. Even a slight amount of heat (created by the sanding process) would throw off the measurement and could cause you to keep sanding due to heat expansion. If I were to do it again I'd have some way to cool the spindle after each session of sanding it ( with 1000 grit sandpaper and slightly warm the bearing before testing bearing fit after each attempt at sanding more off. Its a bit tedious but worth the extra concern, imho. ]
There is more detail needed and I will add more detail but don't have time right now. ZZZZ... sleep is calling me. However I am providing a parts list for those that just don't care about details and live dangerously
Note that items with double asterisk ( ** ) need and will get more detail.
Here is the motor I used:
http://dealerselectric.com/145THTR15540.asp
The AC bearings for the spindle :
qty 1 - VXB Brand 7207C P5 High Precision Angular Contact Bearing 35x72x17 ABEC-5
qty 1 -VXB Brand 7206C-P5 7206C P5 High Precision Angular Contact Bearing 30x62x16 ABEC-5
Pulley ( 2 to one ratio )
**qty 1 : 5.6 inch 10 groove J - Profile pulley
http://www.ebay.com/itm/291936349578?ul_noapp=true
( requires some of the head case to be modified for this pulley to fit inside the gearbox cavity )
** Taper bushing not listed yet... it depends on your motor shaft size ...)
** 2.8 inch 12 groove J profile PULLEY
http://www.ametric.com/p-18443-12j281108.aspx
** taper bushing for 2.8 inch pulley for 28mm spindle ID
http://www.ametric.com/p-13391-110828.aspx
( requires some thin shim as spindle OD is slightly less than 28mm )
( requires a key to be fabricated to go in spindle grooves so Pulley isn't only a friction fit )
** Ametric brand BELT -10 ribs Micro V J groove
http://www.ametric.com/p-30298-260j10.aspx
( the Ametric belt is what I used, but I believe an 8 groove GoodYear brand one is better after some people on this forum suggested the good year brand over Gates, which I think is what Ametric sells, possibly ) McMaster Carr has GoodYear brand :
**
9003K89 Ultra-Flexible J-Section V-Belt 8 Bands, Trade Size 260J8, 26.3" Outer Circle
( could be a bit bigger than the Ametric one... hard to say if its too large. I have one coming so I'll be able to try it and update this )
Cheers,
Jake
note, the motor mount plate is just temporary, something sexy will be made when I decide on how to configure a double pulley arrangement.