Emco Mentor Mill conversion

[Ross77]

So now its time to sort out the ball screws. Or actually the fixing and motor drive arrangement.

I have decided on 5 mm pitch and hopefully a singly suported 2005 on the y axis and double supported 1605 on the x axis but I still cant decide whether to direct drive or use pulleys! probably a silly question but any serious for's and against's?

I have been looking over the build logs and remembered/found Robins old warco conversion, I really like his idea of retaining the manually control. but not sure if it is worth the extra work or if it would put undue strain on the end of the ballscrew.



The other way to do it is with a pendant or such like and manually control it electronically :0) again not sure which will be the most useful.

any advice or suggestions?
cheers

[irving2008]

the advantage of 'manual' control with a pendant through Mach3 (or other control s/w) is you get accurate DRO capability. I wouldn't bother with adding hand-wheels; though there is no real danger of stressing the ball screws its a lot of effort with little benefit IMHO.

[Ross77]

Thanks Irving, yeah I think I'm going back to that idea but just wanted to see what other peoples option were. I was also tempted to put encoders on the ball screws and have a permanent DRO / spindle speed on the machine.

The pendant is easier to implement but I still have in the back of my mind a comment someone said about the how nice it can be to to just grab the handles and machine or drill a few holes.

Looks like I will have to pester Robin on how often he uses the manual side of it :0)

[Ross77]

Well another year has passed and this thing is still not up and running.....I now have all the ballscrews so time to sort the motors and mounts (grandfather clock massacre coming up )

Take 3

I need some help with the steppers. I have read a few threads and it seems that a nema 23 or 24 will be fine for this size mill and for financial reasons I'm stuck with the m542-G drivers that I got from Zapp and using a 40V supply. Hopping to direct drive a 3N motor on a 1605 ballscrew.

First question is which is the best 3 or 4N steeper at the moment?

Ive seen this one from zapp
http://www.zappautomation.co.uk/elec...per-motor.html

or this one from CNC 4U
http://www.cnc4you.co.uk/Stepper-Motor-Plus/Nema23-4Nm

Having bought from Gary before I was going to go the 3N one but if the 4N is just as good Id rather have the extra power.


Thanks in advance

[Ross77]

Bit more progress. I have designed all the plates to convert the x and y axis to ball screws. looking to get these made up but before I put in a request for a quote what is the best grade aluminium to specify?

Also not sure if the motor mounts already exist so If any one knows where I can get them off the shelf then please let me know. google and ebay seem to throw up box section hacks.

Cheers