Emco Mentor Mill conversion

[Ross77]

put it this way once the machine is up and running you can make the bits you need to covert the head later if need be.

That's the plan, always been a bit chicken and egg with this hobby but now I have the egg.......

Not sure what your box is like but most are very noisy which is another good reason to dump

Yep it needs to go, just need to decide if I belt drive The AC Motor or do the DC conversion! fancy doing another 2 castings

Well done Ross, I thought you had a pretty good chance of running that motor on 240V, and am glad you stuck with it, but filing the gears to make it fit - WOW. Congratulations. G.

Yeah got there in the end. Saved me a few quid and learned a thing or two, winner. Filing was a ball ache and not the best way as they are quite noisy in use but I figured that they weren't the originals and didn't fit so didn't have much to lose.

Just got the rest of the problems to work through now

[Swarfing]

To make them quieter you could make them out of phenolite (bakerlite looking stuff) or similar material, this is very quiet. I had a lathe gear made of the stuff on my old Southbend..Brilliant for sound....Going through all that hassle to sort the motor i would stick with that. Why waste money.

[Ross77]

I think they are phenolite (browny redish colour). but I would have to remake the whole gear box as each meshing pair is made up of a metal and a plastic gear. Its mainly the gear I filed that is noisy but as that is in the chain for three of the speeds then its a bit of a problem.

I only wanted to get it working so the machine was complete if I decided to sell it in the future. I think belt drive will be much smoother as the notchy/cogging could be transferred to the tool tip and leave marks in the finish.

[Ross77]

In response to a question from another member I have done a brief step by step guide on rewiring the 440v motor for 240V.

Thought I might as well post it in case it helps anyone else.

[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)