Emco Mentor Mill conversion

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Originally Posted by Swarfing

Looking at the size of the machine i think the DC motor will do you fine. Mine will be running with only 1HP motor and that is more than enough for my needs.

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Hi Swarfing, you posted the same time as me so missed your reply. yeah think the DC will be fine for this little mill but I was just trying to work out which would be best. Didnt what to spend time making mounts etc if the ac motor on vfd would be as good, it seems that the DC wins on low rpm to torqure ratio which is mainly what I need for this machine.

The sad thing is i need to get the ac motor working to make the bits to convert to dc, that is providing the spndle is ok.

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Sounds like your most of the way there then. Just need an appropriate controller and your away :-)

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I was hoping to cannibalise the motor controller from the tread mill and control it with a Adruino.

That DC motor is it a 90v or 180v by the way?

just opened it up and the motor is 180v and 4800rpm so a little slower than I was hoping for. Driver board looks quite compact and control panel is fed from one muiti core wire so shouldn't be to difficult to hack the speed commands.

On the down side it is 10mm to big (diameter) to mount on the existing motor plate so to use that motor I will have to make a new mount and move the motor position over to clear the top of the quill. Looks like I'm going to have to have a go at rewiring the AC motor for 240v and fire up the vfd.

Go for it, at the end of the day your other options are to spend some money. If i does not work...then just spend some money :-)

finally found time to rewire the motor and it was embarrassingly easy, don't know why I was so worried about doing it. Coils measured 50 ohms on their own so in delta config you basically have two coils in series which are also connected in parallel to the 3rd coil, so if I have it correct then that gives 100 ohm and 50 ohm in parallel which is 33.3 ohms. tested each pair of wires and always got 33.3 ohms so hopefully I have got it right.

Attachment 8715
Also worked out how to set up the vfd, connected a forward/reverse switch and a speed pot. tested it on a another motor and all works fine. so hope fully tomorrow I can rebuild the motor and see if it works.

Attachment 8716

Well done Ross:encouragement:

ta, its good to get something done rather than just talking about it. :hopelessness: onwards and up wards.........you never know I might have a working mill by the weekend.:toot:

Problem 1 and 2 solved. Motor works fine on 240v with the vfd and got the gearbox fixed so all 4 speeds are working. :yahoo:

I wasnt going to bother fixing the gearbox as the vfd would have taken care of the speed control but unfortunately though the 1 speed that worked was the slowest (350rpm ish). The previous owner had some replacement gears made but they didn't quite match the gear profile so I had to file them down, not ideal but needs must and at least I can test the rest of the machine.

A BIG THANK YOU to all that have help sort his especially Geoffery, M-C and Swarfing, cheers guys :beer::beer: I know most of the info is somewhere on the net but to have you point me in right direction is great.

Nice one, 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. Not sure what your box is like but most are very noisy which is another good reason to dump it. Get yourself a gear cutter and you can remake them as well if you wanted to.

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.

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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.

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

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

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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 :whistle::whistle:

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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.

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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 :thumbdown:

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.

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.

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.


Attachment 8974

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.

Attachment 8984

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

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.

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)

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 :thumsup:)

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

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

http://www.mycncuk.com/attachment.ph...id=14197&stc=1http://www.mycncuk.com/attachment.ph...id=14198&stc=1http://www.mycncuk.com/attachment.ph...id=14192&stc=1http://www.mycncuk.com/attachment.ph...id=14194&stc=1http://www.mycncuk.com/attachment.ph...id=14195&stc=1http://www.mycncuk.com/attachment.ph...id=14196&stc=1http://www.mycncuk.com/attachment.ph...id=14193&stc=1

my problem is a mystery to me, I have, to my knowledge, tried everything to get my running spindle motor. The spindle motor is a DC motor max. 180 volts, placed on the spindle motor is a Rotery encoder with the outputs A and B and Z (Z but I do not use). The breakout board (5-axes) is a Mach3 HG08, ordered (CNC4YOU) Axes X, Y, Z, A, work perfectly. The B input is used for the spindle motor. Inputs are: GND, Vcc, CK, CW, AND (AND not connected). The first 5 are connected to a DG2S-16035 Servo drive (with 8 inputs total) via a UTP cable. Input 1 (CK) 2 (CW) 3 (GND) 4 (NOT USED) 5/6 (VCC) 7 (external DC power) 8 (External DC gnd). Encoder input of the DG2S-16 035 is connected via a UTP cable to an encoder interface, and the encoder interface is reconnected to the Rotery Encoder on the spindle motor. summarized: I have all the wires, cables, checked for fractures, but all cables are good. The settings in Mach3 (see photos). I have to be sure all components exchanged with new components, ie, the DG2S-16 035, the External Braking Circult Connector, Encoder Interface, and even the Breakout board (HG08), the Rotery Encoder, on The spindle motor, the result was the same, no rotating spindle.

Andre Welcome to the forum. This thread is over a year old now.

It might be better if you start another thread of your own so as to keep all the questions and answers in one place. and tittle it accordingly.

Can you post a picture up of the spindle as well. I am sure others will chime in with offers f help.

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Originally Posted by Clive S

Andre Welcome to the forum. This thread is over a year old now.

It might be better if you start another thread of your own so as to keep all the questions and answers in one place. and tittle it accordingly.

Can you post a picture up of the spindle as well. I am sure others will chime in with offers f help.

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Can you send me The link to start a new thread?, thank you.

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Originally Posted by andre13442

Can you send me The link to start a new thread?, thank you.

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Andre I see that you have this sorted now and started a new thread. Good Luck

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Originally Posted by Clive S

Andre I see that you have this sorted now and started a new thread. Good Luck

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okay, thanks (first time for me...lol)