Bridgeport milltronics re-power

[rockland213]

Hello all I am new to the forum and recently acquired a series one Bridgeport with milltronics control I was able to get it to power on but could only move Y&Z axis the X axis would not never reset. After much fiddling around, now the controller will not turn on. I figured I would have to do something with the controller at some point. But was hoping I could get this one to work for a little bit.
I got a great deal, even if I use it as a manual mill. I would like to take advantage of the servo motors and put a newer controller on it and saw the all-in-1DC controller.

My question are
I don’t know what I Don’t know, so could you all enlighten me on what I’m getting myself into ?
Should I keep the DC motors or put steppers on it?
Should I have the old controller looked at or go with new? (It worked when I powered it on)

This all started when I built mounts to put motors on my cross slide and was using them on my drill press for a small CNC gadget. I showed a fellow worker at work my project and he told me his uncle had a CNC for sale. I wasn’t holding out much hope when he told me he wanted to $250 for it, but to my surprise when I went and looked at it it was a mid 90s Bridgeport series one with Cintron one controls on it I couldn’t get my money out of my pocket quick enough to pay the man and I only had 20s so I couldn’t come up with the 250 so the man said just make it 240 and he even loaded it with his forklift.

[martyscncgarage]

Do you have electrical/electronic experience? Can you follow schematics?
If the servos are good (Those are SEM DC Brush Servos) I would probably put an All in One DC on it. That control has 3 DC brush servos that can control those motors. Some of the Milltronic servo motors had encoders on them along with the Tach. You would have to take the cap off the end of a servo and inspect.

If you want idea of what you might be getting yourself into. Jump on YouTube and search for martyscncgarage. I covered the process on a Ganesh knee mill. Look for the Centroid All in One DC Playlist

Marty

[rockland213]

Thanks for the reply, I do have some electrical experience but I am a mechanical engineer by trade. I/we build all Honda equipment that Honda designs for machining in north America. So Iv got electrical co-workers that can help me out.

I have checked out some of your video's and believe I could handle doing the work. I guess I'm just looking for a vote of confidence.

Does CNC12 come with the controller?

I probably should set down and make a list of everything I'm going to need.

[martyscncgarage]

You'll probably be ok. We are help with suggestions.
Check this page: https://www.centroidcnc.com/centroid_di ... oller.html

All in One DC comes with the CNC12 FREE, you can upgrade to Pro when you are ready.

Take one cap off the end of the servo motors, take a picture or two, see if you can see the maker and model number.
Marty

[rockland213]

Here are the pictures of the encoders.
Don’t know if these are compatible with the all in1 but they worked when I had the machine powered on.
This is X&Y I’m assuming Z has the same

[cncsnw]

You will probably want (or need) to replace the encoders. I believe those are "differential open collector" encoders, not line-driver encoders.

If it had a line driver output (as required by Centroid), then with 5V power applied to the red and black leads, you would measure a voltage, either positive or negative, of between 3 and 4 VDC across any of the output pairs: brown and brown/white; green and green/white; or orange and orange/white.

If it has a differential open collector output, then with 5VDC power applied to red and black, you would not measure any voltage across the other pairs, unless they were connected to pullups (i.e. to +5VDC through a resistor).

In any event, you really want more than 500 lines.

Those are probably standard-sized shaft encoders with 1/4" shafts. If so, you can use TRDA-2E2500VD from Automation Direct as a drop-in replacement.
https://www.automationdirect.com/adc/sh ... a-2e2500vd

[martyscncgarage]

As Marc (cncsnw) suggested, those encoders would need to be replaced. You would need to remove one and measure the shaft.
For an idea:
https://www.automationdirect.com/adc/sh ... 22&start=0

What is your expected budget for this project?
Marty

[cnckeith]

while not specific to these particular DC motors.. i put together this web page a while back showing encoder, cable and cap upgrade on a DC motor with step by step slide show of the process.

https://www.centroidcnc.com/sem_dc_serv ... rofit.html

[rockland213]

[quote What is your expected budget for this project? [/quote]

Not quite sure yet .....hoping to stay under $2500.?????? But it will probably be more when it’s all said and done. I got a good computer that meets the requirements to run the all-in-1.
I may not be able to get the touch screen and MHP right now but should be able to add that later

Maybe it would be better if I ask you guys how much this will end up costing me?

[martyscncgarage]

[quote What is your expected budget for this project?

Not quite sure yet .....hoping to stay under $2500.?????? But it will probably be more when it’s all said and done. I got a good computer that meets the requirements to run the all-in-1.
I may not be able to get the touch screen and MHP right now but should be able to add that later

Maybe it would be better if I ask you guys how much this will end up costing me?
[/quote]

I think your estimate is low. Many underestimate the cost of a conversion. Whether it be Oak or All in One DC or even Acorn
Attached is an estimate for the Ganesh knee mill I did. Granted you don't need a cabinet, or two VFDs. But you do need the control, the software license a PC, perhaps a VFD if you don't have one, perhaps you do. You'll need encoders, and I STRONGLY suggest you buy the ready made encoder cables from Centroid along with their encoders as the cables are made up and designed to plug into the encoder and All in One DC. They also have motor power cables, but those are generally easier to make up, though not terribly expensive from Centroid either. Having the encoders and cables from Centroid helps minimize the chances of encoder errors or damaging encoders or the All in One DC encoder inputs as well.

Acorn will save you some money, but you will have to replace the drives and servo motors.
DMM Technologies sells replacement motors that will replace the NEMA 42 motors on your machine and will take step and direction signals and work with Acorn. They are flexible enough that if you wanted to upgrade to Oak in the future, you might be able to do that. I did work with DMM for over a year to try and resolve the issues in order to use Oak with DMM Dyn4 AC Servo drives. They have decent support, and I have completed one OAK/DYN4 system and it seems to be working ok and as designed. I am cautiously optimistic this will be a good reasonably priced combination.

BUT you should budget about $600 per axis for drives/motors from DMM.

DC Brush servos are old technology, but if they are in good shape, then consider using them. You must test them first before connecting to All in One DC. You can damage a drive on the All in One if a motor is bad. Warranty does not cover that.

Just don't go into a conversion blind. Do your homework, continue to ask questions. Ask yourself what the end game is. Are you hoping to learn about CNC controls? Are you wanting a machine at home to learn and do personal work? Are you hoping to make money with the machine?

Take the time now while the Milltronics control is working to determine the mechanical condition of the machine. If the Centurion I control is working reliably, perhaps learn to use it while getting your feet wet and doing your research, saving your money and deciding what route you want to go.

A knee mill with a Centroid Control around here is worth about $5-$10K depending on its condition.

Good luck with your decision.

Marty