Bridgeport Manual to CNC conversion...

**Colin Barron** · 03-04-2020

How good are the BST servos and drives? Have you tried any other cheap servo motors/drives. Do the incremental controllers operate with stepper drives, for example the Leadshine am882?

**JAZZCNC** · 03-04-2020

Originally Posted by Colin Barron

How good are the BST servos and drives? Have you tried any other cheap servo motors/drives. Do the incremental controllers operate with stepper drives, for example the Leadshine am882?

The BST servos are very good for the money they cost and well worth the price but don't be under any illusions that they are in the same league as Yaskawa or any of the leading brands because they are not. You really do get what you pay for when it comes to Servos.

Regards the controller then if it outputs Step/Dir then it doesn't matter what's on the other end ie: Steppers or Servos. it knows nothing about what's attached. All it does is send out pulses and receive feedback if your using encoders and fully closing the loop.

If you are unsure about Servos and don't need the speed they allow have you considered Closed loop stepper systems? I only use Closed steppers now on all the machines I build now and I can tell you they are much better than standard steppers. They are simple and accurate if sized correctly for the machine. They don't come with any of the issues that AC brushless servos have in that you need to tune the motors to the drives and controller etc. They also don't require the same high-frequency controller that servos need to get best from them.

The difference between servos and steppers in technical terms is quite large and much more costly. I would seriously ask my self if you need to take this route when in all probabilty Closed-loop steppers will serve you just as good with a lot less hassle and cost.!

**pippin88** · 04-04-2020

New Yaskawa servos seem to be about two to three times the price of Delta servos.

Delta servos seem to be 1.5 to 2 times the price of the generic Chinese (e.g. BST).

I am considering 750w Delta servos for a new mill build. Possibly the newer B3 drives, a bit more expensive but look to have good features. I am encouraged by the manual in comprehensible English.

**JAZZCNC** · 04-04-2020

Originally Posted by pippin88

New Yaskawa servos seem to be about two to three times the price of Delta servos.

Delta servos seem to be 1.5 to 2 times the price of the generic Chinese (e.g. BST).

Not really £400 for B3 Delta's on Ebay £525 for Yaskawa and can be found cheaper. While half decent the Delta's don't compare to Yaskawa and I'd gladly pay £100 more for Yaskawa.

**Boyan Silyavski** · 04-04-2020

Check DMM servos

**Boyan Silyavski** · 04-04-2020

Am i missing something? Why you need 750w servos on a Bridgeport. 400w will do the job

**JAZZCNC** · 04-04-2020

Originally Posted by Boyan Silyavski

Am i missing something? Why you need 750w servos on a Bridgeport. 400w will do the job

Ye, I think it was a question from someone else and it's gone off topic a bit. Nothing to do with this thread I think.

**Colin Barron** · 05-04-2020

Originally Posted by JAZZCNC

Ye, I think it was a question from someone else and it's gone off topic a bit. Nothing to do with this thread I think.

Dave who started the thread used 750w servos.on his Bridgeport

**JAZZCNC** · 05-04-2020

To be honest, Colin if your converting a Bridge port then I would seriously consider Closed-Loop steppers because they will easily match the performance that Bridgeport limits you too. In my opinion, Servos are a costly and complicated overkill for a bridge port.

Now Stepper technology as got so much better with Digital drives and Closed-loop feedback then they are a good match for Older machines like Bridge ports.
The secret is using the correct drives and sizing the motor. The Lichuan mains-powered drives that I use with 9Nm 3 phase motors will easily handle anything a Bridgeport will throw at them and are quite a bit Cheaper than cheap Chinese servos. They are simple devices with hardly any setting up required, just Fit and use.

https://www.aliexpress.com/item/3279...3cac6f37EbjJgf

**Colin Barron** · 05-04-2020

On my easyiturn3 lathe it has steppers and Parker CD20/1 stepper drives, would this old tech work with one of these Newker controllers, http://newker-cnc.com/index.php?m=co...=166&l=3&id=91