Bridgeport Manual to CNC conversion...

[Muzzer]

I've not seen the "absolute bus type" (990MDCb) version of the Newker in the flesh but it sounds as if it uses some sort of serial bus to pass absolute motor positional data back to the controller and presumably also does away with the conventional step/dir signals in the process.

Must admit I'd prefer not to have to home the machine each time at power on but the feature comes at a cost. I just accept that both the Newker and the Acorn need homing each time but I'd be interested to hear how the costs for the 2 alternatives compare if you enquire with Newker. Presumably you would need to buy their motors as well as the controller itself for the system to work.

[JAZZCNC]

I've not seen the "absolute bus type" (990MDCb) version of the Newker in the flesh but it sounds as if it uses some sort of serial bus to pass absolute motor positional data back to the controller and presumably also does away with the conventional step/dir signals in the process.

I've been in touch with Newker about Bus type Absolute setup for my VMC and the absolute controller is NEW1000 MiCb-4 series. The absolute drives are dual axis so for a lathe you'll only need one drive.

I've got the manual if anyone wants to see it but it's too large to upload to Forum so contact me directly thru PM.

[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?

[JAZZCNC]

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.!