Quote Originally Posted by m_c View Post
I'd aim for servo's similar power wise to what was fitted, as too big has the potential to do a lot of damage if things go wrong. I got told from a very reliable source that those interacts will handle the original servos running the axis into the end stop without doing any damage, if something does go wrong.

Plus you want inertia to match somewhat, as too big an imbalance can cause tuning problems. I was advised 110 would be better for my Shizouka which is a couple hundred kilos heavier than a Bridgeport.

One thing to be aware of with the cheap Chinese servos, is they use mains voltage for control power, so if mains power gets cut i.e. due to an e-stop, you've lost position. It's not the end of the world, but one of the things I like about my lathe is the position never gets lost during an e-stop, as the encoders are permanently live.
If you want a copy of the BST servo manual, drop me a message, and I'll email it over.



Oh, and is this a potential replacement for Thor, or are you just wanting to burn a few more KW to help keep the workshop warm? :-)
Hi, thanks for the info. I'm in two minds about the sizing. One part of me wants to get the machine running quickly and without too much fuss, so near bolt on replacements is nice. In terms of limits, assuming they work, is there still a concern?

For E - Stop, depends how you wire it. If you use normal E Stop circuitry via the Acorn, you will likely just disable the drives (like what happens on Thor and CS Labs). You do not switch off anything else.

Not a replacement for Thor, I dont think. The table is not as big as I had hoped for but it will do. The idea was to have something that can deal with big flat steel / hard metal plates for things. With Thor, it was designed for high speed alu type machining. I might make new brakes for Thor (motor mounts) on the Bridgeport. It was too good a deal to pass on and I've always wanted one.

I could buy the replacement drives and run with the DC motors but Ive had DC motor issues before (Spindle on Triac) and not keen on that. I just want something that works reliably.

A lot of the drives being shown are all the same manufacturer, so perhaps just find the best priced ones?