[swarf-boy]

Hi,
I am retrofitting a B.P series 1 Interact.
I have most things worked out, but I am wondering if the original vari speed can be integrated somehow.

Does anyone know how this system works with regards to the actual increase decrease part,
I realise the 2 disks close or open to actually change the speed. its just the HOW part I need to understand.

any help welcome, as all browsing brings up in any detail is the hand cranked manual version

[gus]

ti would be difficult, and probably inaccurate. Bridgeport did it with an encoder of some sort where the speed indicator goes

It would be much easier to fit a VFD, for, what, 300 bucks. Leave the spindle at ~1800 RPM and use the VFD

[Handi-andi]

It might be as simple as an electro-mechanical proportioning valve on the air supply, essentially mirror the mechanical valve with an electromechanical one, then its easy enough to go, or alternatively remove the cylinder and fit a linear servo with built in encoder plus at some limit switches. Second option is probably the nicer and has me thinking.

[gus]

It might be as simple as an electro-mechanical proportioning valve on the air supply, essentially mirror the mechanical valve with an electromechanical one, then its easy enough to go, or alternatively remove the cylinder and fit a linear servo with built in encoder plus at some limit switches. Second option is probably the nicer and has me thinking.

I think they used the stock air motor and had some kind of position feedback where the speed dial is. kind of a binary slow speed servo. command 'up' or 'down' and wait x seconds for the encoder to tell you it has reached position

[Handi-andi]

My brain was getting confused between the brake cylinder and the adjuster, anyway. The set up is a little simpler than you describe as there is no feedback system its just a mechanical indicator on the outside, as the instructions for setting it up are run at 3750rpm indicated by tachometer, loosen nut, rotate indicator disk and tighten. Easy enough to replace the air motor with a servo with speed feedback via a Hall sensor on the driven pulley, or just keep air motor and replace mechanical air switch my an electro-pneumatic one. Servo instead of air motor would give finer adjustment but the electro-pneumatic switch is easier. Either way you could do with a relay to ensure speed adjustment can not be operated without the spindle running.

The maintenance manual has part numbers on the pneumatic drawings of the machine, but then those parts are not listed in the parts list.