Sieg SX2.7 (Long Bed) CNC Conversion

[Doddy]

What would I do differently?

I’d start from the outset with an enclosure! I probably wouldn’t have gone for the long bed.... but I don’t think that was a major cost component.

I’d put the home sensors outside the envelope of each axis to avoid crashes. I was taking a puritanical approach that the supplier recommended end-on sensing, but my experience has taught me that the performance difference doesn’t worry me, not as much as inadvertent crashing the axis. That wasn’t helped by me using one control box for two mills, resulting in weird configurations that could result in the sensors being unpowered and subject to crashing.

I’d roll the x axis stepper towards the rear of the bed rather than the front. I believe there’s space there if drawn close to the bed. Y I’m happy with. Z I don’t really worry about so not much in the way of introspection there. Definitely retain the quill lever

I have belt covers on each axis now... 3D printed was easy.

Unspoken of here is the replacement of the bldc motor with a servo... a result of me blowing up the spindle controller trying to adapt it to support 0-10v operation. That is now commercially available from sieg in any case. My solution, not necessarily recommended, requires me to think of adapting the spindle controller pendant. (Another roundtuit job)

Part of this evolution is the chassis wiring isn’t quite what I’d intended, I’d plan that as bit more carefully.

There’s a sieg user group on Facebook which has a couple of cnc’d 2.7s, if you’ve not seen that already. Useful to see what others get up to.

[dazp1976]

Unspoken of here is the replacement of the bldc motor with a servo... a result of me blowing up the spindle controller trying to adapt it to support 0-10v operation. That is now commercially available from sieg in any case. My solution, not necessarily recommended, requires me to think of adapting the spindle controller pendant. (Another roundtuit job)

There’s a sieg user group on Facebook which has a couple of cnc’d 2.7s, if you’ve not seen that already. Useful to see what others get up to.

Have you got a wiring diagram of your inputs / outputs from your breakout board to the servo drive and vice versa please?.
I recently got a 1.8kw one for the spindle on my amat25 conversion.

Daz.

[Doddy]

Further to last: The Chinese servo controllers (only ones I know) have 5V optical-isolated inputs for the step/dir control, with separately excited inputs for the other discrete inputs (so you can use 12/24 for e-stops, etc). But, and this is the big but - the spindle speed inputs are 5V and can be directly coupled to a BoB output.

Edit: I liked the performance so much I replaced the phase/vfd on my ML7 lathe with a 2kW servo and drove that in exactly the same way.

[dazp1976]

Further to last: The Chinese servo controllers (only ones I know) have 5V optical-isolated inputs for the step/dir control, with separately excited inputs for the other discrete inputs (so you can use 12/24 for e-stops, etc). But, and this is the big but - the spindle speed inputs are 5V and can be directly coupled to a BoB output.

Edit: I liked the performance so much I replaced the phase/vfd on my ML7 lathe with a 2kW servo and drove that in exactly the same way.

Mine has a DB44 socket, I have a cable and a DB44 screw terminal block. I was hoping to avoid using an axis control for it.
It says that in speed mode it has a direction control on one of the DI ports, as in relay on is one direction, relay off is the other (apparently). Can drive this from pin 17. Then has the usual on/off which I have a seperate rocker switch for, + various others I'll likely not need in speed mode. Was hoping to use it this way, with the 0-10v servo input driven straight off the bob (board has it built in and I've tested it with a meter).
The outputs I'll just daisy chain to the estop via relays until I update my controller + boards. Then with more inputs I can go straight into the bobs optocouplers and ditch all the relays.

Sounds basically about right doesn't it?.