Bridgeport Manual to CNC conversion...

[JAZZCNC]

JAZZ - how did you wire the enable line to the drive - there is a signal mis-match here as CSMIO puts out 24v but the drive needs to be pulled low - I stuck a relay in which works but....

I do it with a relay tied to the HV option on IP-A that enables all the drives.

[Davek0974]

Thanks, if it really is relays then thats fine, I have that working on the bench setup, just wondering if that was the only option here :)

[Davek0974]

Ok, where did I slip up...

Previously had the motor tuning set as book, 2000 steps per (10,000 / 5mm pitch)

When I fit this on the machine it will be at 2:1 ratio so i set steps per to 4000 (10,000 * 2 / 5mm pitch) and set velocity to 7500 (3000rpm / 2 * 5mm pitch) acceleration is at 750mm/s/s

Works ok in jog mode, works ok in code mode at speeds up to 7500mm/min

If i do a "Goto zero" it runs for a while then stops with ePid fault.

It also allows me to set feed higher than it can handle and then goes into ePid fault.

Is there a reason here?

[Davek0974]

Ok, found it - it seems it does not like running right at the limit of max speed - if kept just below max it all works perfect.


If I set the max at 7500 and command a feed at 7500 it faults, if I set 7400 it works perfectly in all modes.

Won't get t hat high in real life as the bed is not really big enough i think for a 7500mm rapid ;)

[lucan07]

Just to throw a spanner in the works may be completely irrelevant but on my travels today saw a bridgeport (couldn't tell you the model) converted to CNC, that used original and a 24k spindle slightly different setup to your plan.

The 24k spindle was mounted literally beneath the original in a frame so when changing between spinles he just had a Z offset to consider but apparently with Knee or second Z thats not a problem, frame actually locked into a collet then connected to frame, his spindle was shorter than mine and he lost a fair bit of Z travel but this still left a good amount of travel on Z for what he used the 24k for.

Just thought I would share unfortunately I was out on the road bike (lycra man) to escape idiots for a while so no phonewith me to grab a picture.

[Davek0974]

Should these collars just slide off, it feels like they are hitting a hard stop?



Probably surplus on a CNC machine anyway but don't know yet.

[lucan07]

Just a thought, have you tried tapping them round had similar collars in a different setting but they were threaded.