Showstopper Plasma Cutter retrofit

I built a second plasma controller utilising what I learnt making the spaceship plasma a few years ago.
 
This still uses a Mesa 7i76e and a couple of Thcads for torch voltage and Ohmic sensing
Additionally it has a 433 Mhz Wireless pendant which has a wired in receiver. This is the second one of these I have used and I like them a lot
Steve in Melbourne saw some of my videos and asked me if I could help out with his plasma table which was  a bit tired and in need of a refresh.

 
So a deal was struck.
The table was using a 24 volt power supply to drive the motors which was well underpowered. My controller includes a 60 volt AC toroid I had custom made which powered 5 x Lam Technologies D1076 6 amp drivers.
We replaced the motors with industrial quality ones befitting the Lam drivers from Moon's Industries. I wanted to use NEMA34's but we could not fit them in. We also added 5:1 reduction planetary WUMA gearboxes. These needed some customisation to the output shaft. We had to use an 8mm shaft. The 14mm standard shaft just would not fit into the exisring pinion.

 

to continue

To get the gearboxes to mount up, we had to machine up some adapter plates because the gearbox 7mm long flange would not fit.
 

So the compination of near quadrupling the voltage and a significant gear reduction really gave the machine a lift in performance.

The plasma had a 24 volt motor driving the z axis lifter so we replaced that with a stepper driven torch lifter with 200 mm of travel
 
I was annoyed originally about this because despite being assured it would be stepper driven, it had a geared motor. All was not lost as they had spot drilled the mounting plate to take a NEMA23 motor. This has a break away mount and a float switch built in and a bit of tewiring was tequired.

To wire everything up, we used two little breakout boards I made a long time ago so we could use a couple of DB9 cables to wire it up.
 
Thes can be daisy chained together and support proximity sensors,  switched inputs and ooutputs (with flyback diodes built in)
If anybody is interested in these, please let me know, I was thinking of getting a batch made.
The only problem is the connectors are very hard to crimp on (for me) so I sourced some tails that I could join onto the prox sensors.

 

I love these pendants
 
But they take some wiring in.
 
I tried some complex hal trickery to get eveything working but gave up and wrote a custom  component
In addition to that, we are using my Lam stepboost component to get higher performance out of the Lam drivers.
And My Ohmic3 Hypersensing component that uses a THCAD which will be a bug upgrade for Steve.

It was pretty hard to wire up a plasma cutter without a table, so I made a couple of errors to make Steve's job a bit harder.
Shh don't tell anybody but I had to get some hellp to set up  my own ohmic3 component!

I forgot to mention the control box uses a safety relay for the estop circuit. Thats the red relay with the row of lights on it.I elected to utilise an external estop reset button,so we just use the QTplasmac estop as an indicator.

To the left of the safety relay are a couple of force guided relays which add some redundancy to the connection back to linuxcnc that tells us that we are awake! Thse have a plastic pin that forces the relays open to prevent any possibility of the contacts being welded shut. These are the only relays used in the build as the torch is turned on by the 7i76e's onboatd spindle SSR.

So that is a brief summary of the build. Next post will show the after.

 

 

 

I was a bit worried when Steve wanted to mount the control box on the gantry but it worked out OK.
It seemse to have limited rapids to 10 m/min but that is double what he had before.
One of the other issues previously was that traverses were limited to the cut speed so they might be 5 x faster now!

Also thanks to PhilC who worked out the gcode filter that is letting Steve use his Hypertherm nesting system as is with no changes.

Next post will list the unresolved issues that seem to be bugs in qtplasmac even after upgrading  to 2.9.3 today.

So here are the remaining issues:
1. Torch Breakaway does not pause motion when triggered despite the plasmac.breakaway pin going true
2. recovery panel is never displayed. I thought it might be linked to not having a M52 P1 but that is not it
3. If paused, it cannot resume until Linuxcnc is restarted
4. Safe height is ignored. Rapid Traverses are at max height

Its a long time sice I have used qtplasmac but these do appear to be bugs to me.
Any help or ideas will be appreciated.
The config is in git here  github.com/rodw-au/showstopper

Looks awesome, as usual !
The box seems a bit to heavy to be mounted on the gantry, but if he insisted...