Second CNC table build, here we go again....

[Davek0974]

Coming back together now...

[Davek0974]

Z axis wiring...



Table wired up...



The timer on the bottom rail is an off-delay of about 20 seconds for my downdraught fan, every cut start and stop triggers the Aux BOB relay and the delay holds the fan on between positioning cycles etc. At the end of the last cut it runs on for the full delay to clear any remaining fumes.

Preliminary panel wiring...



I've got an old BOB laying around and spare PC which i've installed a basic Mach3 setup on, hopefully be able to get the lot tied together this week for motion testing.

[Davek0974]

IT Lives

Achieved first motion today, got it lashed up to an old BOB and very poor PC (way below Mach3 specs) and it seems happy, a short video...

https://youtu.be/n34DDnw8org

It was running this file...



Which was the simplest file my mediocre G-Code skills could manually type

Have played with motor tuning and it will go way beyond requirements so pegged it back at my 9000/mm/min target. Acceleration seemed very willing to perform but I'm not sure if the PC is hampering it there or not, its only a 500mhz CPU and Mach is supposed to need 1Ghz or more.

Still, it runs and runs VERY well indeed, smooth, fast and gives me the impression it will work nicely with the torch on.

I have tried to make it lose steps - pushing the Mach "Stop" button when running at 9000mm/min give a very abrupt stop indeed but no lost steps, can't get much more severe than that i think.

Next i need to do some book-speed tests with real cut files and verify the home position after each cut, not even sure its worth doing a pen test - it just seems happy and gives me confidence.

The final step is the tricky one - I need to strip the BOB, THC and plasma from my running table, dismantle that to move it out of the way, move the new machine into position, level it and fit the last parts to it. Then install the extract system, bed frame and slats and start test-cutting. Sounds easy but I know for a fact that as soon as i decommission the running table, jobs will come in!!! The only safe way I think is to put up the "closed" sign for a few days and get it done - we are away in a weeks time for a week so i might just extend the holiday closure period a bit to give me some slack.

Good day today

[njhussey]

Looking good...good to see your machine come to life!!! I'm itching to get back on mine and finish it now I've seen yours working...

[Davek0974]

It certainly was a relief, especially when i managed to get Mach3 to auto-square the gantry for me when its homed :)

[Davek0974]

Made the replacement wall panel today, fitted the extract fan to it...




This should replace one of the slabs in the garage wall directly, hopefully be able to undo the two bolts, pull the slab inwards and replace with this one.

The fan is connected to the table via a short length of 12" flexi ducting. Its controlled from my G-code, have altered the post processor to put the on/off codes where i want them.

I'm off for a weeks holiday now, plan is to move the table into position as soon as i return

[Lee Roberts]

Looks great Dave well done so far :).

.Me

[D.C.]

Made the replacement wall panel today, fitted the extract fan to it...
This should replace one of the slabs in the garage wall directly,

Is the fan for dust removal or heat removal?
If you try venting electronics outside you will end up killing your electronics with condensation, which would be bad. :(
You can mount a closed loop radiator externally for heat removal, but air is a no-no.

[Davek0974]

Nah that fan is the table bed downdraught fan - needs to vent outside, intake air will be through the open door. Will be cold in winter but no other way to vent that much air.

[Davek0974]

Back from a way too short holiday Stripped the workshop out and moved the new table into final position...







The extract fan panel fitted perfectly, but shifting that volume of air turns out to be damn noisy, i can probably expect trouble from the neighbours i think, will have to be careful when i choose to do my cutting

Finishing off the panel now, fitting the BOB boards and wiring them in, then i need to build something to hold the monitor and keyboard etc, some sort of workstation.

Then i have to puttee workshop back together again