3.5X1.5 Meters cnc plasma cutter

thefabricator03 wrote:

What kind of power supplies are you using Tom? Are they switch mode units or torodial?

Switch mode, china made V-Tac. A friend of mine is the importer for that company and a while back he asked me to test 7 types of SMPS from different manufacturers, these came out on top. They are 400W each, way to much for what i need, but the next lowest i got are 200W and that would be on the lower limit.

machinedude wrote:

any reason why it's running on the Z axis or is that just for testing movement until everything is configured and finalized?

Z axis has the smaller drive, 4A RMS or 5.6A peak @48V, and i had it set at 2.5A so with two parallel wired motors that gave 1.25A per motor. The other two drives are 6A RMS or 8.6A peak and i had them set at 5 and 6A so it would be to much for those tiny motors. Also this setup uses the Mesa 7i92 with a very fast BOB, all round a very nice setup that can do very high speeds even with microstepping set very high. This will go on the big machine (6X2.1M plus rotary 4th axis) or on my mill, depending on my mood on what to finish first.
Those drives have to be programmed using a USB dongle, and i just wanted to do a quick test.
I do have another set of drives ready that is going to be used on this machine with the PC and everything, but i have preemp-rt installed in it and a parallel port so i could not test faster than 7 meters/minute for now and the drives are set at 8 and 16 microsteps. Need to install RTAI tomorrow and give it a go, should do much faster.
Also the rack are held by clamps so when i pushed it to 36m/m it started to shake a bit. I am eager to put the rack in place and give it another go, probably over 40m/m easily.
Stay tuned !

thefabricator03 wrote:

How do you think the switch mode units go compared to a torodal unit?

When I was building my machine I was not sure how a switch mode unit would go with back current from deceleration so I decided to go with the torodal unit.

They do work nicely, but do avoid the cheap ones, they are made by someone with no electronic experience at all and lack all kinds of protections and output control.
As for back EMF, i do have some switch mode power supplies with multiple output voltages that do not like that at all and they need a chill time of 10 to 15 minutes after such an event.
Never had such an issue with any other SMPS and laptop bricks.

Z axis is mounted with floating switch and fully enclosed, Y axis has some more work to be done like cutting the rail, adding another one, etc. Reduction is finished and working with a temporary motor attached, can not find the wide belt i have somewhere hidden.....
Z axis can do 12 m/m easily !
Computer and electronics are done waiting for a box to put them in.
Now to dismantle everything and send it to paint, then mount everything back, add side and front panels to make it look nice. All in all, it's looking much better than i initially thought, mainly due to me thinking a lot before screwing something to it and later regretting it, thinking about how it will look at the end and how the panels will be mounted, avoiding getting in my own way with parts and later finding out it interferes with something else, etc, etc
Here are some more details:



Regards,
Tom.

Thank you.
Mostly from what i can find in the shop and in my head ( exceptionally big head, or was it a small body??? ).
I am not good at cad, last i used it was in the 90's, and even then i was not good but i was pretty damn good at 3DS Max, assembly, GWBasic, Corel, and some other things, and even started using Maya! Now i am learning Blender as it is hands down the best open source and free software, bar none, as can be seen by huge amounts of money being pored into it's development and the best thing is it has a CAM version. The downside is, it is hard to learn especially with the time constraints.
Am working on two cnc machines and already thinking and preparing parts for the third and the fourth, so it is relentless.....or i am relentless ???
Regards,
Tom.