CNC Plasma Table Project/upgrades

[Hood]

Is your torch height correct, too high will cause a bevel . What height is correct will be torch and plasma source dependant.

 

[Erie Fred]

Yes it does. Its a worn one I've got on there now but it still fires... Could it be causing a wonky arc?

I have a retrofitted P-80 on an old max 100, and found cheap electrodes did not have the hafnium pit
concentric, caused the same problems. Bought higher priced, problem went away.

Concentricity between electrode & nozzle is a must.

Maybe the start cartridge is allowing some movement ?

 

[Munkul]

Is your torch height correct, too high will cause a bevel . What height is correct will be torch and plasma source dependant.

Should be be around right according to the TD manual. The voltage on the THC is correct and the initial height is roughly right (guessed it not checked).

 

[Munkul]

Is your torch height correct, too high will cause a bevel . What height is correct will be torch and plasma source dependant.

Should be be around right. The voltage on the THC is correct and the initial height is roughly right (guessed it not checked)

I have a retrofitted P-80 on an old max 100, and found cheap electrodes did not have the hafnium pit
concentric, caused the same problems. Bought higher priced, problem went away.

Concentricity between electrode & nozzle is a must.

Maybe the start cartridge is allowing some movement ?

They are cheap electrodes to be fair. The real ones are £20-odd each... So these are definitely fakes.

The shield cap seems to make it worse compared to running unshielded as well..

 

[Brad93]

Square the cartridge/cap not the torch to the table,

 

[Munkul]

Square the cartridge/cap not the torch to the table,

yeah that'll be my next thing.

Actually I was going to put the whole torch head in the lathe and check with a DTI for run-out on all the surfaces...

 

[Brad93]

yeah that'll be my next thing.

Actually I was going to put the whole torch head in the lathe and check with a DTI for run-out on all the surfaces...

the hypertherm torches are known for it, the cartridge being out of alignment with the body.

 

[ukracer]

Tonight i went to see a neighbour who has just built his own table.
Its small, but beautiful. He uses a Proma Myplasm controller which has built in software. It's the slickest self-build plasma software I've seen yet, and I've used some high end laser and waterjet software at work.

1. Import dxfs.
2. Nest objects and choose start points and cut order
3. Choose tool (amps, thickness profile)
4. Press start...
No seperate nesting/CAM. No pressing "post". Manual moves all right there, right where you want them. Built in z axis THC, no seperate control unit. Plenty of extra I/O.
I'm seriously impressed at something that's marketed as "simple non professional system". The beauty of the best systems lie in their simplicity and ease of use. It's a system that would take 5 minutes to teach to my brother... Whereas this sheetCAM and Starfire controller will take ages and offer much less flexibility anyway.

Is this the new software @doubleboost now runs from extreme Plasma?

 

[doubleboost]

Is this the new software @doubleboost now runs from extreme Plasma?

Yes it really is a game changer I did a video showing the basics .

 

[Munkul]

Yes it really is a game changer I did a video showing the basics .

I'm not super surprised that one of the table manufacturers has decided to use MyPlasm because it really is a great bit of kit, and as usual with great software, the simple interface hides some really powerful programming.

 

[Munkul]

So I've helped the issue a lot. I did think the o rings on the torch were a bit dry... The start cartridge was a bit too snug. So i lubed them with silicone grease. Definitely helped.
I'm still getting bevel, it doesn't seem to move when I rotate the nozzle 90 degrees (the last two discs and squares in the pics were done one at a time and the nozzle rotated) so possibly its the torch body. That's the next thing, but i didn't get chance to strip it all down today.
The squares look a lot better than the discs, just because the edges are straight and consistent.

It actually cut some useful stuff today... The discs are packers for setting columns in foundations

 

[Hood]

I was using the press today and had a look again at the 32mm piece I cut, it is what I use as the base on the press. Thought for that thickness it looked like there wasn't much bevel and it isn't too bad at all as can be seen in the pic below. Not bad for what Jasic says is the max sever cut of my plasma

 

[Erie Fred]

It actually cut some useful stuff today... The discs are packers for setting columns in foundations

View attachment 466119 View attachment 466120 View attachment 466121 View attachment 466122

 

[Munkul]

I've been messing around with this table a bit more. I've managed to almost cure the perpendicularity problem, by changing the start cartridge which eventually failed, using genuine electrodes and nozzles, and also adjusting the THC to increase sensitivity. Now it seems to want to run 5 volts less than the book settings which after googling, sounds about right for the TD A80 unit and torch.

I say almost. It's still there.

I'm almost at the end of my tether with the SL100 torch. It seems incredibly finnicky and sensitive to every factor just to get a straight cut. And the start cartridges are a really bad design.
I'm also sick and tired of the controls. The adjustments for pierce time and THC auto on/off speed are buried in a sub menu. Even just turning the THC auto on and off manually is a tedious process.
I wouldn't recommend this control to anyone at all.

Money is tight at the moment so I'm not sure what I'll do next, or when I'll do it.

 

[Munkul]

Update, 2 months later! Been so busy with other work that i parked the table up with a tarp over the top.

I ordered a PTM-100 torch for a jasic cut-80, same as @Hood 's. I was very impressed with the cut quality he gets, plus I like the design of the consumables. It seems very sensibly designed without great long stickouts to create alignment and tolerance errors. It really helps that the consumables are cheap

First thing was to take some scissors and chop my spare 1torch lead in half. Well, about 1500mm or something like that.


Then wire in a central connector plug to the lead, creating a flying adapter lead. The wires are all soldered, shrink wrapped, and taped over, then the full lot is taped up with loom tape to make it pretty resistant to knocks etc.




I then needed to adapt the 35mm torch body to the 40mm torch holder on my table... had some 1 1/4" alloy seamless pipe lying around so this was easy. Turned down a section at the bottom to 40mm, and milled some slots in the top. Very snug fit at 35.08mm ID.



I dug the table out yesterday and first job was to weld some cross bars in underneath so I could forklift it around without faffing around with extra long forks no pics of this.

Did some cuts on 60mm dia circles just to test it, using the TD 80 cut charts for speed and voltage. 5mm seemed to cut really nicely on 60 amps at 2.4m/min and 121 volts.


I did a 60 amp cut on 12mm also. Some slight dross but to be expected on 12mm! cut speed was 0.55m/min, book said 0.66 so should have pushed it faster.



There's still small issues with bevel but I think its more torch body alignment than anything (some slight tweaks needed once the table is levelled and set up properly). This torch seems a lot more tolerant of cut height, speed, everything really.
Overall - success. No more SL100 with its horribly priced and easy-damaged consumables.

I'm now ready to move forward with making the water table.

@Hood have you got a copy of the cut charts for this torch? Jasic seem to be using the PM-125 torch instead now and the voltage and cut speed seem much higher than the TD 80 charts. I can't find a chart for the PTM-100 torch.
Having said all that, its just a starting point, and the TD 80 charts seem to be a good starting point already...

 

[Hood]

Jasic don't really have much in the way of cut charts or at least I have not seen any, just the stuff in the manual and it is just for mild steel. I think however even if they did they would not be much use as I think it is more machine dependent rather than torch. I don't have anything written down for 12mm steel but for 15mm I have 112v and 600mm/min and for 20mm I have 120v and 400mm/min, both are at the 80Amps of my cutter.
Regarding Jasic, they still supply the PT100 as far as I know, it is what I got when I bought a spare Cut 80 a month or so ago.

 

[Hood]

Just looked at the new online manual and it does seem they are supplying the PT100 hand torch (what I got) but the TM125 for the machine torches. I also see they are now listing some feeds and voltages etc for machine use, the voltages are way higher than I would expect with my setup.

 

[Munkul]

Just looked at the new online manual and it does seem they are supplying the PT100 hand torch (what I got) but the TM125 for the machine torches. I also see they are now listing some feeds and voltages etc for machine use, the voltages are way higher than I would expect with my setup.

Yeah I think the voltages are way higher because its a shielded setup not bare like the PT100, and also possibly can condense more power in the arc, it looks like a hypertherm copy design.

 

[Hood]

Possibly.
One other observation from their cut charts is the cut height is much lower than I tend to use, 3-4mm works well for me where with the shielded torch they are saying 1.6.

 

[Munkul]

Possibly.
One other observation from their cut charts is the cut height is much lower than I tend to use, 3-4mm works well for me where with the shielded torch they are saying 1.6.

Wouldn't the cut height from nozzle end be the same, and the shielded end cause height stack-up meaning it has to sit lower?

If its the same cut height but higher voltage, then surely that means the TM125 torch can constrict/condense the arc better than the older designs...

I've definitely got some learning and some finetuning to do, cos I was trying to run it at around 2mm which is probably too low.