couple more THC questions

[stirling]

So as I understand it I have to open up the plasma supply and attach wires and such. Doesn't this trash any warranty there might have been on the unit? - are there any plasma units that come with the required interfaces for THC on the panel so I just "plug and play"?

Anti-dive: Again as I understand it when the torch slows, the THC sees this as an increase in V and thinks the gap has increased and so lowers the torch - ouch! So anti-dive somehow stops this happening - how?

Cheers
Ian

[Normsthename]

Doesn't this trash any warranty there might have been on the unit?

The Hypertherm list how to do all these connections in the owners manual, so you would'nt have any problems with the Hypertherm warrranty

Anti-dive: Again as I understand it when the torch slows, the THC sees this as an increase in V and thinks the gap has increased and so lowers the torch - ouch! So anti-dive somehow stops this happening - how?

Like you said, the torch would lower.
So you have an Anti-dive setting that ignores the THC signals below a certain feedrate (60% on my setup)
So on a straight line the THC signals are being read, and as soon as the machine slows down for a corner etc to 60% or less the THC signals are ignored

Andy

[Torchhead]

Originally Posted by stirling So as I understand it I have to open up the plasma supply and attach wires and such. Doesn't this trash any warranty there might have been on the unit? - are there any plasma units that come with the required interfaces for THC on the panel so I just "plug and play"? Anti-dive: Again as I understand it when the torch slows, the THC sees this as an increase in V and thinks the gap has increased and so lowers the torch - ouch! So anti-dive somehow stops this happening - how? Cheers Ian

The Hypertherm 1000 thru 1650 series comes with a rear connector (optional price for the cable) that has all of the signals. You still have to open it up to access the Tip volts terminals. Since everything is on terminals (all signals) you don't have to do anything to modify the wiring. Opening the case does not void the warranty on any of the units I have ever seen.

Anit-Dive is there to keep the tip from diving into the metal on sharp corners where the machine has to slow down (which causes the tip volts to increase, which causes the tip to go down). In most circumstances you WANT the tip to respond to the changing voltage because it forms the ffedback to maintain a constant cut gap.

There are times to use anti-dive and times to leave it turned off. General rule is that if you are not having problems with the tip diving ON ACUTE ANGLES then leave it off.

[stirling]

Thanks normsthename - so anti-dive is pretty simple then - that's not meant to be derogatory - I just thought it would be more complicated somehow - some cooperative change in reference voltage to match the change in speed or whatever - but hey if it works. What flavour THC do you have BTW?

Thanks Tom - another tick in the box for Hypertherm then.

[millman52]

I'm sure most any manufacturer want you to remove the covers to blow out the dust once in a while anyway......

[Normsthename]

What flavour THC do you have BTW?

I have the Campbells THC300
It is a basic THC and works very well on mild steel etc.
But it does struggle a little when I cut Stainless Steel with Finecut consumables.
The cut height is only 0.25mm and the THC300 is an analogue device and struggles with the fine tolerances required for Stainless Steel and finecut.
In hindsight I would have bought the Candcnc THC1000 which is a digital and better (and expensive!) THC
It has other advantages that you can preset the Tip voltage before you cut.
I have to record the knob positions on my THC300 for the different materials etc.
No big deal.
If I was only cutting Mild Steel etc the THC300 is fine.
But with me cutting Stainless Steel 95% of the time I wish that I had got the better THC

Andy

[Mongkol]

Hi Andy,
What plasma cutter do you use with THC300?

Mongkol

[Normsthename]

What plasma cutter do you use with THC300?

I use a Hypertherm Powermax 1000 G3

Andy

[Mongkol]

Hi Andy,
I have some questions. I have planned to order plasma cutter hand torch,model cut-40.Pls take a look from attached file. I will cut the thickness of steel about 6-10mm for my target. Is it possible if I will use it with THC300? Pls help share your experience.

Mongkol

[Normsthename]

Hi Mongkol
That Cut 40 is a chinese Cutter.
You are in luck because I also own one of these!
I think you would be struggling to use one of these on a CNC machine.
Several reasons.

1) It uses HF which interferes with computer and electrical parts. You will have major problems with this. Expensive Plasma Cutters use Non HF which don't interfere with these.

2) The Cut 40 is a 'touch' start. Meaning that you have to touch the torch on the metal to initiate the arc. It is not 100% reliable and you would suffer from a lot of false starts.
The more expensive cutters have trigger start where you press a trigger to initiate the arc without touching the material.
You wire the trigger into the CNC Controller for the software to automatically start and stop the Arc.

3) The consumable life on the CUT 40 is nowhere as good as the Hypertherm units. Again you would be getting false starts when the electrode / tip wears out ruining the part.

Saying that the CUT 40 is a good cheap hand cutter. I bought one for cutting large sheets down to fit onto my CNC machine. I also use it to cut the 'Skeletons' up into scrap.
It works very well as a hand cutter for the price.

Hope this helps.

Andy

[Mongkol]

Hi Andy,
Big Thanks for your help.
I found the chinese plasma cutter model CUT-40B by accident at http://www.ecvv.com/offerdetail/I1323209.html. It has arc-start mode = non-touch. That means "not touch on the metal as cutting" It may help this.

Mongkol

[Mongkol]

Add the infos.
Non touch not over 10 mm.

Mongkol