TD Drag-gun

[xjr-ant]

Hi all first post here!

I have the above plasma cutter with built in comp (not the plus model). Don't really know much about these ill describe best i can. Has a strange problem when i first got it it took a while to get the thing working. First after 5 mins the pilot arc started to come then about 5 mins after the full arc came. I then used it for about 5 days on & off it was absolutely fine. Starting strait away. This was about 1 & a half months ago.

Just went to try and use it today - When same thing. Except only get a green glow and a few sparks which i assume is the pilot? arc. Ive tried new genuine TD parts electrode, tip, gas diffuser & shielding cup seem to make little difference. Any idea what could be causing this - the comp runs briefly about 1 sec then cuts out like it did before.

I suspect possible cause to be the air pressure contact/switch is getting very weak or perhaps the machines on it way out? Its an old one built in 00!! (ebay special....)

To aid any responses ive done the below;

I tested the safety contact for the shielding cup which is fine.
Obv the machines on & seems to be functioning.
New consumables fitted.

Cheers!

 

[rtbcomp]

Welcome to the forum.

Have you got an external source of compressed air you could try?

Is there a warning light which indicates low air pressure?

 

[xjr-ant]

Unfortunately i haven't any external air this is the reason i bought an all in one machine. Going to open it up today & see what's what inside.

Don't think it has a warning light. Only thing it does it cut out after about minute or so of cutting to cool down.

Does anyone on here have this unit?

 

[xjr-ant]

I think possibly the torch is faulty - It seems to be shorting inside on the electrode after 10 goes it turns the electrode black. The shielding cup is also very hot...

 

[NotANormalCoder]

Not 100% familiar with this machine but I think you have low air pressure or a problem with the cutting electrode not moving correctly. I think that this electrode (central piece) is supposed to move a few mm's back into the head when air is supplied, this strikes the arc inside the torch. Check this moves freely, if it doesn't, it'll short on the cutting nozzle and give you the blue/geen sparks that indicate the consumables are eating themselves. Also check the consumables for oil or water traces that are guaranteed to kill the consumables.

 

[xjr-ant]

Ok i will strip again & check for the above. Thanks!

 

[xjr-ant]

No luck with this - still get the green flash & the nozzle heats up quickly. I think most likely the torch is way past it. Need to make sure its that though is there a good plasma specialist in or around London?