Max 42 DOA Question

[Welding_Swede]

I'm looking at an ad for a used Max 42 that "stopped working" on CL for $300.00. I'm a pretty decent hand at electronic repair but am curious if this unit has an expensive main board or some other prohibitively high dollar replacement parts that would make this a bad buy.

The seller is claiming that the last time it happened to him it was the "safety switch". Seems odd to me that if that's all it is why is he now willing to give it away? Sounds like a case of "Caveat Emptor" but I thought I might bounce off the guys with the knowledge of this equip.

Any opinions or experience would be welcome and appreciated.

Eric

[papaharley03]

You'd be surprised at what people will overlook. Where I used to work, the shift before mine switched out the entire wafer handling robot on a tool because it suddenly stopped working. The new one didn't work either and they were scratching their heads. I came into work and went out to the machine and sure enough, someone had bumped the key switch on the front that engaged the robot safety interlock. DOH!

Thanks to them, I had to do a compete robot position teach because they swapped them out without looking for the obvious.

Just saying...

Papa

[soutthpaw]

That reminds me of of one customer's tractor I repaired when working at john deere. $2000 worth of repairs. Anyway the guy brings it back a few days later all upset it stopped working after a few hrs. My fix was removing the gas cap and filling the gas tank. The guys face turned red as a tomato.

[Welding_Swede]

Update:

So, I've talked to the seller and he says the unit turns itself off right after turning it on. Claims this started right in the middle of a big job and he just went out and bought a new unit. I could see myself doing the same thing if the circumstances were right. Anyway, the troubleshooting section of the service manual says that this is caused by the retaining cap sensor microswitch sensing a loose or missing retaining cap. (I downloaded the manual off Hypertherm's site, wish all manufacturers would make these available.)

I have little to no experience with plasma cutters although I do a fair amount of welder repair and am thinking about picking this unit up. A microswitch is not usually an expensive part and appears to be an easy replacement.

Could I just "jump out" the microswitch for testing purposes at the seller's place without causing a seriously dangerous (albeit temporary) condition?

Sure would be good to get a little encouragement one way or the other on this. Any takers?

Thanks,

Eric.

[DSW]

If nothing else I bet Jim will probably chime in on this Monday morning if you can wait till then.

[Welding_Swede]

Right, almost forgot about Jim. Thanks, I'll wait for his expertise. Trying to figure out if a used Max 42 is an average deal for $300.00 or not. Supposedly comes with a bunch of extra consumables.

Anyway, I'll wait. I don't think its going anywhere in a hurry.

E

[Welding_Swede]

Update 2:

Talked to Shane at Hypertherm Tech Support. He says that the switch should should show a dead short across my meter while in-circuit and the cap in place and if it shows open, that I can jumper across the switch to test the unit for arc transfer. So, I'm going to check it out tonight and if I can get it to work, I'll probably pick it up.

Eric

P.S. All the good things I've heard about Hypertherm tech support are true. So, now I know where I'll be spending my PAC dollars from now on.

[jimcolt]

Shane at Hypertherm tech service can help you out with the Powermax42. That unit is probably 15 or so years old.....so if it is a relatively simple problem such as the "parts in place" sensor switch in the torch...then it certainly will be worth the $300. If it is a board issue...it could be expensive to repair....


Jim Colt

[Welding_Swede]

Thanks Jim. Shane said pretty much the same thing. I'll be checking it out tonight. Should be a pretty quick check. I'll post a follow up when I get back.

Eric

[Welding_Swede]

Final update:

Well, it was the switch. Took the torch apart, it read wide open on my meter. Jumped it out, put the torch back together and fired it up. Machine runs fine. So, I now own an old Max42 and a box of consumables for it.

I think I did all right for $300.00.

Thanks for the help.

Eric

[jimcolt]

You should change the switch...with it jumpered you can have live (around 300 VDC) voltage present when changing consumables. At least make sure power is off to the Max42.

Jim Colt


Final update:

Well, it was the switch. Took the torch apart, it read wide open on my meter. Jumped it out, put the torch back together and fired it up. Machine runs fine. So, I now own an old Max42 and a box of consumables for it.

I think I did all right for $300.00.

Thanks for the help.

Eric

[Welding_Swede]

Good point Jim. I was thinking the same thing. My question to you is this:

Do I have to replace the entire torch head that has the switch built into it somehow? Or, is the switch available separately? I have found a few torch body replacement assemblies in the $180.00 range. Seems like a lot just to replace the switch. The insulator material around the torch head looks ok to my untrained eye and I personally don't have a problem making sure that the unit is disconnected before changing consumables.

Eric

[jimcolt]

Eric,

I do not remember exactly what the inside of that torch looks like...and since I am on the road I don't have an easy way to look at one. Tech service at Hypertherm could help you determine if the switch is replaceable. I am just reminding you that the switch is there for your safety.....so be careful.

Jim Colt


Good point Jim. I was thinking the same thing. My question to you is this:

Do I have to replace the entire torch head that has the switch built into it somehow? Or, is the switch available separately? I have found a few torch body replacement assemblies in the $180.00 range. Seems like a lot just to replace the switch. The insulator material around the torch head looks ok to my untrained eye and I personally don't have a problem making sure that the unit is disconnected before changing consumables.

Eric

[Welding_Swede]

I appreciate your advice with this Jim.

One more question if you please. Regarding consumables for the PAC 120 torch, I am a little confused about the difference between the shielded consumables and regular "stand off" consumables. I think I would like to have the drag option for using templates and straight edges. Is that right? That I need a drag cup and nozzle for this?

And, since the torch is so old I'm having trouble sourcing anything except standard consumable kits (which I seem to have plenty of with the purchase). Any suggestions for the other consumables such as drag and gouging parts?

That's more than one question.

Thanks.

Eric

P.S. Been looking at the RT60 torch upgrade. Is it worth the money? Even on this old PAC machine?

[jimcolt]

The "standard" consumables from the day of the Max42 are unshielded......which by todays standards are old school....they provide pporer cut quality, cut thickness and cut speeds as compared to the shielded technology consumables. You should only use the shielded consumables sets in your PAC120 torch for best performance. Attached is a link that will get you to the consumables page on the Hypertherm website.....this gets you to the consumable section for discontinued product...and shows part numbers and pictures of the available consumables. All of the consumables for the Max42 are in stock at Hypertherm and can be ordered through any authorized distributor.

You can drag cut with any of the consumables....but the unshielded consumables will not last nearly as long as the shielded when drag cutting....and are harder to use as they have a tendency to "stick" to the plate when drag cutting.

If you have a few unshielded parts....use them up.....nothing lost there!

Link: http://www.hypertherm.com/en/Products/Consumables/Hypertherm_Plasma_Consumables/Torch_and_Consumable_parts_list.jsp

Jim



I appreciate your advice with this Jim.

One more question if you please. Regarding consumables for the PAC 120 torch, I am a little confused about the difference between the shielded consumables and regular "stand off" consumables. I think I would like to have the drag option for using templates and straight edges. Is that right? That I need a drag cup and nozzle for this?

And, since the torch is so old I'm having trouble sourcing anything except standard consumable kits (which I seem to have plenty of with the purchase). Any suggestions for the other consumables such as drag and gouging parts?

That's more than one question.

Thanks.

Eric

P.S. Been looking at the RT60 torch upgrade. Is it worth the money? Even on this old PAC machine?

[Welding_Swede]

Thanks again Jim. You've been a great help.

Eric

[ccawgc]

I don't think Hypertherm sells the switch by its self any more. But should be able to get one from an electronics or electrical supply store.

[Welding_Swede]

Thanks. I'm running it without the switch. I'm pretty careful about working on any tools and disconnecting the power source. A long, long time ago I changed the bit on a corded drill and bumped the trigger in the process and got myself a good one. Since then it has become habit to unplug the power before changing or working on the business end of anything. Since I am a one man operation, I'll probably leave it that way.

Just a quick FYI:

Got the shielded cup and drag nozzle for the PAC120 the other day. To me, it makes a huge difference being able to drag the torch and use a template or guide bar for cuts. Definitely worth the little bit of $$$ for the new parts.

I like this archaic little plasma cutter. Works just great for what I do and I smile every time I think about the price.

Thanks for the help!

Eric