Consumables

I have a Thermal Dynamics A60 Plasma on a Camaster CNC machine. I have overcome some THC issues but now I seem to be having issues with burning up my consumables pretty quickly. Actually I have no idea how long they shouls last, however probably more than 20 minutes on a single project with many small cuts and starts and stops.

I cut .125 hot rolled steel at 60 amps 150 ipm ( the book number) , my air is dry and I use .19 for cut height and .20 for pierce height and 126 for target voltage. All of these numbers are out of the book.

Anyone have any ideas??

Tony Wish:drowning:

I got around 3 cutting hours on my last set of consumables, which I thought was pretty dang good. It's on a Hypertherm Powermax 45 though, not a Thermal Dynamics...so take it for what it's worth.

I have a thermal dynamics unit and they do eat up nozzle tips fairly quickly maybe twice as fast as a hypertherm.... The idea here is to replace them thats why they are called consumables... But I have also seen the TD cut quality outperform the hyprtherm on many occasions...

Dustin and Ilean,

So we have 3hrs. per consmables and very fast usage of consumables.

I have nothing to compare to.

Is 3 hrs. the norm or Dustin you say they wear out quickly, how much time do you mean by quickly? My consumables are wearing out in 15 to 20 miutes. I use a water table and there is always a mess on the steel and a lot of bubbling and spraying water.

I would just like to know where a good balance id for consumables. I do artistic work so there is a lot of stopping and starting.

Tony

Quote:

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Originally Posted by TonyWish

Dustin and Ilean,

So we have 3hrs. per consmables and very fast usage of consumables.

I have nothing to compare to.

Is 3 hrs. the norm or Dustin you say they wear out quickly, how much time do you mean by quickly? My consumables are wearing out in 15 to 20 miutes. I use a water table and there is always a mess on the steel and a lot of bubbling and spraying water.

I would just like to know where a good balance id for consumables. I do artistic work so there is a lot of stopping and starting.

Tony

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The 3-ish hours seems to be about normal for me. My last nozzle/electrode lasted me through a full sheet of 1/4", and half sheet of 3/8", and about a half sheet of 14 gauge. Since the 1/4" and 3/8" were parts without a lot of pierces, I probably only had about 600 pierces on the set even with all the cutting.

On the cut quality--I think either machine is fully capable of providing really nice cuts, or really crappy cuts. All depends on the correct setup.

I have the A40 and the thing bleeds tips and electrodes. One tip and electrode may last a full sheet of 4x8 16 gauge hot rolled, the next set might last half a sheet. A full sheet being around 2,200 inches of cut with 196 pierces.

It also likes to fail to arc and I have to lift the material up to the torch to make it fire. Don't know if that's just mine.

I've tired everything in the book to make them last longer. I have three different air filters on it. The pierce height is per book specs. I've tried lowering the pierce height, more often than not it shorts the torch out. I've played with cutting speeds, heights, THC settings, and on and on.

I've come to accept it's going to eat tips. I have an 10 inch cubed box half full of spent tips and electrodes. It's not uncommon for me to spend $200 a week on tips and electrodes.

I don't know if that helps any, but that's how mine operates.

I have an A80 and I was lucky to get 10 minutes out of a tip. I went through many tips trying to get this new machine figured out. All of my tips would errode out to one side and the electode would get destroyed at about the same rate. During the first 10 minutes it would cut great but then I would start to experience poor piercing issues and the problems would snowball after that. I became convinced that the sheild cap wasn't helping things.

Just today I decided to remove the sheild cap to see how it would work. The problem I ran into though was that you have to have the sheild cap so that the torch can touch off. The tip won't allow this to happen because the ohmic clip doesn't make contact with the tip. I contacted tech support at TD but they said they didn't have a solution for this. To remendy the situation I mounted the sheild cap in my lathe and drilled the center out and also turned the end down so that there was only .015" clearance between the tip and the workpiece when touching off. My plasma cutter worked better than it ever has before. On the same parts (about 60 piercings) and in the same 10 minute time my tip and electrode still looked new with almost no wear. I really think that the sheild cap was causing some kind of a problem with the arc and damaging the tip and electrode.

Quote:

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Originally Posted by plasmamatt

I have an A80 and I was lucky to get 10 minutes out of a tip. I went through many tips trying to get this new machine figured out. All of my tips would errode out to one side and the electode would get destroyed at about the same rate. ....

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I bought some mig welder nozzle gel that people use to prevent splatter buildup just to see what it would do. I put some in a little dish and after each row of parts (9 parts, 81 piercings, about 500" of cut), I would buff the plasma tip with a scotch pad a bit and dab a little of that nozzle gel on there. That practice has doubled the life of my consumables.

I was having the same issue where after a few rows of parts, the nozzle would become eroded on one side. Cut quality would tank and it wouldn't arch right anymore. I started watching the plasma cutter through my welding helmet and noticed that after a handful of pierces, it would get a little bead of splatter on there and not too long after that it would start burning the orifice out on one side.

I was cutting 63 parts out of a sheet of 4x8 16 gauge. In a given sheet, sometimes I would go through 2 or even 3 tips in a sheet. That's 7 rows of parts. One tip would last 2 or 3 rows and it was toast. I started buffing the tip a little after each row and putting a dab of that gel on the tip and now I sometimes see 2 full sheets on a single tip. That's WAY better.

I used to have a little wire brush I would use to clean the tip every once in awhile, but it never really seemed to help. Doing it this way, though, has helped a lot. Dramatic difference.

There are a lot of things that can cause consumable damage on an air plasma torch....an even if you are doing things perfectly (proper pierce height, pierce delay, clean dry air, correct cut height).....you will find some brands and models that simply use more consumables as compared to others.

The nozzle (some call it a tip) is the part that the ionized air arc (plasma) is forced through at supersonic speed...and at a temperature of over 24,000 degrees F. The nozzle is made from copper, and copper melts at close to 1000 degrees F. That being said....a very good torch design that uses all of the rules of high temperature physics to allow a very hot stream of gas to be focused through a tiny copper orifice...is critical. Some torch and consumable designs are better than others!

The most common causes of rapid nozzle (tip) wear:

1. Operating at higher current (amperage) than it was designed for.
2. Piercing too close to the plate. (one pierce too close ruins a nozzleorifices ability to properly shape the arc...resulting in cut angularity)
3. Not allowing enough pierce time before motion starts.
4.Moisture, oil, or particulates in the air.
5. Piercing too high off the plate or firing the torch in the air.
6.Exceeding the maximum recommendation for pierce thickness.
7. If an unshielded nozzle (tip)....contact with the plate during cutting. (shielded consumables can contact or drag with no damage)



I have a Powermax85 on one CNC machine and a Powermax45 on another. With the 85 I cut most often with the 65 amp consumables on 1/4" through 1/2" steel plate. I typically expect about 600 to 1200 pierces on the nozzle before the cut quality starts to get affected....you start to see some varying edge angularity and more dross. At that point I change the nozzle....I shine up the end of the electrode with a piece of scotchbrite...and it usually lasts for as many as 3 nozzle changes.....when the electrode is near the end of its life the torch will occasionally misfire. The shield is also cleaned with scotchbrite to remove any steel or spatter...and the outside face of the shield is lightly coated with mig anti spatter spray...this keeps the spatter from building up. The shield generally lasts over a year in my cutting operation.

I have a compressor with an 80 gallon tank, outdoors under the eaves (year round) and a small refrigerated air dryer (found on Craigslist for $75) and a small particulate filter (MotorGuard) that has a 3 year old element in it...I check it periodically and it has never showed signs of moisture...so I put it back in. The compressor has an automatic drain (from Harbor Freight...less than $10)

The key to success with consumable life on my cnc machines is multi part. The clean dry air....the properly operating height controls on my cnc machines (PlasmaCam DHC2 and Torchmate with AVHC).....following the cutting specs in terms of pierce height, cut height, pierce delay, cut speed and cut height) religiously.....just as the Hypertherm manual suggests, and using the Hypertherm plasmas with their shielded consumables. The Hypertherm consumable cost more to buy than other brands......but last many time longer....which makes the cost per foot of cut far less expensive than other brands.

I work for Hypertherm...but my cnc machines are in my home shop...and I have to buy plasma systems and consumables just like we all do. I spend way less for consumables than even the import system users that pay $1 dollar for a tip......because mine cut so much further before being discarded!

Jim Colt

Yesterday I ran a whole sheet of 1/4" mild steel with about 500-600 piercings. I did this on two tips. With the standard TD sheild cap installed this would have taken around 5-6 tips. Getting rid of the sheild cap has made a huge difference. I really think that I could have cut this whole sheet on one tip but after a while I was having trouble piercing. The tip looked fine with really no sign of wear but I decided to change it out. With a new tip I was back in business again. The only thing I could see on the used tip was a small build up of debris on the inside of the tip where the electrode goes. Could this cause an issue? I'm going to try a small round wire brush on Monday to see if I can get this tip to work again. The orfice looked fine.

I also had to pause the program periodically to clear build up on my modified sheild cap (which is a fraction of the surface area after drilling the entire center out). I think I am going to machine the sides of the sheild cap out so that there are only a couple small points that come down and contact the work piece when the torch touches off. The idea of having to touch off seems like a poor design. It is nearly impossible to prevent a bead of molton steel from sticking to whatever part is being used to touch off. My thoughts are to reduce the episodes by even further reducing the surface area for the molten steel to stick to. One bad pierce due to a bead of steel and the problem snowballs. I have tried anti spatter spray but it really doesn't seem to be very effective.

Jim Colt it sounds like you are extremely knowledgable. I have enjoyed reading some of your other very imformative posts. It makes me wish that I would have bought a Hypertherm. The tech support at TD isn't very helpful.