Plasma Cutter, should have brought it long ago!

[Ljohnsaw]

On my favorite on line auction, there was a plasma cutter. So I researched it on Amazon. Highly rated and the bidders were heading towards full retail on a returned item. So I just bought it new for less than $200 delivered in 3 days.

I've done a fair amount of oxy cutting and gas is getting expensive. I fired it up today and just made lots of cuts on some scrap. First cuts were a guess on amps and air pressure. I think my speed was too slow as there was lots of slag.

Anyhow, it is a Bestarc BTC500DP. It has Pilot Arc to start it. Adjustable pressure, amps, adjustable cool down air and a water filter/separator. It's a pretty small unit. I was running it off my little air compressor that is really only suitable for my brad and finish nailers. It could only give me about 15 or 20 seconds of cut time. I was just free handing it.

Then I tried it on some aluminum oxygen tanks. It works but I need to hook up my big compressor.


 

 

 

 

 

 

[beenthere]

John
Reminds me of last month when I needed to make a press to remove a brush mower blade bar (1" by 3" by 24") pressed on tapered spline. Picked up a scrap piece of 1/2" steel plate that had been torched off at my welders' shop.

Picked up a steel cutting saw blade at HF that would fit my electric hand saw. That blade cut through that 1/2" plate steel like butter. Amazing surface left with a mirror-like finish. Don't know if the pics do it justice, but the nervous feeling I had going into this part of the project didn't turn out to be any problem.

Sawing through the ½" steel plate


 


Saw blade used for cutting steel, says has "cermet" coating on teeth. Read that cermet is a coating used by dentists on human teeth. ??


 

The smooth, mirror-like finish of the sawcut. Not much noise or sparks as I was expecting.


 

The fabricated press using the ½" steel plate to loosen/remove the bar.

[peakbagger]

On my favorite on line auction, there was a plasma cutter. So I researched it on Amazon. Highly rated and the bidders were heading towards full retail on a returned item. So I just bought it new for less than $200 delivered in 3 days.

I've done a fair amount of oxy cutting and gas is getting expensive. I fired it up today and just made lots of cuts on some scrap. First cuts were a guess on amps and air pressure. I think my speed was too slow as there was lots of slag.

Anyhow, it is a Bestarc BTC500DP. It has Pilot Arc to start it. Adjustable pressure, amps, adjustable cool down air and a water filter/separator. It's a pretty small unit. I was running it off my little air compressor that is really only suitable for my brad and finish nailers. It could only give me about 15 or 20 seconds of cut time. I was just free handing it.

Then I tried it on some aluminum oxygen tanks. It works but I need to hook up my big compressor.


 

 

 

 

 

FYI, You probably know this but the biggest issue with home plasma arc work is crappy wet air. If it is and older compressor that uses oil its probably going to be getting oil in the air and if you do not have an air dryer its going to be wet. Both issues can cause problems. A good air dryer is more than the cost of the plasma arc, so best option is use it on dry low humidity days and have a big tank at the compressor with an auto drain with a long pipe run to the drop for the plasma arc unit. Then install a good moisture separator with a coalescing filter right at the drop. The long pipe run works like an aftercooler to cool down the air and get moisture and oil to condense before taking it out at the drop.

[chevytaHOE5674]

Plasma cutter is one of the best shop tools I own. I have a big machine and compressor that will clean cut 3/4" if needed. Only thing I use my torch for anymore is heating things. 

I do a lot of CAD (cardboard aided design) so the plasma makes cutting odd shapes super easy.

[21incher]

I have used a Hypertherm Powermax 45 for my cnc plasma table for about 15 years and love it. Got the machine torch and hand torch. Really great for gouging out welds and cutting accurate tolerances without much slag. I find that a Motor Guard air filter with the cartridges that look like toilet paper after the shop filter/ regulator almost doubles the nozzle life. 

[Crusarius]

Its funny, my plasma cutter is my least used tool in the shop. Maybe one day I will mount the torch to my CNC and that will change. But when I go to use mine I drain the tank and all the air lines then put an inline Dessicant filter right on the machine.

I used to have issues with it cutting, then the guy I bought it from asked me about the air. then he sold me the Dessicant filters. it was night and day difference. It is critical to have clean dry air.

[Wlmedley]

What is the electrical requirements for a small unit?Probably 1/2" is the thickest I would ever cut. I didn't realize that one could be bought that cheap. I've got a large compressor and plasma cutter would be handy.

[21incher]

What is the electrical requirements for a small unit?Probably 1/2" is the thickest I would ever cut. I didn't realize that one could be bought that cheap. I've got a large compressor and plasma cutter would be handy.

My Hypertherm 45 will pierce cut 1/2 and edge start about 5/8. It requires a 220 volt 30 amp line. It has PFC so it's efficient.  Some of the cheap ones rate themselves 1/2 but it's a gouge and not a pretty cut.

[Walnut Beast]

21incher you have the Cadillac of plasma cutters! 

[Larry]

I have a large Thermal Dynamics that will cut 1".  I just plug it into the 60 amp welder outlet.  Having said that, I only use it to cut 1/4" or less curvy stuff and use a old school bandsaw for the heavy stuff.  A new Hypertherm is on my wish list.

[21incher]

21incher you have the Cadillac of plasma cutters!

At the time I bought it, Hypertherm had the best CNC interface for the torch height controller. I had it about 2 weeks and the main board blew. Never had a company respond so fast. They had me drop it off at a local repair dealer and had their engineers involved because their failure  rate was so low. Has made miles of cuts since then. It's pretty much 100% duty cycle up to 1/4 steel and their nozzle technology makes a set last if you have dry air with very little slag. The Power Factor Control ballances the load on both phases and makes it use less electricity in theory.  It is a good machine. 

For occasional home use many of those Chinese machines will work good at 10% of the cost. Just make sure consumables are available and run then within the duty cycle rating. I would recommend looking for one with gouging capability and second set of gouging nozzles for quick clean weld removal when trying to replace parts. That's where the really shine. It's easy to cut metal with blades but grinding out old welds in tight spots cannot be done easily any other way.

[peakbagger]

Hypertherm is based and manufactured out of Hanover NH. 

[beenthere]

I watch a youtube channel "Farming Fixing & Fabricating" and have seen where they are quite happy with the Harbor Freight plasma cutter performance compared to others that they have used. And they have been using plasma cutters extensively over the years. Just throwing out what I've observed. No idea which one(s) they were using that failed. 

[caveman]

I've got a Hypertherm 45 at work/school hooked up to a CNC. It usually cuts flawlessly but a week or so ago I put a piece of 1/2" on the table, and it started cutting erratically and crashed.  I changed the consumables, ensured I had the cut speed and the other settings right.  It still is crashing on the 1/2".  I put some 16 gauge on, and it cut just right. It does have the height control and the wire seems to be intact.  

I decided to have the kids cut the top they were working on for a small welding table using the oxy/acetylene torch.  The one side they cut looks like a mule's @$$ sewn up with briars. 

21incher or any others who have suggestions, I'm open to hear them.   

[21incher]

Does your torch control use touch off for material height? Usually I go down fast to about 1/2 inch off the table then slow down till touchoff in the post processor. Check that high speed movement number is over 1/2. Another issue  I have seen is oil or other coatings could affect conductivity.  The pierce on 1/2 can spit stuff on the nozzle also messing with the flow. If you triggered the break away the torch may be high also. Any moisture in the air can affect cut quality on thicker cuts.
  It takes the full 30 amps @ 220 input for 1/2 inch so make sure the building wiring is large enough for the run to prevent voltage drop. Mine is an old 45 and I had to run 8 gauge feed. The newer 45 xp are supposed to be better with voltage variations. Not sure which you have.  
  Don't know the consumables you use but the fine cut ones will give you trouble with thick stuff. Good luck finding the issue as it could also be in the torch height controller feedback. When something acts up like that I usually try the hand torch to prove its not in the machine. 

[caveman]

Thanks for the suggestions on things to try.  I do not have a hand torch for this machine.  I did cut some thicker material, 3/8" or 1/2" recently and it cut as it should.  It is not happy with this particular piece.  I'll try to spend a little time on it today.  This year I have been blessed with a bunch of yahoos, so it is often a challenge to give my total attention to something of this nature while still maintaining a little supervision.

[Peter Drouin]

I love mine, Grate to fab stuff on the HOT ROD.


 

[barbender]

 Caveman, I haven't got to use a plasma cutter for many years. I do remember the one I was around, worked great when it worked. Which most stuff it was great on, but you'd get a few pieces of steel that it just didn't like. I think that was because this machine wasn't "self arcing" or whatever that's called, so heavy scale or any rust would make it cut out. Clean steel it cut awesome. 

 It cut so great, when it cut, that I always wanted to use it. Me and my foreman (old school) were truing up a worn cutting edge on a grader, so I got out the plasma to cut a nice straight line. Well, the line I was making was anything but. "I knew we should've just used the torch", said Mr. Old School🤷😊 

[caveman]

Thanks for the suggestions on the rust and scale.  It is not dirty, but it could be cleaner.  I did not get a chance to work on it yesterday.  In the ag mech classes, we did not even leave the classroom.  They were stripping wires, wiring up push button switches, LED lights and horns to drill batteries.  Yesterday, the objectives were for them to learn about wiring in series, parallel and how to solder wire.  

Sometimes we'll wire a horn to a trailer light plug and install it under someone's vehicle.  It is amusing to watch as the push the brake pedal and the horn blows or when they turn on the lights and the horn blows.

When I get back to the plasma cutter, I'll pay close attention to which consumables are in the torch and ensure that the metal is good and clean as well as properly grounded.

[caveman]

I did not want to leave this one hanging.  Yesteray, I cleaned up the cut line area of the plate of metal with a wire wheel (it was not rusty) and I attached the ground clamp to the plate, rather than the table.  It cut acceptably well but not perfect.  There were still a few crashes.  I will try to avoid cutting thicker metal on this machine.  

Sometimes it helps to hear advice you know you need.  I generally cut and weld on clean metal.  I just assumed this was clean enough.  

[Southside]

I generally cut and weld on clean metal.

A farmers dream. :D

[caveman]

I was going to modify the post but instead, I'll just make another.  

All of these cuts were supposed to be straight.  The torch crashed on all of the wavy ones.  The metal does not look too bad (dirty or scale), but evidently, it needed to be cleaner.

The odd shaped things above were supposed to be circles.
It is cutting relatively well here.  I bought some consuma bles that were not brand name.  They have done well.


This is better than I can do with a torch or a hand held plasma cutter.  The corners were not perfect, but a little grinding and a little gumption from some teenagers who are more worried about where they will eat lunch than anything else may result in an acceptable welding table.  This group of boys is exhausting my patience.  I'm with Jeff, I think I'm also a midget doctor.   

[21incher]

Cuts like that look more like it is a controller problem then plasma. Do you have a earth ground rod hooked to your slats to eliminate ground loops and noise? If the sheet is fairly flat try turning  off the torch height control on the cut and just use the fixed offset.  Only the touch off area needs to be clean. Once the cut starts it doesn't matter.  Doing the pierce off the part with a good lead in can help at the end of cut.  Also be sure the torch lead is not running parallel to the motor leads or near them as I think that machine uses servos and emitted noise in the encoder lines would also cause something like that. Could also try plugging the controller into a outlet on a different circuit or get a 60 amp machine . Good luck.