Tons of dross with my new Spectrum 375

[vtwin4life]

Call Miller & ask them what you need to do...If it's the machine, they'll fix it.
If it's you...They'll do what they can to help fix that also!
They WANT you to be happy with your machine....Give them a call.
There should be a toll-free number in your manual....
HTH

I gave them a call, and they are echoing you guys, saying it looks like an air problem. The only thing I can think of is maybe it's the air line. Like I said before, I'm putting 90psi into this thing. The tech again confirmed that even though my compressor is under powered cfm wise - it should be ok because I have 25 gallons in the tank. He just again stated that this would only effect me on long cuts. I'm going to try a few more air adjustments tonight after I finish my 14 hour day...

The other thing he noted, was that it sounded like I was moving too slow with the torch. Problem is, when I move faster with the torch, I don't cut through. Seems like I'm always getting sever cuts even on 1/8".

[harcosparky]

I gave them a call, and they are echoing you guys, saying it looks like an air problem. The only thing I can think of is maybe it's the air line. Like I said before, I'm putting 90psi into this thing. The tech again confirmed that even though my compressor is under powered cfm wise - it should be ok because I have 25 gallons in the tank. He just again stated that this would only effect me on long cuts. I'm going to try a few more air adjustments tonight after I finish my 14 hour day...

The other thing he noted, was that it sounded like I was moving too slow with the torch. Problem is, when I move faster with the torch, I don't cut through. Seems like I'm always getting sever cuts even on 1/8".

I would for the moment forget torch speed. Get the MASS of air flowing. Understand the situation is not a lack of PRESSURE ( PSI ) but a lack of MASS ( CFM ). Think of it like this .... your compressor can deliver 4.5 PINT jars of air at 60 PSI. The 375 requires 4.5 QUART jars at 60 PSI. The numbers are not actual, just used to show meaning.

Another " cheap trick " you might try, add capacity to your air system by adding in another air tank. Like on of those 'portable air tanks " they sell for about $30. The problem with this would be you now increase the demand on the compressor to supply the additional volume. But if you try this and it runs the 375 then you know for sure the problem is air volume.

I would try the largest diameter air hose you can find. This will add volume to the air feed. I had some air tools that seemed starve for power, they were at the end of 50 feet of hose. When I increased the hose from 3/8" to 1/2" it made a difference as it should as the size increase was a 33% volume increase.

[vtwin4life]

I would for the moment forget torch speed. Get the MASS of air flowing. Understand the situation is not a lack of PRESSURE ( PSI ) but a lack of MASS ( CFM ). Think of it like this .... your compressor can deliver 4.5 PINT jars of air at 60 PSI. The 375 requires 4.5 QUART jars at 60 PSI. The numbers are not actual, just used to show meaning.

Another " cheap trick " you might try, add capacity to your air system by adding in another air tank. Like on of those 'portable air tanks " they sell for about $30. The problem with this would be you now increase the demand on the compressor to supply the additional volume. But if you try this and it runs the 375 then you know for sure the problem is air volume.

I would try the largest diameter air hose you can find. This will add volume to the air feed. I had some air tools that seemed starve for power, they were at the end of 50 feet of hose. When I increased the hose from 3/8" to 1/2" it made a difference as it should as the size increase was a 33% volume increase.

Great advice. I did a search online the other day looking for a reserve tank but all I found were the tanks that have a little bicycle fill hose on them. Any good sites out there for these? Also - can I use the same 1/4 NPT fittings on a 1/2" hose? Or does that defeat the purpose?

Thanks again all for the great advice.

[harcosparky]

Great advice. I did a search online the other day looking for a reserve tank but all I found were the tanks that have a little bicycle fill hose on them. Any good sites out there for these? Also - can I use the same 1/4 NPT fittings on a 1/2" hose? Or does that defeat the purpose?

Thanks again all for the great advice.

I would look at those tanks, I realize they have a small Schrader valve on them, but you should be able to remove the valve assembly and install a fitting. What I did on my 1/2 hose was to get fitting on the tool end to make a downsize adapter. Also on your compressor you should be able to remove the fitting on there an install an adapter to upsize.

What I would do is go to a store like Home Depot or Lowes ... where they have the compressors displayed they should also have a large assorment of fittings in all size and configurations.

I opted for installing " quick disconnects " all around so that I could easily plumb air to where and what needed it.

Best way to do it is figure out how to hook the 1/2" hose to your compressor using the least number of parts possible. Then go to the end where the plasma will be connected and do the same.

If you can visualize this, I have 25 feet of 1/2" hose from the compressor out to the tool end. At the tool end I downsized the connector ro 3/8". At this point I will attach a short piece of 3/8 hose at the end of the 1/2" to the tool. I did this for hand air tools because the 3/8 is more flexible.

Hooking up to the 375 is a different matter, you might be able to plumb the 1/2" up to the back of the 375 but make sure the hose is supported to minimize stress on the connector back there. They should be able to withstand the stress, but why risk it.

That should be enough info to confuse you - hopefuly it is clear enough to avoid confusion.

[vtwin4life]

Well, I managed to fix my air problem. I got to the point where I can set the air pressure with the air/gas set knob and get the "machine gunning" to stop. I then set the pressure to the max of the range indicated on the 375 and...... STILL CRAPPY CUTS. Tons of dross, machine is struggling to get through 1/8" and below. I tried new tips/electrodes/etc.

At this point, I have a couple options.

1) Spend even MORE money and get a whole new compressor and see if this fixes the problem

2) Figure out a way to sell this thing and recoup as much money as possible and consider this another "screwed again" situation

3) Find my sledge hammer

[harcosparky]

Well I still think air volume is the issue.

Sounds to me like you are near the min required.

If you have a Home Depot nearby ( or another tool rental place ) try renting a bigger compressor for a day or two ( cheaper than buying ) just to confirm wether or not it is air flow.

Also I dont think you ever said but ... what are you doing to dry the air?

I am not sure what effect moisture has on a cut, but I know it tears up the tips.

I would do the following BEFORE selling/sledge.

#1 Rent/Borrow a bigger compressor

#2 With the bigger compressor online try a new tip ( in case moisture damaged the first )

I do know that when I felt cuts were going bad and switched tips it made a 100% difference.

[garth]

OK lets get this figured out now how big of an air line are you using? is the selector switch on the back of the spectrum on the rigth setting? are you running it with a 1/16 stand off of the material? do you have a good ground? if you are ok with all this see if your dealer would set it up at the shop and try it there but it sounds like the air line in to the machine is under sized. i use a 3/8 line in to mine and have no problem with cutting thicker than rated with good results. and the slag on the other side just knocks off. but then agian my input preasure is 125 psi and it holds it well and then adjust for the thickness of mat. good luck and see if your lws will help out may be as simple as a bad air line has press.but not enough flow.

[bobkrack]

Well, I managed to fix my air problem. I got to the point where I can set the air pressure with the air/gas set knob and get the "machine gunning" to stop. I then set the pressure to the max of the range indicated on the 375 and...... STILL CRAPPY CUTS. Tons of dross, machine is struggling to get through 1/8" and below. I tried new tips/electrodes/etc.

At this point, I have a couple options.

1) Spend even MORE money and get a whole new compressor and see if this fixes the problem

2) Figure out a way to sell this thing and recoup as much money as possible and consider this another "screwed again" situation

3) Find my sledge hammer

In addition to following other suggestions regarding air volume and quality(dry), take your tip, cover, and insert to the dealer. We have 3 plasma machines at our shop - one for up to 3/8", one for 1" and one that will cut through 3" plate. Your dross and control issues sound just exactly like using a damaged tip or even a "gouging" tip.
Goodluck,
Bob

[harcosparky]

In addition to following other suggestions regarding air volume and quality(dry), take your tip, cover, and insert to the dealer. We have 3 plasma machines at our shop - one for up to 3/8", one for 1" and one that will cut through 3" plate. Your dross and control issues sound just exactly like using a damaged tip or even a "gouging" tip.
Goodluck,
Bob

That's kinda why I suggested using a new tip as well as larger air supply.

A 3/8" airling would be sufficient IF IF the air compressor could push the proper volume ( CFM ) of air.

I was 'developing' a problem with mine even though I knew the air pressure and flow was correct, and the air was dry. I knew it had worked initially and something was changing, so I looked to the tip.

ALSO in this case as I recall -

vtwin4life -

'ordered' a Drag tip/cup for his machine.

Maybe he should try using the standard tip / cup setup as well.

A NEW TIP is something he could try easily enough as the 375 came with 3 extras.

[vtwin4life]

That's kinda why I suggested using a new tip as well as larger air supply.

A 3/8" airling would be sufficient IF IF the air compressor could push the proper volume ( CFM ) of air.

I was 'developing' a problem with mine even though I knew the air pressure and flow was correct, and the air was dry. I knew it had worked initially and something was changing, so I looked to the tip.

ALSO in this case as I recall -

vtwin4life -

'ordered' a Drag tip/cup for his machine.

Maybe he should try using the standard tip / cup setup as well.

A NEW TIP is something he could try easily enough as the 375 came with 3 extras.

Yeah, I tried new tip/cup/electrode last night. Same issues. My air line is 3/8". What I keep noticing is the arc is having a really tough time coming out the bottom. It ends up coming out on a severe angle even when moving the torch really slow and using 24-27 amp output on 1/8" stock. My 25 gallon compressor is rated at 3.5 cfm @ 90 psi, but I was told that would just mean that I wouldn't be able to make long cuts which I'm fine with. Maybe, I was told wrong, and this means that less than 4.5 cfm @ 90 psi means horrible cuts. There is a 26 gallon compressor at home depot now that is rated 5.5 cfm @ 90psi. I may either just buy it, or try to rent one like it. Something tells me that this isn't going to make any difference though.

[harcosparky]

What I keep noticing is the arc is having a really tough time coming out the bottom. It ends up coming out on a severe angle even when moving the torch really slow and using 24-27 amp output on 1/8" stock. My 25 gallon compressor is rated at 3.5 cfm @ 90 psi, but I was told that would just mean that I wouldn't be able to make long cuts which I'm fine with. Maybe, I was told wrong, and this means that less than 4.5 cfm @ 90 psi means horrible cuts. There is a 26 gallon compressor at home depot now that is rated 5.5 cfm @ 90psi. I may either just buy it, or try to rent one like it. Something tells me that this isn't going to make any difference though.

The arc coming out at an angle ???

OK, forget about cutting any metal for the moment.

What happens when you just hold the torch in the air and fire it???

I tried that with mine and got a nice well defined flame coming straight out of the torch.

I even went so far as to adjust the air pressure from high to so low it shut down and still the flame from the torch was straight. ( keep in mind I am adjusting pressure at the 375 and in no way cut down on the CFM )

In a bit I will test with a LOW CFM compressor and see what happens

[harcosparky]

OK I just ran a test with a 2.6 CFM @ 90 PSI compressor.

Porter Cable Pancake Compressor

Even with the low flow I was able to fire off the torch and make a short cut.

I did notice some degradation with this configuration.

Try firing the torch into the air and see what the flame looks like.

At this point even with the low air flow, if you do not see a well defined flame coming straight out, take the unit to the LWS and have them check it out.

The arc coming out at an angle tells me maybe something at the torch end is misaligned, but this is truly a SWAG ( Scientific Wild As*ed Guess )

When you tried the new tip, did you try the standard tip or the drag tip ???

[vtwin4life]

The arc coming out at an angle ???

OK, forget about cutting any metal for the moment.

What happens when you just hold the torch in the air and fire it???

I tried that with mine and got a nice well defined flame coming straight out of the torch.

I even went so far as to adjust the air pressure from high to so low it shut down and still the flame from the torch was straight. ( keep in mind I am adjusting pressure at the 375 and in no way cut down on the CFM )

In a bit I will test with a LOW CFM compressor and see what happens

In the air, the flame comes out perfectly straight. It's when I make a cut, it comes out on an angle oppisite of my cut direction. It's like the unit is under-powered and struggling to cut through the 1/8". It really has a tough time penetrating the steal when cutting. That's why I'm beginning to think there are more problems than just air. No matter how slow I go, and how much amperage I throw at it, it's like I'm pushing it to it's limits and getting a horrible sever cut.

Between this and the "Genuine Miller" drag parts that don't give any standoff what-so-ever unless you unscrew the drag shield (Miller tech duplicated this), I'm really questioning the quality.

[harcosparky]

Well don't question the quality based on one unit. It could well have been damged internally during shipping. Hard to say.

I own a 375 and even though new with it am very happy. Watched the Miller rep use a 375 and was amazed at how good it was in experienced hands.

I would take the unit back to the LWS and have them try it.

I've exhausted my limited knowledge at this point.

KEEP IN MIND - I did all my testing with the torch up off the workpiece freehand and did not do any dragging.

[vtwin4life]

Well, I have learned a valuable lesson here. I bought this from a shop in indiana that sells on ebay (no auctions, just brand new). I called this morning basically asking advice of what to do, and his response was "well I haven't had any problems with them and I've sold a lot of them, so take it to a service center". So, he has basically washed his hands of it. I called a couple service centers and they ask "did you buy it here or online?". When I answered them, the whole tone of the conversation changed. "Well that's what you get when you order online" is the answer I got there. They told me that they will most likely be way too busy on a saturday to look at the machine. I work 14 hours a day monday through friday, which excludes me from going to any LWS. So I figured I would save a few hundred by ordering online.

Lesson learned. I should've spent that $1200 on beer, I'd be in a lot better mood right now.