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  #1  
Old 06-23-2004, 10:04 PM
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SlimJim SlimJim is offline
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Default Dross Problems

Here are the details.
New Spectrum375 running off of 230 volts , 36 gallon compressor with water filter and Motor guard 26 filter. I have my switch set to 240 volts, I have air properly adjusted . I can't get clean cuts even on 3/16ths using a standoff guide. I have to push down on the 3/16ths to get it to seperate after cutting and it is really hard to get 3/8ths plate to even sever. The dross is just rewelding back together at the bottom of the cut. I have tried varying cutting speed, power, and stand off. What am I doing wrong?
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  #2  
Old 06-23-2004, 10:45 PM
Franz Franz is offline
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It sounds like you have a gouging tip or a very worn out tip on the gun, unless you're traveling way too fast.
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  #3  
Old 06-23-2004, 11:17 PM
sb62 sb62 is offline
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I don't have that particular machine so I looked at the specs on Miller's site.

With the material thickness you are trying to cut, you should be using the drag method. Rated standoff capacity is 1/16".

The machine has internal checks built in for the air supply but don't count on them. Do you adjust the compressor regulator or just the plasma. Pushing through the filter and any length of hose can induce significant pressure/flow drop.
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  #4  
Old 06-24-2004, 12:08 PM
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I have swapped all parts on the gun, i have tried 3 seperate tips, I have tried varying air pressure at the compressor and at the cutter. I have tried with and without standoffs. I cant cut any faster or the sparks blow back and it does not cut through. The only thing that I can think of is that it may be air flow for some reason. I am pushing through 50 ft of hose 1/4 to 1/4 with no quick connects to restrict flow. I dont know what else it could be. Where is Fla Jim when you need him?
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  #5  
Old 06-24-2004, 01:19 PM
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I forgot to add that I have 60 psi while cutting.
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  #6  
Old 06-24-2004, 01:22 PM
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Yeah were is fla Jim?
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  #7  
Old 06-24-2004, 01:43 PM
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Shade Tree Welder Shade Tree Welder is offline
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Sounds like you may be having issues with grounding. Make sure your ground clamp is secure and the wire/cable is not broken or damaged.

Also on my 2050 there is a "tip saver/expanded metal" switch; don't know if that is on the 675? Set it to tip saver when not running on expanded metal.
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  #8  
Old 06-24-2004, 01:56 PM
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Quote:
Originally Posted by Dman033189
Yeah were is fla Jim?

I bet he's out sailing or maybe buying a sail boat.
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Old 06-24-2004, 01:59 PM
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morpheus morpheus is offline
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Quote:
Originally Posted by Shade Tree Welder
Sounds like you may be having issues with grounding. Make sure your ground clamp is secure and the wire/cable is not broken or damaged.
Shade might be on to something here. My cutter doesn't work for crap unless the work clamp is connected directly to what I'm cutting. Conductive clamping (to my bench where what I'm cutting is clamped to) doesn't seem to work for crap. I think this is because what we call the "ground" clamp normally is actually positively charged IIRC.
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  #10  
Old 06-24-2004, 02:11 PM
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This is probably a stupid question but I am going to ask anyhow. This is new steel, I dont have to grind or brush the plate to get a good ground do I?
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