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  #11  
Old 06-18-2015, 02:10 AM
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Does flux core need a different tip to solid wire? I find it tends to jam in the tip sometimes and it almost looks like the end of the wire is swelling?
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  #12  
Old 01-26-2017, 09:54 AM
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When I did the mods to this welder I still suffered with overfeed. not as bad as before but still annoying.

I did some more googling and discovered it's a common issue with some the cheap wirefeeds with a simple solution. A relay in line with the motor feed shorts the motor terminals to themselves when the trigger is switched off.

this short circuit across the motor effectively creates an electric brake and the motor stops instantly.


I still havent upgraded the earth terminals but the lead I have on it now (the factory one from my thermal arc inverter) never gets too hot so it's no big deal.


Could someone tell me, is there much need/benefit in gas post flow control? it's something that could be very easily added, but to what end?

I will probably change the speed controller pot, either to a multi turn unit, or if I can figure my ohms law maybe put some fixed resistors in line with a different rated unit. All my usable adjustment of the speed is in about 20 degress of rotation which makes adjustment in welding gloves kinda tough
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  #13  
Old 01-27-2017, 07:31 AM
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GWIZ GWIZ is offline
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Quote:
Originally Posted by JohnBoy View Post
When I did the mods to this welder I still suffered with overfeed. not as bad as before but still annoying.

I did some more googling and discovered it's a common issue with some the cheap wirefeeds with a simple solution. A relay in line with the motor feed shorts the motor terminals to themselves when the trigger is switched off.

< Without a schematic it hard to say what would be the best and safest way
Some of the drawings I have seen use transistors to shunt across the motor some also add a series resistor so its not a hard/direct short across the motor.
just remember the power to the motor should be stopped before you shunt across it, maybe a SPDT relay.



this short circuit across the motor effectively creates an electric brake and the motor stops instantly.

I still havent upgraded the earth terminals but the lead I have on it now (the factory one from my thermal arc inverter) never gets too hot so it's no big deal.


Could someone tell me, is there much need/benefit in gas post flow control? it's something that could be very easily added, but to what end?

I will probably change the speed controller pot, either to a multi turn unit, or if I can figure my ohms law maybe put some fixed resistors in line with a different rated unit. All my usable adjustment of the speed is in about 20 degress of rotation which makes adjustment in welding gloves kinda tough
other link I noticed what looks like a 230 to 12 AC Isolation transformer
I assume the feed motor on the other runs around 6 volts and uses a 12 volt source.

If you are running 24 volts that maybe your range problem, what is the lowest voltage that you can use with the PWM.
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  #14  
Old 01-27-2017, 05:48 PM
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I'll be honest it's. A few weeks since I put the relay in so I can't remember exactly how it's wired but it's only a regular single pole auto relay. Took me some time to get my head around it but it's quite simple. Gone from my brain again tho!


The original motor controller ran from the weld transformer so the normally done thing is to use a 24v supply to replace it. I could test with 12v easily enough and see if it makes a difference
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  #15  
Old 01-28-2017, 01:17 AM
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gimpyrobb gimpyrobb is offline
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So I may owe my capacitor an apology.

In my haste to get it wired I may have inadvertantly blown it up by wiring it the wrong way round


To say that I am pissed at myself would be an understatement.
I always enjoyed waiting for my buddy in my electronics class to get up from their project and swapping the + and - on a big cap. The pop that followed when they plugged it in always cracked me up!
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