Fixing a wire-feed welder

amberwolf

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I stuck this in Ebike techinicall because this is directly related to my ebike build here:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=31255
in that if I can't fix this welder, I can't finish the bike. :roll: (or about a zillion other projects I've been putting off mostly because this welder simply doesn't work well enough for long enough to do them).


PReviously, I had electrical problems with it, where it'd stutter power during arcing, and that turned out to be (I think) the thermal cutoff on teh transformer. Taking it out of circuit and shorting across the supply wires to it apperas to have fixed that problem. The main power switch is also bypassed, though I don't think it's the problem.


Now, the mechanical parts of the feed mechanism are giving me grief. Basically, the total amount of friction in the feed tube up to the electrode grip and inside the electrode itself are enough to stop the feed of wire, even if I hold it out straight (although that improves it). The worst is at the electrodes, after a few short welds, even after cooldown, but there's no way I can afford to keep using new electrode tips every inch or two of weld!

There has to be a reason that these specific things are happening, and something I can do to fix it.

I *think* that because it doesnt' feed constantly, it arcs and gets hot inside the electrode, and leaves bits behind on the electrode tip itself, causing further friction, worse sticking, and eventually it just jams so bad I have to unscrew the tip, yank the wire out, cut it off, and run a bit back and forth inside to clear some of that out (or replace the tip in cases I can't).

It's possible that the quality of the flux-core steel welding wire itself is poor, with variations in drawn diameter, making the problem worse, but I haven't got any other stuff to work with, so I don't know if other better (probably lots more expensive) wire would help. I can only get it when Harbor Freight puts the stuff on sale for $10, half price of it's usual, and that's really rare.

If I could make the feed mechanism keep good grip on the wire as it pushes it into the feed tube, instead of slipping when friction gets too high, it'd feed properly, regardless of friction. I just dont' know how to do that.

I have considered filing vertical cross-notches in the horizontal feed-groove in the feed-wheel, to give it something to "catch" the wire with, but I'm not sure that would change anything.


Some pics of what I have to work with:
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I had a similar problem on my MIG welder. The little roller that drives the wire had two grooves in it. One seemed to be plane and the other serrated, guess which one was the one it had been set-up with. I had to remove the retaining piece and turn the roller over to use the serrated groove. Now it feeds perfectly.
 
We have the 140 Miller Mig, in Fl. If it gets a lot of use, we have to change the liner inside the cable. After that, it works as good as new.

This is especially true if we weld a bunch of Aluminum. It leaves a film of dirt buildup inside the liner. We tried several ways to clean the liner, but, nothing was a success.
Slide a clean hand down the wire and see if you get dirty results.
 
When I have wire stick in the little tip, it's when I'm running too large of a tip bore, so it ends up having minimal electrical contact and arcing and welding itself rather than just rubbing against the wire to transfer the current.

Too small of wire size also means less bite on the drive roller.

Could it be your machine is setup for a larger diameter wire than the roll you've got in there?
 
I wish it was one of those suggested things, but I've checked all of those. well, I suspect that the arcing iside the electrode tip is happeing and is part of the problem but i don't know how to solve it. there's a coil-spring-like tube kinda like a copper-tube bender spring, in the pics above, that makces contact wtih the wire in there before it ever reaches the electrode tip, and it's in contact with the metal housing too, so it should be smoothing transferring current in it's curved portion as it feeds down the handle, preventing the arcing at the tip and stuff, but i don't think it's working.

Never had anything but steel flux core wire in there, .030, whcih is the size taht thing is supposed t use according to the manual/etc. and is waht came with it. wire itself is always clean as it comes out, as clean as when it started, even with a "white glove" test.

tips are for that size, too, but remember this is all harbofr frfrieight crap, so it probably has 200 percent tolerance s ior something like that. :lol:

roller does have two grooves, one smaller one larger but neither changes the rpoblem at all. neither is serrated, both smooth v-grooves.


I strongly suspect it's something to do with taht stupid spring-tube, but I'm just not sure. If you look at the pic of the grip section in pieces, you'll see there are two bits of that spring tube, but it appears to have been one piece originally, and is now broken in two and might ahve even arced between them, but leaving out the borken bit on the end doesnt' fix the problem, dunno if there is a way to mechanically clean the spring but i think i will try that.
 
The drive rollers need to be clean and the knurled one needs to be sharp. I have had to file mine carefully with a fine 3 corner file, to get all the crud out of it. You should see the imprint of the knurled roller on the wire as it comes out of the pistol. My steel welder has a "Bowden Cable", like the outer portion of an old throttle cable. If clean, sharp rollers can't push the wire, you have probably arced a spot inside the liner and the only solution is to replace the liner. I had to do this for the first time on my current welder, just last year.

For those welding both Al and steel with the same machine, we always changed the liner when we switch from one to the other. If you run Al though a snorkel previously used for steel, little bits of steel will sometimes cause fireworks and will definitely contribute to a poor Al weld.
AW in Heaven.JPG
 
cassschr1 said:
can you put a few pic of the circut board up
Sure, might be a little bit, gotta go feed dogs and stuff.

Gordo said:
The drive rollers need to be clean and the knurled one needs to be sharp. I have had to file mine carefully with a fine 3 corner file, to get all the crud out of it. You should see the imprint of the knurled roller on the wire as it comes out of the pistol.
There is no knurling on this roller, it's only two shallow v-grooves circumferential to the roller's outer face, one smaller and one larger, flipping the roller over uses one or the other, to no change in effect either way. I can't get a picture of it that close, but I described it best I could here and before.

I haven't yet filed it, as it appears to be perfectly clean, but was considering filing vertical cross-grooves in it to let it help push along (probably would be better to file them diagonally like knurling).


My steel welder has a "Bowden Cable", like the outer portion of an old throttle cable. If clean, sharp rollers can't push the wire, you have probably arced a spot inside the liner and the only solution is to replace the liner. I had to do this for the first time on my current welder, just last year.
If you're referring to the spring-coil type tube I describe in my post above, and is pictured (badly) in the first post, it's certainly possible that it is not making contact with the wire properly due to corrosion or oxidation or whatever.

If it has to be replaced I'll have to see if any of my old bike brake or shift cables are the right diameter, as I don't have anythign else that will work.


For those welding both Al and steel with the same machine, we always changed the liner when we switch from one to the other. If you run Al though a snorkel previously used for steel, little bits of steel will sometimes cause fireworks and will definitely contribute to a poor Al weld.
Since I only use .030 flux core steel wire, it's not that. Certainly could be stuff on the steel wire that gets left behind on the liner, but passes the white glove test (same stuff both before and after passing thru it).
 
Ok, here's the best pics I can get of the feed motor control board, whcih is the only board in it. Essentailly it is just a variable-voltage power supply, rectifying the AC voltage to DC, controlling the amount of DC with the feedspeed knob pot, and then sending that to the feed motor.

Casschr1 suggested a possible problem with a thermistor on that board, based on a problem Hobart helped him troubleshoot on his welder, but unfortunatley mine doesn't appear to ahve anything like that, being the cheapest Harbor Freight box-o'-junk I could get at the time two ro three years ago. I don't really think it's the feed board itself, as the motor runs the same evena fter it physically stops moving the wire. (unlike before, when it'd stutter and whatnot, which appears fixed by bypassing the thermal cutoff on the main transformer).

DSC04855.JPG

View attachment 2

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DSC04859.JPG.
 
Im no expert with welders or welding but I think I would replace the liner as my el-cheapo welder has started to do a very similar thing ever since the grandkids were bending the cable at right angles .. I was not happy :evil:
 
AW;
If the feed rollers are soft crap, is it possible that the grove for moving the wire has become deeper? If so, reducing the circumference of the roller will effectively make the grove shallower and will pinch the wire more. Either take the roller off and use a bolt with nut to hold it in a drill motor while you file it down, or if you can get the file in the welder, use the drive to turn it while you file it. The little MM motor may not be able to handle very much pressure on the file?
Last bright idea is to look at a Lincoln or Hobart to see if the knurled rollers are the same dimensions and will fit. Maybe get lucky and get a used roller at the welding shop from a blownup rig?
Maybe someone else with a HF welder can look at there rollers to see if they are smooth or there is a knurled one in it?
 
gwhy! said:
Im no expert with welders or welding but I think I would replace the liner as my el-cheapo welder has started to do a very similar thing ever since the grandkids were bending the cable at right angles .. I was not happy :evil:

Bend the grandkids at a 270 degree angle... they'll get the message :twisted:
 
I wonder if your smooth roller started out life with a crappy sino-knurl that has now worn off?
 
amberwolf said:
I stuck this in Ebike techinicall because this is directly related to my ebike build here:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=31255
in that if I can't fix this welder, I can't finish the bike. :roll: (or about a zillion other projects I've been putting off mostly because this welder simply doesn't work well enough for long enough to do them).


PReviously, I had electrical problems with it, where it'd stutter power during arcing, and that turned out to be (I think) the thermal cutoff on teh transformer. Taking it out of circuit and shorting across the supply wires to it apperas to have fixed that problem. The main power switch is also bypassed, though I don't think it's the problem.


Now, the mechanical parts of the feed mechanism are giving me grief. Basically, the total amount of friction in the feed tube up to the electrode grip and inside the electrode itself are enough to stop the feed of wire, even if I hold it out straight (although that improves it). The worst is at the electrodes, after a few short welds, even after cooldown, but there's no way I can afford to keep using new electrode tips every inch or two of weld!

There has to be a reason that these specific things are happening, and something I can do to fix it.

I *think* that because it doesnt' feed constantly, it arcs and gets hot inside the electrode, and leaves bits behind on the electrode tip itself, causing further friction, worse sticking, and eventually it just jams so bad I have to unscrew the tip, yank the wire out, cut it off, and run a bit back and forth inside to clear some of that out (or replace the tip in cases I can't).

It's possible that the quality of the flux-core steel welding wire itself is poor, with variations in drawn diameter, making the problem worse, but I haven't got any other stuff to work with, so I don't know if other better (probably lots more expensive) wire would help. I can only get it when Harbor Freight puts the stuff on sale for $10, half price of it's usual, and that's really rare.

If I could make the feed mechanism keep good grip on the wire as it pushes it into the feed tube, instead of slipping when friction gets too high, it'd feed properly, regardless of friction. I just dont' know how to do that.

I have considered filing vertical cross-notches in the horizontal feed-groove in the feed-wheel, to give it something to "catch" the wire with, but I'm not sure that would change anything.

You've got a Harborfreight... I've got one of those. I had the same problem regarding feed speed. I solved it by shaving the plastic post with a razor blade so that the tightening screw can tighten closer on the wire. Now it works "most" of the time. I also put a teflon washer on the spool, and after constant adjusting, you "should" get it to consistently spin out the wire without it loosening up like crazy and creating a bird's nest. Harbor freight welders sucks by the way. Use it with the mods I just told you, and you should be ok for a while, but for serious jobs, I'm saving up for a tig welder... I edited one of your photos to show you where I did my mods.
 

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Gordo said:
If the feed rollers are soft crap, is it possible that the grove for moving the wire has become deeper?
I suppose so; I don't know how hard the steel is. It's easily possible that the sharp edges on the groove have become rounded, too.

If so, reducing the circumference of the roller will effectively make the grove shallower and will pinch the wire more. Either take the roller off and use a bolt with nut to hold it in a drill motor while you file it down, or if you can get the file in the welder, use the drive to turn it while you file it. The little MM motor may not be able to handle very much pressure on the file?
It seems to have quite a bit of torque, so that's probably not much of a problem. I'd only be worried about blowing the little regulator in the speed control for it. :lol:

Last bright idea is to look at a Lincoln or Hobart to see if the knurled rollers are the same dimensions and will fit. Maybe get lucky and get a used roller at the welding shop from a blownup rig?
I'm already calling around to local welding shops, though so far I either get no answer or I get put on hold, or told that the guy I need to talk to is not in right now and I should try back later (but they wont' say which guy it is). I figure I'm getting a runaround or just messed with, cuz that tends to happen a lot, so I'll just keep trying different places till I get lucky or run out of places or time.


Maybe someone else with a HF welder can look at there rollers to see if they are smooth or there is a knurled one in it?
All the ones I've seen at the HF store are smooth just like mine (the feed mechanism appears to be identical in all of their wire-feed welders, AFAICT).

texaspyro said:
I wonder if your smooth roller started out life with a crappy sino-knurl that has now worn off?
No, it was always just liek it is (except that it is possible the edges of the groove used to be sharp and have become rounded; I never looked *that* closely at it to be able to tell).




ebike_rocket said:
I solved it by shaving the plastic post with a razor blade so that the tightening screw can tighten closer on the wire.
I may have to try that.

I also put a teflon washer on the spool, and after constant adjusting, you "should" get it to consistently spin out the wire without it loosening up like crazy and creating a bird's nest.
I dont' seem to have a problem with the reel's tension getting too high, but I have some pretty slick plastic I've used for similar things on bikes that I can try for this. (it's from clip-strips that products hang on around retail stores). I don't have any actual teflon washers that I know of, so it'll have to do. ;)

Harbor freight welders sucks by the way.
No kidding? :lol:

I've started saving up for a better one several times, only to have to spend it on emergencies or regular day-to-day-living stuff each time. But I am fairly certain that if I can find the problem(s) causing this, and fix them, this welder will do fine for what I need it for, or at least be modifiable to do certain things it can't do well yet. (like variable current).
 
For what it is worth, my welds with HF wire are birdshit. Using wire from Aire Liquide I make very good welds.
 
So are mine, with the HF wire, but it's all I have right now. I was hoping to actually talk to at least one welder supply place today, but the results from my last post continued until i got tired of trying, and worked on other things more productive for a while.

Tomorrow I will try again. I wish I had someone local that was buddies with a shop; I could probably at least get the info I am after, if not the parts and/or wire. I don't seem to communicate very well with these people (and it doesn't help that I mostly don't know terminology and such).


I think after i get the dogs fed and stuff I will see about using a complete bike brake or shifter cable housing instead of the liner that's there now, and also use some of the metal part from such a housing in place of the coilspring tube in the grip. Maybe one or the other will help the problem.

But first, I have to find my spare tips, cuz I have misplaced them and the existing one is pretty well trashed.
 
amberwolf said:
So are mine, with the HF wire, but it's all I have right now. I was hoping to actually talk to at least one welder supply place today, but the results from my last post continued until i got tired of trying, and worked on other things more productive for a while.

Tomorrow I will try again. I wish I had someone local that was buddies with a shop; I could probably at least get the info I am after, if not the parts and/or wire. I don't seem to communicate very well with these people (and it doesn't help that I mostly don't know terminology and such).


I think after i get the dogs fed and stuff I will see about using a complete bike brake or shifter cable housing instead of the liner that's there now, and also use some of the metal part from such a housing in place of the coilspring tube in the grip. Maybe one or the other will help the problem.

But first, I have to find my spare tips, cuz I have misplaced them and the existing one is pretty well trashed.

I've had good results swapping out the tips for Lincoln wire weld tips from home depot, and I've generally used the mild steel wire from home depot as well. Not sure if I'd touch HF wire...
 
AW, Amberwolf, Buddy, This quote won't cut it.

(and it doesn't help that I mostly don't know terminology and such).
:lol: :lol: :lol: :lol:

C,mon down and try to buy stuff that doesn't EXIST down here. A good for instance, Baler twine. Rope and some string is called Mechate'. Ma cot tae. The Baler twine stuff, is called Cocaleke Coca lae key. Nylok nuts are "Tuerca de seguridad".

Do what I do, and, just go behind the counter and start opening drawers and boxes. :lol: :lol: :lol: :lol: :lol: :lol:
 
amberwolf said:
I think after i get the dogs fed and stuff I will see about using a complete bike brake or shifter cable housing instead of the liner that's there now, and also use some of the metal part from such a housing in place of the coilspring tube in the grip. Maybe one or the other will help the problem.

How will you clean the lubricant out of the bike cable? It will play hell with the weld.
 
amberwolf said:
I dunno, almost anything would be better than the way it does now. :lol:

I dunno either as I was going to suggest gasoline, but you better run soapy water through it after. :shock: :shock: "Thinking of you with a flaming hot potato in your hand." :lol:
 
Have you considered lubing the feed liner w/ dielectric grease? Yes, silicon may contaminate the weld but silicone is an alloy for steel. Will have to look up those properties should u want to know.
 
If I had any DG, I'd consider trying it, but I don't.

As for gasoline, I've considered using some of that, too, but not exactly to *clean* the welder. :lol:


I'm just gonna try the metal coil part of the cable first, without any liner in it, replacing the spring-coil guide in the grip/nozzle area, and see how that works out. But I still haven't found my spare tips, and until I do, I can't really try anythign else cuz the one on there is pretty messed up. I had a pack of 10 of which I've used four or five, so at least half of them ought to be in the package if I cna find it. :roll:
 
You can grind or file the tip and then use a drill bit by hand which is twice the size of the orfice, to countersink it. Tip files are only a couple of dollars for a set, to clean the hole in the tip.
 
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