New roll, amazing!

[Davek0974]

The old buzz boxes used to adjust the power by screwing the soft iron core in or out so altering the current it is not all about resistance though, as much as introducing induced voltage further along the coil

Yes i had one of them, big knob on front and a pointer on top to show rough amps, it was a cheap box but did work for what it was needed for back then.

 

[Seadog]

it is not all about resistance though, as much as introducing induced voltage further along the coil

There is induced EMF (voltage) as you say. As the arc current decreases the magnetic field starts to collapse and induces a pulse into the coil. This will give a voltage spike but, more importantly, it increase the current flowing so helps to maintain a constant arc. I agree, though, that his arc force control seems not to be functioning.

 

[normspanners]

another idea !! a window sash weight, I think they are cast iron you want something that will not become magnetized if poss.

http://www.ebay.co.uk/itm/Sash-wind...280066?hash=item33d3b66cc2:g:S3MAAOSwiBpZcSA7

 

[normspanners]

I agree, though, that his arc force control seems not to be functioning.

I wonder if the pot has gone OC ??
maybe with grinding dust, a bit of switch cleaner needed?

 

[Davek0974]

I can check the pot out but will do some tests min/max first and get some pictures up.

I must admit that, looking at the suppliers, that Esab Rebel does look very tempting

 

[Davek0974]

Ok, had a quick play, 3mm steel as usual, maxed-out the wire-feed as suggested and set voltage to get a condition that sounded ok.

33IPM 21.3v mid-choke...


33IPM 21.3v zero-Choke...


33IPM 21.3v max-Choke...


Its damn hot, thats one thing! Probably running at 100% power. So the choke IS working BUT....

 

[Arclikeharrypotter]

You could probably go ahead and reduce your voltage to around 19 and that may improve things more

 

[Davek0974]

While doing the tests, i realised that all was not well, the main issue seems to be striking the arc and settling down. I did a lot of short beads, more like long tacks really - 5-10mm only.

It appears that maybe 60% of them work beautifully - the wire hits the steel, the arc strikes and instant bacon sizzle, sounds good, feels good, looks good, NO spatter.

Then comes the other 40%, this time the wire hits the steel, arcs, burns back, hits the steel, bounces off (you can feel the torch jump), then arcs and finally settles down, LOTS of spatter - blobs flying everywhere.

I did a short video as I thought the feed was stalling ----

Then i gave up, I don't think i can debug this on my own, needs more hands/eyes etc. I don't know if its WF stalling/failing, PSU not settling properly or something else.

In the video you can hear the good and bad, the LAST one is the worst and the arc never really stabilised.

 

[Davek0974]

You could probably go ahead and reduce your voltage to around 19 and that may improve things more

See second post first....

 

[Hood]

Are your work lead/clamp/dinse plug all in good condition? If you do not have a good connection it would do that.

 

[Davek0974]

Hi Hood, long time....

Yes, all checked, on these tests i even clamped directly to the steel and not the bench.

 

[Dave H2]

I would wonder about a dry joint somewhere on the circuit board, random intermittent issues are usually caused that way. might even be the torch cable given you have changed the earth lead connections.

 

[Davek0974]

I think the little in-feed liner tells a tale - you can see it bobbing up and down where i'm pretty certain it should just bob once as the feed starts???

Maybe WF is on way out?

 

[Davek0974]

I would wonder about a dry joint somewhere on the circuit board, random intermittent issues are usually caused that way. might even be the torch cable given you have changed the earth lead connections.

Its possible i guess, the torch cable checks ok with a meter but thats not under a 150A load so not a good test really, i'll do some more tomorrow, maybe mark the WF roller with a white mark so you can see if its steady. Could be the WF relay maybe or motor i guess.

If i can find a way, i'll fix the iPhone inside the helmet and do a video through the weld lens so you can see what i see

 

[Hood]

I think the little in-feed liner tells a tale - you can see it bobbing up and down where i'm pretty certain it should just bob once as the feed starts???

Maybe WF is on way out?

I did notice that but I wonder if it is because the wire strikes but doesn't arc so the wire doesn't feed properly?

You could maybe do a test by firstly running the wire and letting it come out the torch into the air. Next would be to do the same but this time have the wire feed against the floor or whatever so that it simulates the wire not arcing.
The results of that may tell you something.

 

[Davek0974]

feed it against the bench and it just spools out, no visible issue. Jam it flat-on and it would probably birds-nest at the rolls, not tried that though. Holding the reel shows its not slipping as well, the feed roll is pretty tight, not too tight but does not slip.

V-roller is new.

Maybe the power is not coming on instantly with the trigger?

One thing i do know is, when the arc starts properly and the power comes in smoothly, its like music to the ears - just so different, smooth crisp bacon sizzle. Totally different than the spattery jumpy noisy mess when it goes wrong.

Trouble is a lot of my welds are short so a bumpy start could bugger half the weld length and cover the work in spatter.

 

[Hood]

Well if it was me I would give it a go and see.
You have already done the first test and it feeds fine, with no jumping of the feed tube I presume?
Second test if it also feeds fine when it dunts against the bench/floor/whatever and the feed tube again is fine then that would suggest it is a machine issue.
What exactly that issue would be is hard to say, it could be lack of power to the wire, it could also be that the wire feed gets interrupted on occasions when the arc starts thus giving the erratic feed. I think your only option would be to send it in for R-Tech to look at.

I could sell you an R-Tech MTS255S which works beautifully, then again only ever used the mig side of it with a spool gun so......

 

[Davek0974]

I'll do some more poking tomorrow, re-do the feed/stall checks and go over the leads/plugs again.

If it gets nowhere it'll have to go back for service, possibly get it fixed then sell it, I'm sure i'm not the only one who loses faith in something when it goes wrong.

Seems the best replacements are the Lincoln 215 or the Esab Rebel 215 - both seem to have great reviews.

 

[Hood]

If wanting to do Alu which is not too thick then I would seriously think about an EWM PicoMig Pulse. Might have to go slightly beyond your 2K budget though.
I bought a second hand EWM 330 Phoenix and it is great. I have welded down to 1mm Alu with it where as previously with a standard Mig I shied away from under 4mm and wouldn't even consider under 3mm.

I have seen people welding thin Alu with Mig but they are using dip transfer rather than spray and it is a spattery way of welding Alu. For my line of work I can not tolerate the spatter, not because it makes a mess of the work piece, as in reality it doesn't, but because the spatter goes everywhere and it can make a mess of things beside where I am welding (GRP on the boats etc)

 

[Davek0974]

Thats a nice box Hood, its going way beyond budget though i think, add on a torch and work lead as they don't come with, and i'm nearly at £3k ! Probably would be the last welder i buy though as it does appear pretty tasty, maybe too good for what i need though?

This is harder than buying a car, so much to choose. The esab has what a appears to be a pretty cool sMig feature plus all controls as usual, the Lincoln 215 multi hast dual gas lines/vales for (presumably) steel and stainless or steel and alu without messing with hoses, then you throw in the Rolls Royce Ewm with more functions than i could ever use