Author Topic: MIG Welder Feed Roller Groove Shape ?  (Read 407 times)

Offline awemawson

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MIG Welder Feed Roller Groove Shape ?
« on: December 08, 2018, 03:58:52 PM »
The feed roller on my Migatronic KDX-250 is worn to the point that the feed is erratic, and my welding is even worse than usual.

As I'm having a bit of a problem sourcing a new one (email sent to Migatronic but no replay as yet) I'm thinking of skimming the feed roller and cutting a new groove - but what shape?.

Now the current one is very rounded, but I thought that round grooves were just for aluminium wire not steel ?

If the consensus is Vee as I suspect, then I will use a small 60 degree threading insert as the steel is pretty hard.

Of course if someone has a Migatronic 0.8 (or 0.6) mm feed roller in their pocket I'd like to hear from you !

Andrew Mawson
East Sussex

Offline chipenter

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #1 on: December 08, 2018, 04:56:57 PM »
My Clark has a knurled groove bet a vee would work as it will only cost a little time .
Jeff

Offline b4dyc

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #2 on: December 08, 2018, 05:58:01 PM »
IIRC My welder has a vee groove in it, but had/has a different type for using with my emergency gasless rolls that has a knurled groove. Not seen that for years though  :Doh:
I didn`t do it...

Offline PekkaNF

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #3 on: December 08, 2018, 06:28:44 PM »
There was some science to it....can't remember exactly, but I think for normal solid steel wire V-grove is the way to go. There were some complications with tubular wire and aluminium wire.

Those looks expensive:
https://www.ikh.fi/en/w-drive-roll-v-axle-0-6-0-8-m25610184
https://www.ikh.fi/en/w-drive-roll-v-axle-0-8-1-0-m25610185

Pekka

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Offline awemawson

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #5 on: December 09, 2018, 07:16:23 AM »
Yes that's the one, but their 'shop' doesn't know it  :bang:

I registered with them the other day when I found that on the web, but it looks like it exists in one part of their site but not the other. So far emails haven't been answered  :(

Andrew Mawson
East Sussex

Offline chipenter

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #6 on: December 09, 2018, 08:09:22 AM »
Does the wire come out of the torch easily ? I had a problem with spider webs on the wire and compacting at the torch , as the drilled finished in a cone it griped the wire and concertinaed the wire occasionally .
Jeff

Offline awemawson

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #7 on: December 09, 2018, 09:00:06 AM »
Yes Jeff no blockages at the torch end, liner is clear, but the groove in the feed roller is shot, and is almost as deep as the wire is thick.

Since I've had this welder, which is a good few years, I've been unable to remove the grooved roller - it should be held on by a washer and knurled screw which are missing (replacements made this morning) and then just pull off the 10 mm gearbox shaft but it was rusted / jammed solid.

Yesterday I made up a puller and got it moving slightly but it was very difficult with the wire feed in situ, so I took the entire unit out so that I could work on the bench with better access and visibility. It's now all cleaned up and back in the machine as I can now remove the feed roller at will.

If Migatronics or their agents don't come up trumps I'll convert it to rollers from another maker. So long as the rolls are approximately the same diameter (35.2 mm about) and the bore is 10 mm I'm sure I can sort out the connection issue, as there are two small flats on the 10 mm shaft that engage in that odd shape on the gear, and it will just need a suitable / similar bit fixing on the replacement.

I tried a file on the original roller this morning - very hard but I'm sure carbide inserts would cope. But as the groove is now so deep I think it's a close run thing if skimmed that the gears won't bottom out before the wire is pinched.

Andrew Mawson
East Sussex

Offline Pete.

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #8 on: December 09, 2018, 09:49:38 AM »
Drayton welding does Migatronic's repairs Andrew. Perhaps they can supply a roller.

https://www.draytonwelding.co.uk/contact-us

Offline WeldingRod

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #9 on: December 09, 2018, 10:15:41 AM »
When I was doing this for a, um, skunkworks project, I used a double gothic arch configuration.  It had the good angles feature of the V, but lower wire stresses.
Tricky to make.  I was doing it for huge wire, so not too bad.

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Offline awemawson

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #10 on: December 09, 2018, 10:30:49 AM »
Thanks Pete, I'll give them a call on Monday  :thumbup:
Andrew Mawson
East Sussex

Offline awemawson

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #11 on: December 10, 2018, 05:33:51 AM »
I received two emails from Migatronic in Denmark this morning:

The first one said that as I wasn't a "B2B" customer (what ever that is!) that I couldn't use their 'Webshop' and sent a link to their dealer network map.

The second was a bit more helpful, said that they did have both the feed and pressure rollers in stock, and giving the number of their UK Parts Sales Manager in the Midlands. Ringing the (UK) number I ended up speaking to Denmark anyway  :bang:

After a bit of chasing through the system the result is good - two rollers on the way to me by courier expected Thursday - not cheap but the welder doesn't owe me anything having given good service for many years - I got it second hand about eight years ago, but it was made in 1995 so 23 years old.
« Last Edit: December 10, 2018, 03:46:35 PM by awemawson »
Andrew Mawson
East Sussex

Offline tom osselton

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #12 on: December 10, 2018, 01:34:46 PM »
Sounds like business to business.

Offline awemawson

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Re: MIG Welder Feed Roller Groove Shape ?
« Reply #13 on: December 14, 2018, 05:32:35 AM »
New feed rollers arrived late yesterday, so this morning I popped them in. They frankly don't look that much different however I laid a few test beads this morning, and the low wire speed erratic feeding and burn back problem seems to be a thing of the past  :thumbup:

So hopefully that's another old friend returned to the working list, mind you, it was cold in the welding shop this morning - (about -1 deg C or so) or so, and the bearings on one of the internal fans were rather croaky - they are both what looks like a 'standard'  230 volt boxer fan as might be found in many a computer cabinet a few years back, so I probably have some tucked away somewhere.
Andrew Mawson
East Sussex