Help - changing pinch rollers.

Hi all

Firstly - thanks to everyone here for a great newsgroup!

Can anyone tell me how to change the drive roller on my "new" welder?

I bought it without a manual :(, it's an Oxford MIG300.

This is a pic of the drive mechanism:

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is a pic of the drive roller:
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I guess the pin sticking out of the drive spindle is something to do with it but it does not seem to want to push in or pull out easily, it looks like a previous owner has been hitting it with a hammer.

Thanks Chris

Did you hear about the weldor, the lawyer and the pilot in an airplane?

The pilot comes back and says "The plane's going to crash and there's only two parachutes", he puts on a parachute and jumps out the door.

The lawyer is about to talk the weldor into letting him have the second parachute when the weldor says "It's OK you have the second 'chute". Amazed the lawyer says "That's so kind, what will you do?".

"No problem" says the weldor, "I'll grab my welding cables, there're bound to snag on something on the way down"

Reply to
Chris Glen-Smith
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If it behaves like an old Hobart I fought with you will have to take two screwdrivers and slip them behind the drive roll. It should slide off the hub. It definitely looks like the thing was abused. Check to see if the drive shaft is bent by watching it as it turns when you pull the gun trigger. Randy

Reply to
Randy Zimmerman

Hi

Thanks, it does look like it ought to simply slide off, apart from the keyway there are no locking grooves or anything on the inside of the second roller.

There's no gap behind the roller, I did try gently to create one with a chisel but no joy. I assume the pin on the end of the shaft is something to do with it, what else can it be? Maybe a bit of rust has locked it on, I'll try penitratig oil and gentle heat next.

I don't think the shaft is bent, the abuse is on the end of the pin, it would bend way before the shaft.

How is the roller held on other large mig weldors, (do I mean weldor or welder? me confused! again!) friction?

Cheers Chris

Randy Zimmerman wrote:

Reply to
Chris Glen-Smith

A weldor is a person; a welder is a machine. Both person and weldor have an "o" as the next to last letter. I don't own a MIG machine, so I can offer no help with that question.

Reply to
Ecnerwal

This looks just like the assembly on my Eland 160 MIG. The small shaft in my case has a knob screwed onto it which holds the drive roller in place. Once removed the drive roller can be pulled off quite easily. The

2 grooves are for different wire sizes and you just turn the roller around as appr> Hi all
Reply to
David Billington

Hi David, thanks for the input!

I've got the pin out - threaded into the end of the shaft with a left hand thread. I think there is a bit missing similar to yours, there's no sign of a thread but there is a couple of grooves on the end of the pin and there must have been some sort of clip that snapped on and held the roller. I can fix a nut or sumint on the end of the pin and fit a spring and big washer to hold the roller.

I've budged the roller - looks like some animal glued it on!

I have the second roller thats hand engraved as being for 1.2 & 1.6 mm wire, it came fitted with .8 mm wire using the larger groove on the glued on roller - I'm not sure which roller to use if I get 1 mm wire, probably does not matter too much.

Cheers Chris

David Bill> This looks just like the assembly on my Eland 160 MIG. The small shaft

Reply to
Chris Glen-Smith

Doughnut shaped rols are quite common. I think we have a couple of old hobarts that still have keyways to transfer the torque. In some cases the rolls are held in by three screws, on others I have seen large circlips. We have some Lincolns that are recent and they just snap on and off the shafts making it very fast. You can get a set of rollers for every single wire type but in the practical world everyone violates the rules. I even ran .023 wire on my .035 rolls rather than go to the trouble of replacing. Randy

Reply to
Randy Zimmerman

Reply to
Chris Glen-Smith

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