SIP 105DP Problem

[Wookster]

Hi, I know there are topics on modifying the wire feed, I'd just like a little help diagnosing the problem/testing stuff and then a parts supplier.

From cold the wire will feed normally for about 1.5m and then stops and starts.
I've stripped and cleaned the gearbox and nothing obviously wrong so stuck a voltmeter on the motor.
Voltage at first is around 14v but when the wire feed hesitates increases to around 16v, then back to 14v.

Impossible to do more than a spot weld before the problem starts so need to fix it. I'm Ok at soldering so can replace parts etc but I don't have a clue which ones.

Can anyone advise please.

Cheers

Wookster

 

[rtbcomp]

If the voltage increases when the wire hesitates it sounds like a bad connection within the motor (most likely commutator or brushes).

If it was a mechanical problem (increased load stalling the motor) the current drain would increase, thus dropping the voltage.

 

[Wookster]

Thanks for the info, just checked SIP and a new motor is £52.06 that seems outrageous.
Don't suppose you know of an alternative.

 

[rtbcomp]

I think for an extra £30 you could get a Eurotorch conversion and feed motor combined, have a look on Ebay. Whether it's worth spending that kind of money on a SIP is debatable.

 

[Sean]

there is a SIP for sale which is only usefull for spares on this forum

Ive looked for other motors and if you were to take the motor out an go to a model car shop im sure they could match it

i tried for months to get an upgrade motor for it but as the first cog is a press fit on the tiny shaft thats the limiting factor, plenty motors out there just none any bigger with the same shaft diameter.

always worth flicking all the switches on a sip before using it and make sure the myriad of lucar terminals are all tight.

 

[Wookster]

Thanks for the replies guys, eurotorch option sounds interesting if it comes with the wire feed mechanism. This assumes that it is the motor not the board.

I've used a big cebora mig and I know there's no comparison but the eurotorch is the only feature I miss for car bodywork, got used to the sip I guess over the last 20 years.

My cousin has kindly posted the motor out of his sip so I can swap it out and see if it cures the problem. Reckon I can probably sweat the gear off so might be able to source another motor.

If it's not the motor then I'll pull the circuit board, anyone know which part is the guilty one to replace or is this covered in the upgrade topic.

Shipping is the issue with s/h stuff, motor and circuit board are both £50ish so it doesn't leave much for the welder. Changed the swan neck & liner recently so don't need those spares etc.

Keep looking in the sale section for an upgrade with a eurotorch, going to have to spend decent money eventually. Shipping is less of an issue then.

Cheers

Wookster

 

[rtbcomp]

A windscreen motor might do the trick.

You'll have to remove the crank though, otherwise it'll just pull the wire in and out all day, although you probably wouldn't notice the difference with a SIP

 

[Wookster]

Shhhh, don't upset my little toy. I only thought about an upgrade and look what's happened.

 

[Wookster]

Motor arrived in't post so fitted it this evening, problem diagnosed.
Thanks to everyone for their help, "new" motor is drawing around 13v steady regardless of load and welds are back to normal.

Going to take the old motor apart this evening out of curiosity, if its brushes I'll buy something close and adapt them. If successful will provide full details, and offer a repair option hopefully for under £10 inc postage.

Enquired about the SIP 130 for sale, sounds promising unless someone collects in the near future.

Thanks again

Wookster