Migmate on go slow..

[Spiyda]

I have a Migmate 130 which has had a wire feed brace fitted and a separate supply for the wire feed roller (using a toroidal transformer, just to be different).. both of which improved the machine considerably..

The current problem is that the wire feed slows down after maybe 10 seconds welding...

0.8 wire, on about 5 metres/minute on top voltage.. CO2 from a pub bottle

Anyone any thoughts on what might be the problem ?

Logic says it might be heat related, but I can't feel any hot spots / loose connections etc.

The motor runs at the right speed when freewheeling (eg not driving wire)

btw hiya Mininut

 

[Sean]

plastic liner?

dirty swan neck liner, they fill with plastic from the liner which then melts and sticks the wire.
Sean

 

[Spiyda]

plastic liner?

dirty swan neck liner, they fill with plastic from the liner which then melts and sticks the wire.
Sean

Its certainly still got a plastic liner.. chnaged about 5Kg of wire ago..
(before I heard of curtain wire :-) )

I'll swap it for a curtain wire tomorrow and clean out the swan neck..
any tips on cleaning it ? solvent? heat until the dirt turns to carbon ?

 

[BillJ]

Knackered tip? That would give problems once it heated up.

 

[Sean]

Its certainly still got a plastic liner.. chnaged about 5Kg of wire ago..
(before I heard of curtain wire :-) )

I'll swap it for a curtain wire tomorrow and clean out the swan neck..
any tips on cleaning it ? solvent? heat until the dirt turns to carbon ?

buy a new one.....its a thin wound wire liner with a cone at one end. I tried curtain wire once i found the wire i had was too soft and kinked and bent at too tight a radius and just caused problems. Weldquip will sort you out or MMart has them on the shelf if you cant wait a day for the postie.

a new set of liners wont cost much more than a tenner and makes it silky smooth.

Sean

 

[Spiyda]

buy a new one.....its a thin wound wire liner with a cone at one end. I tried curtain wire once i found the wire i had was too soft and kinked and bent at too tight a radius and just caused problems. Weldquip will sort you out or MMart has them on the shelf if you cant wait a day for the postie.

a new set of liners wont cost much more than a tenner and makes it silky smooth.

Sean

cheers Sean,

new liners ordered, and also the bits to try the mosfet motor brake.

I'll post how I get on.

and Bill, the tip was new, and I also drilled one out to see if this was the sticking point..

Chris

 

[Spiyda]

Good stuff !

the new liners cured the 10 second problem..
the swan neck had no liner in at all from new..

the new swan neck liner (clarke part No 8132185) fitted almost perfectly (I had to take a couple of turns off the tapered end of it for the main liner thread to bite)

The main liner (clarke part No 8132175) fitted nicely once I'd modified the swan neck liner.

I also completed made a modification to the motor drive using a capacitor and Mosfet http://www.mig-welding.co.uk/forum/showthread.php?t=9206&page=3 .. my version of the circuit works fine and seems to increase the torque of the motor without increasing the run-on

Bluekoop did say he guessed the wiring, and after a bit of head scratching I had to modify the circuit to make it work as per the thread, but the motor now feels much more stable.

I had already fitted a seperate power supply for the motor using a toroidal transformer and already added a brace to the drive wheel moulding..

after all that, I can now only blame my welding skills

thanks to everyone who contributes to these forums...