Overfeeding wire

[Johnseat]

I've got a cebora boxer 195.
My issue is the wire constantly over spools or over feeds when I let go of the trigger.
Instead of it finishing nice and short, it constantly finishes at least 20mm too long so I have to cut the end back.
My machine doesn't have an option for how much run on after letting go of the trigger.

Anyone have any tips on how to stop this.

Cheers.

 

[rtbcomp]

You could add a relay to the motor circuit such that it shorts the motor out when the trigger is released.

 

[the snooper]

You could add a relay to the motor circuit such that it shorts the motor out when the trigger is released.

a very simple circuit to do the above, shown power off and braking the motor

 

[rtbcomp]

^^ Make sure the relay will work over the full range of motor supply voltages, ie speed settings. If you can feed the relay after the trigger but before the speed control all the better. The coil of the contactor would be a good place.

 

[the snooper]

^^ Make sure the relay will work over the full range of motor supply voltages, ie speed settings. If you can feed the relay after the trigger but before the speed control all the better. The coil of the contactor would be a good place.

even better and more reliable power source

 

[Johnseat]

That machine should really have a motor brake already...

Where would the motor brake be?

I'm happy to mod the machine and add a relay, any instructions on how to do this, any pictures to help point me?

 

[TechnicAl]

snip it off
personally I like it that way........you can cut it back to 20mm or so perfect for the next start

 

[Johnseat]

Personally I find it annoying as I have to have a pair of snips close by.
I'll have a look into the relay side of repairing this issue.

 

[roofman]

has your wire reel spindle got a friction brake on it...tighten to stop a full reel of wire rolling on plus tighten the feed roller a very slight tad,this can make things better with regards to wire still feeding after release of torch trigger.

 

[mike 109444]

Does your pcb look like this one ?

 

[mike 109444]

And this is where the pics came from! http://www.mig-welding.co.uk/forum/threads/cobra-boxer-problems-help-please.51266/
Note original poster did not return !!! So don't know if it was a fix and fly........

 

[Johnseat]

I'll have a look on Saturday as I'm away till then.
Ilk give the spindle a tighten and check the feed rollers tension.

I'll also take a picture on Saturday and post up here.

 

[Johnseat]

On a side note, could anyone recommend me a new liner please.
I've got a 3 meter torch.

 

[TechnicAl]

Personally I find it annoying as I have to have a pair of snips close by.
I'll have a look into the relay side of repairing this issue.

every MIG welder has a pair of snips in his pocket

 

[Kram]

Relay on PCB could be sticking and easy to replace.

its a DC motor and they can be reversed by swapping polarity, which is often quite a useful thing and easy to wire up. DPDT switch, centre pins go to motor and the supply wires at each end.

http://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=DPDT&_sacat=0

 

[rtbcomp]

^^ To be pedantic, you can only reverse a permanent magnet DC motor this way, if it has field coils you reverse either the armature or the field coils.

 

[Kram]

Or turn it by hand

 

[Appyasme1]

Looking at top right hand of the PCB it looks like there is a braking transistor.The photo is not that clear.We have a lot of problems with the dymamic break on our wire feeders.Try replacing it or you could check the transistor if you have an Avo.Iit could be your over spin problem.Please advise,thro the forum we will sort it!

 

[Appyasme1]

Sorry I should have said check the Transistor,not replace it