Boxer 195 overrun

[Richard.]

hey up Cebora experts
I bought a mig off a member on here a little while back. Wonderful tool and I was very aware of this issue on the day I bought it and I can live with it easy enough. However if someone can help me eliminate this little niggle I’d be very happy. The wire feed motor over runs slightly when the trigger is released. We are talking a fraction of a second and it’s difficult to see unless you weld. However when you release the trigger welding that over run causes the wire to stick in the pool every time
I have to move the torch away on release. So is the motor brake knackered? Is there a doobrifurkle thingamewhatsit that I need to look at. Anyone else experienced and hopefully fixed the same issue.
Cheers gents.
Lamen terms please mind. I can get lost when you start talking complex circuit bits.

 

[rtbcomp]

You need a relay to short the motor out when you release the trigger, thus providing dynamic braking. Something like this:



RLA could be powered from the existing relay and the motor power from the two wires already going to the motor. Really need to see the circuit.

 

[Richard.]

You need a relay to short the motor out when you release the trigger, thus providing dynamic braking. Something like this:

View attachment 144287

RLA could be powered from the existing relay and the motor power from the two wires already going to the motor. Really need to see the circuit.

Gonna be a little while before I can show you the circuit mate. Traveling a lot but your description is very helpful.
Chances are a relay is on its way out.

 

[Richard.]

You need a relay to short the motor out when you release the trigger, thus providing dynamic braking. Something like this:

View attachment 144287

RLA could be powered from the existing relay and the motor power from the two wires already going to the motor. Really need to see the circuit.

Got a chance to whip off cover and see the board. Haven’t time to remove it but there is only one 24v dc relay on the board.

 

[Richard.]

Could this be the suspect

 

[rtbcomp]

I don't think there's a suspect as such, seems more like a design issue. What you could try is increasing the tension on the wire spool (usually a large nut/knob in the middle of the spool) ever so slightly. Don't over do it as this could put strain on the feed motor.

 

[Richard.]

I don't think there's a suspect as such, seems more like a design issue. What you could try is increasing the tension on the wire spool (usually a large nut/knob in the middle of the spool) ever so slightly. Don't over do it as this could put strain on the feed motor.

I’ll try it mate.
It is quite free running

 

[Richard.]

Ok I’ve given it a little nip. Still seems to over shoot by an inch of wire but we shall see what it does when welding.
It’s not really a problem to be fair as I know how to overcome the wire sticking by simply raising the torch away on trigger release but it would be nice to get it to behave properly.

 

[Richard.]

Yeah it’s no different unfortunately . Never heard of Cebora owners mentioning this problem before. Must be a fault on it surely

 

[bwservices]

Did you check the function of the clear finder relay?looking at it pulling and releasing the trigger

 

[Richard.]

Did you check the function of the clear finder relay?looking at it pulling and releasing the trigger

No I haven’t done that
Cheers I’ll have a look this evening and report findings. What would you expect that relay to do up on release of trigger?

 

[roofman]

I used to have this problem on a welder i once owned, plus the torch head was live until it grounded out with a small flash...used to really annoy me Richard all the running on after trigger released...Anyway i found using small reels and screwing down the rollers half a turn stopped the inertia a tad and it helped no end

 

[mike 109444]

The relay MAY be being used to short the motor to brake it. As yours does not seam to be braking, just running down then IF it is using the relay for braking then it could be that the normally closed (ones touching when no power is applied/trigger NOT pressed) contacts are pitted/dirty and could be cleaned.
It is possible that some of the circuitry on the pcb is used for braking and that could have failed. It may only use a resistor and the relay to short the motor and resistor could be duff.
If you look at the two pics below you can see that they short the motor when the relay is relaxed (no power applied/trigger released)

 

[Richard.]

I used to have this problem on a welder i once owned, plus the torch head was live until it grounded out with a small flash...used to really annoy me Richard all the running on after trigger released...Anyway i found using small reels and screwing down the rollers half a turn stopped the inertia a tad and it helped no end

Cheers roof man. Unfortunately my problem won’t be resolved with those tweaks. I’m using 5kg spools and got the rollers well nipped up. It’s over shooting as if there is no brake on the motor.

 

[Richard.]

Relay is opening and closing when the trigger is operational and released.
I dunno how good the contact points are.

 

[roofman]

Cheers roof man. Unfortunately my problem won’t be resolved with those tweaks. I’m using 5kg spools and got the rollers well nipped up. It’s over shooting as if there is no brake on the motor.

Ahhh gotcha...i know it sounds daft but is the spring on the trigger holding back a bit

 

[mike 109444]

Could be that the normally closed contacts are not even connected ! Would need to see the underside of pcb and an indication of which pins on the multi way plug the two wires from/to the motor go to.
You could also pull one of the wires off the motor and meter between the now free wire and the one still on the motor. Meter set to Ohms, lowest setting and you would like to see a dead short (with machine unplugged !!) If you get a very high or open then if there is braking via relay/circutry then it's no worky worky

 

[mike 109444]

ps try your meter leads both ways round and you should get same reading UNLESS there is a diode across the motor on the pcb (there to stop back EMF).

 

[Richard.]

ps try your meter leads both ways round and you should get same reading UNLESS there is a diode across the motor on the pcb (there to stop back EMF).

I can do this.
Report back tomorrow cheers mike