Cebora 130 pocket turbo, dodgy feed + no arc

[stickycreambun]

Hello. Story is, I bought myself this welder several years ago in apparently GWO. I have finally got round to be able to try and recomission it now. Maybe I was working ****-backwards, but anyway - Ive changed the liner, tip and shroud, and fit a new reel of wire (0.7kg reel, 0.8 wire). Turning the machine on, it seems to power up fine, fan comes on fine. Then the first issue is the feed seems to be really noisy, grating sort of sound. And seems very weak, even on full speed. Then second problem, good earth on a piece of scrap, but no arc at all.
I'm not really sure what or where I could look at next? Any ideas appreciated, cheers.

 

[rikrobson]

Wire feed.

Its basically a low voltage motor on a gear box. if its noisy it could be the gearbox that has gone. There are available from ebay and I think weldequip. You can manually turn the drive roller. it will require some torque to move it though. shpuld just hear the whirr of the gears and momentum will carry on turning it. If it's noisy or clicky or won't turn its may be ********. if the gears are ok then check the motor. Its 24 or 48 volts iirc and is driven from the small circuit board. The motor/gearbox is whirry not grating. A best guess without 1st hand look would be the gears

as for no arc, check the contactor. Its on the earth side of the circuit after the choke. you should hear this clunking in when the trigger is pressed. if not check the actuator's feed voltage is correct (230v) there is a relay on the pcb operated by the trigger circuit which feeds the 230v to the contactor.

Wiring Diagram

 

[stickycreambun]

Thanks for the info. Been poking around just now, and better than I first thought. I cut down the reel tensioning spring which seems to have helped, then took the motor off and roller out. Greased the bearing and it is a bit better. However very jerky. I also have got it to arc! So have just about laid a few very crap welds, but not connected the gas yet and jerky feed made it utterly rubbish, plus it seems to skip about over the place. Is it a question of the arc either works or it doesnt, which would leave me just the wire feed to try and sort out? Thanks.

 

[rikrobson]

did you change the swan neck liner in the torch or the long liner in the torch feed? Does the wire move freely in the torch?

The Arc either works or not fairly simple. another thing to check is the tension on the rollers and make sure the wire feeds up the liner smoothly. If there is not enough tension on the roller the wire will stick, but to much and they do bird's nest. Get the wire running smoothly first. test with the torch lead straight.

Does the motor/feed run smoothly without the wire?

 

[stickycreambun]

I changed the long liner, I looked at the swan neck and it seemed fine. The wire does move freely enough from the tip down to the roller. It seems and looks like the actual motor, looking at the roller as it feeds it is very jerky as if it is stuck or something. The welds I managed also make me think this as they are almost like rows of blobs of welds.


Edit: I was half expecting to need to do some messing around, does anyone have any idea if the feed motor is available to buy new or second hand? As I have a feeling this could be the main issue. Hunted around but cant find one myself.

 

[Robotstar5]

I was half expecting to need to do some messing around, does anyone have any idea if the feed motor is available to buy new or second hand? As I have a feeling this could be the main issue. Hunted around but cant find one myself.

Try contacting Weldequip (at top of page) he may be able to help?

 

[rikrobson]

Lindsey Welding Supply Co Ltd also used to do them in ebay but none at the moment.

 

[stickycreambun]

Soo, I came in from work and had a bit more of a prod around. Running the motor unconnected to the gears it sounds much less grating, just whirry EXCEPT it seems to have a jerky action. I mean, holding it rather than it just being smooth it seems to stick part way round, if that makes any sense. It is a bit erratic too I think, almost like a bad connection but I looked these over in the torch and they seem ok. Also, the noise made seems much louder when the motor is connected back into the gearbox (I take it this is the black plastic cover over the gears, that drives the wire feed roller?). I did try greasing the rollers in the bearing the feed roller sits in but doesnt seem to have helped much. I'll see if weldequip have anything, just got the new liner and reg from them. Cheers.

 

[Sean]

When i hd that welder the torch trigger really gave problems - the switch has small hard contacts that crap up and burn use some emmery paper or a points file to clean them up. as for the rest of it seemed to work fine.

 

[stickycreambun]

Can I just check we are talking about the brass block in the torch, with the brass switch?

 

[mike 109444]

If the motor when disconnected from the gear box is jerky (it will jerk due to torque as it starts but should run smooth once going) will run fast as it then geared down to run feed roller. You should not grease the feed roller or it's pressure roller (the free running one)
If the motor on it's own is jerky then could be the brushes sticking / build up of carbon dust. Locate the brushes and lightly tap the end of the motor where they are located. This will loosen up the dust and you can then blow it out using compressed air (watch out for the dust cos it's messy!) Could even be worn brushes but unlikely as the motor has probable not done that much work. I work on these type of motors quite regularly (24v dc geared motors 20 odd per machine!)

 

[Sean]

yep there are contacts in there - the other thing was that the feed roller is a bearing race It was a cheap un shielded one and it suffered condensation and rust - i replaced it with a shielded, its just a stock ball race. measure it and order off one of the on line supplies

 

[mike 109444]

Just so long as you keep the grease off the face of the bearing and the drive roller (one with groove on it) clean with some spirit if unsure. You might find that the grease in the gear box has dried out and would benefit from being cleaned out and a fresh lot put in. If you do split the gear box then be aware there may be some thin shims/washers on the ends of some of the gear shafts that will stick to the grease as you take it apart. Take pics before removing any gears so you know how they all go back in !

 

[stickycreambun]

ok great thanks guys, think I'll take the motor in to work tomorrow to blow it out with air, and then am I understanding correctly that the bearing I can just replace with a new one that is the correct size for the roller? Thanks.

 

[Sean]

you can check the roller - open the tension device and see if the idler spins smooth if its got any grittyness then change