Help fitting universal wire feed assembly with euro torch

[robche]

Hi all! I'm uprating my Cebora Pocket Turbo 130 to Euro gun and replacing the wire feed assembly. The thing seems to fit together OK and seems decent quality but I have a couple of questions and wondered if anyone had any pics of one of these fitted?

Q1) I assume the DC motor can be wired in either polarity to get the correct direction?

Q2) The only real mounting holes are on the base of the unit without any through-chassis bolt holes. Best to make a shelf/bracket for it?

Q3) Anyone know what the two little plastic tabs are for? They fit into either side of the bottom bolt holes so I'm thinking they're for cable management?

I plan on doing some photos of the build so I'll keep you posted!
Cheers in advance
Rob

 

[eddie49]

Q1. Yes, the DC motor can be wired either way to run the wire in the correct direction.
Q2. The holes in the base are for mounting the wirefeed assembly, you probably will need to fabricate a bracket.
Now the important bit:
Q3. The MIG wire, the drive roller, the brass Euro socket and the entire wirefeed assembly including the motor body will be "live" - i.e. at positive welding power voltage! As opposed to the original plastic unit, this matters when you have invested in a good-quality all-metal wirefeed assembly. So the entire unit will have to be isolated from the metal casing of the welder. That is what the shouldered plastic tabs are for - to insulate the mounting bolts. The threaded part of the brass Euro socket will also need clearance at the front panel.

[ On all welders, both the positive and the negative of the DC welding output are fully-floating - i.e. isolated from the case of the welder and from AC mains earth. Thus the "Earth" cable and clamp is not , it is the work return lead.]

 

[a111r]

If you use the just two plastic insulator pieces to separate the feeder from a made up metal bracket, I don't think it will work using metal fasteners.
Maybe plastic or nylon ones, such as reg. plates use?

 

[eddie49]

Each piece of plastic forms two shouldered washers, the larger bit underneath the diecast frame and the smaller one on top, under the nut or the bolt head. The flat plastic "strap" wraps around the edge of the alloy frame.

 

[a111r]

Of course!
For some reason, (stupidity?) I was thinking that there were four mounting holes and the two pieces were simply insulating spacers.

 

[a111r]

Similar isolation shown here:

 

[robche]

Amazing, all really helpful - thanks!

@eddie49 I assumed they didn't share an earth but the whole circuit being 'floating' is a great description, that makes perfect sense. Thanks! So while the trigger is pulled is there a potential for a shock from the housing... or would I need the earth clipped to my toe?

@a111r Thanks, is that yours? More pics if it is

 

[robche]

@eddie49 The threaded connector fits into the plastic housing in the last pic so it will be isolated.

 

[a111r]

@a111r Thanks, is that yours? More pics if it is

No it's not mine.
I searched on Ebay for (£500 to £250) generic inverter MIGs until I found the best image of the feeder mounting, as most seem to use those feeders.
You won't get a shock in use, unless you're wet, and even so it won't be a harmful one.
Hope it works out well for you.

 

[robche]

Thanks @a111r - I'll post pics of the install (and a picture of one of my welds if you're really unlucky!)

 

[mike 109444]

Once you have installed the unit BEFORE powering on meter (set on ohms) between the feed assembly and the machine chassis you are looking for an open circuit (NOT low resistance) between them !

 

[robche]

@mike 109444 I was going to just do that on continuity, will looking at ohms give me a more precise reading?

 

[robche]

Hi all... I have all my parts and I've started the strip down. All looks possible but I have a question...

On the Cebora there are only 2 wires coming from the torch assembly... a single trigger wire and the main feed. To operate the wire-feed the circuit is completed by the trigger connecting the main feed cable to the trigger wire. I've tested this on the bench.

My new assembly has a terminal on the brass body (which I assume is for the main feed cable) but also has two trigger wires, red and black.

My solution was to join the red to the old trigger wire from the welder and the black wire would go to the same terminal as the feed cable.

Does this sound correct?

 

[a111r]

Yes that's right, the trigger connects the two wires to feed DC welding voltage to the PCB.

So one torch wire goes to the PCB (via your old wire) and the other torch wire is connected to the rectifier +ve (as is the thicker cable to the Euro socket)

 

[robche]

Here's my latest progress... Still need to make the filler panels

But - I have a question about gas below the video...

I assume I now need a gas solenoid when using a Euro torch? I'm happy to fit one but need to know how to power it so any suggestions welcome.

Here's the general layout:

And here I can find the voltage changing... (sorry, wrong setting on MM)

Can I use these connections? I can't see any low voltage connections... any ideas? Cheers!

Thanks for your help so far, nearly there!!
Rob

 

[Hutcho]

I’d use a 240v one and then use the contactor as the power source

 

[a111r]

Best way is a 240 Vac valve, wired off the contactor's mains input.

Haha!

 

[robche]

Cheers both!

So are my leads in the right place to take a feed then? I'm not entirely sure which part the contactor is, sorry!

Rob

 

[a111r]

Next to the rectifier, hr0910 Fantini Cosmi

 

[robche]

Great, thanks @a111r - I'll do some probing of those connections