The mods that made my topmig 150 actually rather good

[skotl]

Been meaning to say thanks to the various people who have helped me convert a £50 knackered old topmig 150 to a really pretty decent welder.

Here's (from memory, but with some links) the mods I've made. I would probably have spent less if I'd bought a used (or possibly new!) Clarke but I now know my SIP inside out so I wouldn't swap the experience!

Before I go any farther, take a bow all mig-welding forum members! Without the people on here, I'd have given up after a week and taken up woodworking

1. Moved the wire feed off of the welding transformer and onto a permanent 240V switch mode power supply, as here
2. Bought a steel liner and torch repair kit for around £30 from weldequip
3. Threw the bell-wire earth strap in the bin and replaced it with a 300A 6M cable and clamp off ebay for, I recall, around £10
4. Fitted a brace across the wire-feed mechanism, as here
5. Replaced the 1K wire speed pot with a 100 ohm pot, which gives far more wire speed control. Discussed halfway down here

And it runs great! OK, it seems a lot of faffing around, but I have no idea how my lawnmower works but I now have an intimate knowledge of how my welder works

Thanks, all!

 

[rtbcomp]

Thanks for your feedback.

 

[123hotchef]

great list I have done 3 and 4 might brave 1 and 5 next

 

[rikrobson]

Why did you not do a euro torch conversion?
Did you put a dinse connector for the earth lead?

 

[cumbriasteve]

I am a bit like that, will battle for ages to beat a lost cause with some old machinery and often fail but it's a fantastic feeling when it works out.

I had a damaged item recently, hunted down a similar part that was never going to fit in a million years but after some head scratching, a big hammer and some very accurate milling (well a round file actually), some home made spacers and a couple of prayers and it works as good as it would have when new.

Her indoors spoiled the moment by not allowing me to display it in the living room for all to see and allowing me to boast to visitors

 

[123hotchef]

Why did you not do a euro torch conversion?
Did you put a dinse connector for the earth lead?

didn't want to spend any money on it! nope no dinse connectors either, I will probably not bother with 1 after reading more but the trim pot adjustment or replacement seems easy enough

 

[skotl]

didn't want to spend any money on it! nope no dinse connectors either,...

Ditto - I probably spent around £50 on the mods and, to be honest, the torch was never an issue for me (being a rank amateur).

Same thing with the earth lead - the new lead was 100 times better and, if I still had the machine and the lead gave up (presumably in ten years) I'd just do the same and buy another one and plumb it straight in.

Having said all that, I have subsequently sold the SIP and bought a substantially more expensive R-Tech

 

[skotl]

... I will probably not bother with 1 after reading more but the trim pot adjustment or replacement seems easy enough

Have to say that, after fixing the torch, the transformer upgrade made the most significant difference - pretty scary experience, tho...

 

[123hotchef]

i dont use it enough really to warrant spending any kind of money on it

 

[The_Yellow_Ardvark]

I have a Top MIG 140, biggest thing wrong I found was were Halfords store them for a long time was a thick oily substance on the drum spindle and wire spindle and wheels.

When I contacted SIP about an issue I had, Halfords refused to accept it was fault, turns out my machine was 15 mouths old (based on the serial number) SIP swooped out my machine.

Another one I have found in the past is the 2 self tappers what hold the no driven wire guide. They can bottom out in there holes, so never tighten up.
See the attached image.

 

[123hotchef]

i did clean the wheels up and did the mod with the angle brackets to keep the lower wheeltrue,


the wire speed does seem to slow down as the arc is struck and the wire is flowing

 

[The_Yellow_Ardvark]

@123hotchef
2 Extra checks.
The wire feed motor bearings dry out, a drop or 2 of a light oil helps a lot.

Oddly as well. I noticed when I was welding the cooling fan would slow down in time to the wire speed and welding going wonky.
Striped it down. no lubrication on the bearings . Ok the smallest amount. Clean and lubricate and it was OK.

 

[123hotchef]

thanks mr ardvark ill take a look at the weekend not looked at the fan yet well i have not taken the side off at all to be honest cooling fan is a bit noisy, are the wire feed bearings under the rollers

 

[The_Yellow_Ardvark]

@123hotchef
1 Degrease the 2 wire feed wheels.
Then soak the motor driven one in oil along with the bearing in the fixed wheel holder.
See Below.

The wire feed motor is accessible by removing the assembly and there it is.

When doing the fan, make and remake all the elec. connections, Some of the Lucas style female spades are famously for being loose, any that are re place.

 

[123hotchef]

i did clean the 2 wire feed reels with brake cleanner when i did the bracket mod a few weeks ago
mine is slightly different to that

good shout on the spade connectors too

 

[Swift&Bold]

I've got a sip 130 languishing about if you want it for spares?

 

[the snooper]

Ditto - I probably spent around £50 on the mods and, to be honest, the torch was never an issue for me (being a rank amateur).

Same thing with the earth lead - the new lead was 100 times better and, if I still had the machine and the lead gave up (presumably in ten years) I'd just do the same and buy another one and plumb it straight in.

Having said all that, I have subsequently sold the SIP and bought a substantially more expensive R-Tech

do you think an earth lead made any difference ? the reason i ask is the power supply feed cable to the torch isnt as thick as the original earth lead, so if the earth lead wasnt upto the job then the cable to the torch certainly wont be

 

[skotl]

...the wire speed does seem to slow down as the arc is struck and the wire is flowing

That's what fitting a dedicated wire motor transformer fixes.

 

[skotl]

do you think an earth lead made any difference ? the reason i ask is the power supply feed cable to the torch isnt as thick as the original earth lead, so if the earth lead wasnt upto the job then the cable to the torch certainly wont be

Aha - I know you meant it in semi-jest, but this is actually a very good point.

If I had replaced it because I thought "Hmmm... that doesn't seem very manly - I must away to ebay and buy a ship's anchor chain!" then no, I doubt it would have made any difference.

But, in my case, the original earth lead was well and truly rubbered. In fact, if it had been made of actual rubber, it would probably have been more conductive than the rusted, de-stranded, over-pinched, piece of wirewool dental floss that I took off

 

[123hotchef]

I've got a sip 130 languishing about if you want it for spares?

I may take you up on that one day thanks.