Questions about questions; topmig 150

[skotl]

Hi all

been lurking for a while, did an oxy & mig course at a local college late last year and just splurged all of £50 on a SIP topmig 150.
I've read all the warnings against SIPs on here but the guy showed me it sparking up and did a couple of lines with it, so I reckon it's a bit of a bargain.

The wire that has come with it is rusty and it's defo seen way better days, so I'm going to spend a bit of money on replacing the liner, getting a new spool, doing the brace mod and the power supply mod.

So my question is about the best way to ask questions I've taking a bunch of pics and would like to ask your kind opinions on a variety of topics (the regulator, wire feed, motor, PCB, etc). Would I be better to have a single big thread with all of the pics and questions around each, or create a separate thread per question?

And is the SIP section the best place to post (it's all equipment-specific) rather than the general newbie section?

I already owe thanks to the folks on this forum as I've learned a ton from you all, already.
Cheers
Scott

 

[Paul.]

Welcome to the forum, as you have already started this thread in the correct forum just put your questions about the SIP in here, that way all your replies will be together

 

[skotl]

Thanks, Paul. Aiming to have a serious R&D session tomorrow so I'll post my many questions here, after that!

 

[skotl]

OK - got my pictures and questions ready!

So, this is my SIP topmig 150, bought for £50, including a large bottle of Argon/Co2 (which I know I'll end up having to ditch when it runs out). Everything is a little rusty so I've removed the first few layers of rusty wire from the spool and sparked it up and there's some mixed news.

It does spark and, when the motor runs, it managed to lay down a half decent seam. There are two obvious problems, however; 1) the earth lead has had an extension added and all the connections (welder, mid and clamp) are horribly crusty and 2) no surprise, the wire feed is awful. Slow to get going (if at all), pauses and stutters and irregular speed.

So my next steps are;

1. Replace the earth cable and strap
2. Add the bolster mod to the wire feed
3. Add a switched-mode PSU for the wire feed, as per BillJ's mod
4. Get a new wire spool and liner

I wasn't planning to fit the new liner and wire spool till I'd sorted out the PSU as I presume I'll just be burning through crap wire till I get that sorted.

So, I have a few questions, if you don't mind. First one is to ask whether you think the above plan of attack is reasonable, and have any comments or additional suggestions?

Some more specific questions;
1. From the badges in the pics, can anyone put an approximate age on the unit?
2. I have a laptop PSU which is 20v at 4A - I'm guessing the voltage will be a little low, right?
3. How useful do you think it is to have a switch-mode PSU rather than a wire-wound transformer?
4. If you look at the last pic, compared to other SIPs, I think I'm missing a gland or grommet on the case - essential to replace?
5. The regulator does not have a gauge - is this normal - does the reg look ok to you?
6. Really dumb question - which bit in the bottle/reg picture is the regulator? In other words, when I need to remove the bottle, which parts do I separate?

Appreciate any insight I've been a lurker here for a while and I'm looking forward to getting stuck in.
Ironically, assuming that I get the wire feed sorted I think there are definite benefits to buying a SIP - having only owned it for four days I know way more about its workings (thanks to this place!) than if I'd bought a dare-I-say-it completely working unit!
And if I can get a 150A MIG up and running for south of £80 then that seems a good deal.

Thanks
Scott