SIP / Cosmo Mods

[malcolm]

Probably best to post some photos of the circuit board and where you have connected the wires to the transformer. Take them from the power into the welder and the wire feed will be always on.

The wires will need to come from some point after the contactor on the circuit board (ultimately the inupt to the first transformer).

 

[BlaydonBodger]

Will stick some photos on tomorrow.

It dawned on me that this top bit that I thought had been snapped off was dangling on the end of a wire inside the case somewhere.

Well I went for another look and its not, but as I looked I saw on the top left side of the pcb what appered to be the snapped off bit. It is mounted on the pcb and two white wires lead off from this and go to a relay type thing that is mounted on the center partition under the wire feed.

This relay thing makes a loud click when you fire the torch up. I get the feeling this is where I need to be making a connection... but where and how?

 

[BlaydonBodger]

Here's the Photos

Here's a shot from the back.




Here's one from the side.



Obviously the piggyback is on the wrong terminal. This is the only difference I can see to the way other machines in this post are wired.

and here's one of the relay thing.



There are white wires leading from the connector on the top left of the pcb to this and there is a wire to it from the middle power selection switch.

 

[malcolm]

I think they've changed the circuit board without telling us.

For the input wires to the transformer you are on the right track - connect one to the wire that goes between that relay and the middle power selection switch. The other wire I would guess to the lower of the two connection blocks (marked R in your photo). If that doesn't work try the one marked S (don't know if the contactor is fed from live or neutral on that board).

 

[BlaydonBodger]

Thanks Malcolm,

I will try the middle power selector first thing tomorrow. When I had the piggyback on the "S" terminal the feed ran all the time.

Fingers crossed

 

[BlaydonBodger]

Well I couldn't wait- I have just hooked to the middle power selector switch and it works.

Big thanks Malcolm.

 

[oneeyeguy]

will this work on a sip 80

 

[Paul-n]

The trim pot ?

Hi all

Yes fell for the Cosmo150 is a great welder and now trying to graft a silk purse from a sows ear ! such is life.

I have done some gas in the past [ like 20 years ago ! ] but this MIG is new to me and I have yet to lay a bead ! with the pigging thing !

I will be mostly building bikes with it so 40mm x 40mm x 1.5mm box section and smaller is the stuff I want to glue together with it.

I have added the strap and awaiting Maplins delivering the transformer but I am a bit puzzled by the trim pot.

it is mentioned twice in this thread :-

Hairyone says he adjusted his down to 3volt

Bump seems to say he adjusted his to cope with the change from 20 volts to 24 volts ?

So do I have to adjust it at all ? and if so what am I looking of ?

regards paul

 

[hairyone]

Hairyone says he adjusted his down to 3volt

Bump seems to say he adjusted his to cope with the change from 20 volts to 24 volts ?

So do I have to adjust it at all ? and if so what am I looking of ?

regards paul

Paul,

before I switched over to the new transformer I took voltage readings from the power to the wire feed at the min and max settings. Then after the switch over i then adjusted the trim pot to mimic those settings (i.e, to give the same range of wire feed speeds as there were before). I ended up adjusting the voltage range down as I think on max I was getting a little more than 24V and not wishing to apply too much voltage to the motor (I think someone mentioned that the motor is a 20V unit) I ended turning it down a little more which resulted in a Min voltage of 3V.

Now that I think about it, with the original set-up the range of wire-feed voltages would have varied with each power setting, so the readings I took in the "before" state may not have been very useful since the min-max range should have varied at each power setting.

Essentially what I was trying to achieve was a good range of feed speeds from slow to fast without sending too many volts to the motor on the max feed setting (which is what Mr Bump was saying ... I think).

 

[Paul-n]

Hairyone

Makes sense now thanks , will trim to get 20 volts from it.

regards Paul

 

[Paul-n]

Hi there

Nearly done !

I used 3 holes that are under the wire feed and covered with the sticky label that has the warning about feeding the wire from the bottom.

I fastened the Bridge to the righthand one and put my bridge output wires through the lefthand hole.

Like someone said earlier you can cut off the 2 wires that need connecting to the output of the Bridge and just feed them through the hole mentioned above and fit spades and connect to the bridge.

The mains cable I fed through the grommet with everything else.

Tested without the wire tension on and found that I get way more than 24 volts and could not turn down the trim pot enough to reduce the motor feed to 20v when the front speed control was at max ?

When my front wire speed controller is at 3:00 o'clock [ full power being about 5:00 o'clock ] I am at 20 volts , should I really only measure when I am feeding wire ?

Otherwise thanks to this thread it all went like a dream.

regards Paul

 

[zequ]

Will this work for a fleaBay 90 amp flux welder?

http://cgi.ebay.com/DC-Motor-Speed-...71393QQcmdZViewItemQQ_trksidZp1742.m153.l1262

and this?

http://cgi.ebay.com/Power-transform...ryZ43375QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Thanks

 

[furry1]

Hi All, Just want to say a big thanks to this forum and this thread! I got a dreaded sip 130 - off ebay cheap, and it was just crap. Found this site, wished I'd found it earlier and got something better.. After reading all the excellent ideas to improve the thing I changed the liner, still crap but the wire came out the end now! The drive motor speed changed like crazy all the time, if you liked gobby welds (as some garages famously seem happy with!) it was fine, but not good enough for me.. Took the bait and did the wirefeed transformer mod - used a 50va transformer with 2x 9v secondaries, giving 18v at a little over 2a, which I guessed would be OK seeing the rather puny motor it was driving. Got a rather over specced bridge too, all off ebay. Total of £12 all delivered. Wired it up with reference to the excellent pics, though I managed to squeeze it all in amongst the gubbins already on the electrics side. Pressed the button, seemed to work. Today did the first necessary job - exhaust bracket on my motorbike, 2mm steel. Quickly got smooth welds like the tutorials on this site.. So happy - it was never possible as it was before, but it's now a usable bit of kit! Can't get over the improvement. Thanks again!!

 

[Scraggydog64]

Can't stop the wire feed on my SIP 150

Hello all,

Hopefully someone out there can help me. I've fitted a separate transformer and bridge rectifier for the wire feed on my SIP 150 as shown on Bump's thread. When I switch it on the wire feed motor runs continually.

I spoke to Blaydonbodger who lives nearby but the circuit board on his welder is differnet to mine. My 150 has the same circuit board as Bump's.

There is no problem with the 240v side. The -24v is connected to the negative on the wire feed motor the +24v was connected onto the incoming side of lowest black wire that is on the connector just above the trim pot. IE so the new transformer / rectifier are suppling onto the connector.

Any ideas as to what I've done wrong? Any help would be much appreciated.

Thanks in advance.


Scraggydog

 

[Sean]

Just did the transformer mod for my Sip105 again what a differance! altho nearly cooked the transformer by wiring it up wrong

Output on the Maplins is 0 24 0 24..link the 0 to 0 and the 24 to 24 before soldering on the output +ve from the 24 on the left and the -ve on the 0 from the right, and DOUBLE CHECK which spades are to be linked to which on the bridge or the smoke leaks out

On my PCB the black wire from the multi plug links/piggybacks to the lucar on the pcb between the two sets of plugs( single red wire on Bumps photo), this was snipped as close to the single spade as possible leaving the lone wire to the pcb in place, a new connector was crimped on to the now short black lead from the multi pin.

Everything works fine there was even space to get all the gubbins in the trabsformer side of the welder which is good as i use the wire side as storage bin for spare tips and shrouds and cutters etc not happy having all that rolling round in proximity to 240v

Thanks to all of you that have contributed

Sean

 

[HANCYM]

Just wondering... can anyone tell me if it's be possible to use either one of these instead as they are nice a compact
http://www.tlc-direct.co.uk/Products/LTYT250.html
http://www.lightinstyle.co.uk/default.aspx?act=Uprod_C16_S214_P2122

 

[maddog7]

1st Post

Hi all,
Noob here
Been lurking about gleaning info for a while. I have a SIP 150 I got new from B&Q a couple of years back. When I first got it we could get some good results. It's not been used for a while and when I came back to it I could not weld for toffee.

A friend of mine said he'd seen some mods for SIP wire feeds on some forum somewhere (here of course) and off I went looking for solutions.

I take no credit for any of the following mods (except perhaps the motor run in thing ???) . All credit to those who took the time and trouble to share the info.

I was gonna do (and might still do) the transformer thing. The reason I posted my findings in this thread is that folks might want to try this instead of or as well as the transformer mod.

I did try cleaning the liner and bracing the pinch rollers.
This helped a little, but I have to say I stripped and rebuilt the gearbox and re-greased it with very light clear grease as per instructions from dave21478.

I also noticed that the brushes on the motor were only contacting the commutator on the edges (as they do when brand new) I used a trick I know to artificially accelerate the wear process and bed the brushes against the comm. (just dunk in a glass of tap water while connected to a 12v battery for a few minutes until worn in, being careful not to leave too long or there'll be nothing left of them) Spray with motor cleaner and leave to evaporate.

Re-assembled the lot, and tested. Sure enough, brilliant. Considering how easy it was to do the results are amazing. Very consistant motor feed.

Below I'll post some pics of my efforts after the job, now as you'll see, I'm no expert welder but I think the welds look OK? looking at the inside of the tube, it looks like there is good "PENO" (hehe new word for me, makes me chuckle just a little!!)

I'd welcome any feedback from those of you actually know what to do! regarding what I could do better.

Cheers and thanks again.
D

 

[malcolm]

Welcome maddog. Looks like it's working from the photos. I've found the wire liner change to make a lot of difference - the other mods can compensate for that which isn't always a good thing.

Do you think the motor mod made more difference than the gearbox and extra clamp?

Also how did you bed in the brushes again? Did you take the wire feed assembly off the machine and power the motor up with external 12V with the end dipped underwater - or is there more or less to it than that?

 

[maddog7]

Thanks Malcom,
I've now decided to "go the whole hog" and mod everything that's relatively inexpensive to do.

I'll replace the liner with a steel one and I've already bought the bits for the transformer mod. (Can't hurt can it )

quote: "Do you think the motor mod made more difference than the gearbox and extra clamp?"

I honestly dont know, I did the motor and gearbox at the same time which I think made much more of a difference than the clamp. The factory grease was still quite gloopy, the stuff I put in (from model car ball diffs) seems to kinda go runny like a thick oil after a while but still lubes completely.

The brush thing, I removed the motor from the gearbox, connected it to a 12v lead acid, and then completely submersed the motor in a glass of tap water. It took about 5 minutes for mine, but I have seen brushes completely dissappear in around 2 minutes so be careful.
My thinking was that if the contact area on the comm was small and all the current goes through such a small contact patch the arcing on the comm could cause erratic running.

I hit it with motor spray to remove any residual water, then gently warmed it with a heat gun to evaporate the solvent.

Might have a go at the transformer tonight!!

Cheers D

 

[dirtytorque]

Hello.

Well I bought a SIP T130P and so I am tyring to make the most of if.

Ok so I have got this old hifi amp knocking around.
It has a ac power rating of 160 W so should be about 160 VA.
It seems to have two secondary windings.
Between earth and each winding I get about 35 volts.
Will the trim pot be able to reduce the PD enough for the SIP control board do you think or is this unit just too juicy ?

I also have found the smaller unit seen in the second picture.
It also has two secondarys,10 volts each.However I am not sure on the power rating on this unit.Can find any info on the machine it came from to help me out in this respect so i am worry the smoke will escape from it.
Saying that the drive motor for the wire feed is tiny..

Neither that suitable?
Thnks in advance