Me or the machine

[addjunkie]

welded the other day, it wasnt the pretiest weld (dont do much these days) but welded and penetrated 5 mm box section no issue. Machine is an oxford 270-1

Today no matter where I set the machine, it seems to have less juice than it should, weld sitting on top of the metal, sounds awful, wire burning back and stuck to 3 tips in about 5 minutes. Tried various settings, in the approx area I used the other day adjusting both the volts and wire speed, to no avail. Wire feed seems smooth tension about right.

Also while I was changing tips, noticed with out the trigger pulled there was a bit of leccy left in the torch, ie when I touched the wire on the bench with out the trigger pulled there was a spark.

Any suggestions, all feed back greatfully received.

Off to the pub to mull it over!

 

[frank horton]

as for the residual elec, quite normal......
u say the wire feed is smooth but is it fast enough.......can u adjust the speed and see the difference........?

 

[w124]

welded the other day, it wasnt the pretiest weld (dont do much these days) but welded and penetrated 5 mm box section no issue. Machine is an oxford 270-1

Today no matter where I set the machine, it seems to have less juice than it should, weld sitting on top of the metal

this is probably the same issue i had last year, but dont know the answer what was the cause.
a 500A unit was set at 31V
here are the results...

one day later it welded like it should

 

[henry Kadzielski]

^^^ it needed a day off

 

[Hitch]

Is it a 3ph machine, or single phase?

 

[addjunkie]

Single

 

[w124]

^^^ it needed a day off

from what i remember we had same problems with tig, i mean it required outrageous amount of amperage for lets say welding 2mm aluminium

 

[Hitch]

Single

That's my idea of being a phase down for some reason out then.

 

[addjunkie]

That's my idea of being a phase down for some reason out then.

Been busy with other things, but we had a power cut today or emergency mauntenance, made me wonder, if our supply voltage has been down or fouctuating?

 

[addjunkie]

Right an update, had a bit of time today, had a play and had the Mrs adjust wire speed whike I was welding.
So with machine set on position 14 of 16 ( 20 -270 amp machine, so logically in laymans terms roughly 15 ish amps per step, so 14 of 16 would be (20-270)x14/16=218 amps) now I know it works on volts, and wire speed etc, but thats my simplistic view. I was welding 5mm box, clean and earth clamp about 5 cm from the torch also on clean steel. And no matter what I did, weld stayed ontop of the steel at no point could I get it to fully penetrate. Though with wire speed right up at 9 it was spraying and laid a nice bead, but no penetration.
Before all this after speaking to tech arc I adjusted the burn back timer a tad, and it seems to have fettled the burn back melted tip scenario.
Liner is like new and correct for the wire size, new tip. Wire not corroded. Now at roughly 30 amps per mil Id have expected to lay good beads at 150 /160 amps, Im starting to wonder if my machine isn't delivering the output it should be, supply voltage is spot on 240, so cant blame living in the sticks at the end of the supply line.

Are there any tests I can do to measure the voltage etc being supplied to the torch, and if so what gear do I need. My only other option is go borrow my son in laws torch, to eliminate mine. This is the first time I ever used it on higher settings, now according to advertising his machine is supposed to do 10mm steel. I know the manufactures claims are opomistic but surley it should handle 5mm.

Still like the machine and its simplicity, but getting a bit frustrated by it, to the point Im about to have a warrenty trip to york. Today it crissed my mind thed fitted the wrong transformer?

Help

 

[Rig Pig]

Right an update, had a bit of time today, had a play and had the Mrs adjust wire speed whike I was welding.
So with machine set on position 14 of 16 ( 20 -270 amp machine, so logically in laymans terms roughly 15 ish amps per step, so 14 of 16 would be (20-270)x14/16=218 amps) now I know it works on volts, and wire speed etc, but thats my simplistic view. I was welding 5mm box, clean and earth clamp about 5 cm from the torch also on clean steel. And no matter what I did, weld stayed ontop of the steel at no point could I get it to fully penetrate. Though with wire speed right up at 9 it was spraying and laid a nice bead, but no penetration.
Before all this after speaking to tech arc I adjusted the burn back timer a tad, and it seems to have fettled the burn back melted tip scenario.
Liner is like new and correct for the wire size, new tip. Wire not corroded. Now at roughly 30 amps per mil Id have expected to lay good beads at 150 /160 amps, Im starting to wonder if my machine isn't delivering the output it should be, supply voltage is spot on 240, so cant blame living in the sticks at the end of the supply line.

Are there any tests I can do to measure the voltage etc being supplied to the torch, and if so what gear do I need. My only other option is go borrow my son in laws torch, to eliminate mine. This is the first time I ever used it on higher settings, now according to advertising his machine is supposed to do 10mm steel. I know the manufactures claims are opomistic but surley it should handle 5mm.

Still like the machine and its simplicity, but getting a bit frustrated by it, to the point Im about to have a warrenty trip to york. Today it crissed my mind thed fitted the wrong transformer?

Help

Sounds like my machine when the capacitors died, also check the diodes.

 

[addjunkie]

So different torch, made no difference, so in the morning Im off to screwfix to buy a clamp meter, and see if it is actually delivering the right voltages and approx amps.

Then regardless of results I shall end up in the pub, to partake in the 70s sitcom type gentlmens club.

 

[addjunkie]

Well, took the grandson back, along with his fathers mig torch, and borrowed a clamp meter.
Came home to do some more investigating.
So with multimeter measuring voltage, between the earth clamp and the power connection to the torch, set wire speed in the middle 5. And welded at each setting, the volts were in 16 steps between 14v and 27.2 during welding, with a max of 34 with the trigger pulled but not welding. Unfortunatley within 5 seconds the clamp meter was found to only read AC amps.
With 1 mm wire clean 5 mm steel no matter where I set the machine I cannot get the weld to penetrate fully. See picture full bore wire speed right up too, did try at full power with wire rates between 7.5 and 15.6 m per minute.
None of my test welds have fused toes and all apear to just sit on top of the steel. No sign on the back other than colour. I have tried various bits of steel too, supplied by different firms at different times.

In short I cant find anything wrong but at full power my 270 amp machine wont fully penetrate 5 mm steel. And what Im makeing needs to be right as it will be exposed to load.

What do I try next, according to miller I should be at 180 amps in dip 21/22 v and 210 amps 24 volts in spray. Between 5 and 10 m per min wire. Thats roughly as they are imperial etc.

 

[Al Strachan]

You say you have 240v, but is that under load? Maybe check ac volts under load. You could also check ac current under load and work out with the dc voltage?

 

[addjunkie]

You say you have 240v, but is that under load? Maybe check ac volts under load. You could also check ac current under load and work out with the dc voltage?

Explain how I would do this. My 240 v was at a look low load on the front jb og a phase convertor I use in the same plug I use the welder. My tig also works fine from the same socket!

 

[Al Strachan]

Work our power in watts from the ac side then Divide that watts with the voltage from the dc side to give you current.

There will be losses in the welder fans, wire feed etc (can be measured on their own and subtracted later) and the unit is self where you could maybe lob off 10%-20% for losses, but maybe you are looking for a much more accurate current measurement.

It was more of a suggestion for just monitoring the incoming supply under load, but if you are 100 percent certain, just ignore my ramblings

 

[octo0072000]

daft question is it in din plugs for earth wire if so remake the din plug lead on the earth cable into the machine
i have known that cause problems with high resistance before

 

[addjunkie]

Work our power in watts from the ac side then Divide that watts with the voltage from the dc side to give you current.

There will be losses in the welder fans, wire feed etc (can be measured on their own and subtracted later) and the unit is self where you could maybe lob off 10%-20% for losses, but maybe you are looking for a much more accurate current measurement.

It was more of a suggestion for just monitoring the incoming supply under load, but if you are 100 percent certain, just ignore my ramblings

Ill stick the clamp meter on the input side, see what its doing, not sure if there is an easy ish way to get the volts on the supply, but will have a look see.

If there is a volt drop on the input underload, would that not consequently reduce the volts at the torch, as its a simple transformer machine?

daft question is it in din plugs for earth wire if so remake the din plug lead on the earth cable into the machine
i have known that cause problems with high resistance before

I shall look at this too.

Im starting to wonder if its just me, not used to using mig at higher currents, with 1 mm wire. Always used 0.8 in the past.

 

[addjunkie]

So the mystery is solved, after a morning knocking 3/4 of my barn wall down and clearing up, I departed to my shed and left the builders to rebuilding.
Last month we went on holiday, our house sitter used my gear to weld up his van outside, and guess what he used gasless wire, put everything back except the two bloomin leads + and -

So swapped them and back to normal I can weld again!

I am a muppet....check the basics before looking for more complex issues.

 

[henry Kadzielski]

^^^ You are not 'Robinson Cruso' we've all done something like that before