Robot welding twin wires arcing off each other

[happylarry]

Hi all, it seems ive a job coming up where i have to keep maximum stick out on one of our robot cells...its twin wire 1.2 mm ..plate is 50 mm v butt ...problem is the wires are arcing off each other...the helix and cast of the wire is good..the robot manufacturers cant seem to solve this problem... for me....has anybody come accross it ...the way the plates are cut i have to sit twin torch on top of plate ...dont think i can get tips any longer than i have ...maybe introduce slave after master us an option...tks

 

[seriesonewelder]

@Robotstar5 needed here

 

[Robotstar5]

Just a few questions, are both torches mounted on a single robot arm, do they share the same welding power source and what make is the power source?.

 

[happylarry]

Yes @Robotstar5 they are on a single arm.. with interchangeable torches ...single and twin torch....the power source is fronius ...there are 2 power sources .master power source and slave...the power and parameters are controlled via igm teaching pendant...any help would be great tks

 

[Robotstar5]

It's been a few years since I did any robot welding but normally you light the master/lead torch first to establish the weld pool then light the slave/trail torch to provide filler, are you saying when you light the master torch it is arcing over to the slave instead of the workpiece?.

A quick google found an example of twin torch welding for those that haven't heard of it

 

[happylarry]

They light at the same time,and when the stick out is 2 inches approx ..they arc off each other...i get what your saying about lighting one after the other ....i must get talking to igm ...the only way we can control wire feed is by arc length correction ...not ideal ...tks for the help

 

[Robotstar5]

2 inches!, never seen anything like that, I've normally worked on 10 - 15mm, your shielding gas usage must be quite high as well to guarantee coverage that far away.

 

[Richard.]

2” stick out doesn’t sound right at all.
Gas coverage aside you must have some serious current drop and wire wonder which would explain the arcing together.
I’d be reducing that as a first port of call.

 

[Wozzaaah]

2" stickout would just result in a mess of burnt bits of wire sat on the workpiece, surely?

 

[Richard.]

2" stickout would just result in a mess of burnt bits of wire sat on the workpiece, surely?

With a good bit of voltage you’d get it to stabilise but it certainly wouldn’t be great.
You’d need a lot of wire to compensate for the current drop and a lot of voltage to cope with that wire. It’s just not good and almost certainly a player in the initial problem

 

[happylarry]

I shouod have said contact tip to work distance is approx 50 mm...not stick out...stick out is about 12 mm..tips are very close to flush with nozzle

 

[Wozzaaah]

That gives you approx 38mm arc length??!!

 

[Richard.]

contact tip to work distance is approx 50 mm..

Hi Larry.
Where I come from mate that’s stick out. Distance between tip and job

 

[TechnicAl]

I cant visualise how you know they are arcing across......they wont arc until earthed and when they do they are supposed to form one weld pool....is the exposed wire 50mm long or 12mm long? there seems to be some confusion

 

[happylarry]

Ok due to the job the job this is necessary ..as in stick out...but the wires get very poor contact and basically arc off and cause a very poor plasma...we have to have a long stick out for the camera to see...tks for all help...igm cant come up with a solution and they sold it to us...