Semi-Automatic Welding Cell

[Brad93]

I've received yet another enquiry for hardfacing of a large surface area to very close tolerances.

The last job i passed on to a contact with the understanding that I either carry out the labour or get a commission. A month down the line, customer reported that the job was underway, and nothing from the contact I passed the job onto. Sneaky sods.

Anyway, I now need to build a welding cell to carry out straight line welding, to do this in house.

Now, one way would be to go to Welding Alloys in France and purchase a motorised H-frame. Unfortunately these are a bit cost prohibitive, as they're about 17k plus VAT for even the most basic unit, which would not allow traverse across the part. An actual cell like this is north of £30k.

https://www.welding-alloys.com/wp-content/uploads/2022/12/1752_H-Frame-Machine_French.pdf

If the surface area was smaller i might get away with this, but at £1200, still expensive for a small unit.

Gullco Motoried Slides X & Y Accessories

For Sale - Used Gullco Motoried Slides X & Y Accessories . Available Today | Worldwide Delivery

www.westermans.com

Now, what can i buy in the way of modular rails with steppers and ideally racks. The welding alloys frame profile looks like the attached image. They're not machine tool accurate but more than accurate for welding work. The welding carriage runs along these beams on v-rollers.

Need to stay away from ballscrews unless they're seriously enclosed due to dust generation and spatter.

 

[Brad93]

Budget £2000
Needs to be stout enough to take 380A radiant heat.

 

[Brad93]

The welding alloys design is very simple but incredibly robust and ideally suited to welding environments

 

[Maker]

If I'm understanding this right, it sounds an awful lot like a plasma table, but with a welding torch?

 

[Brad93]

If I'm understanding this right, it sounds an awful lot like a plasma table, but with a welding torch?

Yes, however a plasma table, unless you have koike or esab etc, will not stand up to the abuse.

Imagine an open arc cored wire, 2.8mm in diameter. Stabbing at the part your welding, with a fair few Nm of force, at 380-420A which generates a lot of radiant heat, making tonnes and tonnes of fume and dust, plus globules of spatter up to 1/8' in diameter.

Also, i need to be able to get parts under the welding torch up to 1.5m in diameter/thickness. So a plasma table on stilts, would be a better explanation.

 

[hotponyshoes]

If you find the rest of the bits I've got some of the parvlux dc motors for it...

 

[Brad93]

Here are some setups with such equipment. You can see the height required.

This is 1.6 ton roll on 5 ton positioner


This is 200kg roll on a 250kg positioner!

 

[Brad93]

On rotators you only need two linear axis, the third axis is the rotator.

To do flat cladding you need three linear axis.

 

[Brad93]

The job i passed on was a 5 ton roll.

 

[Brad93]

120kg of weld metal went onto this roll.

 

[Maker]

To do flat cladding you need three linear axis.

How does the motion control work? Is it just the X axis moves at 500mm/min (Or whatever feedrate) until it reaches the end of the part, then it steps a few mm over in Y and goes back the other way, or is it cleverer than that? How do you program a ready made machine?

 

[Brad93]

How does the motion control work? Is it just the X axis moves at 500mm/min (Or whatever feedrate) until it reaches the end of the part, then it steps a few mm over in Y and goes back the other way, or is it cleverer than that? How do you program a ready made machine?

Yep, so the systems I'm used to are very basic digital. Welding alloys now have a fully digital system with GUI (likes to go wrong).

You program the length of travel in say the x-axis, the feedrate in mm/min, then you program stepover distance in the y-axis. You can also program the z axis to step up or down, when the y-axis steps over (this is useful for inclines or curves).

You can also set oscillation for doing weaves etc.

Wirefeeder is controlled via the pendant, so you set your wirefeed there, the pendant also controls the contactor in the welding power source. Water cooling, gas, rotator, etc can all be controlled from the pendant.

Believe me, if i had £30k id buy the welding alloys system. The problem is this work is profitable, if your overheads are low. Don't need a 30k bit of kit costing you on a job with large wire cost. You can google the cost of a 15kg spool of hardfacing wire. The 300kg drums are getting on for a few thousand pounds.

 

[hotponyshoes]

If its only for facing flat sheet you could make something up so you slide the y axis to the size of the sheet you want, put the limit switch on it so it triggers the x to reverse when hit.
Then a mechanical arrangement to drive the y across each time x hits the end.

I'd think something like that could all be controlled without cnc/complex electronics easily enough

 

[Maker]

If its only for facing flat sheet you could make something up so you slide the y axis to the size of the sheet you want, put the limit switch on it so it triggers the x to reverse when hit.
Then a mechanical arrangement to drive the y across each time x hits the end.

I'd think something like that could all be controlled without cnc/complex electronics easily enough

That's a bit like what I was going to suggest, like an automatic surface grinder where you set stops to limit the travel in one axis and it shuttles back and fourth at some prescribed feedrate and stepover.

A more versatile idea (And perhaps actually easier to implement) might be to buy a CNC control board and generate G code to run the machine as if it were a very big mill facing a part. That way it doesn't need a complete re-design when something other than just a straight sided, solid rectangle needs hardfacing.

 

[Erie Fred]

Competitor to Gullco is Bug-0, have you looked at them ?"

Mechanized Welding Systems | Track, Trackless, Weave & Circle

Bug-O Systems manufactures high-quality mechanized welding equipment. Our systems include track, trackless, weave & circle welding applications.

bugo.com

How about Jetline ? (Looks like Miller bought them):

https://www.millerwelds.com/products/automation-solutions/jetline-fixed-automation

Panjdiris :

Pandjiris Side Beams and Carriages - Pandjiris Inc.

Pandjiris® offers three sizes of sidebeam carriages of welded steel construction and two precision built side beam track for heavy duty applications. .

pandjiris.com

Koike Aronson:

Welding Positioners - Koike Aronson, Inc.

www.koike.com

Hopefully glean some details off each one to make your own hybrid.
Too bad they aren't running sub-arc, the radiated heat would not be such a problem.

 

[voipio]

Out of interest, how much warp does hardfacing generate in flat sheets?

 

[Brad93]

Out of interest, how much warp does hardfacing generate in flat sheets?

enough that you have to roll the sheet into a cylinder over a water cooled drum

 

[Brad93]

Competitor to Gullco is Bug-0, have you looked at them ?"

Mechanized Welding Systems | Track, Trackless, Weave & Circle

Bug-O Systems manufactures high-quality mechanized welding equipment. Our systems include track, trackless, weave & circle welding applications.

bugo.com

How about Jetline ? (Looks like Miller bought them):

https://www.millerwelds.com/products/automation-solutions/jetline-fixed-automation

Panjdiris :

Pandjiris Side Beams and Carriages - Pandjiris Inc.

Pandjiris® offers three sizes of sidebeam carriages of welded steel construction and two precision built side beam track for heavy duty applications. .

pandjiris.com

Koike Aronson:

Welding Positioners - Koike Aronson, Inc.

www.koike.com

Hopefully glean some details off each one to make your own hybrid.
Too bad they aren't running sub-arc, the radiated heat would not be such a problem.

Problem is all of those are two axis.

 

[Robotstar5]

Pick up a used welding robot & positioner?

This is closing up a cylinder on a 1600kg positioner

Or if it's just welding round, torch moved in to position with a pneumatic cylinder

and a simple belt driven rotator

 

[Agroshield]

Problem is all of those are two axis.

I am curious about the Z-axis for flat plate. Does that move when the welding is taking place? Or is it used only once at the beginning to set the correct torch height? Could you get away with a manual control in this direction? Or, if the Z needs to move at the end of the run, use a limit switch on the X to trigger the Z movement rather than a 3-axis controller.

As an alternative to rack and pinion, would a fixed chain and moving sprocket work?

On the big one with the green rotary, if you set the angle of the rotary so the surface to be welded was parallel to the travel of the torch, you might get away with just one linear axis. For a curved surface, you could use a template and a follower to control the Z-axis.