Semi-Automatic Welding Cell

[Brad93]

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.

The problem with g code, or any type of robotic hardfacing. is the need to alter the feed rate on the fly. G code can be sped up by % i suppose.

Pick up a used welding robot & positioner?

This is closing up a cylinder on a 1600kg positioner

View attachment 385892

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

View attachment 385890

and a simple belt driven rotator

View attachment 385891

It's not the cylinders i'm trying to do.

 

[Munkul]

Most decent CNC controllers will let you alter the feed speed on the fly via a pot.
IMHO your two decent 2nd hand options are: welding robot (obviously just using it to weld straight lines) or an appropriate 2nd hand plasma table - rob for the bits, and set up how you need.

 

[Agroshield]

Most decent CNC controllers will let you alter the feed speed on the fly via a pot.

Could you clarify on that as I have always understood that the feed rate alterations do not happen _within_ any particular move, but only at the end of each move.

So if you do a G01 X1000 F=300 (mm/min) starting at X=0, any change in F will only happen at the end of that move (i.e. after it has moved 1m).

If you need to alter it on the fly, within a long move, it might be difficult to do in G code*.

*It would be possible, by breaking the 1m move up into a series of 100 No. 10mm long moves, but what a pain.

 

[Brad93]

Most decent CNC controllers will let you alter the feed speed on the fly via a pot.
IMHO your two decent 2nd hand options are: welding robot (obviously just using it to weld straight lines) or an appropriate 2nd hand plasma table - rob for the bits, and set up how you need.

Used robot or a bloody big cobot could be an option. only problem again is radiant heat with a cobot.

 

[Maker]

Used robot or a bloody big cobot could be an option.

Not for £2k.

 

[Brad93]

Not for £2k.

No certainly not. Welding alloys bought a 1.5m cobot and it was £27k

 

[knighty]

I've seen big robot arms go pretty cheap in auction, some welding some not... I have no use at all for one but I always stop for a second and try to think of a use for one :-o

depends on your timeframe I guess.... if you can code it etc. then a big robot arm will be the most versatile thing ever

 

[stuvy]

Global robots is down the road from me

He has a yard full of older arms

Our Z height is manually controlled via a screen and someone watching it to avoid any inclusions

Sensors aren’t available just yet to do this so if you had any kind of error with wire feed delivery or a momentary blip in power you could end up with a catastrophic flaw, or ruined work piece

 

[Munkul]

Could you clarify on that as I have always understood that the feed rate alterations do not happen _within_ any particular move, but only at the end of each move.

So if you do a G01 X1000 F=300 (mm/min) starting at X=0, any change in F will only happen at the end of that move (i.e. after it has moved 1m).

If you need to alter it on the fly, within a long move, it might be difficult to do in G code*.

*It would be possible, by breaking the 1m move up into a series of 100 No. 10mm long moves, but what a pain.

My 1998 centroid and the 2020 haas's at work (I've been told) have a pot that you turn up or down to finetune the spindle speed and feed. Its in % of set speed. Eg i set a spindle speed of 2000rpm, but turn the pot to 80% so only get 1600rpm. Same with any of the feed moves. It's instantaneous, as its interacting at a motion controller level, not a g code software level.

I even have a button that overrides the rapids to bring them down in speed as well, so you can prove a program without crashing.

Any decent cnc controller will have some form of option like this, I'd have thought... And if not, others will... Fanuc controls have it too

 

[Maker]

My 1998 centroid and the 2020 haas's at work (I've been told) have a pot that you turn up or down to finetune the spindle speed and feed. Its in % of set speed. Eg i set a spindle speed of 2000rpm, but turn the pot to 80% so only get 1600rpm. Same with any of the feed moves. It's instantaneous, as its interacting at a motion controller level, not a software level.

I even have a button that overrides the rapids to bring them down in speed as well, so you can prove a program without crashing.

Any decent cnc controller will have some form of option like this, I'd have thought... And if not, others will...

Here's the override section of the Haas controller:

I think "HAND CNTRL" feed lets you use the MPG as a pot, I've only ever used the buttons though.

The overrides don't change the G code, so it doesn't have to wait for the next block to come around to make the change.

 

[Munkul]

Here's the override section of the Haas controller:

View attachment 385964

I think "HAND CNTRL" feed lets you use the MPG as a pot, I've only ever used the buttons though.

The overrides don't change the G code, so it doesn't have to wait for the next block to come around to make the change.

Sometimes I wonder why our machinist hates the Haas machines, then i see those stupid controls and i kinda see why, lol. The control designers have never heard of Human Factors!

 

[stuvy]

Sometimes I wonder why our machinist hates the Haas machines, then i see those stupid controls and i kinda see why, lol. The control designers have never heard of Human Factors!

The designers much like my place have no experience of the end product and what the user wants

Happens the world over with every industry the same

 

[Brad93]

Global robots is down the road from me

He has a yard full of older arms

Our Z height is manually controlled via a screen and someone watching it to avoid any inclusions

Sensors aren’t available just yet to do this so if you had any kind of error with wire feed delivery or a momentary blip in power you could end up with a catastrophic flaw, or ruined work piece

inclusions? so i'm guessing you're automating tig for cladding? valves?

 

[m_c]

If I'm understanding this right, you essentially want a big 3-axis machine?

Given the atmosphere it's going to be in, I'd probably look at V-rollers with a suitable running edge.
Something like this - https://www.pbclinear.com/Products/Cam-Roller-Technology/VW-V-Guide/VW-V-Guide-Roller-Bearing-Wheel (US as my googlefu is failing to find a UK source, but I have seen UK suppliers).

Rack and Pinion is easy enough, but you'll likely need suitable reduction gearboxes to get fine enough control.

I would also suggest CNC control, but the electrical noise from the welding could cause problems if not implemented correctly.
You could always start with basic potentiometer control of some servo drives, and automate later.

 

[Brad93]

If I'm understanding this right, you essentially want a big 3-axis machine?

Given the atmosphere it's going to be in, I'd probably look at V-rollers with a suitable running edge.
Something like this - https://www.pbclinear.com/Products/Cam-Roller-Technology/VW-V-Guide/VW-V-Guide-Roller-Bearing-Wheel (US as my googlefu is failing to find a UK source, but I have seen UK suppliers).

Rack and Pinion is easy enough, but you'll likely need suitable reduction gearboxes to get fine enough control.

I would also suggest CNC control, but the electrical noise from the welding could cause problems if not implemented correctly.
You could always start with basic potentiometer control of some servo drives, and automate later.

That is the sort of thing used on column & booms.

On the kit i used the cables were double shielded.

 

[Robotstar5]

Global robots is down the road from me

He has a yard full of older arms

Our Z height is manually controlled via a screen and someone watching it to avoid any inclusions

Sensors aren’t available just yet to do this so if you had any kind of error with wire feed delivery or a momentary blip in power you could end up with a catastrophic flaw, or ruined work piece

I used to work with one of the guys that started Global when I was at ABB

 

[stuvy]

I used to work with one of the guys that started Global when I was at ABB

Iv met him at the bike night as they are about 10 minutes away each other

 

[Robotstar5]

Iv met him at the bike night as they are about 10 minutes away each other

Steve Hollingsworth?

 

[stuvy]

Steve Hollingsworth?

I can’t remember his name but will see him when the weather improves

I know a few of my guys know him and a few others from previous projects together

 

[Brad93]

today i aqquired a sandvic TNS 32X424 silent boring bar rescued out a skip , it has an adjustable modular head
need to make a holder when i get a spare few hrs View attachment 386007View attachment 386008

scary money new