shenion
Tool Pack Rat
- Messages
- 7,586
- Location
- Stone Mountain, GA USA
I have been trying to resurrect this old Airco wire feeder. Now have it working 
Since the Airco is basically an stick/TIG machine (constant current), I did not expect much. Took me a while to figure out a guide tube was missing. Without it, the wire feeds through a large tube before reaching the start of the torch cable. That allows it to to form an S-bend. By the time it goes through 5m of cable, it gets too tight.
The Airco welder has a start circuit that selects a higher current for starting the arc. Without it, the entire wire from tip to work melts slowly then breaks, then the normal short-circuit starts and works. With the start set up it works ok. On dirty metal it gets sloppy.
The wire feed is sensitive to get right. Once set, it works surprisingly well. The "buzz" of the arc is probably the best I have ever heard when right. Very stable and clean welds. When the speed is just a little too fast, it really gets messy.
The feeder only supports 0.9mm and 1.1mm wire. I was amazed I could do welds on 1.2mm steel tube with 0.9mm wire easily without blowing through (wire just crawls). Did some tests earlier on 5mm steel and actually blew holes in it. Amazing for a machine from 1973.
I have a constant-voltage controller design drawn up. Should make it more forgiving on wire speed/current. Will also put control on wire feed unit.
Anyway, was doing some research on this MIG feeder and stumbled on a history of MIG welding. It has an interesting take; it does the history from patent info.
I knew Airco was an early developer of MIG and had several patents. Linde has several key ones too.
Here's the link; an interesting read: http://www.netwelding.com/History_MIG 1.htm
Note: anyone with a lathe that is willing to make me a 0.8mm 0.6mm feed roller PM me. Noone makes these rollers anymore. I have a drawing of what is needed. Should be easy to do. Someone in the US would save me shipping costs.
Since the Airco is basically an stick/TIG machine (constant current), I did not expect much. Took me a while to figure out a guide tube was missing. Without it, the wire feeds through a large tube before reaching the start of the torch cable. That allows it to to form an S-bend. By the time it goes through 5m of cable, it gets too tight.The Airco welder has a start circuit that selects a higher current for starting the arc. Without it, the entire wire from tip to work melts slowly then breaks, then the normal short-circuit starts and works. With the start set up it works ok. On dirty metal it gets sloppy.
The wire feed is sensitive to get right. Once set, it works surprisingly well. The "buzz" of the arc is probably the best I have ever heard when right. Very stable and clean welds. When the speed is just a little too fast, it really gets messy.
The feeder only supports 0.9mm and 1.1mm wire. I was amazed I could do welds on 1.2mm steel tube with 0.9mm wire easily without blowing through (wire just crawls). Did some tests earlier on 5mm steel and actually blew holes in it. Amazing for a machine from 1973.
I have a constant-voltage controller design drawn up. Should make it more forgiving on wire speed/current. Will also put control on wire feed unit.
Anyway, was doing some research on this MIG feeder and stumbled on a history of MIG welding. It has an interesting take; it does the history from patent info.
I knew Airco was an early developer of MIG and had several patents. Linde has several key ones too.
Here's the link; an interesting read: http://www.netwelding.com/History_MIG 1.htm
Note: anyone with a lathe that is willing to make me a 0.8mm 0.6mm feed roller PM me. Noone makes these rollers anymore. I have a drawing of what is needed. Should be easy to do. Someone in the US would save me shipping costs.
