Electronics > Projects, Designs, and Technical Stuff

Homemade IGBT MIG welder with ATX PSU parts. [blown yet again][blown count: 5]

<< < (15/32) > >>

Refrigerator:

--- Quote from: tautech on July 02, 2019, 08:53:05 pm ---
--- Quote from: Refrigerator on July 02, 2019, 08:27:55 pm ---While i was looking up wire feed mechanisms on the internet i found quite a few that use a 24V windshield wiper motors in them.
--- End quote ---
Yes because the 24V wiper motor is a good match for MIG welding voltages and simple speed control circuits are needed as the motor is only energised when the handpiece trigger is pulled.

--- Quote from: Refrigerator on July 02, 2019, 08:27:55 pm ---One problem that i came into though is that the bearing is so cheap that the races are not even hard, my dull file bites pretty well into it.

--- End quote ---
More likely you annealed the hardening from it by welding it.

--- End quote ---

I dumped it into water right after welding but i guess it wasn't hot enough to harden.

techman-001:

--- Quote from: mikerj on July 02, 2019, 06:59:45 pm ---<snip>
 All the cheap MIG welders have problems (flexible plastic rubbish held together with self tapping screws).

--- End quote ---

Really? what utter junk. Chinese I assume ?

Refrigerator:
Wire feed is done and i'm getting really excited, seems my MIG welder might be finished sooner than expected. (knock on wood)
Also the copper pads i left around the speed controller circuitry came in handy as i had to add an enable transistor.
For that i changed the inverting and non inverting inputs of the second comparator so that my duty cycle went up as control voltage went down.
Next i added an NPN transistor that would pull one of the potentiometer leads to ground this way enabling the speed controller as soon as a high signal is received.
Last thing i added was a 47µF cap between the collector of the aforementioned transistor and the control voltage, this way there's a period of high duty cycle on startup, which made a big improvement on the motor speedup.

strawberry:
I am not sure about post flow gas for MIG

Refrigerator:
Construction begins on none other than good old plywood, since wood can absorb moisture and become slightly conductive i separated any wood from high voltage with a sheet of plastic.
Now i'll have to find the PS3 power supply that i had laying around somewhere and bodge*ahem* i mean add a variable DTC feature into my TL494 circuit board.
Feeling a bit nervous as i inevitably start thinking about all the things that might go wrong.


--- Quote from: strawberry on July 03, 2019, 04:33:22 pm ---I am not sure about post flow gas for MIG

--- End quote ---

Not necessary as far as i can tell, many MIGs don't even have it.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod