Preso
Plastic
- Joined
- Mar 12, 2015
- Location
- Sunshine Coast, Queensland Australia
Hello machinists.
I have just recently completed building a small spot welder based on the ubiquitous microwave oven transformer which has been rewound to supply around 2.5V and, I am guessing because my ammeter won't range that high, around 1000 amps. I wanted to end up with a machine that looks professional and functional so I used home made aluminium castings for the mechanical components and a digital timer relay to control the weld time. I saw lots of similar machines on YouTube but nearly all of them, although electrically similar to mine, were constructed using wood and aluminium extrusions or fabricated steel. I know that many home builders must work within the capabilities of their shop but my version was more about the build and less about the need to own a spot welder.
The design for this welder is based on the Aston portable spot welder which was supplied to many secondary schools in Queensland, Australia. I used one of these machines for many years when I was working as an Industrial Technology teacher however since retirement I no longer have access to the machine. Working mainly from memory and from a few low res photos that I found on Google, I was able to replicate the mechanism which is used to lift and clamp the welding tongs.
The Aston welder looked like this:
I made use of a wide range of disciplines to get this build done. They include:
If you would like to see more details about this build you can find all the engineering data over at Thingiverse DIY Spot Welder (Super Scary Weldy Thingy) by Preso - Thingiverse
The videos are on YouTube. I will post the url's here so you don't get distracted by all the funny cat videos.
Super Scary Weldy Thingy Part 1 - YouTube
Super Scary Weldy Thingy Part 2 (DIY Spot Welder) - YouTube
Super Scary Weldy Thingy Part 3 (DIY Spot Welder and how to make it go) - YouTube
Please feel free to comment on the videos and the Thingiverse post. Use any or all of the information if you wish. I'm all into sharing and we shouldn't spend all our time reinventing that round thing they put on cars.
Regards,
Preso
I have just recently completed building a small spot welder based on the ubiquitous microwave oven transformer which has been rewound to supply around 2.5V and, I am guessing because my ammeter won't range that high, around 1000 amps. I wanted to end up with a machine that looks professional and functional so I used home made aluminium castings for the mechanical components and a digital timer relay to control the weld time. I saw lots of similar machines on YouTube but nearly all of them, although electrically similar to mine, were constructed using wood and aluminium extrusions or fabricated steel. I know that many home builders must work within the capabilities of their shop but my version was more about the build and less about the need to own a spot welder.
The design for this welder is based on the Aston portable spot welder which was supplied to many secondary schools in Queensland, Australia. I used one of these machines for many years when I was working as an Industrial Technology teacher however since retirement I no longer have access to the machine. Working mainly from memory and from a few low res photos that I found on Google, I was able to replicate the mechanism which is used to lift and clamp the welding tongs.
The Aston welder looked like this:
I made use of a wide range of disciplines to get this build done. They include:
- 3D CAD modelling for designing and verifying the design. I use Autodesk Inventor although I also use Fusion360 if I have to do a lot of CAM.
- 2D CAD for creating the engineering detail drawings for each part.
- 3D printing for creating the patterns from which I cast light alloy parts used in the clamping mechanism and the chassis of the front end.
- Metal Casting for the more complex parts where strength and durability are important.
- CNC machining of some of the slots and pockets in the parts. I also drilled all the cooling holes and a decorative hole pattern in the casing using a generated toolpath.
- General lathe and mill machining for the more straightforward features
- Laser cutting and etching for making the switch panels and for validating the clamp mechanism. I do this by making a 2D mockup from acrylic sheet so that I don't waste a lot of time on metal parts only to find out that the mechanism doesn't work as I expect it to.
- Powder coating for finishing the metal components.
- Electrical and electronic control systems for the weld timer, cooling fan and the heavy current switching.
If you would like to see more details about this build you can find all the engineering data over at Thingiverse DIY Spot Welder (Super Scary Weldy Thingy) by Preso - Thingiverse
The videos are on YouTube. I will post the url's here so you don't get distracted by all the funny cat videos.
Super Scary Weldy Thingy Part 1 - YouTube
Super Scary Weldy Thingy Part 2 (DIY Spot Welder) - YouTube
Super Scary Weldy Thingy Part 3 (DIY Spot Welder and how to make it go) - YouTube
Please feel free to comment on the videos and the Thingiverse post. Use any or all of the information if you wish. I'm all into sharing and we shouldn't spend all our time reinventing that round thing they put on cars.
Regards,
Preso