TIG welding overhead: How I run the pedal laying on my back!

Domenstration of overhead welding. The overhead welding is nothing special, but in some cases there is not enough space to stand, making it hard to...   more Domenstration of overhead welding. The overhead welding is nothing special, but in some cases there is not enough space to stand, making it hard to run the pedal with your foot.

So this is how I do it - I use the side of my leg. I'm pulsing the pedal because I like to have manual control of the pulse, which helps me control the surface tension of the melt puddle. This seems to be most important in vertical welding, but I tend to do it no matter what position I'm welding.

It seems really awkward to run the pedal with your leg, but I can't think of many better options. I'm curious how others handle this problem. Maybe with a hand control? Or manually setting the amperage at the control panel and overriding the pedal?

The machine is a Miller Syncrowave 250 with the TIG Runner package, but without the automatic pulse control.   less

DIY Foundry: Demolding Foam+Petrobond Experiment

Demolding my an address sign for the house, which I cast from aluminum using a simple investment casting technique. See my other video for the pou...   more Demolding my an address sign for the house, which I cast from aluminum using a simple investment casting technique. See my other video for the pour. The pattern is foam, which is vaporized by molten aluminum, which then fills the cavity.

I design plastic housings for a living and so constantly think about the part as it exists in a mold. A lot of effort goes into designing parts that are manufacturable and then chosing gating and mold constructoins that work.




Some of that experience has been proving useful in my DIY casting efforts, even though plastic injection tooling is a totally different world.

If there's interest, I'll keep posting videos of my metal casting experiments.   less

DIY Foundry: Lost foam + Petrobond Casting

Another casting session. This time, I'm trying out a super-easy lost foam technique: bury the foam pattern in Petrobond sand. After ramming, th...   more Another casting session. This time, I'm trying out a super-easy lost foam technique: bury the foam pattern in Petrobond sand. After ramming, the petrobond should maintain its shape, even as the molten aluminum is vaporizing the foam pattern.

Investment casting typically involves coating the pattern with layers of ceramic slurry, waiting for it to dry, burning out the pattern and finally pouring. This technique allows me to skip most of these steps.

Patterns were drawn in Inkscape, converted to gcode with MeshCAM, built by my homemade CNC foam cutter. Gating and vents were attached by hotglue. My attempts to use was to attach foam gating to foam patterns failed. Hotglue seemed to work pretty well, although I will be experimenting to find a better alternative.

Disclaimer: This is dangerous. If you've worked in a foundry for 25 years, I respect your experience and value your suggestions... but please don't imagine that I am putting myself forward as the picture of safety.. or industry standard practice.   less

Starting a Bobcat 975 in below freezing weather.

I've decided to sell my Bobcat 975 skidsteer, a beast of a machine! I made this video to show the machine starting for the first time in a few mon...   more I've decided to sell my Bobcat 975 skidsteer, a beast of a machine! I made this video to show the machine starting for the first time in a few months. It had been below freezing for over a week and into the teens the night prior.

Working load: 3700lbs!
Tipping load: 7400lbs!!!!
Weight: over 12k lbs
Hydraulic pump: 37.8 GPM

Check it out on portland.craigslist.org
(search for "bobcat 975")   less

DIY Foundry: What is Dross? (Part 2)

Another demonstration of what exactly dross is. This time, I show you what it looks like floating at the top of a crucible.