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Sunday, January 25, 2009

Stressing steel and a robot builders limits

After spending weeks building the escape pod, I added nice trim and some paint. I reinforced all the joints and I was confident that it could support 500 pounds without any problems. Plus it looks pretty cool too.

The crane assembly however was another issue. Today was stress test day. The day I would load a lot of weight into the escape pod and "attempt" to get it into my truck. The first test was a relatively simple one where I attached the chain hoist to the escape pod and quickly whisked it into the back of my truck. Ahhh this will be a piece of cake I thought.

The next test, I took several 40 pound buckets of paint, several full 5 gallon gas cans (leftover from hurricane supplies), my floor jack and a couple pieces of junk and load it all into the escape pod. I estimated it was about 175 pounds give or take 20 pounds.

I knew I was in trouble when shortly after cranking on the chain hoist I started hearing some strange noises. At first I thought the hitch pieces were just getting ready for the load and it would be ok. But after a few more cranks and a few more unsettling noises I noticed now deformed the hitch piece that the pole that was attached to the crane was. By this time the pod was only a few feet off the ground but that was as far as I was willing to go. The deformity of the steel bars was pretty scary. I didn't think that would happen with steel. But that's because I'm no engineer and just a garage hack. At least I figured this out taking my time and didn't have this stressing of the metal happen outside of my home. Could have been dangerous.

So what does this mean boys and girls ? Once again I'm "back to the drawing board". C3PO was right - This droid is sure going to cause me a lot of trouble.


Mike D. said...

What if you scrap the crane idea and add a set of low profile wheels to the escape pod.

Then build a set of ramps and use the winch to tow the escape pod up the ramps and lower it back down?

Another thought might be those receiver hitch mounted lifts for mobility scooters. Some of those have motorized ramps and winch combos and some of those scooters are big and heavy so they should be up for the task.

You might be able to find a used one on Craigslist or a local mobility scooter store.

Jim Quinlan said...

I agree with you about scrapping the crane idea Mike. The ramps would have to be long and wide and the pod would be on quite an angle coming in and out. If the ramps slipped it would spell disaster. It's something to think about but I'm not sure. Too bad I couldn't equip the droid with working Boosters and just have him fly into the back of the truck !