I was surprized somewhat at what I noticed with my RC Lawnmower on what must be its 20th run. Yesterday after doing the lawn I saw a front caster was leaning to one side. I pulled it apart and sure enough the 1/2" All Thread caster stem was bent by almost 3/4" of an inch. I recall running into things, but must have really underestimated these motors and the momentum behind its 170 lbs (now that I have a small crane scale I know its weight).
I don't have a pic of the 3/4" bend in the All Thread because I straightened it out. However, before replacing it I thought it best to inspect the other caster. That was bent too, although not as much (see pic). So with that in mind I made my way to Bolt Supply House to pick up some stronger All Thread. Turns out they don't carry "G8" All Thread anymore (or it is harder to find). Instead they sell ASTM A307 Grade B, ASTM F1554 Grades 36, 55, and 105, and a few others. Not sure which one I got as I already lost the receipt, but it's roughly Grade 8.
One thing I'm learning as I get older is to plan for failure/improvement. My 1/2" All Thread goes through Acetal bushings fitted inside 1/8" wall pipe. The casters themselves have bearings so technically the bushings aren't required. But I did this intentionally on the off chance that something like this could happen. If the upgraded All Thread doesn't solve the problem, I can remove the bushing and move to 3/4" All Thread.
On the positive side the Acetal bushings I turned on the lathe are holding up great, and I got to use my shop crane to lift the mower, making the repair easy.
I'll have to humble up and downgrade (flatten) the response curve on the transmitter joysticks. These powerful motors just ain't a good idea in the hands of an old fat guy in a yard filled with obstacles.
I don't have a pic of the 3/4" bend in the All Thread because I straightened it out. However, before replacing it I thought it best to inspect the other caster. That was bent too, although not as much (see pic). So with that in mind I made my way to Bolt Supply House to pick up some stronger All Thread. Turns out they don't carry "G8" All Thread anymore (or it is harder to find). Instead they sell ASTM A307 Grade B, ASTM F1554 Grades 36, 55, and 105, and a few others. Not sure which one I got as I already lost the receipt, but it's roughly Grade 8.
One thing I'm learning as I get older is to plan for failure/improvement. My 1/2" All Thread goes through Acetal bushings fitted inside 1/8" wall pipe. The casters themselves have bearings so technically the bushings aren't required. But I did this intentionally on the off chance that something like this could happen. If the upgraded All Thread doesn't solve the problem, I can remove the bushing and move to 3/4" All Thread.
On the positive side the Acetal bushings I turned on the lathe are holding up great, and I got to use my shop crane to lift the mower, making the repair easy.
I'll have to humble up and downgrade (flatten) the response curve on the transmitter joysticks. These powerful motors just ain't a good idea in the hands of an old fat guy in a yard filled with obstacles.
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