kmcelhinney
This is only our second year and my team is trying to build a front caster style wheel, and are running into problems. I put a store purchased one on a programing practice platform and they really liked how it drove. The one they are building will not swivel when they try to turn. They are trying to use some L brackets and the roller blade where that is in the return kit. Any suggestions you can give me, that i can give them, that will help them design a better wheel. Or an suggestions about what we could do as a front wheel. Again this is only our second year, and at our small school the students do not have any design or engineering style classes. Thank you!

Kevin McElhinney
Plankinton Schools
American Gears "Coach"
Plankinton SD
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esmith
They say that a picture is worth a thousand words, so maybe this will help. The pivot pin for the caster wheel is made from the 1/2" dia aluminum rod that is in the consumable kit. We did perform some machine work on it on our lathe, but this could be done with the 1/4" dia rod and washers from the kit. The little flange bearings also came from the kit.


https://drive.google.com/file/d/0B0OYn8fzC9leM3FmZFh1RTR5Snd3SC1lNGdZaWNkcUwwMUhr/view?usp=sharing


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jgraber
The key to getting a caster design to swivel is a horizontal offset of the wheel axle from the swivel axle.  If you purchase (and can later return unused) several sizes of casters from Harbor Freight or a big box home improvement store, you may be able to see if there is a constant offset, or a constant angle between the swivel point and wheel axle, or at least the ranges of these things.  
  I've seen casters using lazy susan as swivel, with L brackets to hold the wheel axle.
 I've seen casters with sheet aluminum u bracket to hold the wheels, and a 1/4" rod or bolt through bare wood, or through a steel bearing for the swivel.
  I've seen casters discarded and sliders used instead, because the caster swivel jerks the robot sideways when trying to do precision left-right alignment to pick up a game piece.
Sliders work best on flat floors, but need larger edge ramps in games with doorway thresholds like Paydirt.   I'll upload my Background_training.ppt to the MAIN / Public Resources & Training / Team Resources  File manager location
  Slide 43 shows a caster example:
caster_example.jpg
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