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Originally Posted by ttldomination
Super snazzy.
For someone of us that haven't had a chance to take these parts for a spin in Inventor, what's the output shaft length on those gearboxes? What's the distance between those railings?
And, just for general sheet metal design is "safe" (for lack of a better word) to use dead axle bolts directly like that on a sheet so thin?
- Sunny G.
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I have a section-view at home, but there's some build up around the axle slots to distribute the loading over a larger area and to deal with side-loading on the tensioning system. This is using a sheet-metal variant of the sliding bearing block tensioning method.
The output shaft of the 2-stage ball shifter is a bit more than 1.5" long measured from the face of its housing. The rails are 3" apart -- inside face to inside face.
Quote:
Originally Posted by AllenGregoryIV
Great concept, I've spent a little time with the VEXpro CAD files myself and one my favorite parts is how much ease of maintenance was included in the design. It looks like the rear wheel would block the awesome access holes that VEX designed into the gearboxes for removing the CIMs. That is one of the reasons their mounting bracket has the cutout in the middle.
Also what chain reduction did you use in the design? I've been playing around with a couple and haven't really made a decision yet.
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The chain reduction is 1:2 right now; 16 tooth hex sprocket to 32 tooth sprocket bolted to a versahub. I just tossed those in there for the sake of figuring out the overall width of the assembly; I'd look more closely at the ratios if we were to build something like this. Generally, I'm less concerned with penciling out the math at this stage and more interested in packaging and assembly.
The ball shifter is face mounted to the inner rail and should be pretty easily removed. The slots in the belly pan around the CIM motor and the hole in the rail allow you to remove the entire transmission assembly as a whole. I've never had to replace a CIM motor on an FRC robot, so I'm not very worried about accessing their mounting holes without a bit more disassembly.