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Originally Posted by aldaeron
Will all machined parts be available for purchase?
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The machined parts will not be available for purchase. This project was developed as an "example of using Vex parts" like the VersaFrame Chassis models Vex shows on their homepage. All the CAD and machining drawings are online, and the module was designed so that a team with a manual mill, lathe, drill press, chop/miter saw, and a 3D printer could build it on their own.
Quote:
Originally Posted by aldaeron
I see only a few that require machining (some are hard to tell if they are tightly toleranced diameters or clearance holes). For example the side C channel (Item 1) has a 1.125 hole, but also has face bearing gussets to support the bearings inside the upright. Is that a clearance hole in the C channel or is it meant to be tightly toleranced and support the bearing?
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For the most part, the tolerance is pretty loose, within 0.015" should be fine.
You picked a very interesting example with the question about the clearance v. tight-tolerance hole. The face bearing mount was attached to help with the machining process as much as to be the extra support. Although not critical, the bearing holes in the C-channels should come out easily within a tight tolerance if you machine smartly.
For the face bearing gusset, the machining operation should be:
1. Attach gusset to the C-Channel by match drilling and putting screws in the corners. (I suggest milling these holes precisely on one of the C-channels and then match drilling the others with that one)
2. Put 3/8"ID bearings in the large holes in the gusset so that the bearings can't slide around sideways. At this point there still wouldn't be a hole in the C-Channel for the bearings.
3. Use a transfer punch through the hole in the bearings so that you now know exactly where the centers of the bearings would be on the C-channel.
4. Take the gusset off and drill out the holes in the punched locations.
5. Assemble, and the holes should match up!
Quote:
Originally Posted by aldaeron
Great use of the 3/8 hex gear as a VersaHub (didn't know they don't have a 3/8 hex VersaHub).
Still can't figure out the square cutout on the main 2x1 tube
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So the reasoning for using the 3/8" gear was that Vex only sells hubs that are supposed to be broached by the teams to the size they need. We quickly realized that many of the teams wouldn't have an expensive 3/8" Hex broach just lying around in their shops. Since it's way cheaper to buy the gears with the pattern than buy a 3/8" hex broach for just the modules, we decided to go ahead and use the gears as hubs.
The square cutout is clearance for the tube that extends through the VersaBlock. The large area allows plenty of room for machining tolerances and tensioning the system by moving the VersaBlock.