Annotate and tweak retractable.scad

[brandonheller]

First two commits induce no changes to dimensions. Third one uses sizes that seem to better fit a 2mm allen wrench.

[brandonheller]

I didn't realize that a commit request would auto-update to include following pushes to the pull-request-specified branch. Regardless, I've printed a part to test the later two commits in the series and the fit is now much better. Way less wobble with the 2mm wrench vs the 1.5mm, and no bending. It's not perfect - even printing at 0.2mm, the corners of the wrench catch in each layer. I wonder if there are allen wrenches that are bent around a corner, rather than around a flat, which would eliminate this friction problem.

[jcdoll]

Nice. I made some similar changes to make it more parametric and make more room on the inside edge so that it doesn't bump into my push connector. I also ended up needing to use an M2.5 hex in order to reach the bed past my J Head Mk IV, which is a bit longer than the Mk V that you guys are using, so made similar changes to allow for easy hex switching.

See:
https://github.com/jcdoll/kossel/commits/master/retractable.scad

[brandonheller]

It sounds like we're thinking in the same direction. Do you notice a lot of friction from the corners of the wrench grabbing the detents? I'm tempted to add a cutout for a small strip of UHMW tape for this - not sure if I have the patience for 0.1mm layers :-)

[jcdoll]

I noticed some tightness and cleared out the tunnel with a drill. I'll
revisit it at some point, always nice to not need any postprocessing, but
it's working pretty nicely for now.

On Tue, Jul 9, 2013 at 11:50 PM, Brandon Heller notifications@github.comwrote:

It sounds like we're thinking in the same direction. Do you notice a lot
of friction from the corners of the wrench grabbing the detents? I'm
tempted to add a cutout for a small strip of UHMW tape for this - not sure
if I have the patience for 0.1mm layers :-)

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[brandonheller]

I could also print the part with the flat side that faces the microswitch
down to eliminate the effect. I'll hit it with a drill first, though.

On Wed, Jul 10, 2013 at 9:23 AM, Joey Doll notifications@github.com wrote:

I noticed some tightness and cleared out the tunnel with a drill. I'll
revisit it at some point, always nice to not need any postprocessing, but
it's working pretty nicely for now.

On Tue, Jul 9, 2013 at 11:50 PM, Brandon Heller notifications@github.comwrote:

It sounds like we're thinking in the same direction. Do you notice a lot
of friction from the corners of the wrench grabbing the detents? I'm
tempted to add a cutout for a small strip of UHMW tape for this - not
sure
if I have the patience for 0.1mm layers :-)

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Reply to this email directly or view it on GitHub<
https://github.com/jcrocholl/kossel/pull/12#issuecomment-20724505>
.

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