Team 254 Presents: 2013 Build Blog

[Travis Covington]

Originally Posted by ttldomination

That looks mighty...sketchy. I suppose the fact that so many people use this method speaks to its validity, but doesn't the encoder want to spin with the axle? While I expect that the zipped down wires help some of that, I can't help but think that there's a little wiggle in there.

- Sunny G.

These are the ball bearing S4 encoders. This will not work with the bushing ones. We do not use the bushing ones anywhere. We typically hot glue the connector and add additional strain relief to the wire to prevent damage to the wire/connector. If done properly there is no "wiggle" as the bearing drag is the only friction that exists and is quite minimal. We have done this (on 254/968) for as long as I can remember using encoders (nearly 10 years now).

[sanddrag]

Originally Posted by Travis Covington

These are the ball bearing S4 encoders. This will not work with the bushing ones. We do not use the bushing ones anywhere. We typically hot glue the connector and add additional strain relief to the wire to prevent damage to the wire/connector. If done properly there is no "wiggle" as the bearing drag is the only friction that exists and is quite minimal. We have done this (on 254/968) for as long as I can remember using encoders (nearly 10 years now).

I thought it was rather bizarre as well until I learned it while on 968. It really works a treat, and ensures that there is no binding or misalignment anywhere. As Travis mentioned, the bearing friction is very minimal, so there is no real load on the wires.

[AdamHeard]

It's also really nice in that it's darn short axially. Lets you sneak them in on a lot of things real easy.

[Brian Selle]

This year we used a couple 050 brackets to prevent the encoder from rotating. The idea was to connect the 2 pieces with a loose bolt so the encoder was prevented from rotating but still allowed to translate based on the alignment. The idea worked well until at some point the students found a "loose bolt" and tightened it. This led to 2 broken S4 ball bearing shafts.

One thing I learned was the shaft on the S4 is actually only 1/8" in diameter when it necks through the ball bearing. See images below.

I'm liking the wire + zip-tie idea!

[kellymc]

Sorry to keep derailing this thread.....I called to order the S4 from US Digital, it seems that they are having a manufacturing problem and as such they will only sell their current inventory to customers who have ordered them in the past.

Being that we haven't used them in the past it looks like we can't order them. Does anyone have an alternative encoder we can use?

Kelly

[DonRotolo]

We had great performance from the Grayhill encoders recommended by VexPro for their ball shifters. We got ours from DigiKey.

http://www.vexrobotics.com/vexpro/ge...l-shifter.html

Great idea Travis, Thanks for sharing.

This year Team 751 is going to try using an organization tool called Trello. This is a an open source project management system popular amongst new product developers here in Silicon Valley.

Instead of a blog, which tells you what was done, this is a task tracking system were people can tackle unknown problems and collaborate and monitor progress on the task. I am pretty sure it will work well as a mobile app for Android or iOS.


“The motto of all the mongoose family is, "Run and find out," and Rikki-tikki was a true mongoose.”

― Rudyard Kipling, Rikki-Tikki-Tavi