Competition-Legal Encoders

[Shira]

My team wants to buy optical encoders and not use the ones from the KoP. What are the rules on non KoP optical encoders? (besides restrictions on cost). I can't seem to find anything in the manual but somebody on the team mentioned that there might be strict rules.

[Teched3]

You need to read this section of the Competition Manual:8.3.3.1 Cost Determination of Additional Parts for the rules governing additional purchased parts for your robot. You must cost account for everything you purchase within these rules and stay within $3500 maximum, with no single part costing more than $400. Your encoders must be compatible with the control system. Parts provided in the
K of P do not count toward the total cost of the robot.:)

[waialua359]

My team wants to buy optical encoders and not use the ones from the KoP. What are the rules on non KoP optical encoders? (besides restrictions on cost). I can't seem to find anything in the manual but somebody on the team mentioned that there might be strict rules.

Try DigiKey.

[Shira]

That's not what I meant--I know the cost restrictions, and I know where to buy encoders. I need to know if there are any rules about encoders themselves, like there are about actuators, etc.

[usbcd36]

There are no rules specifically governing encoders. As long as they comply with all of the other rules, (safety of materials, etc…) they are fine.

Don't see why you aren't using the KOP encoders, though. In case you're wondering, they are 250 CPR optical quadrature encoders, part E4P-250-250-D-D-D-B. The datasheet can be found online from the part number.

[Shira]

I'm not sure why I'm not using the KOP encoders either. I know nothing about using encoders so I asked a fellow team member, but he only has a little more experience than me so he could be wrong. Anyway, he said he wanted something different, I think something with a 1/4" hole in the middle to fit around the shaft on which our wheel is mounted.

The truth is, judging by his history on this team, I shouldn't really take his word on anything without doing a whole lot of research first.

[MikeE]

I'm not sure why I'm not using the KOP encoders either. I know nothing about using encoders so I asked a fellow team member, but he only has a little more experience than me so he could be wrong. Anyway, he said he wanted something different, I think something with a 1/4" hole in the middle to fit around the shaft on which our wheel is mounted.

The KoP encoders do have a 1/4" hole in them, but you have to mount them onto the end of a shaft, and they only have a push fit onto the shaft. There may be good reasons why this mounting is difficult in your design, but the E4P is also available with different mounting options. Check out the US Digital website for details http://www.usdigital.com/products/encoders/incremental/rotary/kit/e4p/

[Dad1279]

We like the Grayhill 61K128-050 available from Digi-Key. Easy to mount. Other resolutions available.
http://media.digikey.com/photos/Grayhill%20Photos/61K128-050.jpg