One of our programmers has heard that the standard encoders are not very accurate. We’ve never used them for any real reason. Do they work fine for normal use?

I’d suggest a link or make/model for what you think are standard encoders.

…and also define what is meant by “normal” use.

I found 3 of them in the electronics parts. I assume they came with the KOP in past years. That’s why I call them standard.

Not sure the models because I’m not there at Robotics. I think they are all US Digital E4P-250-250-N-S-D-D-B encoder (am-0174). And also the one attached to the KOP item Gearmotor (PG71 gearbox + RS775 motor + encoder) which the encoder is a am-2816a Hall Effect Two Channel Encoder.

Not quite sure yet what speed the manipulator team is going to be running these at. Probably both less than 1000 RPM.

Properly done, they work well. Properly means the optic wheel is clean & undamaged. The shaft the optic wheel is on needs to be concentric & have very little end float. The optic wheel needs to be tight on the shaft & properly positioned. Other encoders that have their own shafts & bearings are easier to set up & use.

So very true. The above post is definitely a keeper.

I have a different question regarding encoders.

Has anyone used a Grayhill 61K128 encoder with the mini-toughbox?

That’s what we’re planning to use but I notice that it is a very tight fit with the body of the encoder right smack against the motor sides. We’re using a 1/4" to 1/4" shaft coupling to connect the encoder to the output shaft. I’m tempted to take a file to the sides of the encoder body to see if we can open things up a bit. I’m worried about side-loading the encoder shaft.

To avoid loading the encoder shaft, couple the two shafts with a piece of surgical tubing with the ends of the shafts inserted into the holes in the tubing and clamp it down with zipties. It works very nicely for misaligned encoders.

99% of the issue people have with encoders have more to do with the physical installation/positioning of the encoder than they do with the encoder themselves. junk data in, junk data out.