Mounting encoders?

[waialua359]

I have been having a little problem mounting the encoders for the robot. Plus I am not sure if the encoder is receiving enough electricity. One of the PDF docs says that the encoder needs 12V. Is this true and is there a way around it. I would appreciate any suggestion. Thanks

Waialua Robotics

[Jared Russell]

The grayhill encoders I use (and I believe the US Robotics ones as well) use 5V power.

As for mounting, it depends which type you got. If there's a small shaft on it, you can either couple it to the end of a driven shaft (in the gearbox or on the wheel, assuming the wheel shaft isn't free spinning), or put a small gear/sprocket on it and run it off of your existing geartrain configuration (this is what Miss Daisy does). Then, use the threaded shaft cover to tighten a nut between the encoder body and the shaft with a thin piece of metal in between.

If it's a hollow shaft encoder, just slip it over the end of a gearbox/wheel shaft and secure the body to the frame using the mounting holes.

Remember, if you mount an encoder somewhere other than on the actual output shaft, you have to take into account the gear ratio to convert to standard units (which is optional).

[devicenull]

The one's in the kit this year require 12v, and there is no way around it. I'm not sure how that's a major problem..

[waialua359]

the 12V power supply when connected directly to the encoder doesnt seem to be functioning at all.

[dtengineering]

There are two mounting holes in the KOP transmission. You can identify them as they are countersunk on the outside of the plate and just happen to match the holes in the gear tooth sensors.

You will need to adjust the position of the CIM by rotating it about 10-15 degrees. You will notice that there are holes already drilled that make it easier for you to do this.

Then as you put the gearbox together, make sure the first stage gear (the first big gear) goes on the shaft closest to the sensor... the sensor should be about 3 mm from the gear. You will notice there is even a small hole to allow your wires to exit.

Don't forget to electrically isolate your sensor by using nylon washers to move the board up and off the gearbox.

As for hooking up the sensor, you need to solder a +12 v line into one of the inputs (check the wiring diagrams)... and then you need to get your software working right to sense it.

It DOES work... in fact once you get it all working it seems rather elegant. The only catch so far is that as far as I know, the RC is not quick enough to determine the difference between the clockwise and counter-clockwise pulses reliably.

Good luck,

Jason