Quadrature Encoder Disk outer diameter?

garyg

Hi
I'm planning on using Parallax Quadrature Encoder Set # 29321 to mount to my under construction robot platform.
It's this encoder set http://www.parallax.com/sites/default/files/downloads/29321-36-Pos-Encoder-Set-v1.0.pdf

I would like to find the outer diameter of the encoder disk so that I may be able to see if it will fit on my platform.
I'll need to mount it to the outside of the wheel and I need to see how large to make my mounting brackets.

I'm developing this system to be controlled by Quickstart board.
I'll order one of these sets as soon as I can determine if it will fit.



Thanks
Garyg

Whit

Garyg - the encoder disks have a diameter a bit shy of 1-5/8".

garyg

Thanks Whit
That's exactly what I was looking for.

My robot project was on hold for about a year or so.
I needed to become at least somewhat familiar with Spin program language.

My Robot platform really needs encoders because it has two motors.
the 1 9/16" outer diameter shown in your photo looks promising.

I was concerned that the disk may be too large for my situation.
I think this Parallax product may work well.

I'll find out in the morning.

Thanks
Garyg

Whit

No problem! Good luck with your project! I think you will be very impressed with these encoders...

garyg

Hi
I ordered the Encoder set today.
Now I can start working on designing mounting brackets etc.

Just one more question.

On the OBEX there are several Quadrature encoder objects.
Any suggestions on which one would be best to use for a simple start when using these encoders?

Thanks

Duane Degn

garyg wrote: »

On the OBEX there are several Quadrature encoder objects.
Any suggestions on which one would be best to use for a simple start when using these encoders?

What do you want to do?

Is speed control important?

I've been actively working on code to precisely monitor the speed of these encoders as part of my effort to modify the Eddie firmware to work with a Propeller Activity Board.

The object I'm working on times the interval between both encoder transitions and full encoder cycles to calculate the speed of the wheel. So far the code looks very promising and I'm busy incorporating the new encoder code with the Eddie firmware. Besides monitoring the encoders, the object also generates PWM signals for up to four motors.

I should have an update to post to the OPP#8 in the next couple of days (maybe today). Hopefully the encoder/motor control object it will use will be useful in your robot project.

The code will work with both HB-25 motor controllers and normal h-bridge motor controllers.

garyg

Hi Duane
My under construction robot platform is differential drive using two HB-25 controllers.
What I'm hoping to accomplish is to be able to drive the platform in a relatively straight line,
So speed control will be important.
I'm currently running this platform using a BS1 controller, so I know that this platform appears to work very smoothly.
This part of the project will be to control the platform using a Quickstart board and do my logic in spin.
I will also be attempting to use an RC tx/rx to control this platform.
I did this in a minor way with my 1st platform and it worked quite well using a BS2.
General idea is to use the RC tx/rx to get the platform where I want it, then I let the platform roam until I wish to stop it.

Based on your description, it sounds like the code you are developing is pretty much exactly what I'm looking for.
I will be spending some time figuring out how to mount the encoders to my wheels, so I'm not in a particular rush to get this done.
The mechanical part of this type of project always takes me a very long time to accomplish.

I'll keep an eye out on your progress with the code you are working on.
I'm looking for the OPP#8 that you mentioned in post #6 of this thread.
I just today started looking at the OpenPropellerProject link that you mentioned in post #6 of this thread.


Thanks
Garyg