With the encoder wheels and some of the boards looking different I need a way to identify which is which.
Chris, Have you seen those cards with mineral oil and iron filing which allow one to visualize magnetic fields? Here's a link to a large one. I've seen them as small as business cards. I've seen them given out as swag at science teacher conventions.
You could use one of these to examine the disk and count how many magnetic poles it contains.
I have not seen those, but they are interesting. I could probably find some use for one occasionally around the shop. For now I mount the motor into a vise and I have a board setup to interface the encoder and power to. It displays the real-time count as the wheel is spun. I usually do it three times to verify the counts. When I wrote the docs for the motor I went one step further and attached a reflective disc to the magnetic wheel so that I could detect each rotation and get an accurate count while the motor was running. It's clear the larger disc has more counts (64) than the smaller ones (48). Seems so difficult to find a supplier of these motors that can provide consistency.
This is the same (or very similar to the) one I have laying about. It's pretty nifty, but it needs a fairly robust magnetic field to move those iron filings inside. Note sure if the encoder discs have a strong enough field, but it's easy enough to find out.
Note sure if the encoder discs have a strong enough field, but it's easy enough to find out.
I can't find my business card sized viewer but I'd bet (a small amount) the encoder discs produce a visible pattern when viewed with one of these gizmos.
When I place two encoder discs right next to each other, I can feel them "engage" and one disc will cause the other to rotate (a little).
I just wanted to follow-up and say that the documentation for both the motor and the wheel/bracket kit have been updated to reflect the changes in the encoder counts as well as to fix my error of using the term pulses incorrectly.
Comments
Chris, Have you seen those cards with mineral oil and iron filing which allow one to visualize magnetic fields? Here's a link to a large one. I've seen them as small as business cards. I've seen them given out as swag at science teacher conventions.
You could use one of these to examine the disk and count how many magnetic poles it contains.
Edit: Here's a small one.
http://www.arborsci.com/magnetic-field-viewer
I have not seen those, but they are interesting. I could probably find some use for one occasionally around the shop. For now I mount the motor into a vise and I have a board setup to interface the encoder and power to. It displays the real-time count as the wheel is spun. I usually do it three times to verify the counts. When I wrote the docs for the motor I went one step further and attached a reflective disc to the magnetic wheel so that I could detect each rotation and get an accurate count while the motor was running. It's clear the larger disc has more counts (64) than the smaller ones (48). Seems so difficult to find a supplier of these motors that can provide consistency.
This is the same (or very similar to the) one I have laying about. It's pretty nifty, but it needs a fairly robust magnetic field to move those iron filings inside. Note sure if the encoder discs have a strong enough field, but it's easy enough to find out.
I can't find my business card sized viewer but I'd bet (a small amount) the encoder discs produce a visible pattern when viewed with one of these gizmos.
When I place two encoder discs right next to each other, I can feel them "engage" and one disc will cause the other to rotate (a little).
http://www.parallax.com/sites/default/files/downloads/28819-6-15V-Gear-Motor-with-Encoder-Guide-v1.1.pdf
http://www.parallax.com/sites/default/files/downloads/570-00080-Motor-Bracket-Wheel-Kit-Guide-v1.2.pdf