Is it okay for the CTRE mag encoders to be yellow constantly?


#1

I was checking the video for installing the encoders it mentioned that it’s okay for the encoders to flash yellow time to time and the best would be green. Is it okay for it to be constantly yellow?


#2

I would assume so, it doesn’t affect the measurements significantly enough to be noticeable. Obviously it would be better for the encoders to be green but as long as they’re not red they’ll work just fine.


#3

Straight from the user guide:

When properly installed, the LED should be green. A yellow LED is acceptable however there is less tolerance to mechanical deviation that may cause the Z distance to change, as this state is farther away from ideal. The LED should remain green through the shafts full range of motion and speed. If the LED transitions or “blips” a color other than green, confirm that the mechanical relationship between the encoder, shaft and magnet are consistent. This can be done through manual movement of the components until the cause is isolated. Determine whether the problem is shaft end play, encoder mounting or magnet installation.

If you start with it yellow, then any deviation through the season may cause it to transition to red, which would be bad - it doesn’t work when it’s red. And if it just blips red, that’s worse, as you’ll think it’s working but you’re really missing counts. I would do what was needed to make it green when setting it up.


#4

It depends on how reliable you need them to be. You may get greater error while in the yellow, and being in yellow means you’re not too far from red - if it drifts over there it won’t work well if at all.

The adjustment to be made is simply to move the encoder nearer or farther from the magnet. If the encoder is mounted with the screws supplied or similar, proper adjustment is probably just a matter of turning those screws in or out and maybe adding a gasket.


#5

We installed a couple of them using this kit just last night. Very easy to do. The grommet provides a compressible interface that lets you get the spacing just right - you just need to tighten the screws until it goes green and stays green.


#6

The same here. (OK, not last night.), on TB-mini, TB-micro, and TB 3 motor using an encoder mount pad. You can likely also get the same parts today at a hardware store - two 1/2" long #3-48 machine screws (I could only find them in stainless), and a rubber gasket with an inside diameter of 1/2" or 9/16" per mount.


#7

so we were connecting the mag encoder in its shell directly on the 3 cim ball shifter. But it was yellow and nothing else. But I decided to see if it will turn green if I try to position outside of it shell. It turns out that the encoder needs to be DIRECTLY in front of the magnet to be green without its shell (which is useless) and it is just yellow when it is in its shell.
You can see the diagram here for the transmission (page 14).


#8

Have you tried not mounting the encoder, just putting it in its shell, and moving it around to see where (and if) it turns green? If you can’t get it green at all, it looks like the standoffs are too long, or the shaft is mounted so that less of it is sticking out than intended. If the shaft is mounted correctly, and as the green range is 0.75mm deep per the manual, you should be OK to take off standoff lengths in steps between 1/4 and 1/2 mm (thinking a sander/grinder) until you get green.


#9

We have had the same issues with the shell. Mounted without it, it’s green. With it a constant yellow. We ran last year on yellow and had no ill effects.


#10

What’s the height of that grommet?


#11

We ran ours on yellow without without major issues last year. One of them would occasionally become red, but as far as we could tell it still operated fine. Of course it is best to design the gap between the magnet and the encoder to the distance CTRE specifies, but it seems they are pretty robust.


#12

I can agree, I got to test the encoders for the gear box, and from my math calculations 1 revolution on the wheel should equal to 30,720 encoder ticks. We spun the wheel with our hands to go around once and we got a reading of 30,830. This is all when the encoders are yellow, and the difference is minor and the change could also be led by human error.

Thanks for the help!


#13

I don’t have one handy, but based on the distance required on the toughbox (metal motor plate) I have handy, the grommet must be about 3/8" thick.


#15

Perfect. Thanks as always. For anyone who sees this in the future, it looks like https://www.mcmaster.com/9600k115 would stand in well.