Where we last left this story, I had decided the encoders were the cause of issues and had begun the search for replacements. Marty had offered some suggestions, but I had already been looking at US Digital. One of their mounting options of their inexpensive E5 “kit” line jumped out at me, the addition of 1.812 spaced “ears”.
That’s an odd measurement, where have I seen that before?
Looks like it’ll fit. I ordered two 2000cpr kits to fit my 6mm shafts with the differential option and the ear mounts for $85 each. The connector wires added a rather steep $13 per unit, so let’s call it $100 per encoder. Not too bad. Interestingly, the 5000cpr option (their max in this model line) is the same price. I opted for the 2K since I had read my drives can get finicky when paired with high resolution encoders (although that may have been due the the lag introduced by the capacitive encoders that were used by the person reporting this issue, but I digress).
While there is no online shop for US Digital, you use their configurator and send the model number to sales@ and they send you back a link which enables you to pay online via payfabric.com. They were quick to respond and since I ordered before 11:00am Pacific, they shipped that same day!
A few days later, I got my kits, the contents of which are shown here:
Assembly is trivial. Here’s a quick walkthrough:
Mount the base:
Install the spacer. This ensures the right height for the optical disk.
…which you tighten down via set screw.
The differential line driver is a module you press onto the standard 5 pin connector of the optical module:
Install the optical module:
Install the cover, and you’re done. Whole process takes five minutes.
Now, some of you have already guessed at the issue I faced. You’ll notice that the differential module adds almost a quarter of an inch to the length of the encoder, a fact that I did *not* pick up on in ordering (although I now see it clearly in the data sheet; ugh). This means that when I plug in the connector, it’s actually too long to fit within the rim that defines the encoder protector. More than that, because the connector sits on that rim while the encoder is lower, the connector “finger” doesn’t engage its slot, so it doesn’t lock into place.
Not sure how I’m going to solve this one. I’ll probably crimp female pins onto wire and solder each of them to the differential pins. A bit hacky, but it should be secure and allow me to use the existing encoder protectors without modification. So much for the expensive connectors!