Banebots 1/2" shaft encoder for Toughbox?

I was looking at the banebots web page, and found this

http://banebots.com/pc/ELECTRONICS/EN-G0561-KT

it’s a quadrature shaft encoder with 128 resolution that mounts on a flat surface and works with a 1/2" shaft.

Like it was made to put on a KOP transmission…

It was actually made to fit last year’s Banebots KoP transmission (which had mounting holes for it).
Word of warning though. Unless you pre-plan the mount strategy and carefully machine your mounting surface to have the mounting holes EXACTLY where they need to be, you will encounter problems. 116 attempted to use these on our 1/2" drive axles last year, and encountered a number of problems with mounting them. I’d highly suggest carefully machining your mounting plate, if not CNCing it.
I have not heard any complaints about these when used with the Banebots transmissions they were intended for though.

perhaps we could make an adjustable mounting plate…the encoder screws into the plate, the plate is larger and has “loose” mounting holes to allow precise positioning.

I wonder how much radial shaft runout is allowed? looks like it could probably tolerate a little bit.

Thanks for the info!

We used them last year with the Banebots. I can not remember off hand how we mounted them. Which probably means it was fairly easy. The only downfall that I remember was that the encoded ring gets glued to the shaft. Luckily with our self made double d plates we did not have to replace the Banebots. We were concerned that removing it from the shaft would damage it if we needed to replace the Banbots.

Yes they work well when mounted properly. Our team, however, machines to a precision of .25 inches which isn’t good enough for these. Last year the Banebot transmissions had the mounting holes for these encoders, but the output shaft axial play was greater than the gap for the encoder wheel. We killed a few encoders. But if you can get them mounted and positioned correctly on this year’s transmission, they will work well. Try to avoid using an adjustable mount strategy unless you can be sure it won’t move once you get it straight. The only thing worse than having no encoders is having unreliable encoders.

I would not recommend the BaneBots encoders at all. We used them with the BaneBots transmissions as intended, and encountered many problems.

An excerpt taken from a previous post I made:

In short, if everything isn’t perfect, these will break in a flash.

Jacob

This bears repeating. We had a lot of trouble getting the encoder wheel to actually stay fixed to the shaft last year. Not recommended.

how about a spacer, broach a keyway and use a lock collar to hold it on?

It starts to look like work, though.

Did anyone use their divider circuit?

Axial distance isn’t such a concern, because you mount the encoder wheel according to where the sensor is located. It slides on the axel and gets super glued in place. The trick is to get the radial distance just right, then mount to the transmission via stand offs. You guys might be able to get it right. Maybe use a template with a temporary bearing/shaft in it to get the mounting holes just right, then transfer the holes to the real transmission. Also note that on the other side of the transmission plate is the output gear, so there’s not much clearance for mounting hardware.

We never made the divider cards. You would think with all the EE students on our team someone would know how to solder!

We used the BB encoders and divider cards without problems… well, at least without problems we couldn’t fix… last year.

There is a little allowance for shaft runout… last year with the BB trannies we had some runout issues, and the metal encoder disc ended up grinding down the sensors on one encoder. It had to be replaced. The blame for that lies more with the tranny and us than it does with the encoder.

We did not have any problems super-gluing the encoders to the shafts… just make sure they are on square, or the room you have to deal with run out gets eaten up quickly.

The divider cards worked great and really took a load off the programmers and processor.

That said, we’re using gear tooth sensors this year. Or at least we’re planning on it… that part of the code isn’t implemented yet.

Jason

Thanks for all the comments about your experiences with the BB encoders, it’s a big help!

Yes, we used the divider circuit, our programming team found them a lot easier to program against, and we didn’t experience any problems.