Shaft encoder in KOP transmission?

[MrForbes]

We took the second stage out of the KOP transmissions, and have the bad GTS issue to deal with, and I found this sensor at digikey

http://rocky.digikey.com/scripts/Pro...102&M=AMT102-V

looks like it might fit right inside the transmission where the other gears used to be, and slip over the 8mm (5/16") shaft of the motor, and maybe even work, and for only $30 per side.

what do you think?

[TubaMorg]

Hmmm...do you think those things can take the RPMs? It's advertised at 300 rpm max and looks a little "plasticy"

[MrForbes]

the pdf datasheet shows it goes to 30k (30,000) rpm....where did you see 300?

(and yes it's plasticy, but it looks like a versatile design)

[JimWright949]

Jim,

Have you looked at these encoders yet?
http://www.usdigital.com/products/e6/

For a little more you can get something that can slip over any size of shaft (add the -h for a through hole).

949 used them on 2006, we are going to use them this year, 492 has also used them as well.

The only draw back is that you have to keep the count down to 200 and under (100 for this year). Any thing higher and the Robot Controller is just counting ticks.

If you order from them, you get all the tools you need to mount them to the gear box with the exception of the centering tool, You will need to order a centering tool with the first order, however you will only need one centering tool per shaft size you use.

-Jim

[MrForbes]

No I had not, thanks for the link.

Looks like they could mount on a bracket on the end of the output shaft on our design. They do get a bit pricey with the options we'd need.

[TubaMorg]

Page 2026 (the link you provided):

Me chan i cal Char ac ter is tics: • Shaft Rotation: Continuous in either direction, 300RPM maximum
• Ter mi nals: P/C Type: .025” (.64mm) by 0.12” (3.05mm) thick brass, gold plated to facilitate soldering
• Cable Type: • Four lead rib bon cable, color-coded, with .050” (1.27mm) spacing • 28AWG stranded
copper wire, .039” (.99mm) diameter • Strength: Terminals withstand 2 pounds push and pull and a
90° bend.

Edit: I just looked at the data sheet and it does, indeed, have a max RPM of 30,000. I think the max RPM described in the data sheet is in reference to the sensitivity/resolution as these things are more like potentiometers. They are made for manual manipulation, so the datasheet is specifying what happens if somebody twists it really fast. I do not believe that these encoders are made for continuous rotation because they have a plastic on plastic wearing surface. You could install it, however, then take bets on how fast it will fail.

[MrForbes]

Originally Posted by TubaMorg

Page 2026 (the link you provided):

Oh...you were looking at the wrong item on the page, the ones I was talking about are at the bottom of the page, part number AMT102-V, and don't state an RPM limit in the catalog, only on the datasheet.

[MrForbes]

You might be surprised how long plastics can last in continuous rotation applications. Let's see....how about 40 year old plastic speedometer gears in cars?