shaft coupling

[rdmendola]

We have a problem with our drill couplings that we bought from SPI. We have installed them -- drilled and put a pin in as instructed -- and they are not true. Has anyone else experienced this? Does anyone have any advice?

[MrB]

We had zero problems with the SPI couplings.

We used a 1/8" keyway on the drive shaft to mate with the keyway in the coupling and a 1/16" Steel roll pin on the drill motor shaft (threaded end) as specificed by the SPI documentation.

We have not experienced any problems and have been testing (beating up) the drive train for about 1 week now.

We should be ready for FULL bot testing (read FULL WEIGHT) within the next 2 days. I'll be sure to post any problems if they arise.

[Ken Leung]

Originally posted by rdmendola
We have a problem with our drill couplings that we bought from SPI. We have installed them -- drilled and put a pin in as instructed -- and they are not true. Has anyone else experienced this? Does anyone have any advice?

Not sure what your problem is, "and the are not true", but let me take a guess.

Are you talking about the hole size and pin size are different? The pins SPI shipped with the couplings are 1/8" and the hole on the coupling is actually 1/16". You will have to use the 1/16" hole as pilot hole, and fit the 1/8" dowel pin in instead.

Other than that, I can't imagine any other way they can be wrong... The couplings should screw on drill motor output shaft just fine, and the other should be able to fit in a 3/8" shaft. If you have the right keyway on the shaft, you can match up with the keyway on the couplings' other end, and put in a 1/8" by 1/8" key.

If you are experience problem with screwing in the coupling into the drill shaft, or fitting in the 3/8" in the other end, try using the allen wrench that came with the package to unscrew the socket headed screw on the side a little bit, although you would want to tighten them after you install everything.