Old SEM Servo Encoder retrofit/replacement.

[2xEngineer]

Hello gang,
I have some older SEM MT30 servos, Bridgeport oem parts. They have Heidenhain 115-125 encoders. These give analog output, supposedly something like 125 counts per rev when translated, and the controller hardware had a multiplication of 5 to make it 625 counts per rev. I think this is a too few for my application, and am wondering if anyone else has found suitable replacement encoders? Preferably ones that bolt right up, and either have their own compatible enclosures, or fit in the existing ones.

Any help is appreciated.

[Al_The_Man]

If these are through-hole shaft mount encoders, Renco or Hengstler should be able to supply a substitute US Digital is cheaper made, but some use these.
A nicely made cheaper shaft style is made by Koyo.
Heidenhain extract a much higher encoder resolution than the native counts/rev with the sine wave output type, due to angular extraction between the two sine/cosine signals.
Al.

[2xEngineer]

Thanks for the names. My particular model was a goofy one, with washers/nut on a threaded shaft holding the diffraction grate, and a manually adjusted little frame holding the reader. Luckily it has a usable 10mm shaft coming off of the main 17mm shaft going to the tach drive commutator. It looks like Renco should be able to hook me up, but they are off on Holiday and I will have to wait a bit. On the plus side, the newer ones are self aligning, I just have to set the phase!

[Al_The_Man]

Originally Posted by 2xEngineer On the plus side, the newer ones are self aligning, I just have to set the phase!

Set the phase?? On a DC motor?
Or do you mean for correct direction?
Al.

[2xEngineer]

Well, ya got me. I took one look at those alignment instructions and I never thought of what I would be measuring, all I saw was waveforms. Although yes, I will have to set the direction.

[gridley51]

Hi 2xEngineer,I`ll buy the Heidenhain encoder parts from you if you want to sell them.
Mark.