What I have been up to (4th axis)

That resolver model is used as feedback on your typical Fadal DC rotary axis system.

If you still have the pigtail I would perhaps buy it from you if the price is right and provided it is a -35pin male milspec connector.

FWIW, almost nobody pays Danaher their listed retail price for resolvers--last time I bought a new one IIRC I paid around $230 for it...Also, at least one of the Fadal service houses offers "rebuilt" resolver units for around $120 last I checked.

Rather than considering use of a resolver at all I would suggest go to a encoder instead if it is at all possible--size 11 resolvers are highly prone to rapid bearing failure given even the slightest shaft misalignment and they will also will develop an internal open circuit at basically the drop of a pin.

Did not know

What pigtail are you talking about?

What I know is that this particular resolver is mounted the way it was originally mounted. Since this is a troyke table, I expect they did a good job at mounting.

I thought a lot about resolver vs encoder issue, and right or wrong, decided that I want to reuse the resolver with "resolver converter".

Mil-C-5015

Similar to :

Well, if I could find a converter that allows replacing the resolvers here with an encoder likely that I would immediately purchase about ten of them--because I have about 6 bad resolvers mostly harowe from glentek motors in my desk drawer but have yet to see a single encoder failure on fanuc motors.

Do not have one

Do you know how hard is it to drill and tap a shaft of that servo motor, coaxially, to install a stem to mount the encoder disk?

Is the shaft hardened?

Motor shafts are generally fairly soft in my experience though I suggest check and see if it can be easily molested with a file.

I would probably spin in a lathe using a roller support opposite the chucked end and spot, drill then ream.

Hmm ... the resolver has specs at 400 Hz (aircraft use) and at

Probably for experimentation without long signal leads.

Hmm ... I would instead put each of the secondary windings from the resolver in a separate shielded twisted pair instead of individual leads shielded. Better common mode rejection.

Best of luck, DoN.

I have NO idea, this is a good question. I wondered about the same thing.

Yes, this is what I tried to say, every pair is shielded.

thanks.

Any thoughts on this excitation frequency?

Whatever the resolver wants. The datasheet provided above says 400 Hz through 2500 Hz. I bet it is not critical within that range, but 10 KHz is too high. I would ask Pico. Much more important to accuracy than excitation frequency is good shielding.

Joe Gwinn

I believe that that board has a freq select jumper and the max freq is 10kc.

John

That is the min frequency.

I use a multiconductor cabnle where each pair is shielded.

That's good and usually necessary. Pico may have an opinion on how best to connect the shields and pairs so the capacitance from pair to shield has little effect. The point of the shielding is to prevent leakage of excitation drive signals into the signals coming from the resolver, which will cause phase shifts and thus angle errors.

The resolver angular accuracy is +/- 10 minutes of arc, according to the datasheet. If we assume leakage in quadrature with the true signal, then leakage ratio exceeding Tan[10' of arc]= 0.0029:1 voltage, or about

-51 dB will cause that magnitude of error. Now, it is not hard to achieve this much shielding effectiveness, if one does a reasonable job.

Joe Gwinn