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Future tech directions?

 

So, here's a question...

As we may all recall, until we knew of the existence of GII, there was much talk of options. One of the obvious candidates was of course the SiTech system. I presume such talk is probably currently much reduced now, as the feature set of the GII is really pretty lavish.

There is however one feature of the SiTech I'm wondering if we may see come the GII way. That is the tick management feature used with high-resolution external encoders. Using tick-management they are basically able to eliminate PE (on Losmandy mounts as well). That would certainly be a killer feature for GII I think, especially, as a GII needn't be bound to a PC like the SiTech software. Latest talk on the SiTech group seems to be headed in the direction of Heidenhain absolute precision encoders with 33M tics for < $500.

Is this a feature that may be in GII's future?

Thanks,
-esy

Erik Sigurd Young
"My punctuality is well known. When The Revolution takes place, I'll be late, and I'll be shot as a traitor."
 

oops, that should read ...absolute position...

--- In Gemini-II@..., "notparticularlyleet" <sigurd@...> wrote:

So, here's a question...

As we may all recall, until we knew of the existence of GII, there was much talk of options. One of the obvious candidates was of course the SiTech system. I presume such talk is probably currently much reduced now, as the feature set of the GII is really pretty lavish.

There is however one feature of the SiTech I'm wondering if we may see come the GII way. That is the tick management feature used with high-resolution external encoders. Using tick-management they are basically able to eliminate PE (on Losmandy mounts as well). That would certainly be a killer feature for GII I think, especially, as a GII needn't be bound to a PC like the SiTech software. Latest talk on the SiTech group seems to be headed in the direction of Heidenhain absolute precision encoders with 33M tics for < $500.

Is this a feature that may be in GII's future?

Thanks,
-esy

Erik Sigurd Young
"My punctuality is well known. When The Revolution takes place, I'll be late, and I'll be shot as a traitor."
[email protected]
 

This feature was talked about in the beta group quite a while ago. Here is one of Ren???'s responses. I will say no more and maybe Ren??? can shed further light on his thinking.

We've been thinking about this for a while. Oh yes, I would prefer a
closed loop to a stored PEC solution. I think Gemini is well capable to
do it. According to Shannon's law the encoders must have about the
double resolution of the accuracy requested. At the worm they could
only
reduce the spur gear error with higher frequency, for eliminating the
worm PE they must reside at the main axis. That means that for
achieving
1" PE about 2 million ticks/rev are needed. Maybe they can be attached
to the worm wheel using some gearing.

Ren???
Tom Hilton
 

I'd be very interested in what Ren¨¦ has to say on the topic. I think it could be done without gearing using a Heidenhain (maybe a 23-bit encoder) mounting it directly to the rear of the RA shaft.

-esy

Erik Sigurd Young
"My punctuality is well known. When The Revolution takes place, I'll be late,
and I'll be shot as a traitor."

--- In Gemini-II@..., "tom@..." <tom@...> wrote:

This feature was talked about in the beta group quite a while ago. Here
is one of Ren¨¦'s responses. I will say no more and maybe Ren¨¦ can shed
further light on his thinking.

> > We've been thinking about this for a while. Oh yes, I would prefer a
> > closed loop to a stored PEC solution. I think Gemini is well capable to
> > do it. According to Shannon's law the encoders must have about the
> > double resolution of the accuracy requested. At the worm they could
only
> > reduce the spur gear error with higher frequency, for eliminating the
> > worm PE they must reside at the main axis. That means that for
achieving
> > 1" PE about 2 million ticks/rev are needed. Maybe they can be attached
> > to the worm wheel using some gearing.
> >
> > Ren¨¦

Tom Hilton
 

Interesting question. I would agree that with the appearance of Gemini II, that the push to adopt SiTech hardware and software to the Gemini platform is all but gone now. I do find the tic management capabilities of the SiTech platform intriguing. I guess this must be answered by the Gemini II developers. I am not overly fond of the cost of the high precision encoders though.

Keith

--- In Gemini-II@..., "notparticularlyleet" <sigurd@...> wrote:

So, here's a question...

As we may all recall, until we knew of the existence of GII, there was much talk of options. One of the obvious candidates was of course the SiTech system. I presume such talk is probably currently much reduced now, as the feature set of the GII is really pretty lavish.

There is however one feature of the SiTech I'm wondering if we may see come the GII way. That is the tick management feature used with high-resolution external encoders. Using tick-management they are basically able to eliminate PE (on Losmandy mounts as well). That would certainly be a killer feature for GII I think, especially, as a GII needn't be bound to a PC like the SiTech software. Latest talk on the SiTech group seems to be headed in the direction of Heidenhain absolute precision encoders with 33M tics for < $500.

Is this a feature that may be in GII's future?

Thanks,
-esy

Erik Sigurd Young
"My punctuality is well known. When The Revolution takes place, I'll be late, and I'll be shot as a traitor."

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