Gurley on a Losmandy Titan


Che
 

Anyone here installed the Gurley encoder on a Losmandy Titan.  If so can you share pics of your intallation.  A friend has a G11T(titan RA) and is considering the Gurley.  I couldnt find any pics on this site so thought I'd ask.
Thanks
Che


Allen Ruckle
 

The Gurley encoder ( and all other high Precision encoders ) require direct connection to the RA axis shaft.   Access To the shaft would require a major modification of the mount rear housing and extension of the RA shaft.

aruckle

 


Che
 

thanks aruckle, I've only seen those mounts once or twice and didnt really look with an encoder in mind.  Didnt know what the ra housing was like.  I guess thats why nobody has posted that they did it!!!

Che

On 6/14/2021 11:46 AM, Allen Ruckle wrote:

The Gurley encoder ( and all other high Precision encoders ) require direct connection to the RA axis shaft.   Access To the shaft would require a major modification of the mount rear housing and extension of the RA shaft.

aruckle

 


BR
 

Che, in the SiTech setup manual I believe Don modded a losmandy. Not the Titan but it utilized the hollow polar shaft used for polar scope as a point to mount an adapter,. As I have no personal experience with the Titan, I can't say for sure but take a look at the manual and maybe ask Don.


On Mon, Jun 14, 2021 at 3:54 PM Che <cheman@...> wrote:

thanks aruckle, I've only seen those mounts once or twice and didnt really look with an encoder in mind.  Didnt know what the ra housing was like.  I guess thats why nobody has posted that they did it!!!

Che

On 6/14/2021 11:46 AM, Allen Ruckle wrote:

The Gurley encoder ( and all other high Precision encoders ) require direct connection to the RA axis shaft.   Access To the shaft would require a major modification of the mount rear housing and extension of the RA shaft.

aruckle

 


Che
 

thanks BR

I should be face to face with the mount in the next day or two and able to see what I can figure out.

Che

On 6/14/2021 2:09 PM, BR wrote:
Che, in the SiTech setup manual I believe Don modded a losmandy. Not the Titan but it utilized the hollow polar shaft used for polar scope as a point to mount an adapter,. As I have no personal experience with the Titan, I can't say for sure but take a look at the manual and maybe ask Don.


On Mon, Jun 14, 2021 at 3:54 PM Che <cheman@...> wrote:

thanks aruckle, I've only seen those mounts once or twice and didnt really look with an encoder in mind.  Didnt know what the ra housing was like.  I guess thats why nobody has posted that they did it!!!

Che

On 6/14/2021 11:46 AM, Allen Ruckle wrote:

The Gurley encoder ( and all other high Precision encoders ) require direct connection to the RA axis shaft.   Access To the shaft would require a major modification of the mount rear housing and extension of the RA shaft.

aruckle

 


Don W
 

The SiTech Setup Manual show images of Chuck Shaw's installation of a Gurley on a G-11 mount.  I converted an AP1200 mount to use a Gurley by machining an adapter mount for the RA shaft.  My installation on the AP mount is also shown in the manual.
Don W


BR
 

Sorry people, it has been a while since I read the manual. Old age really does mess with your gray matter. Even got you and Chuck mixed, so I'll shut up now.....


On Mon, Jun 14, 2021 at 7:32 PM Don W <westergren@...> wrote:
The SiTech Setup Manual show images of Chuck Shaw's installation of a Gurley on a G-11 mount.  I converted an AP1200 mount to use a Gurley by machining an adapter mount for the RA shaft.  My installation on the AP mount is also shown in the manual.
Don W


jervisbayastro
 

Many years ago I tried fitting a Gurley via its central shaft threaded hole to a matching screw protruding from centre of the RA clutch knob on my Losmandy GM200. The GM200 was the precursor to the Titan and uses a similar knob which is stationary as the mount rotates. I removed the grip bars from the knob and attached the Gurley body via an arm to a clamp on the RA/Dec housing. I later tried a tubular housing in place of the arm. Unfortunately neither method was successful and I eventually concluded the Gurley was either faulty or the fact that it was not one of the recommended versions and/or of too high resolution.
Sorry I can't provide any photos at present as I am away from home.

Col Shepherd
Vincentia, NSW
Australia


Che
 

Hello Col and thank you for your response

I had my hands on the titan(actually the G11T) yesterday and it does seem like a challenge to fit a Gurley on there.  I would like to see your pictures when it's convenient for you to send them.  I'm thinking the easiest solution would be to use a Renishaw readhead and scale tape.  I've been using this  on my mount for years with great success and seems a bracket to hold the Renishaw would be fairly easy to make. 

Thanks for your info

Che

On 6/18/2021 1:25 AM, jervisbayastro wrote:
Many years ago I tried fitting a Gurley via its central shaft threaded hole to a matching screw protruding from centre of the RA clutch knob on my Losmandy GM200. The GM200 was the precursor to the Titan and uses a similar knob which is stationary as the mount rotates. I removed the grip bars from the knob and attached the Gurley body via an arm to a clamp on the RA/Dec housing. I later tried a tubular housing in place of the arm. Unfortunately neither method was successful and I eventually concluded the Gurley was either faulty or the fact that it was not one of the recommended versions and/or of too high resolution.
Sorry I can't provide any photos at present as I am away from home.

Col Shepherd
Vincentia, NSW
Australia


Don W
 

Hi Che,
Look at the SiTech Setup Manual, in Appendix P there are pictures and description of how Chuck Shaw installed his Gurley on his G-111.
Don W


Che
 

Thanks Don but the G11 and the Titan are completely different animals.  The G11T which this mount is has the G11 dec assy but the  Titan RA  Pic attached
Che


Che
 

I have some spare renishaw readheads and scale tape.  that has been working well on my Iott IPI 262 mount.  We are going to fab a bracket for the readhead for the G11T and see how it goes.


jervisbayastro
 

Hi Che, Sorry but I just looked at images of your mount and while it looks like it uses the fixed polar shaft design of the original GM200/Titan, the clutch operation appears to be very different plus it's hard to tell if there is a place where the polar shaft is exposed for a Gurley to attach.
As you've concluded, the Renishaw tape sounds like the best option. I was also considering Renishaw for my mount as well but last time I looked into it I decided it was too expensive. I'll be interested to hear how you go with it.
Regards,
Col


jervisbayastro
 

Che,
Photo of my heavily modified GM200 but without Gurley.
You can see the clutch tightening "capstan knob" protruding from the Dec  housing and the Gurley was mounted in line with that.
Col


Allen Ruckle
 

The only access to  the polar shaft to attach an encoder is to lengthen the polar axis shaft and position the encoder against the polar shaft clutch nut.

aruckle


Che
 

Hi Col

Yes I think the Renishaw is what I will suggest to my friend.  You can often find renishaw readheads that will work on Ebay used.  Thats where I picked mine up.  Sometimes you can even find the RGs20 scale tape.  We have figured out a bracket design and once he fabs that, we will hook it up to my  controller and use some  scale tape I have here.  If it works out as it should, I think he will be buying a Servo II

regards

Che

On 6/18/2021 5:42 PM, jervisbayastro wrote:
Hi Che, Sorry but I just looked at images of your mount and while it looks like it uses the fixed polar shaft design of the original GM200/Titan, the clutch operation appears to be very different plus it's hard to tell if there is a place where the polar shaft is exposed for a Gurley to attach.
As you've concluded, the Renishaw tape sounds like the best option. I was also considering Renishaw for my mount as well but last time I looked into it I decided it was too expensive. I'll be interested to hear how you go with it.
Regards,
Col


Che
 

Hi Allen

after seeing theTitan RA axis im person, I think you are correct.   We will by trying out a Renishaw readhead with scale tape soon. 

On 6/18/2021 6:52 PM, Allen Ruckle wrote:
The only access to  the polar shaft to attach an encoder is to lengthen the polar axis shaft and position the encoder against the polar shaft clutch nut.

aruckle


Rory Duncan
 

So you all have just blown my mind... I didn't realize there was an
alternate to the rotary encoders. My problem with big blue is that my
RA axis is a 4' long 100mm diameter piece of SOLID stainless steel. I
could never figure out a good way to get an accurate center on the end
of it. If I can just stick a piece of that encoder tape around the
outside of the shaft, I should be golden. How many ticks per
rev(inch?) are we looking at with these encoder tapes/encoder
combinations?

Does anyone have a good link to where to get these tapes? My google fu
is failing me and giving me lots of pictures on renshaw's site, but no
products...

RAD

On Fri, Jun 18, 2021 at 11:31 PM Che <cheman@charter.net> wrote:

Hi Allen

after seeing theTitan RA axis im person, I think you are correct. We will by trying out a Renishaw readhead with scale tape soon.

On 6/18/2021 6:52 PM, Allen Ruckle wrote:

The only access to the polar shaft to attach an encoder is to lengthen the polar axis shaft and position the encoder against the polar shaft clutch nut.

aruckle


Don W
 

Hi Rory,

Search Renishaw encoders.  They have two types of tape/encoders - Optical and Magnetic.  The Optical read heads need mor precision and must be mounted closer to th tapes, while the Magnetic are very tolerant and easy to setup (they sense across a greater distance.  The magnetic tapes are not as high resolution.  They should get you around 400K to 500K with your 100mm shaft.

Don W


Don W
 

Hi Rory,

Look at this Renishaw page for magnetic encoders and tapes:
https://www.renishaw.com/en/9801.aspx
Don W