RAPAS on AP900 with CP4


Dan_Paris
 

  Hi everyone,

I have an AP900 with a CP4 mounted on the dovetail above the RA axis.

Since the CP4 protrudes a bit at the rear in this configuration, I was wondering whether there's enough clearance to install a RAPAS?

Thanks,

Dan


Dean Jacobsen
 

Hi Dan, check out the RAPAS page on the AP site.

https://www.astro-physics.com/rapas

There is a picture of one mounted on a 900.

I used one on my 900 with the controller mounted on the RA axis as shown in the photo without any problem.

Don’t forget to also pick up the 900 specific adapter.

--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Dan_Paris
 

  Hi Dean,

thanks for your message. Did you use a CP3 or a CP4 controller with your AP900?  Unlike the CP3 the CP4 has to be rotated by 90 degrees to fit between the forks so protrudes at the rear.

best regards,

Dan


Dean Jacobsen
 

Aha, I didn't realize that the CP4 has to be rotated 90 degrees vs. the CP3 box.  My 900 had the CP3 box and there was plenty of clearance. 

The 900 RAPAS adapter does push the RAPAS further back from the rear of the mount though.

What is the length of the overhang?  How far does the CP4 extend past the polar axis rear cap?
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Dan_Paris
 


The CP4 extends about 34mm / 1.35 inches past the dovetail (see the picture).

best regards,

Dan


Dean Jacobsen
 

On Sun, Jun 26, 2022 at 01:25 AM, Dan_Paris wrote:
The CP4 extends about 34mm / 1.35 inches past the dovetail (see the picture).
The adapter for the 900 [RAP900] will push the RAPAS further to the rear.  Maybe far enough to clear the 1.35 inch overhang of the CP5.  Unfortunately I don't know how tall the RAP900 is.  The folks at AP would know though.
 
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


George
 

Please see:

https://www.astro-physics.info/tech_support/mounts/servo/cp4-upgrade-inst.pdf

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

Video Tutorials: https://www.youtube.com/astrophysicscorp 

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Dean Jacobsen
Sent: Wednesday, June 29, 2022 10:02 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] RAPAS on AP900 with CP4

 

On Sun, Jun 26, 2022 at 01:25 AM, Dan_Paris wrote:

The CP4 extends about 34mm / 1.35 inches past the dovetail (see the picture).

The adapter for the 900 [RAP900] will push the RAPAS further to the rear.  Maybe far enough to clear the 1.35 inch overhang of the CP5.  Unfortunately I don't know how tall the RAP900 is.  The folks at AP would know though.
 
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Robert
 

Yes. It will clear the end of the CP4 with about 1/8" to spare.  Also, the eyepiece cup should be about 3/4" above the top of the CP4 cover.


Regards,
Robert


Dan_Paris
 

Thanks Robert, great news!

best regards,

Dan