Astro-Physics Rings

47RING - 130 Starfire EDF GT refractor or other telescope tubes of 4.7" diameter; weight of set: 1.9 lb. (0.8 kg.).

55RING2 - (new top-of-ring hole-pattern and taller base for increased clearance) 130 Starfire GTX and 130 Starfire EDT/EDF refractors or other telescope tubes of 5.5" diameter; weight of set: 2.80 lb. (1.3 kg.).
Note: New top-of-ring hole-pattern allows direct connection of dovetail plates (no riser block needed).

65RING - 140 StarFire EDF and all 155 mm and 160 mm Astro-Physics refractors or other telescope tubes of 6.5" diameter; weight of set: 3.4 lb. (1.6 kg.).

80RING2 - 175 StarFire EDF, 180 StarFire EDT/EDF, 206 StarFire EDF and other telescopes with 8.0" diameter tubes, pair; weight of set: 5.4 lb. (2.4 kg.).

80RING21 - 175 StarFire EDF, 180 StarFire EDT/EDF, 206 StarFire EDF and other telescopes with 8.0" diameter tubes, single ring; single ring weight: 2.7 lb. (1.2 kg.).

Bottom of rings: Drilled and tapped for 1/4-20 screws. The hole patterns fit the 800 mounts, our Dovetail Plates (SBD12 and SBD16), our Ribbed Plates (900RP, 1200RP15 and 1200RP), our Flat Plates (FP1500 and FP1800) and the SBDAPB Riser Blocks.

Please click the illustration at left for a detailed schematic of the Ring Hole Patterns.

Parallax Rings

Parallax Instruments is a great source for a variety of mounting rings for other scopes. Let Joe Nastasi know which mounting plate you plan to use and he will drill the hole pattern you need. If you are planning to use them with our mounting plates, specify the Astro-Physics hole pattern on the top and bottom of the rings. Please order the rings directly from Parallax Instruments.

Our counterweights are precision machined from 303 stainless steel. The weights slip easily onto the counterweight shaft and are secured in position with a large hand knob/brass pin assembly. The brass pin will not mar your shaft.

Note: Some weights may not use the bronze insert as depicted in the photo.

Keep in mind that you can adjust the position of the weights to counterbalance varying loads. However, the addition of a guidescope, camera and other heavy accessories may necessitate an additional counterweight. If you plan to mount your catadioptric, Newtonian or any other scope, figure that you will need a counterweight total equal to approximately 90-125% of the weight of your tube assembly and accessories (large diameter scopes require a higher percentage). The 1100GTO and 1600GTO mounts require slightly more weight than the older 900GTO and 1200GTO mounts.

See Balance to Optimize Guiding for proper counterweight placement.

Below are the nominal weights and dimensions of our counterweight line.

Counterweights for 1.125" Shaft - 400, 600E, 800 and Mach1GTO mounts:
Use these dimensions to determine how many counterweights will fit on each shaft:
6 lb. Counterweight (6SLCWT) - diameter: 5", thickness 1.1"
9 lb. Counterweight (9SLCWT) - diameter: 5", thickness 1.8"
14 lb. Counterweight (14SLCWT) - diameter: 6", thickness 1.8"
Mach1GTO Counterweight Shaft (M8084-A) - usable length 13.675"

For 400, 600E and 800 mounts, measure the length of your shaft.

Counterweights for 1.875" Diameter Shaft - 900, 1100, 1200, 1600 mounts (and Mach1GTO using optional shaft):
Use these dimensions to determine how many counterweights will fit on each shaft. Note that the diameter of the 24 lb. counterweight is larger than the others:
5 lb. Counterweight (5SCWT) - diameter: 6", thickness: 0.75"
10 lb. Counterweight (10SCWT) - diameter: 6", thickness: 1.4"
18 lb. Counterweight (18SCWT) - diameter: 6", thickness: 2.5"
30 lb. Counterweight (30SCWT188) - diameter: 7.5", thickness 2.5"
900/1100 Counterweight Shaft (M9404-B) - usable length 16.675"
1200/1600 Counterweight Shaft (M12601-E) - usable length 22.0"

Counterweight for 2.5" Shaft - 3600GTO and 3600GTOPE mounts:
Information pertaining to these counterweights is on the 3600GTO webpage.

The KEYPRO keypad protector (shown with the keypad so that you can see how it fits) is a heavy-duty molded rubber casing with a full 1/4" thickness on all impact surfaces. If you accidentally drop your keypad, the rubber casing will absorb much of the blow. Your display, keypad, electronics and the case itself will be protected from damage. In addition, the rubber prevents the keypad from sliding when placed on a table or other flat surface and the keypad will feel secure in your hands as you observe. The KEYPRO also offers protection during transport and storage.

The black case is designed with cutouts for the cable and retractable hanger.

The keypad protector is now included with the 900GTO, 1100GTO, 1200GTO, 1600GTO and Mach1GTO .

This revolutionary design has been enthusiastically praised for its ease of use and accuracy by customers in both the northern and southern hemispheres. See a larger image of the reticle.

Advantages of the Right-Angle Polar Alignment Scope: Right-angle viewing eliminates neck strain during polar alignment. Reticle suitable for Northern and Southern Hemispheres through 2040. Precise adjustments are made without rotating the Polar Alignment Scope or the Right Ascension axis. Polar Align in light polluted areas and during early twilight (only Polaris needs to be seen) Battery-powered Illuminator with adjustable brightness control. Easily interchange between all of your Astro-Physics mounts that have the appropriate backplate/adapter. Optical Specs: Objective lens: 200 mm FL, 25 mm diameter Eyepiece: 22 mm Widefield Orthoscopic, focusing ocular Field of view: 6 degrees Right-angle prism diagonal

Methods to Determine Position of Polaris on Reticle:

• Astro-Physics Polar Alignment Scope Utility - now a part of the AP V2 ASCOM driver
• iPhone/iPad/iPod Touch App - Click this link to the "Astro-Physics PolarAlign" App
• Windows Phone App - Click this link to the "AP Polar Align" App
• Android App - Click this link to the "Polar Finder" App

Use with these Astro-Physics mounts:

• 1100GTO and 1600GTO - All mounts (including those with absolute encoders) include the appropriate backplate to use the RAPAS.
• Mach1GTO - All mounts shipped beginning in 2014 (serial number M10670 and later) will have the adapter for the Right-Angle Polar Alignment Scope built in. Mounts shipped in prior years must purchase the Right-Angle Polar Alignment Scope Adapter for Mach1GTO (RAPM1), shown below, separately.
• All versions of the 900 mount - must purchase the Right-Angle Polar Alignment Scope Adapter for 900 Mounts (RAP900) described below
• 1200 mounts (except the original 1200 black version and the 1200DA) - must purchase the Right-Angle Polar Alignment Scope Adapter for 1200 Mounts (RAP1200) described below

Note: 400, 600 and 800 mounts - the larger aperture of this polar alignment scope cannot be adapted to the smaller shaft diameters of the 400, 600 and 800 mounts.

In order to obtain extreme precision, it is possible to perform a precise polar alignment using a traditional drift alignment (visually or with CCD camera), or by using Ray Gralak’s PEMPro / Polar Align Wizard. Once the alignment is spot-on, the push/pull adjustment screws on the adapter are used to orient Polaris into its specific location on the reticle. This needs to be done only once and many users may find it unnecessary at all, as the RAPAS is extremely accurate out-of-the-box.

RAPAS instructions are found on the Technical Support page of the website under "Current Products - Instruction Manuals and Sheets...Mount Accessories."

These covers allow you to keep your Polar Alignment Scope protected while remaining threaded in your mount. They were designed to work with all models of the polar alignment scopes that we have offered except the earliest PASILL and our upcoming Right-Angle Polar Alignment Scope. If you are uncertain which model polar scope you have, please compare yours with those pictured on this Polar Scope Identification page.

• all 900GTO mounts shipped since October 2005

• all 400 mounts
• all 1200 mounts, except the original black, metric mount
• all 900 mounts shipped prior to October 2005

Q9700 attached on the 900GTO

A scribe line has been carved into outer diameter of the bell of the Q12700 to differentiate it from the Q9700. If you have an older AND a newer 900GTO, knowing which cover belongs to what mount is easy!

These covers were tested on current 900 and 1200 model mounts, both constructed with their respective taller polar fork assemblies. You may wish to review the images for the 900 Polar Fork Assembly (S900PF-A) and the 1200 Polar Fork Assembly (S1200PF-B) to confirm which version is installed on your mount.

If you reside where your mount is set to the highest latitude setting (52-68 degrees for the 900, 57-69 degrees for the 1200 mount) and you have the shorter polar fork, you may have clearance issues while installing and removing this part. We did not have either mount available in this configuration during our testing phase. However we have provided a scale diagram that you can use to determine whether you will encounter interference in your current latitude setting. Please print the Polar Scope Cover Illustration at 100% to cut out and use as a test piece.

We do not expect that customers using the Hi-Lo Wedge for Latitudes from 0-22 or beyond 68 degrees will experience a conflict with either polar scope cover and their mount in that configuration.

If you are uncertain when your 900GTO shipped, please use the photos (right) as a reference for where to measure on your mount to determine the correct cover size. We used a 1200GTO since it was readily available; however, the measurement points are identical on older 900 mounts.

Note that all LEDs and illuminator units must be removed from the polar scope before installing these covers.

For more detailed information regarding the measurements of these parts, please refer to the Polar Scope Cover Illustration.

If you plan to use the original battery pack that came with your polar scope and your polar scope has reverse polarity: You will need the CABPAS3.

If you plan to use the original battery pack that came with your polar scope and your polar scope has normal polarity: You can use the CABPAS4.

The 800 mount requires part #E0187 (RCA phono to 3.5mm adapter).

CABPAS3 - Cable for Polar Alignment Scopes with reverse polarity LED - for PASILL3 and some PASILL4. Plugs directly into reticle output on mount (part #E0187 required for use with 800 mounts).

CABPAS4 - Cable for Polar Alignment Scopes with normal polarity - for some PASILL4. Plugs directly into reticle output on mount (part #E0187 required for use with 800 mounts).

Click here for photos and illustrations that will help you to identify which polar scope you have.

The CABPAS cable enables you to power the PASILL2 Polar Alignment Scope (previous version, sold from January 2001 to July 2002) directly from the reticle output on your 400, 600, 600E, 800, 900, 1100, 1200, 1600 or Mach1GTO mount. The 800 mount requires part #E0187 (RCA phono to 3.5mm adapter). This method allows you to control the brightness level with the keypad (GTO mounts) or controller (non-GTO mounts) and it frees you from relying on batteries.

Click here for photos and illustrations that will help you to identify which polar scope you have.

If you own a 1100GTO, 1600GTO or some Mach1GTO mounts and wish to use the PASILL4, PASILL4L or PASILL3 that you already own, you will need to substitute this adapter for the one that originally came with your Polar Alignment Scope. It was designed to be thread into the 1.79" diameter opening on the back plate of the 1100GTO, 1600GTO and some Mach1GTO mounts (those shipped beginning 2014 with serial number M10670 or later).

When purchasing a new Losmandy Polar Scope a PASILL4-179 version can be purchased which already includes this adapter.

Please note that we cannot guarantee that the adapter will fit all Losmandy polar scopes from prior years.

If you own a 400, 600, 600E, 800, 900, 1200 or Mach1GTO mount and wish to use a Losmandy Polar Alignment Scope that you already own, you will need to use this adapter with your Polar Scope. It was designed to adapt the scope to the AP thread size.

When purchasing a new Losmandy Polar Scope a PASILL4 version can be purchased which already includes this adapter.

Please note that we cannot guarantee that the adapter will fit all Losmandy polar scopes from prior years.

This adapter threads into the rear of the right ascension axis of the mounts specified below to allow use of the Polar Alignment Scope (these models - PASILL, PASILL2, PASILL3, PASILL4 or PASILL4L). Some 400 mount models require this part to attach encoders as well as the polar scope. This is one of the most common items to be misplaced and we maintain an extra stock if you have lost yours.

NOTE: Do not order this part if placing a new mount order (already included when needed).

Mounts: Most 1200 mount models (except the original black 1200DA models), all 900 mount models (HDA, QMD, SMD and GTO). It is also used in some 400 mount models that have been produced.

Our mounted encoders will allow you to use digital setting circles with your Astro-Physics mounts. The 10,000-step encoders are enclosed in machined aluminum housings that were designed to look like an integral part of your mount, rather than an after-market add-on. The encoders read the movements of the shaft directly. One encoder is mounted securely to the declination axis just above the counterweight shaft and the other to the polar axis housing.

You can upgrade previous models of our 400, 600E, 800, 900 and 1200 German Equatorial Mounts (see exceptions below). If you have a GTO model mount, you will not need these encoders since the encoders built into your servo motors are much more accurate. However, it is possible to use them, if you wish. See this PDF for instructions.

ENC10-400   - 10K-Step Encoders for previous models of 400 mount
ENC10-600  - 10K-Step Encoders for previous models of 600E mount (cannot be used with some early models, please call before purchasing)
ENC10-900    - 10K-Step Encoders for previous models of 900 mount (cannot be used with 900GTO mounts shipped October 2005 or later, serial numbers 900451 or larger (with the exception of 900501, which can use the encoders))
ENC10-1200  - 10K-Step Encoders for previous models of 1200 mount (cannot be used with 1200GTO mounts shipped May, 2006 or later, serial numbers 1200572 or larger).
ENC10-800    - 10K-Step Encoders for previous 800 model (cannot be used with some early models of the 800 mount, please call before purchasing)