2" Jaeger's Focuser with Red Knobs

This focuser was provided with our very earliest refractors in the early and mid-eighties. The red knobs were a very distinguishing feature.

• Shorten tube an unknown amount from the focuser end. We do not have one of these focusers available to measure. You can determine the amount of the telescope tube to cut off by comparing the length of the Jaeger's and current focuser. You may wish to shorten the tube further, if you plan to use a binocular viewer or other accessory that requires alot of backfocus. It would be wise to check the backfocus of your current setup before cutting the tube so that you can allow for all desired accessories.
• Square the end of the tube.
• Machine new adapter plate for the new focuser that will install on the end of the tube. Alternatively, if you have a 6" OD (5.88" ID) or 7" OD (6.88" ID0 tube, you can order the backplate (adapter plate) and Astro-Physics focusers from D&G Optical or have a custom adapter machined by Precise Parts.
• Install new adapter plate squarely onto telescope tube.
• Thread new focuser in place.

2.7" Focuser with Aluminum Casting

• Shorten tube approximately 1" inch from the focuser end. You may wish to shorten the tube further, if you plan to use a binocular viewer or other accessory that requires alot of backfocus. It would be wise to check the backfocus of your current setup before cutting the tube so that you can allow for all desired accessories.
• Square the end of the tube.
• If the original focuser adapter fit into the tube as shown in the photo, you will need to machine a new adapter plate for the new focuser. Alternatively, if you have a 6" OD (5.88" ID) or 7" OD (6.88" ID0 tube, you can order the backplate (adapter plate) and Astro-Physics focusers from D&G Optical or have a custom adapter machined by Precise Parts. Once the adapter plate is complete, install it squarely onto telescope tube.
• If the original focuser is attached to a machined adapter that fits over the end of the tube, loosen the set screw on the underside of the focuser adapter with a 3/32 inch (2.38mm) wrench - no metric equivalent. The thread used on the older focuser body is the same as used today, so you should be able to substitute one for the other. Please note that the tube will still have to be shortened as mentioned above.
• Thread new focuser in place.

2" Japanese Focuser

• Shorten tube approximately 1 inch from the focuser end. You may wish to shorten the tube further, if you plan to use a binocular viewer or other accessory that requires alot of backfocus. It would be wise to check the backfocus of your current setup before cutting the tube so that you can allow for all desired accessories.
• Square the end of the tube.
• You can probably use the original focuser adapter, however you may have to machine a new one. Alternatively, if you have a 6" OD (5.88" ID) or 7" OD (6.88" ID) tube, you can order the backplate (adapter plate) and Astro-Physics focusers from D&G Optical or have a custom adapter machined by Precise Parts.
• Install adapter plate squarely onto telescope tube.
• Thread new focuser in place.