GSO Base Plate for 2" GSO Reflector Focusers - 303mm Curve (For 12" Telescopes)
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Overview:
- GSO 303mm base plate # FF434 for use with GSO 2" reflector focusers only. Not for use with GSO's 1.25" or 3" focusers.
- Will fit GSO-made 2" reflector focusers sold under other brands like TPO, Apertura, TS, Zhumell, some Orion, some Meade, etc. Should also fit 12" Celestron Star Hopper and Meade Lightbridge (but not Meade Lightbridge Plus) telescopes. May fit some model years of Orion XT 12" dobsonians (but not most). Do not assume that your focuser is made by GSO. If you are not sure about this, email us with a photo of your focuser and we can advise you.
- Not for use with reflector focusers from any other brand (such as Celestron, Sky-Watcher, Long Perng, Astro-Tech, Kuming United Optics, most Orion, most Meade, etc.).
- Designed to fit telescope tubes with an outside diameter of about 12", just smaller than that of many 12" aperture telescopes.
- If your tube OD (outside diameter) is a little less than 303mm, there will be a small, inconsequential gap between the underside of the base plate and your telescope tube surface. You can plug this gap with foam if you want to.
- If your tube OD is slightly larger than 303mm, you will need to add shims between the base plate's mounting holes and the tube surface and/or carefully align the focuser orientation to make it perpendicular to the telescope's optical axis.
- No mounting screws are included. You may be able to use the ones already on your scope or may need to purchase other ones locally.
- Includes allen key to attach this base plate to your GSO focuser.
- We cannot advise you if this base plate is the right fit for your telescope or focuser as these specifications are not standardized in the astronomy industry. Hence, please do not purchase this item without carefully comparing its specifications to that of your telescope tube.
Key Specifications:
Please detailed the schematic diagram above for more information.
- Base plate curve diameter: 11.93" (303mm)
- Base plate dimensions: 3.54" x 3.54" (90mm x 90mm)
- Hole Spacing (center-to-center along telescope tube/optical axis): 70mm (2.76")
- Hole Spacing (center-to-center perpendicular to telescope tube; straight line measurement): 73mm (2.87")
- Hole Spacing (center-to-center perpendicular to telescope tube; measured along curve of base plate): 74mm (2.91")
- Inside diameter of central hole: 3.07" (78.0mm)
- Mounting hole specification: Unthreaded inside diameter of 4.9mm
Other Information
- Country of Manufacture: Taiwan
Overview:
- GSO 303mm base plate # FF434 for use with GSO 2" reflector focusers only. Not for use with GSO's 1.25" or 3" focusers.
- Will fit GSO-made 2" reflector focusers sold under other brands like TPO, Apertura, TS, Zhumell, some Orion, some Meade, etc. Should also fit 12" Celestron Star Hopper and Meade Lightbridge (but not Meade Lightbridge Plus) telescopes. May fit some model years of Orion XT 12" dobsonians (but not most). Do not assume that your focuser is made by GSO. If you are not sure about this, email us with a photo of your focuser and we can advise you.
- Not for use with reflector focusers from any other brand (such as Celestron, Sky-Watcher, Long Perng, Astro-Tech, Kuming United Optics, most Orion, most Meade, etc.).
- Designed to fit telescope tubes with an outside diameter of about 12", just smaller than that of many 12" aperture telescopes.
- If your tube OD (outside diameter) is a little less than 303mm, there will be a small, inconsequential gap between the underside of the base plate and your telescope tube surface. You can plug this gap with foam if you want to.
- If your tube OD is slightly larger than 303mm, you will need to add shims between the base plate's mounting holes and the tube surface and/or carefully align the focuser orientation to make it perpendicular to the telescope's optical axis.
- No mounting screws are included. You may be able to use the ones already on your scope or may need to purchase other ones locally.
- Includes allen key to attach this base plate to your GSO focuser.
- We cannot advise you if this base plate is the right fit for your telescope or focuser as these specifications are not standardized in the astronomy industry. Hence, please do not purchase this item without carefully comparing its specifications to that of your telescope tube.
Key Specifications:
Please detailed the schematic diagram above for more information.
- Base plate curve diameter: 11.93" (303mm)
- Base plate dimensions: 3.54" x 3.54" (90mm x 90mm)
- Hole Spacing (center-to-center along telescope tube/optical axis): 70mm (2.76")
- Hole Spacing (center-to-center perpendicular to telescope tube; straight line measurement): 73mm (2.87")
- Hole Spacing (center-to-center perpendicular to telescope tube; measured along curve of base plate): 74mm (2.91")
- Inside diameter of central hole: 3.07" (78.0mm)
- Mounting hole specification: Unthreaded inside diameter of 4.9mm
Overview:
- GSO 303mm base plate # FF434 for use with GSO 2" reflector focusers only. Not for use with GSO's 1.25" or 3" focusers.
- Will fit GSO-made 2" reflector focusers sold under other brands like TPO, Apertura, TS, Zhumell, some Orion, some Meade, etc. Should also fit 12" Celestron Star Hopper and Meade Lightbridge (but not Meade Lightbridge Plus) telescopes. May fit some model years of Orion XT 12" dobsonians (but not most). Do not assume that your focuser is made by GSO. If you are not sure about this, email us with a photo of your focuser and we can advise you.
- Not for use with reflector focusers from any other brand (such as Celestron, Sky-Watcher, Long Perng, Astro-Tech, Kuming United Optics, most Orion, most Meade, etc.).
- Designed to fit telescope tubes with an outside diameter of about 12", just smaller than that of many 12" aperture telescopes.
- If your tube OD (outside diameter) is a little less than 303mm, there will be a small, inconsequential gap between the underside of the base plate and your telescope tube surface. You can plug this gap with foam if you want to.
- If your tube OD is slightly larger than 303mm, you will need to add shims between the base plate's mounting holes and the tube surface and/or carefully align the focuser orientation to make it perpendicular to the telescope's optical axis.
- No mounting screws are included. You may be able to use the ones already on your scope or may need to purchase other ones locally.
- Includes allen key to attach this base plate to your GSO focuser.
- We cannot advise you if this base plate is the right fit for your telescope or focuser as these specifications are not standardized in the astronomy industry. Hence, please do not purchase this item without carefully comparing its specifications to that of your telescope tube.
Key Specifications:
Please detailed the schematic diagram above for more information.
- Base plate curve diameter: 11.93" (303mm)
- Base plate dimensions: 3.54" x 3.54" (90mm x 90mm)
- Hole Spacing (center-to-center along telescope tube/optical axis): 70mm (2.76")
- Hole Spacing (center-to-center perpendicular to telescope tube; straight line measurement): 73mm (2.87")
- Hole Spacing (center-to-center perpendicular to telescope tube; measured along curve of base plate): 74mm (2.91")
- Inside diameter of central hole: 3.07" (78.0mm)
- Mounting hole specification: Unthreaded inside diameter of 4.9mm
Other Information
- Country of Manufacture: Taiwan
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GSO Base Plate for 2" GSO Reflector Focusers - 303mm Curve (For 12" Telescopes)


















