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GSO 1.25" Crayford Focuser (with 176mm base plate) for Reflectors - Single Speed
| Brand | GSO |
| Part Number | - |
| Availability | available |
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Product Info
Manufacturer Description
New from GSO! This high quality, single-speed 1.25" Crayford focuser for reflector telescopes from Guan Sheng Optical (GSO) is a joy to use. You will wonder how you ever lived without it once you install it! It will greatly aid in achieving precise focus for visual observations and astrophotography and you will experience very smooth and precisely controlled focuser motion with zero backlash and zero image shift.
CNC machined from aluminum and anodized black, this focuser comes with a base plate to attach to your reflector telescope. The inner drawtube glides on 4 precision bearings and a roller shaft and provides 47mm of focus travel. The inner barrel is baffled and painted a flat black to minimize reflections for maximum contrast.
The focuser also has two large thumbscrews. The thumbscrew on the telescope side can be used to lock the focuser, allowing the use of heavy accessories or cameras without fear or slippage or losing focus. The other thumbscrew on the eyepiece end can be used to adjust the tension of the focuser to achieve a focusing "feel" that you like. At the easiest (lightest) setting, the focuser moves very smoothly. At tighter settings, you can still use heavier accessories without sacrificing much of the smooth focuser action.
Focuser Specifications (With 176mm Base Plate):
• Minimum focuser height = 3.01" (77mm)
• Maximum focuser height = 4.88" (124mm)
• Tube travel = 1.86" (47mm)
• Focuser weight = 14oz (397gm)
• Focus knob diameter = 1.24" (31.6mm)
• Microfocus knob diameter = N/A
• Outer drawtube diameter (on telescope side - your telescope tube cutout must exceed this) = 1.83" (46.6mm)
• Millimeter markings on focuser drawtube: No
• Rotatable: No (But body can be rotated by loosening two allen screws that connect the focuser to the base plate)
• Dust plug: One 1.25" dust plug included
• Brass compression rings: No
176mm Base Plate Specifications:
- Base plate curve diameter: 6.93" (176mm)
- Base plate dimensions: 2.8" x 2.8" (71mm x 71mm)
- Hole Spacing (center-to-center along telescope tube/optical axis): 57mm (2.25")
- Hole Spacing (center-to-center perpendicular to telescope tube; straight line measurement): 55mm (2.16")
- Hole Spacing (center-to-center perpendicular to telescope tube; measured along curve of base plate): 56mm (2.20")
- Diameter of cutout hole for focuser body: 2.4" (60.9mm)
Please note: Most GSO Crayford focusers have or will soon develop two bearing marks/lines on the upper side of the drawtube. This is caused by wear on the barrel anodizing where is makes contact with the roller bearings. In some focusers, you have to look hard to find these marks. In others, it is very prominent, even for brand new items received from GSO. This does not indicate a defective or used product and is essentially just cosmetic.
Reviews
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Sep 22, 2018
Very pleased!
Pros: Cons: Comments:Excellent buy.
Bottom Line: Would you recommend this item? Yes
Focuser fit my Meade Polaris 130 perfectly.
Enlarging the opening to accommodate the focuser was easy using a 2 inch hole saw.
Changing the focuser on my Meade Polaris was well worth every penny spent.This review was provided courtesy of AgenaAstro.com
Mar 1, 2018Nice Crayford Style Focuser
Pros: Cons: Comments:Very impressed with my new GSO 1.25" Crayford Focuser. Build quality is good. Big improvement over my old rack and pinion focuser.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Sep 12, 2017Wow, what a difference!
Pros: Cons: Comments:Compared to the stock focuser that came with my scope, the GSO is light years ahead. No flop or play, great craftsmanship, smooth action and a nice feel. I couldn't be more pleased.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Dave In Vermont Well-Known Member
- Skill Level
- Unknown
- Time with Product
- Unknown
- User Notes:
- Review by Dave F. of Vermont.
Apr 29, 2016Excellent As A Crayford Tends To Be
Pros:Strong Construction,Easy to Use
Cons: Comments:All the good things already stated. Only minor tiff was a lack of mounting-bolts for attaching the base to the OTA of a Newtonian reflector. Bought as replacement for a 2002 GSO 200mm F/4.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Feb 4, 2016Good Price/Performance focuser for DIY telescopes
Pros:Easy to Use,Strong Construction,Accurate
Cons: Comments:This focuser will give you the highest accuracy and precision according to its price. Shipping and handling also are superb. I can highly recommend for beginners and also professionals who is making a DIY telescope.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Jul 1, 2015Definitely an upgrade
Pros:Strong Construction,Easy to Use
Cons: Comments:I bought this focuser as a replacement for the stock, rack-and-pinion focuser that came with my ca. 2002 GSO 8-inch f/4 Newtonian reflector. The new focuser was a drop-in replacement for the old one, with the holes on the OTA aligning perfectly with those on the new focuser. Installation took only a few minutes. I was immediately impressed with how much smoother and more refined the action on this Crayford focuser is when compared to the action on the old one. Under the stars, this led to significantly improved focusing, especially when imaging with my DSLR. Because the profile of this focuser is lower than that of my old one, I had hoped that it would allow me to bring the DSLR to focus without a barlow lens, something that the old focuser was unable to do. Despite the lower profile, however, it turns out that I still need to employ a barlow to achieve focus. Nonetheless, I remain absolutely pleased with this focuser.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Aug 11, 2014Excellent upgrade for my Vixen R130Sf
Pros:Strong Construction,Accurate,Nice fit and finish,Lightweight,Easy to Use
Cons:Retrofit Takes Some Work
Comments:Finally, a nice and affordable upgrade for the cheap plastic stock focuser on my otherwise beautiful Vixen R130Sf reflector. You'll have to enlarge the hole on your scope for the focuser tube by a few mms, but that is easy work for a Dremel tool. You'll also have to drill 4 new holes to attach it to your OTA. Also, you will need an inexpensive 1.25" Blue Fireball extension. The result? A solid 1.25" focuser with no flexure and looks like it was made for this scope. It should be a fine replacement for similar cheap, plastic focusers on other popular 130mm and 150mm reflectors.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
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