SVBONY SV181 Rack and Pinion Focuser, 1.25 inch, Newtonian Reflector Focuser for Newtonian Reflector Telescope

I replaced the focuser on my Orion 6" dob telescope. Researching I learned that all reflector scopes 6" and smaller share the same cheap sloppy focuser and this is the only one I could find to replace the cheapy. I did have to enlarge the drawtube hole with a rotary tool and drill 4 small holes to mount the base. I am mechanicaly inclined so that was no problem for me. The SVBony focuser is a qaulity unit consisting of a metal base and a far superior drawtube that fits tightly in the base and rides on nylon or delrin guide strips which makes its travel very smooth. The strips also take out all of the drawtube wobble and sloppy fit of the stock plastic focuser. The rack and pinion gears are helical cut and have much less gear backlash than the stock focuser. You cannot beat this focuser for the price period! This focuser is built every bit as good as the replacements sold costing over twice as much as this focuser. This focuser was my introduction to SVbony products and since I have purchased some of there eyepieces as well and boy was I surprised! Very good products indeed. I have no concerns buying SVbony parts and will continue doing so when they have something that I want. Thank you SVbony for bringing your products to the market. You have earned a loyal customer.

Nice upgrade for an old focuser on my 1950’s Newtonian

Plus for all metal construction. Curve on plate is for a 5 inch tube. I have a 4 1/2 inch tube and needed to make a spacer to fill the gap between the tube and the focused. The focus adjuster was very loose and wobbly. Strap that holds the adjuster knob shaft is poorly designed and doesn’t do the job properly. I was able to tighten in up by bending the straps so it pushes the shaft closer to the gear. The strap is made of thin steel and this should have been done at the factory or a better tighter fitting part made. Once tightened it seemed to work acceptable but it might loosen again over time. Tension locking screw on adjuster is a nice feature that OEM adjusters don't have. Good product with some flaws which can be fixed with a little effort. The draw tube and gears are all metal which is nice.

Like all metal hardened steel construction. Like oversize drawtube. Like silver steel knobs. Like brass eyepiece locking system and screw. I will use cutting wheel to reduce tube length. Radius of base may need adapter for other tube sizes. Knob shaft reports confirm wobbly spring tension, but maybe able to fix. Suggest the manufacturer use flat base with rectangular edges for universal fit. Overall, for price and in view of it's hefty feel. This focuser will outlast any plastic type currently found on commercial scopes. Ok, if you look at the pictures this is the way the springs need to be to do their job. If the springs are bent down flush, the knob shaft will be loose. At first I thought Svbony was Rusky, but it's Chinese, and the little gal who works 18 hours a day, just didn't understand the mechanism involved. Hope this helps.

Prime day purchase. About 5 hours of effort to modify for my DIY 80mm objective, 520 mm refractor telescope. Focuser has precise helical brass gears, anti-friction pads for aluminum draw tube stability, tube position tension/lock screw, all metal construction. Total play is minimum. Gear ratio should be good at least up to 200x. Very stable for 1.25 optical eyepieces or to focus into camera. Enjoying the great value. Would be great to have a standardized 2.5 inch tube as an option for refractor. FYI -2 inch tube extension is not big enough for both linear gear and draw tube.

Much nicer focuser than the original .965. Smoother motion and longer stroke. However the radius of the base is to large. I made a shim of pvc to keep it from distorting my tube when I tighten the screws. The description said it would fit a 114mm telescope and it does, just takes a little bit of creativity. Would be nice to include a shim. Also when its all the way in it interferes with the secondary mirror. But that being said, still a good deal and a major improvement on my telescope. Now I can use 1.25 eyepieces and they focus on near and far objects. Definitely a 5 star item. I should give it 4 stars because of the radius issue, but its auch an improvement I'm gonna give svbony a pass. Thanks svbony.

Very nice quality Newtonian focuser. I just wish it fit my application. The main tube is m42 female threaded if anyone is asking.

Mounting plate not even close for mounting to a Celestron 114mm. You can shim, but what a pain when accuracy of positioning is critical. It's also way oversized for this application. The focus tube will clearly strike the mirror if installed in any manner, and requires drilling out the hole to allow for its travel. A total pain.

Este soporte lo ocupe en un telescopio que fabrique y gracias a la cremallera puedo hacer un mejor enfoque, les comparto una foto la Luna

Bought this because i wanted an upgraded focuser for my cheap bushnell 4.5" newt. If you are looking to do the same i would absolutely recommend it... but you will have to be a little handy, i didn't check the focuser tube diameter itself on my current scope and it was 41mm as was the whole in the telescope tube. The focuser tube on the SVBony focuser is 46.4mm i believe and of course did not fit. However if u have a large step drill bit or some sharp tin snips you will easily be able to enlarge the whole and it fits perfectly. Also as mentioned in previous comment the mounting of the actual focuser to the telescope will likely require some shims as its sized for 6" scope i believe. I also had to modify handle to attach motor focuser but was easily done. Overall great Quality all metal (except tiny plastic shim) and no wobble in the focuser tube. I collimated it after installation which was almost pointless with original focuser and works perfect.

Nice precice focusing ability thanks to their rack and pinion design

Producto de buena calidad relación precio y muy funcional

For the price it's built pretty decent, however I did have to modify my Orion 4.5" starblast in order for it to fit properly. Reading other reviews on this product, I found out that it is possible to fit it on to my smaller scope. Though the radius of the base of the focuser mount is meant really for a 6" telescope, and the inner tube length and radius is larger than whats meant for the scope. I was able to shave the radius of the hole for the inner tube on the telescope with a rat tail file, drilled 4 new holes for the bolts, and placed a rubber shim in between the scope and the new focuser. colimation to finish I am a fan of the all metal, and there's virtually no wobble on this focuser so I can definitely recommend it. However the draw tube is way too long and can't get proper focus on my 4.5"