Turn a SWFA rear focus into side focus?

Forums Optics, Scopes, Rings, & Mounts Turn a SWFA rear focus into side focus?

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    Franklink
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    As I’ve commented online a few times, I have 3 of the 20x SWFA scopes. I use them for field target and pesting. They are great scopes, very repeatable clicks, serviceable glass, not too heavy, and tough as nails.

     

    I have had one on my USFT for about a year and a half. For the first year I just put tape on the little step down right in front of the rear focus ring. I made marks on that tape corresponding with yardages. It worked okay but the further marks were mighty close to each other. So, around December of last year I brainstormed and came up with a contraption (using half of a cutting board) that worked kinda like a speedometer. It spaced the marks out, but was pretty fiddly and I had to hold up the face of the “speedometer” for each shot and line it up correctly through a small hole.

     

    Meanwhile, one of the members of our Field Target club (Don) found an ad for a broken 3d printer online. He lives out of his truck so doesn’t have internet. He used fast food restaurant wifi to figure out how to get the printer fixed and teach himself how to use it. This coincided with my showing up for a match with my cutting board/speedometer contraption.

     

    He took one look at my cutting board range finder and said, “I’ve got an idea.” Over the next few weeks he would text me asking for various measurements on my scope and gun. One day he asks for my address and (after I gave it to him) says he’s got a prototype in the mail for a side focus attachment for my SWFA SS rear focus scope. It showed up a few days later, and amazingly, bolted right on and worked like a charm. He engineered some adjustability into the design by using different thickness shims to space the wheel off the gears teeth so that they engage correctly.

     

    Quite ingenious.

     

    Before the end of the day I asked him to make me two more for my other scopes!

     

    So, the one that I have used the most is the one on my USFT. The wheel’s gearing allows for about 270 degrees to be used for 10-55 yards. The wheels have a 4 inch circumference so it works out to about 11 inches of usable space on the wheel to make yardage marks. I’ll try to attach pics to show that the spacing between 50 and 55 yards is quite good. The simple lens, fixed power nature of the SS scopes, coupled with Don’s wheel, has allowed for some very accurate ranging. Since I have been using his wheels I have been placing at or very near the top of the scoreboards for our monthly matches. I say that, not to brag, but to emphasize how big a difference Don’s wheel made for my scores. I was definitely not scoring as well before the wheels were made.

     

    I also have one on my Taipan Veteran that is used primarily for pesting. That one doesn’t even have yardage marks, it is just used for quick focus when shooting prairie dogs, it is much easier to focus quickly with the wheel than with the rear focus. They'll pop up anywhere from 10 yards away to 100+ and it's nice to be able to quickly focus on my target.

     

    The third one I have is on my HW50s for open class springer piston. It is marked for rangefinding by focus but only one other guy shoots open class piston and his gun is at the doctors office (Hector back east) so I have just been sitting on that one, waiting for some competition.

     

    He has played with various wheel designs. One has holes. One is solid. One has a cool fractal pattern where he reprogrammed the print head to lay down the filament differently.

     

    So, the cons, they are plastic. He tried various types of filament, one was a total failure and literally melted on his dashboard when he was testing for heat/uv sensitivity. The filament he is using now has stood up well and doesn’t melt in the sun. I haven’t broken one yet but I imagine sitting on your wheel or some other unfortunate accident would spell disaster. I can put them in and out of hard cases without any trouble. I have had to play around with various materials to keep the parts lined up correctly. Felt has worked the best but I think that sticky tape that comes inside scope rings might be even better. So, there is a little bit of tinkering to get a repeatable configuration with them.

     

    Not long after Don sent me this wheel, I started telling him he should sell these. First, I thought it was a brilliant idea to make the 16x and 20x SWFAs side focus. I know you can buy the 10x in side focus but the 16 and 20 don’t come that way. The 16x should make a perfect hunter class setup, especially with the mil quad or mil moa reticle. I have gotten a lot more mileage out of these scopes with the wheels than I did without, and I assume others could too. Second, his only income is Social Security. I thought he could help SWFA owners out with a cool product, and supplement his income a little bit.

     

    So, I’ve been working on him to sell the wheels for about 6 months. He told me he just did it to help me out and for a fun project but didn’t want to bother selling them. He finally agreed when I told him I’d tell people about them, take orders, and mail them out. I live a few blocks from the post office and have more reliable internet than he does so it makes more sense for me to do that part.

     

    So, before he prints up some extra sets of these, is there any interest? I asked him what he’d like to get for each wheel set-up and he said $60. He says each set takes most of a day to print, and his only source of electricity to run the 3d printer is an old worn out generator. So, at $60 he’s not paying himself minimum wage, once he subtracts his time, failed prints, filament, and gas. I’m thinking a flat fee of $10 shipping.

     

    So, $70 shipped to turn your fixed power SWFA scope into a side focus?

     

    Mod edit: Moved to Optics, Scopes, Rings and Mounts forum

     

     

    • This topic was modified 1 year ago by a Moderator.
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    aerotulz
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    PM sent.

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    spysir
    Participant
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    Just outstanding.  I'd of gone with a large donut just like a front A/O and thought no more. Nor had the talent to figure out such a set up, seems it could be popular.

    Lot's of years back I saw someone at a match who had fashioned their own (metal, before printers) , gismo, that clicked the elevation correctly for the A/O setting.

    Thanks for sharing. Very slick idea.

     

    John

     

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    josh3rd
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    Sorry brother but I'm confused as to how this works. So a swfa rear AO can be changed into a side focus. Can is there a more simpler was to explain to me how it works. Much appreciated

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    Franklink
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    After the 3d printed parts are mounted on the scope, you turn the wheel and the gears turn the rear focus. It works just like a normal side focus. When adjusted correctly there is zero slop in the mechanism, every millimeter of rotational wheel movement turns the rear focus the same amount. It's two geared/cogged wheels, one printed at 45 degrees to the plane of the wheel and the other at 45 degrees to the plane of the scope tube. Together, they creat a wheel, 90 degrees to the rear focus, Wich happens to be at a completely convenient sidewheel location. 

    We initially feared the teeth would wear, but I've been cranking on them since January and haven't seen any wear. They mesh so perfectly (again, when adjusted correctly) that there isn't any wear on the gears. 

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    steve123
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    Hey C, I'm Steve M.

    Both Franklink, Don, and myself belong to the same FT club. 

    After looking at and trying out Don's creation on Franklinks's rifles, I have to say I was very impressed, it seemed plenty sturdy and I liked that there was no lash! If I had a SWFA fixed power I'd buy one for sure. 

    Does this also fit the SWFA fixed power 6x, 10x, and 12x rear focus scopes?

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    Franklink
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    Hey Steve! 

    To my knowledge, all of the SWFA SS fixed power scopes have the same dimensions. I know for a fact that the 16x does, because I've handled one and compared it next to my 20x. So, in theory, Don's wheels should fit any of them. I think only the 10x has the option of a factory side wheel focus instead of the standard rear focus that comes on the rest of them. To my knowledge, Don's wheel is the only way to get a side focus on any of the flavors of SWFA SS fixed power, except for the 10x that can be purchased that way. 

    A new shooter in the club has a 16x SWFA on his Marauder. He seems pretty excited to get one of Don's wheels on his set-up for Hunter Class. We tried to set him up with one in June but he had the scope in low mounts and there wasn't enough clearance. He already remounted with higher mounts so he can throw a wheel on there for the July shoot. So, please note that you need at least medium mounts to get the clearance between the bottom of the scope tube, and the top of your gun's receiver. The other option would be if you have your scope mounted rear ward enough that the rear focus, and about 3/4 of an inch worth of scope tube in front of the rear focus, is past where your receiver/breech ends. 

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    Yossshooter
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    that's amazing and great ingenuity from his part !!!!! 

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    sgtBunny
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    That is awesome.

     

    I know some guys at work with me that does 3d printing and are experimenting with some 3d printable metals.  If he would sell his plans, I could also talk to the guys here that has CNC machines to do it in aluminum.

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