A cylinder for magazine for Air Arms S200 or CZ 200 air rifle

Last crawled date: 4 years, 2 months ago

A cylinder for magazine for Air Arms S200 air rifle, which also fits CZ 200.
The plastic version of cylinder is much better because with the stock aluminium cylinder you will wear out the plastic body of magazine much faster.
The cylinder consists of two parts which can be fixed by screw and nut, so you don't need to glue both parts. You'll need the M2.5 x 10mm flat head screw and M2.5 nut.
I used the O-ring 13 x 3mm which is different from the original one (12 x 3.5mm). They have the same outer diameter (19mm) but smaller ring height (difference is 0.5) make the ring be more softer and it reduces the pressure amount you need to apply to move the push rod. The bullets stay in their position just as well as before. I tested on different sizes and shapes, all went well.
Also mine cylinder is a little bit bigger in diameter than the original one I have because it sits better in the magazine. I'm talking about 30.25mm diameter instead of 29.66mm. Don't worry, it works fine even in cold weather, I tested it at -20 Celsius.
I tried to print with 0.4 nozzle and 0.2mm layer and the quality was the same, I mean I haven't noticed the difference in how the pellets went from the cylinder into the barrel.
Instead I would recommend to decrease the printing speed to get better quality. I printed at 15mm/second.
Some note about the screw:
Ideally we need the 9mm length but there is no such screw on a market. We have 8mm or 10mm. 10 works fine, don't worry, it fits, but if you want perfect look you might want to sandpaper it to 9.5mm which is quite enough.
If your printer prints with bigger size or smaller, there is a chance you can resize the model in slicer in X/Y plane by 0.5-1% without touching the Z axis.
If you need to make better holes for pellets then use the 5.2mm drill.
More photos and video: https://photos.app.goo.gl/YT6UbgmzyWhWtEg18
Link to the design: https://a360.co/2pm8wAf
Update: I've added a version which has 3 locking pins instead of 2.
Update (4 Dec 2019): I've added "v3" version after I changed the o-ring on the push rod (it has 3 x 1mm size) and found out that I can't longer go through the pellet channels with the new o-ring. I happened because my old ro-ing was slightly smaller due to it's age (almost 7 years), and the new one appeared bigger. I tried to make the channels diameter bigger (+0.2mm), but it appeared that the surface of the channels must be very smooth (the FFF printer can't get on this level). I decided to take a 5.3mm drill bit and drill the channels to this diameter. The surface became smoother and roughly equals to original channel diameter. To be precise with original you need to find 5.26mm drill bit. Also I had to use the original O-ring (12 x 3.5mm) because with more space my 13 x 3mm ring can't hold the pellet steady anymore. Also it's a good idea to lubricate the channels with some grease. Also, you can make the channel ever bigger in diameter (5.4mm) to avoid grease and polishing the channel surface, but it adds more space and pellet might go out from the channel.
Also this version was re-designed to make the channels "solid".