|These instructions are presented here for informational purposes only. Any modifications you choose to do to your gun, you do so at your own risk. Be sure to REMOVE the CO2 or other gas source from any paintball marker before you attempt disassembly. Wear eye protection when using ANY power tools. If unsure about safely modifying your gun, consult a professional airsmith. Remember, safety must ALWAYS come first!|
Submitted by Chris (aka Sugar Ray)
Velocity Screw Modification
1) Item Modified - Velocity Adjustment Screw/Porting the Valve
2) Intended use and effect of modification - By enlarging the hole for the velocity adjustment screw and using a larger screw to adjust the velocity, a larger portion of the power tube can be closed off. This should result in better velocity control.
3) Tools/equipment/supplies needed - Tap wrench and 1/4-20 tap, round file, Dremel with small sander drum, X-Acto knife, drill with 13/64" bit, 1/4-20 by 1-1/4 inch stainless steel allen head machine screw
4) Complete Description of Process - **Note: This was suggested as a mod on Sid's Stingray FAQs. This is a much more detailed explanation with a few slight changes. See Maintanance and Disassembly Guides for some tips on disassembling the valve assembly.
Disconnect any co2 source and disassemble the Ray. Remove the valve assembly from the hammer tube. Remove the velocity adjustment screw from the valve. CAREFULLY drill out the hole for the velocity adjustment screw with a 13/64" drill bit. The part to watch here is that you do not drill down too far and drill into the bottom of the valve body. Next, you have to tap out the hole. You must be careful here. Make sure you start off the Tap wrench as straight as possible. You will have to press a little hard to get it started. Just press firmly and turn to the right in a steady motion. Again, be careful not to tap into the bottom of the valve body. It also helps to put a few drops of ATF on the tap and in the hole to help lubricate. Reverse your motion and remove the tap. Insert the appropriate size allen wrench in the allen screw and insert in the hole to test the fit. It should be snug and nice. Remove the screw.
Now for the icky part. You have to disassemble the valve and clean out the metal shavings. Follow the instructions on Sid's page and use the technical drawing as a guide for valve disassembly/assembly. After reassembling the valve, put the velocity screw back in. The spring will not fit this screw. If you want, you can take the screw to a hardware store and find a spring that will fit. I don't have a spring on mine and it seems to work fine. Another option, one which I always do, is to wrap the screw with a thin layer of silicon tape. This helps prevent blowback gasses. You must widen the hole in the Ray body for the velocity adjustment screw. The screw won't unscrew all the way if you do not do this. Here, you have your choice. I used an X-Acto knife, drill, and round file to widen the hole. I had the best luck with the bastard cut round file. You have to remove a good bit of plastic so the screw will unscrew all the way. Wash out the Ray receiver and dry it. Re-assemble the Ray.
5) Results of the modification - This is the reason for the 1/4" screw. This size screw can completely shut off the power tube. The Mod works well. Not empirical evidence at this time..
6. Pictures - coming soon
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