Quote:
Originally Posted by Ross
I spent a long time shimming my new gears I purchased recently. The gun makes a somewhat higher pitched noise when I pull the trigger. Do new gears need to be worked in?
|
All the other advice here is valid.
The other big thing in shimming and reducing whine is being able to execute a lot of iterations and shimming positions/permutations QUICKLY.
If you're putting your entire compression set and all your gears back in every time you test the sound of your gears, you are wasting a lot of time that could be better used.
Some people in here are telling you to focus on motor height and the bevel gear. In my experience, this is the single most important thing when swapping gears, a motor, or a pistol grip (all will affect shimming and pinion/bevel alignment). This is where you want to focus all of your energy until the bevel sounds perfect.
You want to narrow down the number of iterations in your search for the right mesh, especially if you are unable or unwilling to use a method where you can confirm the meshing visually.
Raise and lower your bevel gear until you see that the pinion is engaging it within spitting distance of what "looks good". Figure out a good motor height from there. I like to use the half-shell-with-pistol-grip-attached method and it's serving me VERY well. Some will disagree that this gives you an accurate picture of the mesh but even if you disagree with the method, it still gets you close enough to start somewhere and narrow down your search space.
Once you are close, test your sound by running the mechbox in the lower receiver, but with only the bevel gear installed (i.e. no spur, no sector, no ARL, no compression parts or spring). This will save you time. Once you have that bevel gear down the rest is pretty easy. Having a lot of 0.1mm shims (like the Modify Advanced shim set) is useful to get it super precise.
Once you have the bevel sounding awesome, put the other two gears in and leave the ARL out. Test, re-shim, etc, until perfect. Then put your ARL and compression set and do the final testing (including piston/sector engagement).
edit: I'll also add that isolating the parts so that you are only listening to the bevel and pinion making noise with nothing else running has proven to be a fantastic way to get an idea of what noise each individual part contributes without the distraction of the other parts.. This was the point of my reply. You can at least narrow down a sound issue to to (bevel + pinion) vs. (other gears) this way (unless you have some crazy stuff going on like the sector dragging against the cutoff lever, but it's easy to see that with the naked eye before making that mistake..