Hey guys, Kent here with Fox Airsoft with another Tech Talk video. Today, we are going to be talking about shimming your gearbox. Shimming is one of the most important aspects of toning your AEG, simply because it provides the gears with the greatest strength possible, it keeps them from wobbling around, and keeps the surface contact of the teeth at it’s max.
So, you’re going to start by opening your gearbox. Remove your entire gear set. As well as all previous shims. Razor is helpful, for getting those stuck shims off the face of the gear. Alright, once you have all your shims off, go ahead and get a good bit of the grease off the gears,make sure you clean up the sector gear teeth– all that good stuff.
Clean off the dirt and grime. Again, cleaning the the grease off of your gearbox shell. Just like that. Alright, so when we start shimming we want to start with our spur gear, which is the middle gear in the train.
Fix right into this slot here, so you can see when I spin this here, is a little bit of rubbing on the bevel gear bushing here. So, I’m going to take a .01MM shim. We’ll start with that on the underside of this gear.
It looks like that is going to give us the clearance we want over those other two bushings. So we are good on our spur gear for our base. Next we’ll go with the sector gear. The big thing with the sector gear is we want to make sure we shim it as low as possible and keep it in contact with the spur gear teeth without rubbing on the lower base of the spur gear.
We also want to make sure we are not rubbing on the face of the cut off lever causing extra wear resistance there. The heights actually not bad right now, I’m going to throw, again, a .01MM shim on the bottom of this sector gear.
Alright, looking pretty good there. Finally the Bevel, again same process, make sure we’re not rubbing on any faces. Looks like we are moving kinda slow there, so we’ll go on and throw .01 MM on there again.
Give that a shot. Now you can see we are spinning a whole lot smoother. So, from there we want to go ahead and screw our gearbox shell together. You can see I’m using an ICS split V2 lower gearbox, just for sake of illustration, that you guys can really see what the gear spinning should look like.
This will look the same for just about any gearbox, regardless of design. Snug it down like you typically would. Just install your gear set and new trigger switch, cylindar assembly, anti reversal latch.
Alright, so after we got screwed together, our gears are spinning pretty well. So we got good rotation there, however, we have alot of play up and down on these gears. So I’m going to take a look at these gears and just guess what kind of shimming we’re going to need on each when we go ahead and pull this back apart, and add more shims to the top of the gears.
It’s looking like just about all these are going to need somewhere in the range of .5MM shims. Go ahead and start with that, see how tight we are. As you can see shimming is really a bit of experimentation just go from one prevision to the next.
Try and find that perfect balance. Again we are going to snug down our gearbox shell. Since we normally would. We’re actually still spinning quite well, so we are going to check these gears again for play.
Our sector gear, very little play, really nice shimming there. The spur gear, probably about a .1MM, again. And our bevel about the same as our spur, .1MM. Take it apart one more time. And .1MM on our spur and bevel.
Give that a try, see where we are at. Alright, so we are still spinning nice and smooth, full contact on all of our gears, really working nicely here. Check out that play on the spur gears, still a little bit but not what we are going to fix with shimming.
Totally expectable. And our bevel gear, same deal, perfect shimming. So, that’s what we like. Good four-five rotations. On steel bushing, just spin of the finger. Just what we’re looking for. So now that we have our play set correctly.
We’re going to go ahead and move our bevel gear around a little bit. Now the trick with the bevel is getting it to sit, just right with the pinning gear on your motor. So in order to do that, you want to shim it to about mid way, mid height in the gearbox shell.
So, I’m actually going to go ahead and swap with .01MM from the top side down to the underside of the gear. Just raise the gear up a little bit, get it more into that midway point and still maintained good, full contact with our spur gear, on our bevel gear teeth.
I’m going to go ahead and shut this one more time. Alright, still spinning smooth and beautiful, just like we want. Next thing I’m going to do, is go ahead and install our motor. Again, different for every gun design.
This is going to differ highly, depending which model you are working on. I’m working on an M4 today, so I’m going to go ahead and install the grip. Alright, so now that I have my grip installed I can actually see, can’t see it on the video there, but ICS actually cuts a window into their gearbox shells prior to.
.. in the factory. The purpose of that window, is so that you can see the pinning gear and bevel gear mesh in here. You can widen this to get a little bit better view. And you can cut it in any gearbox that doesn’t have it already, doesn’t hurt the structure at all, but it does give it that opportunity to get a better view of the pinning and bevel mesh there.
Here I’m going to go ahead and tune my motor by eye here. My motor hight to make sure I’m getting the best possible mesh on my bevel and pinning gear. That looks about right, right there. So again, can’t see it on the video, but what you are looking for is for the backside of the pinning gear teeth to line up with the edge of the bevel gear.
Get that full contact once again, you need to shim your bevel up and down from there, or your motor back and forth, to get that perfect, best mesh. So, go ahead and throw a trigger switch in this guy.
So you guys can hear the results, make sure we don’t have any squealing or whining or anything like that. And ah, show you guys just what a good shim job can do for the sound of your AEG. Alright guys, so we just got this wire harness installed, got our motor in, tuning is good, so let you guys hear here.
No real squeals or anything– a little chatter between the gear teeth, nothing unusual, so our shimming is good, motor tuning is good, and this thing is ready to be build the rest of the way. So, if you guys have anymore questions about shimming your own AEG’s give us a call or shoot us an email http://www.
foxairsoft.com and we will see you next time. Fox Airsoft 10244 S Progress Lane Parker CO 80134 (888) 316-7816 http://www.foxairsoft.com