M4 CQB-R Build Part 1

I just about had everything set to assembly this "as is" but my attention to detail got the best of me. I figured while I was here, I would do a step by step of what's on my work bench this week.

The first thing I started with was gearbox cleaning and disassembly. I bought an AIM TOP V2 gearbox almost a year ago and I had it in my KM4 until I found a KWA gearbox that fit better. I disassembled the gearbox and cleaned it using degreaser I bought at the local AutoZone. I had this gearbox overhauled a while back by a local shop and they did an ok job but not quite up to specs. The only changes they made were to replace the wiring harness, and even that broke.

After I got the thing apart, I removed all the gears and springs, the trigger, the selector plate and switch, and the wiring harness. I repaired the broken motor clip and shrink wrapped it. Once the inside was appropriately clean I added a couple drops of TurtleWax finishing compound, smeared it around, and fired up the wire brush on my Dremel to start polishing the interior of the gearbox. Some recommend doing the entire gearbox, which is a good idea, but I just do the areas where the moving parts are.

In the mean time, I used liquid gasket maker and seal the cylinder head inside the cylinder. This should create a complete air seal provided the piston is in good shape, which it does. On the advice of others, I sanded down the front of the tappet plate and super glued the air nozzle to the tappet plate

Now I'm just waiting for the other parts and I'll move on to assembly.

Adventures in Repairs

I finally got my KWA KM4A1 out to play, which was pretty nice. The motor kept making the high pitched whine which means that the motor was at an incorrect height. I get the thing home, and yeah, one of the screws cracked the hole it screws in to causing the motor plate to not adjust properly. While it was annoying this is an excellent time to replace the pistol grip with a MagPul grip, however.

I am supposed to get a big shipment from Evike soon to finish an M4 CQB-R build I hope to take up to Mooseherd when I get a chance. I could have finished it immediately but my attention to details got a hold of me, or maybe it was boredom. I decided to go hunting for a metal M4 body, and I think I found one. I also decided to tear the gearbox down and give it a good polish, seal up the cylinder, and do some other detail work to the internals. Of course I'll reshim and relube the gearbox, and the thing will roar when I get it finished.

I got my pinion puller the other day and I used it to pull one of the pinions off my Matrix motor. As I screwed it down, it shattered the pinion gear right off the shaft. It made removal easy since the set screw stripped inside the pinion. My Dremel couldn't cut a deep enough groove for a screwdriver to get a bite and my drill battery was dead. That motor will now go into my KM4 and the stock KWA motor will be moved over to the CQB build. Should give me a rate of fire increase, and now I'm in the market for LiPo batteries.