Airsoft Canada - View Single Post - Maintenance Log: A well-worn Velocity Arms VA36 / JG G36 (56k warning!)

MaciekA · November 13th, 2011, 17:29

Update:

It's been a while since my last update but I've been tinkering with this gun on ever since my last update, and I've toyed with many things.

Swapping the Bushings and replacing the gears

Contrary to my initial report earlier in this thread, this gun has Nylon 6mm bushings, not metal ones as I initially thought, and not 7mm as stated on the VA website. Hopefully they update their listing. Anyway, it took me a while to notice this as I didn't inspect the bushings very closely. I've read that plastic bushings are the first thing to go in guns firing beyond stock Japanese limits, and this thing is firing around 360fps, so I figured I'd get metal bushings.

This actually turned out to be trickier than I expected. In this gearbox, most of the bushing holes can be described as "innies", with a small inset circle for the bushing to rest in, but the sector gear's hole is an "outie", with an outset circle rising above the surface of the gearbox shell. This was fine with plastic bushings that were able to slightly deform and squeeze, but with metal bushings, it actually made the stock sector gear a tight squeeze with considerable friction against the bushings. Shimming to raise or lower the gear was thus impossible (since there's no extra room). The raised outline represented a decent amount of thickness, so I decided to risk it and file it down flush with the gearbox shell, which helped quite a bit.

To give myself even more room, I swapped the gears for a G&G set which had ever so slightly more wiggle room. I'm happy with the shimming now, easy/free rotation with very little play.

New selector plate

Tossed out the stock selector plate (which had bent out of shape somewhat from my carelessness) for a new one. Works great.

Metal Bearing Spring Guide

For the heck of it, decided to replace the stock plastic spring guide and throw in a metal one with a ball bearing washer. I'm re-thinking this decision due to possibly having slightly less space for the piston+spring to be pulled back towards the rear of the gearbox. Not sure how much of an issue that could be.

Checked AoE / piston tooth removal

After some more usage of this rifle and closer inspection, there was a very slight amount of wear on the piston from the sector gear engaging the second-to-last tooth, so I filed it down. Tooth engagement looks a tad better now.

Modify G36 Cylinder Set

I gave the Modify G36 cylinder set from airsoft parts a whirl. It comes with a nice piston, piston head, cylinder, and cylinder head. All of these parts look to be really nicely made. Unfortunately, the cylinder head is completely incompatible with this gearbox shell and seems to be made for some other G36 gearbox shell, so now I have an extra cylinder set lying around. If you have a V36 or a JG G36, don't try this cylinder set, it won't work. Live and learn I guess

.

G&P M120 small type motor

I decided to try one of these in this to see how it would do, but even with good bevel to pinion alignment, I had trouble making this combination work. The motor seemed to get fairly hot, even though I could move the shimmed gears with a feather touch. When the gearbox did cycle, it would get a good RoF and feel snappy. Occasionally though, it would seize (with the spring fully compressed) and the motor would get hot. Pulling the trigger would only jiggle the piston a little bit but not complete the cycle.

I also observed some blue arcing inside of the motor itself. I've gone back to the stock JG motor, and it has absolutely none of these heating or cycling issues. I'm still scratching my head over that, because I don't see why it would be the motor's fault -- especially since I took a lot of time with motor height adjustment too.

The current incarnation of this rifle, with metal bushings, better shim job, spring bearing guide and G&G stock gear set, remains firing in the mid 360s.

November 13th, 2011, 17:29	#15
MaciekA Trader rating Join Date: Jun 2011 Location: Portland, Oregon, USA	Update: It's been a while since my last update but I've been tinkering with this gun on ever since my last update, and I've toyed with many things. Swapping the Bushings and replacing the gears Contrary to my initial report earlier in this thread, this gun has Nylon 6mm bushings, not metal ones as I initially thought, and not 7mm as stated on the VA website. Hopefully they update their listing. Anyway, it took me a while to notice this as I didn't inspect the bushings very closely. I've read that plastic bushings are the first thing to go in guns firing beyond stock Japanese limits, and this thing is firing around 360fps, so I figured I'd get metal bushings. This actually turned out to be trickier than I expected. In this gearbox, most of the bushing holes can be described as "innies", with a small inset circle for the bushing to rest in, but the sector gear's hole is an "outie", with an outset circle rising above the surface of the gearbox shell. This was fine with plastic bushings that were able to slightly deform and squeeze, but with metal bushings, it actually made the stock sector gear a tight squeeze with considerable friction against the bushings. Shimming to raise or lower the gear was thus impossible (since there's no extra room). The raised outline represented a decent amount of thickness, so I decided to risk it and file it down flush with the gearbox shell, which helped quite a bit. To give myself even more room, I swapped the gears for a G&G set which had ever so slightly more wiggle room. I'm happy with the shimming now, easy/free rotation with very little play. New selector plate Tossed out the stock selector plate (which had bent out of shape somewhat from my carelessness) for a new one. Works great. Metal Bearing Spring Guide For the heck of it, decided to replace the stock plastic spring guide and throw in a metal one with a ball bearing washer. I'm re-thinking this decision due to possibly having slightly less space for the piston+spring to be pulled back towards the rear of the gearbox. Not sure how much of an issue that could be. Checked AoE / piston tooth removal After some more usage of this rifle and closer inspection, there was a very slight amount of wear on the piston from the sector gear engaging the second-to-last tooth, so I filed it down. Tooth engagement looks a tad better now. Modify G36 Cylinder Set I gave the Modify G36 cylinder set from airsoft parts a whirl. It comes with a nice piston, piston head, cylinder, and cylinder head. All of these parts look to be really nicely made. Unfortunately, the cylinder head is completely incompatible with this gearbox shell and seems to be made for some other G36 gearbox shell, so now I have an extra cylinder set lying around. If you have a V36 or a JG G36, don't try this cylinder set, it won't work. Live and learn I guess . G&P M120 small type motor I decided to try one of these in this to see how it would do, but even with good bevel to pinion alignment, I had trouble making this combination work. The motor seemed to get fairly hot, even though I could move the shimmed gears with a feather touch. When the gearbox did cycle, it would get a good RoF and feel snappy. Occasionally though, it would seize (with the spring fully compressed) and the motor would get hot. Pulling the trigger would only jiggle the piston a little bit but not complete the cycle. I also observed some blue arcing inside of the motor itself. I've gone back to the stock JG motor, and it has absolutely none of these heating or cycling issues. I'm still scratching my head over that, because I don't see why it would be the motor's fault -- especially since I took a lot of time with motor height adjustment too. The current incarnation of this rifle, with metal bushings, better shim job, spring bearing guide and G&G stock gear set, remains firing in the mid 360s.