JM gen9 - shimming the motor HTaF?!?

JinMing gen9 m4a1 black nylon box for the new SLR build but

How the **@$ @$@%@ do we shim / adjust the motor without guessing and ruining the pinion and crown?

on the wells we’d dismantle the thing attach the grip and peer into the nether realm little window whilst standing on one ear and playing with the set screw…

how are gen9 peeps doing this?


surprised I didn’t get any response to this query. creds to @BigWeetBix who suggested drilling my own sight hole in another thread - not good for warranty though.

I did however manage to get input from a tech i respect about how to set about this given that the nylon box i got doesn’t have a sight hole.

there are two ways,

  1. pull it down entirely and shim the motor with the top half off - uhuh…drop in you say…
  2. screw the tensioner in completely and then wind it out slowly by ear.

thankfully my drop in box was DOA and the shop is now sorting it out as a warranty.

I know this is old now but maybe still relevant.
I also had the same question with my custom SLR v2 build.
One important thing with the SLR v2 receiver is the handle is designed to take a 480 motor which is longer the the 460 so make sure what you have or you will have issues.
Here is a video I found which helped me.

Here is a pic of my SLR build

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I think this is one of the first JM queries I’ve read where someone hasn’t just replied low Guido YouTube lol😆

Timing couldn’t be better

I’m almost about to do the new build.

What build you doing. Oh and I went around and seen jack known him for years. He got that m24 going good. So aide def going to getting one soon lol

retro arms split box

it was supposed to be a full metal build but supplier pickles and the such.

it will go into a full nylon JJ SLR exterior which i will deliberately make look exactly the same as my all native JJ SLR :slight_smile:

i’ll be chopping off the end of the m24 this week to fit a hopup and if needed, a smaller spring for consistent ranged accuracy - time will tell

zeHamish, in regards to putting a retro arms split box into your SLR, what are you doing about the tpiece and nozzle to make it work? Also are you using the SLR outer barrel set and adapter? Cheers.

Well …still waiting on parts from GBA but

Original spec was all metal specific to suit - supply issues

So JJ nylon…

Charge handle fouls on gearbox
Adjustable nozzle needs modification to fit into the t piece
Need to check t piece / nozzle / mag alignment - today
Awaiting FB metal t piece Adapter

Outer barrel will be the same as my full native JJ SLR build so I’m not expecting issues.

I wasn’t expecting any issues when I ordered the build months ago either so we’ll see

t piece / nozzle / mag alignment

internal alignment is good between the receiver and the box.

mag prime (ra split doesn’t have one) drags on the top of the box. slimmer spring may not.

So tpiece nozzle and mag alignment on stock SLR parts for these are fine? What did you do for the mag terminals?

Alignment ok. Tight.

I have a 3dp mag block.

What do you mean by tight bud?

good fit but not so tight it is an assembly problem. if i were so inclined to put orings on the box and mag (as an example of extra space) the t would no longer fit or line up.

i need to get the barrel adapter side of things to do any more. atm i can hold the t piece in place with blue tack and while i need to be mindful to knock it out assembling the upper receiver its no more a jigsaw than my other SLR which is pretty straight forward.

I don’t want to be the bringer of bad news but if gel blasters Australia did anything to it you in for a world of pain !

only supply of parts. it was supposed to be a complete GBA OOTB build but between some accounting requirements, supplier and customs woe…

i picked up the parts to build myself. still waiting on parts before i can start anyway.

Why so rattler? I’m probably going to just be buying the parts, but I am having a hard time getting info from them in regards to fitment etc… They should have all of the info available, but it seems they don’t know… Thing is, it’s not a 50 dollar gearbox we are talking about so I don’t want to spend coin on something that won’t work.

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They no nothing about what fits what and their workmanship is shocking, the worst I have seen.
For instance when I got my first blaster I ordered all the parts to upgrade it and almost every part was wrong. They sent me a gen 8 cylinder head to fit my vector !
8mm bearings intead of 6mm, a custom piston that looked like a child modified it and the list goes on. They then said I should send them the vector and they would make sure everything was correct and I told the I didn’t care how much it cost, I just want it perfect. $330 and a over a month later I received it back and every screw was stripped, and 2 were missing,the gears look like they were ground on and angle grinder, the bushing were flogged out completely and it sprayed gels like a shot gun.
They also did not return the brand new mag I just purchased from them.
When I spoke to the owner he basically blamed me and said there was no warranty since I stripped the blaster!
He also said I did not send a mag with it.
They also said that the screws missing were not a problem and it is normal lol

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seems like i may have dodged a bullet…

@JeliWorks where are you based. you could always eyeball my bits in person