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Initial Impressions of the TM SOPMOD M4 AEG

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That's just downright weird. The EG1000 might be old tech but it's by no means a slouch of a motor, I'm very surprised to hear that a 7.4v 3000mAh didn't do the trick. What other internals are you running?

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I'm always trying to source cheaper from japan, but they make all the best stuff! some times its just nice that we can get it.  You wouldn't believe what stuff they get for NEXT GEN which we never even see, from all the little gun smith shops around japan.  its like heaven over there for next gen owners.  Alot of the parts they just plain refuse to sell over here :(

 

Sometimes i found that over time on older sopmods the stock tube you would thread till it stops, after enough times your actually threading an extra mm to much becuase of worn threads.  Now the back of the gearbox is physically closer to the piston head.  So theoretically you add in bearing spring guide, bearing piston head and now you have reduced space for compressing the spring.  The strain at full compression is often too much for it to travel the last mm it needs to drop off the final tooth on the sector gear.  Its like cycling up a steep hill, and just before the top you run out of momentum.  Obviously the anti reverse latch stops said cyclist rolling backwards.  so there he sits, not enough power to move from this compressed state over that hill.  

 

Thats why typically in the past players have just thrown more power at it, as long as they have enough guts to get over the crest of that hill every time, there's no lock ups.

 

If you can get us some pics though of where you think its catching, and a list of changed parts, maybe we can all have a crack at figuring this one out for good.

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I'm always trying to source cheaper from japan, but they make all the best stuff! some times its just nice that we can get it.  You wouldn't believe what stuff they get for NEXT GEN which we never even see, from all the little gun smith shops around japan.  its like heaven over there for next gen owners.  Alot of the parts they just plain refuse to sell over here :(

 

Sometimes i found that over time on older sopmods the stock tube you would thread till it stops, after enough times your actually threading an extra mm to much becuase of worn threads.  Now the back of the gearbox is physically closer to the piston head.  So theoretically you add in bearing spring guide, bearing piston head and now you have reduced space for compressing the spring.  The strain at full compression is often too much for it to travel the last mm it needs to drop off the final tooth on the sector gear.  Its like cycling up a steep hill, and just before the top you run out of momentum.  Obviously the anti reverse latch stops said cyclist rolling backwards.  so there he sits, not enough power to move from this compressed state over that hill.  

 

Thats why typically in the past players have just thrown more power at it, as long as they have enough guts to get over the crest of that hill every time, there's no lock ups.

 

If you can get us some pics though of where you think its catching, and a list of changed parts, maybe we can all have a crack at figuring this one out for good.

 

Seems there's a gap in the market for a Japanese nextgen enthusiast to set up an international store and make some big money!

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Seems there's a gap in the market for a Japanese nextgen enthusiast to set up an international store and make some big money!

From what I recall, that's been done before but the retailers all figure out what people are doing and stop selling to them quite quickly. It's the same with getting spares for TM guns direct from TM.

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You wouldn't believe what stuff they get for NEXT GEN which we never even see, from all the little gun smith shops around japan.  its like heaven over there for next gen owners.  Alot of the parts they just plain refuse to sell over here :(

 

Like what?

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We already discussed it - I'm going to let blobface be the guinea pig for this particular piece of technology, since neither of us can understand a word of the language the instruction manual is written in...

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zase9y5a.jpg

 

Used the marui 8.4v 1300mah nimh sopmod battery right off of the charger.

 

paze3eju.jpg

 

Has a cut down guarder sp120 spring and a guarder infinite torque motor. Everything else is oem marui.

 

7ame6uja.jpg

 

Same battery. Chronoed this gun first. Shot about 20 rounds before chronoing the other TM HK416 DEVGRU.

 

Another cut down guarder sp120 spring and guarder infinite torque motor.

 

Prometheus air nozzle, piston, piston head, bearing spring guide, cylinder head, and silver wiring. Systema teflon cylinder, magic box metal bushings, shs next gen gears.

 

 

Sent from my SGH-M919 using Tapatalk

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Right, here are some images to try and explain what's going on.

 

post-37787-0-46445000-1394202455_thumb.jpg

 

Here you can see the gearbox shell and piston. Note the recess where the cylinder goes.

 

post-37787-0-96940400-1394202462_thumb.jpg

 

Above - How I'd expect this to be in a working setup. The piston head is as far back as it can go, and the lip of the piston head catches against the gearbox shell as designed.

Contrast this with the picture below (which you get when applying side pressure, even with the cylinder in) and you can see the piston won't come far enough back and therefore doesn't release.

 

post-37787-0-73763900-1394202469_thumb.jpg

 

When it's in this locked up situation it's possible to drop the motor and wind the gearbox on manually, with some effort.

 

Parts that have been upgraded and are relevant here are prom piston head, cylinder head, spring guide and nozzle. A new stock tube has also recently been added, and it's running a large pistol grip which I have modified since previously it was putting pressure on the bearings from outside the case (the notches in the grip weren't deep enough to clear them). I think this is trying to run it with an Eagle M110. Had similar results with the M100.

 

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<snip>

Put a sector gear in there and look to see how far it draws the piston back, under normal circumstances the piston should never go that far back.

 

Otherwise, it could be the mix of the SHS piston with the Prometheus/Laylax pistonhead making the distance between the pistonhead and the release tooth too short, but in all my experience with AEGs in general and the Marui recoil M4s, the pistonhead should never withdraw from the back of the cylinder.

Edited by Aod

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We already discussed it - I'm going to let blobface be the guinea pig for this particular piece of technology, since neither of us can understand a word of the language the instruction manual is written in...

 

 

Why else do you think it's still in the box untouched. 

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Put a sector gear in there and look to see how far it draws the piston back, under normal circumstances the piston should never go that far back.

 

Otherwise, it could be the mix of the SHS piston with the Prometheus/Laylax pistonhead making the distance between the pistonhead and the release tooth too short, but in all my experience with AEGs in general and the Marui recoil M4s, the pistonhead should never withdraw from the back of the cylinder.

 

I have and it draws it back far enough to be an issue. Only just, but it does.

 

I had overlooked the SHS piston. Definitely a possibility, although I was getting blown fuses prior to replacing it anyway (although that *could* be the shimming at that time). I don't have a different piston to test this against. Other people must be using this combo though. Hrmm.

 

Edited to add - I guess short stroking the piston by removing one of the teeth from the front would test the hypothesis that it's this which is causing an issue. Of course, the lower fps might then negate putting an uprated spring in it in the first place, but at least it'd confirm the theory.

Edited by Hatchet

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Why else do you think it's still in the box untouched. 

 

Don't be an airsoft girlie man![/schwarzenegger]

 

Surely there's a fluent Japanese speaker somewhere on here?

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Hatchet, if you are worried about it coming back two much you can fit a spacer or two between the piston head and piston. The piston will move the same distance but the piston head won't reach the same point. If your theory's correct then that will rule it out.

 

More likely there's some issue with the pistol grip causing poor Engadgement with the bevel gear and there for making it more work to turn over than it should be. Hence it no having the guys to carry on over the hill, since as you say you can turn it manually.

 

Refit the original pistol grip, add 1mm or 2mm of spacers and test again, double check shimming to. What bushings are they ? I may have a shim sheet already written down for that part config.

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Hatchet, if you are worried about it coming back two much you can fit a spacer or two between the piston head and piston. The piston will move the same distance but the piston head won't reach the same point. If your theory's correct then that will rule it out.

 

More likely there's some issue with the pistol grip causing poor Engadgement with the bevel gear and there for making it more work to turn over than it should be. Hence it no having the guys to carry on over the hill, since as you say you can turn it manually.

 

Refit the original pistol grip, add 1mm or 2mm of spacers and test again, double check shimming to. What bushings are they ? I may have a shim sheet already written down for that part config.

 

I think the spacers will be the next port of call, but I've lost the will to tackle it tonight. I did chuck some in initially, but of course that threw the AoE off... It's all good fun.

 

I have a few more theories to test as well, including getting a known good higher voltage battery to try.

 

Shimming was triple checked the last time I had it opened and I'm happy enough with it. Original pistol grip no good due to stripped threads on the baseplate, but the replacement is good. Bushings are the 5.9mm ones.

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is it a sopmod ? rear wired ? is it using the original quick change system etc ?

 

Make sure when you test shimming to put just the gears in then tighten up the gearbox tight!  then try and turn the gears if they feel at all stiff its too tight.

 

Secondly the gap between the flat top of the bevel gear and the inside the of the gearbox casing needs to be 1mm.  If its + or - then it could cause problems, like slowing down or worn pinion.   I use a feeler blade set from halfords.

 

Its so easy to test without over tightening the casing which turns what was a perfect shim before installing it into the lower, into a set of gears which hardly turn.

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A little birde just told me the BTC Next GEN Spectre unit is dropping.. :) Getting mine this sunday!!!

 

Waaahhh? After all this time? I did see a post from BTC on the Airsoft Mechanics forum saying there would be a reveal anytime now, but after all the other release dates have come and gone I just thought 'I'll believe it when I see it'.

Let us know how it goes and I'm looking forward to seeing a review.

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A little birde just told me the BTC Next GEN Spectre unit is dropping.. :) Getting mine this sunday!!!

Good to hear as I started using 11.1v lipos. It works well(20 rps with a heavier recoil weight, it almost feels like a weaker gbb) but I will feel safer with a mosfet installed.

(btw is there a place where you can preorder one?)

Edited by Zereck

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