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scubastevemk1

New Product: Piston Saver Shims

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Interesting! I have been using hand cut felt rings (like most others), but they wear out fast. What is the build material on these?

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£5 for a solution that isn't going to necessarily do the job...great.

 

While its certainly a noble endevour people who already know about sector/piston AoE will have most likely already made their own spacers, I made mine by cutting up the plastic packaging from a gear set and they didn't look as if they were going to fail any time soon. The thing is like that article says not all pistons are the same, neither are all gearboxes - for example ICS pistons are slightly out of spec length wise compared to TM but I have reason to believe their gearboxes are slightly off too with regards to the piston's at rest position or the position of the sector gear. This is evidenced in practical experiance of seeing people only needing 2-3mm of adjustment in TM based guns, but my ICS M4 needs a whopping 5mm of adjustment, possibly 6mm if you account for the cylinder heads rubber bumper and in the case of dropping an ICS sector into an A+K M249 the piston started having chunks taken out of in in typical poor AoE wear.

 

The second thing that irks me is that in the case of extreme adjustment being needed, you potentially have the piston head not docked into the piston and nothing but screw pressure holding the shims in place leaving the potential for them to slide around out of place, if anyone has seen Corvid's AoE pictures he has a sleeve on the screw which appears to widen the diameter of the screw so theres no chance of shim 'orbit' around the screw.

 

It's useful for perhaps the majority of cases or people looking for a quick fix but not something I would say is the be all and end all of AoE correction

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They are made of polystyrene(sp?).

 

RSM, very well put. I like the idea of Corvid's spacer, but I have never experienced a need for this. Since the piston rails hold the piston in place, even if the piston head could slide, it would have very little room to move. The only room to move, that I can see, will be the play between the piston rails and the gearbox rails, as well as the space between the edge of the piston head and the cylinder wall. It seems to me that even the further back the piston s pull, the more it wll engage the rails, preventing much movement. I guess the worst case scenerio would be that the piston head could wiggle a tiny amount with each shot and eventually work the piston head off, but I always use Red Loctite thread locker to hold the piston head on.

 

I like it because it is a simple solution to a problem and it will save me time and hassle.

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They're doing it wrong, it'll open up in the fire and they'll get burned.

 

You shim the cylinder head, shimming the piston head weakens the connection between piston and head, adds weight to the piston assembly and often doesn't work because the supplied bolt is too short.

 

Shimming the cylinder head also gives you a softer impact which prolongs the life of your 'box.

 

The only downside is you loose the tiny bit of pressure you would get from compressing the last cubic centimeter of air in the cylinder.

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The only downside is you loose the tiny bit of pressure you would get from compressing the last cubic centimeter of air in the cylinder.

 

I observed this in my M4, going from 350fps to 320fps (but I had to put in a bearing spring guide) but I'm conducting an experiment in fitting some cylinders (when they arrive) for slightly longer barrels to see if its possible to bring the FPS back up by using a cylinder with a slightly larger compressable volume of air than the barrel volume.

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I can't believe people are paying for these when you can go to the hardware store and get 2-6 in a pack for less than $1USD. I'm almost certain they would have a similar hardware store in the UK and most of Europe, much less in the other states here within the US. But then again convenience is everything nowadays right?

 

I can actually go to my local Home Depot(a huge retail hardware chain in the US) and purchse 4 3/4in plastic washer in a pack for $0.45 - yes that's 45 cents plus tax.

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Im with you sc0rp10n, I dont see why any one would pay $10 for a pack of three of these when you could get double that for less that a dollar at a local hardware store

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