A while back I receieved Some sorbothane sheets to experiment with sorbothane cylinder head dampers. The sheets were 1/8in thick and 50 durometer. I really wanted 70 durometer but haven't received any yet. Although there is a sheet on it's way soon.

I decided to see what results I would get if I replaced my KWA M4's rubber cyl head pad with sorbo, so I took some before and after data and was about to post results when I stumbled upon TPE's Thermoplastic Elastomers.

You see, here in Japan, earthquakes are common. So in just about every hardware store you can find TPE and SORBO pads to attach to large pieces of furniture to absorb all impact from an earthquake.

First I'll post the original results from the sorbothane.

Test subject,... KWA M4A1 sp120 spring Guarder aluminum piston head.


Here is a video of the gun firing before the sorbo pad install


Here is an audio analysis of the stock pad sound...


I took out the old cylinder head and pryed out the old rubber pad...



I then took some ordinary objects and sharpened them into sorbothane "cookie cutters" using a trusty angle grinder.






I then used a hammer/cookie cutter to cut out some sorbo pads for various cyl head designs...




Then I cleaned the new pad and the cylinder head with alcohol...


Then I glued on the new sorbo pad...


Sorbo pad equipped head ready for reinstallation


The Sorbothane pad definitely had much better properties for shock absorbtion than the rubber pad, but I was dissappointed with the results.

The gun still jolted just the same as before and the sound report went pretty much unchanged.

Does this mean that the sorbo pad isn't working?

No, only time will tell if it is helping the gearbox from cracking. But the gun sounds and feels no different than before.

Anyways here is a video of the gun with the sorbo pad installed..


And the audio analysis with the sorbo pad.


Now, being dissapointed with these results I promptly ordered some 70D sorbothane to see if any different results could be achieved.

But, like I said, I stumbled upon these TPE pads at a hardware store.


They are designed to be placed under 30kg+ pieces of furniture for years at a time and absorb any earthquakes!

So as you can imagine this stuff is pretty durable, but just to be sure.....

I struck the piece on the right 153 times with a metal claw hammer. It escaped virtually unblemished and completely intact! It can definitely handle a poly carb piston head being pushed by an sp120 spring.


Now using my sorbothane cookie cutters, I made a new pad using the clear blue TPE and installed it into an Area 1000 cylinder head and put it into my CA SG1 G3 which also has an sp120 spring and ver 2 gearbox.

I don't have before and after videos but I can assure you, the attitude of this gun completely changed. A "thud thud" sound replaced the "Crack crack" sound from before. and the gun does not jolt in my hands like the KWA.

Here is a video...


and audio analysis of the TPE G3...


I am very impressed with the TPE so far. Soon I will install it in more of my guns and post further findings.

here is wiki on TPE...
http://en.wikipedia.org/wiki/Thermoplastic_elastomer

Very Interesting findings..

I am ordering 2 sets (hopefully) from a friend who sells these as a ready to use package soon. I personally think Louder is better, but I know a bunch og people on our field who would love Silent setups like this on AEGs.. Should do a compairson with an AK verient, METAL Cylinder head and Metal System piston head.. :) Taking it to the extreams, So I want to see how effective these are under Very intence conditions.

definitely post your findings!

As far as sound report , I wasn't primarily concerned with sound as much as I wanted a more reliable gearbox. The sound of teh sorbo was indicitive that nothing had changed whereas the sound of the TPE indicated that there was some effective dampening going on.

Quick question.... Were you using 50D or 50OO? 50D would be rather had for a bumper, as in shopping cart wheel hard according to McMaster.

Also, these TPE pads, would it be to get some shipped to the US? I'm interested in trying and comparing my self, but can only find it in rather hard tubing.

From what I understand, These sets cant be effective unless there is also a smaller pad on the Piston Head.. I may be worng, but This is the case with AEP Damper head sets (As you know my AEP friend!), And I think it may be the case with the sets I am purchaseing. I am buying the sets Just because I think it would be a good exsperiment to try.. Especially those out there who work with Ver. 2 Gearboxes a lot and are consirned with survivability.

Going to try this with a Ver 3 and Ver 2 base just b/c the Ver 3 gearbox is an easyer base to test with If I think I screwed something up. Other than that, I think I am going to try to rig something like this with my Parts Mp5.

Also, What about Silencers? In RS it would be a bit off if you would want a normal M4 to be Silent, You would need a Suppressor. I think If a suppressor was added to Eather of the 2 pads, There would be a much better effect..

EDIT!

Gilo, Very Nasty chewing on that Piston BTW.. Haha Madbull?..

This post has been edited by airsofthawaii: Oct 17 2008, 12:18 AM

It is 50D but it is nowhere near being as hard as a shopping cart wheel. This stuff is like jello. As far as the TPE Just pm me if you want some. I can problably ship it out for $5 a pack.

Nice report!
Only one question : would you mind to show some data about the sound figures?

Thank you!

Pad set Recvived and I tryed a Soft set w/ a Stocked Vector AKsu... Not the best results, but I may have installed it incorrectly, Plus Its rated at 380, So I think a Hard set should have been used..

Reguardless its not as loud, But not as good unless you don't have a Mock Silencer. I recoded my Results on video aswell, and it will be up sometime next week after I Sweep my computer clean..

This should be referenced to in one of the stickies around here, so it's not buried and forgotten. Good stuff, I'll have to try this out.

golgo, do you happen to have any more of the stuff left or know where one can buy some of it off the net?

You should be able to find on the net if not PM me. I sold a bunch to a guy on here and I am sure he will put out kits but we will see.

nice!!
One question: How did you get the area 1000 cylinder head to fit in a CA gearbox?

It just dropped in suprisingly. It is possible they have modded it to fit a larger variety of gearboxes these days, or maybe classic army changed their box.

In the past I would just use a jewlers file to widen the holes in the cylinder head.

sounds great more "thuddy" than sorbo too where can I get one? does someone here make a kit? or just sell me a square of gel?

This post has been edited by skag187: Oct 14 2009, 10:24 PM