HDD Testing

[mr007s]

I grasp the concept of how the HDD controls the repeated motion of the hammer, really I do. Thanks to the detail spooned up in the opening post by Carl. This got my mind wondering (sometimes good, others not so good.). The Disco tube and hammer were out on the workbench/kitchen table so I zeroed the calipers and took some measurements. The I.D. of a Disco tube is .748. I will carry it to work tomorrow and use some hole mics on it for checking roundness and a closer overall diameter. The Disco hammer measures .736". I'm thinking the tube is probably .75 so that leaves .014" of play for the hammer to bounce around in.
  I am wondering to myself if this was closed up some with a very small amount of play if the hammer would react differently to a degree when the trigger is pulled. Would bounce be lessened any? A light coating of moly paste would aid in the forward motion. Just wondering about this and would like members thoughts in this area.I have the experience and machinery at my disposal to fab one and heat treat it but would the benefits be worth the time?

[quickster47 †]

I think that with the moly and perhaps a tighter fitting hammer it would still suffer from the infamous bounce problem.  Gotta remember that the HDD acts like a brake to basically stop the hammer after the initial contact with the valve and the beginning of the backward motion.

Carl

[Oane]

How about other pistols? we are crosman orientated but wouldn't a benj EB gain something by a HDD? are there any that fit with a EB?

[tatsumi]

If thats what results they give then got to get one,any one know a supplier in the uk?

[eric]

How about other pistols? we are crosman orientated but wouldn't a benj EB gain something by a HDD? are there any that fit with a EB?

i don't think there is ,only the crosman (style/s) and rjmachine breeches(closer tolerences).the eb reciever is different than the aboved mentioned.think someone tried it a few years back but looks like nothing came from it.the benjamin/sheridan rifles on the other hand, yes but they are different in design

[quickster47 †]

There is one designed for the QB-78 series of rifles.  I think Steven Archer commissioned Steve-of-NC to design one for them.  Not sure of any others though just as Eric mentioned.

Carl

[Gunhippie]

Wow, Carl--those are some spectacular results!

It's strange that I get nothing like this with my AoA HDDs in my 2300S'. Since I now have one gun with and one without, I can testify there's no difference in noise level, nor (before I went bulk) any difference in Powerlet consumption. I always got between 65 and 75 consistent shots/Powerlet--before installing the HDDs and after one broke (yep, the little hook busted off). Of course, the 2300 series have a volume reducer in the valve, but I can't see how this would reduce hammer bounce. THe absolute only time I notice any bounce is when the guns are running out of gas--they kind of "burp" and that's my warning to refill--and both guns do it the same.

I wonder if your home made HDD has closer tolerances than the ones from AoA? Or did I just get unlucky and buy a couple of lemons? Getting twice the shot count/fill and less noise would be a dream come true!

Timm.

[arkmaker †]

How many shots did you get with the one I sent you before it self destructed?
Thanks,
Rich

[quickster47 †]

I actually had three of the HDDs, two from AoA and the other from ArkMaker.  Don't know what happened to the first one.  And actually I think I decided it did NOT work and discarded it.  The AoA second one yielded the best results but remember it was installed on a brand spanking new 2240 and was the only mod done to the gun.  The 2300 is a different animal entirely.

Rich. I was right at 45 shots when it failed.  The hammer pin just kept going right through the groove that was supposed to act like the brake.

Carl

[NorthStaR]

Does anyone have a link to an old thread that showed installing one of these HDD?
Not sure who posted it before, it had pictures but I can't find it! 
I can't quite visualise how it fits from the description 

[arkmaker †]

Rich. I was right at 45 shots when it failed.  The hammer pin just kept going right through the groove that was supposed to act like the brake.
Carl

Well, I'll just have to try again!!  
Rich

[arkmaker †]

https://www.airgunsofarizona.com/

Look on the left for Crosman
then Custom Parts
Installation guide is a link under the pic of the HDD

[NorthStaR]

Ah-HA! 

Thanks, thats the one! 

[redpuntohgt]

Who sale these?
Where can i get one??
Do you someone have a photo of the internals and instalation??

[NorthStaR]

Who sale these?
Where can i get one??
Do you someone have a photo of the internals and instalation??

redpuntohgt
Have a look at Arkmakers post, the one before mine.
Theres a link and instructions for the HDD.

Cheers