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Dater hole size & location

Posted: Wed Mar 05, 2014 6:34 pm
by punkinhead
Where should I put the dater hole? How about a size? This is an 0.898" diameter baffle for a .22. The center hole is 17/64.

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Re: Dater hole size & location

Posted: Wed Mar 05, 2014 6:40 pm
by whiterussian1974
Position 1 allows the face to symetrically direct flow to mouth cut. Off side would create a cross jet cutting across cross jet, from right to left. Disrupting the throat's turbulant process. Though the high pressure would probably prevent this turbulant disruption.
Pos #2 avoids axial jet pushing into mousehole. This forces gas along outside of cone causing further cooling and stagnation. So I vote for #2.
As for hole, I have no #s for this. I would prefer 1/16", others may prefer smaller. The high pressure should prevent fouling, yet lower total chamber pressure be allowing additional "escape hatch."
The size of your red dot seems about the size I have seen on Commercial builds.

Hopefully someone will post a link to free Dr Philip Dater's papers.
I have searched exhaustively. But "no Joy."

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 7:47 pm
by L1A1Rocker
This is going to be good info.

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 8:22 pm
by whiterussian1974
Why do so many builds use straight lined cones instead of curved Frustum-cones?
The Bell shape creates suction behind baffle skirt pulling blast backward and outward retaining pressure surge longer.

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 8:40 pm
by doubloon
L1A1Rocker wrote:This is going to be good info.
http://silencertalk.com/forum/viewtopic ... 10&t=72030

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Re: Dater hole size & location

Posted: Wed Mar 05, 2014 8:47 pm
by Bendersquint
Most "Dater" holes are 1/8" holes and only Gemtech uses a different location of the hole. They use #2 location from the OP diagram.

All other commercial cans use the location of the one from my picture that Doubloon posted.

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 8:50 pm
by Bendersquint
whiterussian1974 wrote:Why do so many builds use straight lined cones instead of curved Frustum-cones?
The Bell shape creates suction behind baffle skirt pulling blast backward and outward retaining pressure surge longer.
Ease of manufacture. Most Form1 builders don't have the CNC's needed to produce the sloped cones under the plate.....not to mention the lower performance it yields.

The straight cone performs better.

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 10:30 pm
by doubloon
Bendersquint wrote:...
All other commercial cans use the location of the one from my picture that Doubloon posted.
Didn't realize that was originally your picture I salvaged it from google cache and can spin it back into oblivion if you prefer.

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 10:32 pm
by doubloon
whiterussian1974 wrote:...
Hopefully someone will post a link to free Dr Philip Dater's papers.
I have searched exhaustively. But "no Joy."
I can't say I've ever seen a paper from Dr Dater on the hole ... in conversations quoted from others Dr. Dater only seems to indicate it is to help eliminate FRP ... Robert once referred to it as "hot rodding" the first baffle IIRC

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 10:38 pm
by Bendersquint
doubloon wrote:
Bendersquint wrote:...
All other commercial cans use the location of the one from my picture that Doubloon posted.
Didn't realize that was originally your picture I salvaged it from google cache and can spin it back into oblivion if you prefer.
Nope its fine, I put it on the internet to begin with and someone doodled on it to explain to someone where the dater hole was.

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 11:01 pm
by whiterussian1974
doubloon wrote:
whiterussian1974 wrote:...
Hopefully someone will post a link to free Dr Philip Dater's papers.
I have searched exhaustively. But "no Joy."
I can't say I've ever seen a paper from Dr Dater on the hole ... in conversations quoted from others Dr. Dater only seems to indicate it is to help eliminate FRP ... Robert once referred to it as "hot rodding" the first baffle IIRC
Yeah. Seems like a supercharger injecting gas around skirt before it enters from below through mousehole.

Bender, thanks for info. Why does it perform worse? I've only heard theory that it should help. I have no experience w it, but others support curves and I thought of trying it on a Future F1.

BTW, ANY papers from DR Dater would be greatly appreciated. He's often cited, but I've never found his reports.

I noticed that some builds use a swiss cheese type blast baffle, then no mousehole on 1st skirt. This would lower blastchamber static pressure and also act as turbulance inducing, occluded 1 way valve. Capturing the high pressure pocket until boreline pressure decreases enough to allow the cooled and expanded gas to reverse course. This is often used primarily on high power/volume rifle builds that use a version of cones whether: straight, stepped, clipped or K.

This would seem to be a K on METH!
Dumping all that energy into a pocket w nowhere to go.

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 11:09 pm
by 57fairlane
Bendersquint wrote:All other commercial cans use the location of the one from my picture that Doubloon posted.
Well, not all of them :wink:

Re: Dater hole size & location

Posted: Wed Mar 05, 2014 11:29 pm
by Bendersquint
57fairlane wrote:
Bendersquint wrote:All other commercial cans use the location of the one from my picture that Doubloon posted.
Well, not all of them :wink:
Which other commercial cans have dater holes in other locations?

Re: Dater hole size & location

Posted: Thu Mar 06, 2014 8:35 am
by 57fairlane
Bendersquint wrote:
57fairlane wrote:
Bendersquint wrote:All other commercial cans use the location of the one from my picture that Doubloon posted.
Well, not all of them :wink:
Which other commercial cans have dater holes in other locations?
element 2

Re: Dater hole size & location

Posted: Thu Mar 06, 2014 11:53 am
by Bendersquint
Good call, forgot they changed that on the element2.

Only seen one of those come in for repair.

Re: Dater hole size & location

Posted: Thu Mar 06, 2014 11:56 am
by whiterussian1974
Bender, what's your company contact info for repairs/recore?

Re: Dater hole size & location

Posted: Thu Mar 06, 2014 11:59 am
by chrismartin
whiterussian1974 wrote:Bender, what's your company contact info for repairs/recore?
http://www.stalkingrhino.com

Re: Dater hole size & location

Posted: Thu Mar 06, 2014 12:19 pm
by whiterussian1974
chrismartin wrote:
whiterussian1974 wrote:Bender, what's your company contact info for repairs/recore?
http://www.stalkingrhino.com
Thanks. I searched SRI NC, but got State University and Racing Supply info.

Re: Dater hole size & location

Posted: Thu Mar 06, 2014 7:51 pm
by doubloon
whiterussian1974 wrote:...Thanks. I searched SRI NC, but got State University and Racing Supply info.
There's a link in his profile.