Critique my Neilson device

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McLarenross
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Critique my Neilson device

Post by McLarenross »

Ive had my F1 sitting here for my 45 can for 2 months now while debating material choices. I wanted to use Titanium but Ive never machined Ti and its expensive. Were expecting a baby in a few weeks so my wife wouldnt let me spend $250 on Ti anyway. I had all the stainless needed except the tube so I just decided screw it and went for stainless throughout. Gonna be a little heavier but whats another 18oz when Im putting it on a 5" double stack 1911! lol. The Can will be 1.375 OD / 1.245 ID and ~8" long. I started yesterday by spinning the Neilson device. Here is the final product. The piston Im using is from an Octane/Osprey, the spring is from McMaster-Carr.

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Im still torn on the baffles Im gonna use. I really like the CTA style baffles cause they keep the tube clean but I cant do the radius on the nose. I can fit 11 of the CTA baffles in the length though. TiRant style K baffles are my other option but I can only fit 6 in the length. The CTA baffles weigh about 0.50 oz each for a total of 5.5oz in the baffles. The TiRant baffles weigh 0.65oz each for a total of 4oz in the baffles. That extra 1.5oz probably isnt gonna be discernible in the hand but I think nearly 2 times the baffles will be discernible to the ear. Opinions?

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Historian
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Re: Critique my Neilson device

Post by Historian »

Sir, you surely do nice machining.

Impressive.

I am curious about the spring you are using. How
did you pick its K ( Happy HOOKER* :) ) spring constant? From the image it
looks beefy. If you have reference tables for the springs proper for
different calibers please post.


* Hooke's Law SPRUNG to mind. :)
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McLarenross
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Re: Critique my Neilson device

Post by McLarenross »

Thank you for the complements.

The spring is kinda an experiment in this. Very little information available on the spring weights used in the industry unfortunately. From what Ive seen though the spring needs to be fairly stiff. I choose a spring from McMaster that is 66lb/in and 1.5" long. We will see how it holds up.
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T-Rex
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Re: Critique my Neilson device

Post by T-Rex »

Looks very professional.

If you remove put some milled cuts down the boosters long axis, you will add some volume to your blast chamber.

You could make your end cap like this
Image

and get rid of the need for a dis-assembly tool.
Obviously get rid of the internal threads.

Very nice work.
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Re: Critique my Neilson device

Post by Hatchetjoe »

How are you keeping the piston from rotating? If the spring is too stiff the booster wont work, as long as you have other springs in the same size to fit your assembly and have different wire thicknesses you will be all set, at that weight I think you would need a lighter than industry standard. As for the baffles well that is up to you personally I think the Ti-rant K baffles are quieter to my ear, and BTW most of that stack is Al so lighter.
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Re: Critique my Neilson device

Post by Capt. Link. »

Outstanding work.
You can place vents in the side to make it lighter and it should add to the suppression.
PM inbound for spring tuning tip.
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Re: Critique my Neilson device

Post by john.t.little1 »

Looks ok send it to me for further testing and review :D
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Re: Critique my Neilson device

Post by McLarenross »

Thanks for the compliments guys.

Joe - the plan is to insert a set screw or pin from the front to index the piston with. I havent done it yet, cause I honestly had forgotten. It will be done before complete though.
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Re: Critique my Neilson device

Post by whiterussian1974 »

Can't really Critique it. But SURE Can PRAISE IT!!!
Beautiful work and highly efficient use of materials vs weight. :)
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apd855
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Re: Critique my Neilson device

Post by apd855 »

Should there be a rubber o-ring in the bore of the cap to prevent gases from leaking out?
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Re: Critique my Neilson device

Post by gunny50 »

apd855 wrote:Should there be a rubber o-ring in the bore of the cap to prevent gases from leaking out?

That is an option, Not all silencer manufacturers use one.
With a piston like the one used (SilencerCo Osprey / Octane as far as I can recall), with the cut along the cylindrical part it might not work, as it could cut the O ring fast.

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Re: Critique my Neilson device

Post by Historian »

apd855 wrote:Should there be a rubber o-ring in the bore of the cap to prevent gases from leaking out?
You raise an interesting point in can design as there have
been some obscure ones with actual cuts strategically placed
to facilitate pressure reduction and in turn reduce report. As it was explained
" ... like puncturing a balloon with many pins simultaneously, hisses not blast.".

Again, masterful work.


Best.
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Re: Critique my Neilson device

Post by gunny50 »

gunny50 wrote:
apd855 wrote:Should there be a rubber o-ring in the bore of the cap to prevent gases from leaking out?

That is an option, Not all silencer manufacturers use one.
With a piston like the one used (SilencerCo Osprey / Octane as far as I can recall), with the cut along the cylindrical part it might not work, as it could cut the O ring fast.

Gunny

as used by me in the MK23 can as posted what back.

Image

Gunny
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L1A1Rocker
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Re: Critique my Neilson device

Post by L1A1Rocker »

Very very nice.
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Re: Critique my Neilson device

Post by T-Rex »

gunny50 wrote:
apd855 wrote:Should there be a rubber o-ring in the bore of the cap to prevent gases from leaking out?

That is an option, Not all silencer manufacturers use one.
With a piston like the one used (SilencerCo Osprey / Octane as far as I can recall), with the cut along the cylindrical part it might not work, as it could cut the O ring fast.

Gunny
The Octane does use an o-ring inside the booster end cap.
But you are right to worry about the spring compression length and the milled cuts hitting the o-ring.


You could put the drill rods, from the removal tool, inside the booster assembly to index the piston and keep it from rotating.
Drill shallow holes around diameter of piston's "semi-circle/moon" cut-outs, cut short pieces of rod and tap into holes with drift punch.
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Re: Critique my Neilson device

Post by McLarenross »

Hmm I hadnt considered the gas seal at the piston. Never seen a piston endcap with an o-ring in it. I just cut the clearance in the cap to have about 0.0015 per side to facilitate free movement. With the lengthwise cuts in the piston Im not sure if an o-ring in the ID like Gunny showed would seal. I think Im gonna try it as is and if I have a lot of gas leakage I will put an o-ring groove in the ID of the endcap and install one. Thanks for pointing that out for me.
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Re: Critique my Neilson device

Post by Bendersquint »

McLarenross wrote:Hmm I hadnt considered the gas seal at the piston. Never seen a piston endcap with an o-ring in it. I just cut the clearance in the cap to have about 0.0015 per side to facilitate free movement. With the lengthwise cuts in the piston Im not sure if an o-ring in the ID like Gunny showed would seal. I think Im gonna try it as is and if I have a lot of gas leakage I will put an o-ring groove in the ID of the endcap and install one. Thanks for pointing that out for me.
Just about all piston endcaps have orings.
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Re: Critique my Neilson device

Post by oneindianrider »

BEAUTIFUL work
I am waiting on my first Form 1 and been looking for plans on making this for a pistol can Ill be making as soon as it gets approved so thanks for the great pictures! Keep us posted how it works please!!!
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Re: Critique my Neilson device

Post by baba »

great work!

Would you mind posting general dimensions of that piston? I have been playing around in my cad program trying to draw up a booster of my own and i feel like I'm over doing it. I'm not looking to copy their design, just get an idea of the dims. Like the OD of the shaft and OD of the tines on the end.

Thanks,
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McLarenross
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Re: Critique my Neilson device

Post by McLarenross »

Sure. The Piston OD is 0.75" and overall length is 2". The OD of the flange at the front is 1.0" and it is 0.125" thick with 10 cuts through it that are 0.250" diameter each.
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Re: Critique my Neilson device

Post by baba »

Thanks!
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