"All caliber" cone design questions

[tjones96761]

Im trying to mimic the idea of the "hidden storage cups" as seen on eBay and Amazon, except cut from Inconel 718 and more functional with the correct 60deg angle. So I'm trying to come up with an 'all caliber' design that will work for 90-95% of applications that would use cones. The end user would have to drill the thru hole to the correct size (obviously). I've read a lot and picked up the basic concepts from this forum and others, but I'm reading between the lines on a lot of this.
How does this look for a "D" size maglite or SDtac type tube? Not a lot of info for how tight the base of the cones should fit to the ID of the tube. Also the .132 lip where the spacer will sit, should it be narrower/smaller? I read that the cone thickness could be less than 0.090", but didn't give an exact recomendation. Also didn't say if the base thickness should be the same or thicker. Any input on any/all of these dimensions welcome.
Basically, if you could hop on Amazon and buy cone shaped battery spacers, what would you ideally like to see?

[Grounded]

Drill through inconel, on home shop equipment.... no thankyou lol

[Samson104]

I would make the bottom of the cone flat with something like a 5/16" flat on the inside , this will be easier to machine and will be easier to drill out later.
unless you are running a lot of full auto on an SBR or running a really short barrel like 7.5" I honestly do not see the benefit of Inconel over 17-4 or even 316L considering the material cost and machining issues.

[Historian]

One 'back-of-the-envelope' sketch extrapolated from
a long ago seen project, as an indenture student
at Institute's machine shop, would be to make a collet that
holds the cone and then run it against a grinding wheel.

Image: Ice-cream cone atop a cylinder. This would allow
rotating the cylinder while controlling the cone.

e.g., << http://image.mathcaptain.com/cms/images ... -solid.png >>

[Dr.K]

Why not just make the cones the way you want from the beginning? I'm also curious as to the insanity of battery spacers being made from inconel?! Is that a real thing?

[tjones96761]

To answer a few questions:
DrK
If I was making these for myself under a Form 1, I would certainly do that. I'm trying to retail these. Sorry if that wasn't clear.
I'm not a card carrying FFL manufacturer, so I can't machine or sell "silencer baffles". There isn't a law (currently) against selling battery spacers, or solvent trap components, or whatever other non-firearm use one may dream up. Not having a thru hole seems to be the way this is being done.

Samson104
I have the Inconel at little to no cost. Any other material I'd have to purchase. I'm just trying to increase profit on the material that I'm currently selling for just a few bucks above scrap rate.
Originally, I had left a flat in the bottom V of the cone. I removed it with 2 thing in mind:
Coming back and drilling to size would be easier with less material to drill through and remove. That may not be correct thinking though. I might need to test that theory.
The inside of the cone is all removed with a #10 center drill with the 3/8" pilot point ground off to match the 60deg angle of the main body. with the cone or stock material in the chuck running about 90rpm and the modified center drill mounted in the tail stop. It's just faster and easier to cut it this way than to single point it at 60deg from the tool post. I could cut the 3/8" tip off flat and maintain the cutting edge and do the same thing. But that's 3/8" at the nose, not 5/16". That would leave a fair amount of material and weight in the nose if the through hole were only cut to 1/4" for .223 caliber.

No one commented on the wall thickness of the cone or base. It is Inconel so heavier than Aluminum, but it will be nearly identical to any grade of SS. Can you go thinner that other grades of SS because it's Inconel? I think its stronger than titanium, but not sure on that. Would you go thicker/thinner/same as titanium? If so, what is that thickness? These are the things I'm not familiar with.

[tjones96761]

Here's the "hidden secret storage cups" and direct website.



http://www.jmperformancefittings.com/

Here's what I'm trying to do.

[300sniper]

Do I have this correct? You are asking on a silencersmithing forum about making "All caliber" battery spacers that will not work as battery spacers because they will short out but are intended to be modified by the end user "obviously"? You plan on selling them retail but can not design them yourself?

If I could jump on Amazon and buy a cone shaped battery spacer, I wouldn't because it makes no sense.

[Capt. Link.]

A single stamping covering all reasonable sizes could be made. If you reduce the cone base diameter to .900 and the flange to 1.370 would be a more universal size.
If you were to build several different sizes a rim of .075 would better than .132 w/ a diameter slightly larger than current id of tubes would allow a precise fit.
The requirement for final fitting would be beneficial to the consumer.The tools required for final fit would be minimal and simple for a novice to build or buy.
-CL

[tjones96761]

300sniper,

The aluminum battery spacers that are being sold retail now will short without some sort of insulating material between them and the ID of the tube, but it doesn't seem to be curbing sales any...
I'm not here asking how to make battery spacers, but advise on the correct thickness of an Inconel cone baffle. If I were asking for advise on electrical conduction of DC current, this wouldn't be the best sounding board. OBVIOUSLY...

CL,

I'll throw something together in CAD and see what you think. I was planning 2 sizes, D and C. The material I have is 1.500 OD max, so I can't make anything larger than that. Appreciate the input.
Out of curiosity, how would a novice go about trimming the OD for precise fit?

[tjones96761]

something like this CL?

[whiterussian1974]

Perhaps this would be a good config for your parts.

And batteries require an opening at the apex for the Positive Terminal nipple to fit through w/o shorting. So a .25" or equivalent should work fine.
As stated above, Inconel would be pretty tough to work in a garage shop. Maybe you should offer 1 Inconel, and the rest SS.

And if you're machining rather than stamping, maybe thin ridges along the length every .25". Like the 2 lines I drew at .25" and .375" IDs. only along the entire length. It would be a stepped cone variant w/o adding extra weight. They would cause eddies and create turbulence for the return trip back up the length. Maybe have them extend 1/8-1/4"D outside the cone?
The horizontal green lines are flat washers surrounding aprox 5/6 of the cone to help direct gas across the mouth and delay return back around the cone base to reenter the mouth.

The bottom shows 5 configurations of the endcap. Simply forming an inward cone, adding small cones, or even Gunny50's vented snorkel exit.

[whiterussian1974]

You could have several external, belts that marked the stopping point for removing the tip. IE for grinder removal.
I mean the 1 on the right. (The left is another design that I';m working on. I just scalped your jpg for my own ease of use.)