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Tom Liakopoulos
Guest
I know it's more then likely a $250,000 solution to a $5,000 problem but....
Has anyone seen or heard of somone doing this?
Has anyone seen or heard of somone doing this?
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squeakie
Guest
I'd imagine they're doing it with a sinker, and it must be a huge machine! We had a big one at work that had the largest power supply made, and it might have been able to do a 16" barrel. Perhaps somebody builds a horizontal spindle machine these days, and even then you'll need at least a 36" table to do a 22" barrel
gary
gary
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4Mesh
Guest
Just curious, but, EDM'ing a hole ain't rocket science. A holes a hole. How would chambering a barrel be "patented"? And certainly it's not because of the C-axis cause that's not exactly unique either.
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Tom Liakopoulos
Guest
http://www.freepatentsonline.com/7262382.pdf . Proof that anything can be "Patented".
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squeakie
Guest
you can copyright the process, but the rest is not yours. What interests me is the plug they're using. Some are graphite and some are copper inert tungstin ($$$), and maybe there are a couple other materials in use now. The plugs can really only be used once with any accuracey. They leave absolutly no burrs, and induce zero stress into the parent metal. Making the plugs can be time consuming, and this is why sinkers are used for one up part runs most of the time. If they are using somekind of a mold to make the plug; you may see a variation between the plugs. I'd love to see their process up close
gary
JerrySharrett
Senile Member
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NesikaChad
Guest
They leave absolutely no burrs, and induce zero stress into the parent metal.
Machining a material does not induce or create stress. It relieves it.
We can demonstrate this easily with a material that has a great amount of "inner turmoil"; Delrin. Take a block of the stuff and bore a hole in it. Then slot one side of the bore. What happens? The hole and the slot clams shut. We relieved the stress that was already present within the material. We did not create more "drama" within that piece of material.
Take a flat plate of cold rolled that's a 1/2" thick and fly cut a 3rd of it off. When you pop it out of the vise it'll likely bow up like a banana. Again, the stress was taken out of the material and it warped. You didn't add to what was already there.
Take that same piece of material and have it stress relieved. (an oven process generally) It'll likely come back looking like a banana and now you have to fly cut it flat again. Only difference is now it lays there dead as a post when you take it from the vise.
So, whether you cut a chamber with a sinker, a reamer, or a post hole digger if there is stress in the material you are going to have an effect on it. A barrel doesn't know or care what tool makes the chamber, if the material condition is bad (meaning the stress relieving process sucks) it's going to have a greater potential for distortion when whittled on. That being said a reamer will be just as accurate dimensionally as the graphite plug. (assuming both are done using appropriate machining procedure)
As for burs.
In general terms most modern high performance centerfire rifle cartridges operate in the 50-60k pressure range. That pressure combined with flash chamber temperatures of over 5000 degrees means the probability of any little burr or booger loitering past the 1st or 2nd pull of the trigger is quite small.
Have a great new years.
C
Machining a material does not induce or create stress. It relieves it.
We can demonstrate this easily with a material that has a great amount of "inner turmoil"; Delrin. Take a block of the stuff and bore a hole in it. Then slot one side of the bore. What happens? The hole and the slot clams shut. We relieved the stress that was already present within the material. We did not create more "drama" within that piece of material.
Take a flat plate of cold rolled that's a 1/2" thick and fly cut a 3rd of it off. When you pop it out of the vise it'll likely bow up like a banana. Again, the stress was taken out of the material and it warped. You didn't add to what was already there.
Take that same piece of material and have it stress relieved. (an oven process generally) It'll likely come back looking like a banana and now you have to fly cut it flat again. Only difference is now it lays there dead as a post when you take it from the vise.
So, whether you cut a chamber with a sinker, a reamer, or a post hole digger if there is stress in the material you are going to have an effect on it. A barrel doesn't know or care what tool makes the chamber, if the material condition is bad (meaning the stress relieving process sucks) it's going to have a greater potential for distortion when whittled on. That being said a reamer will be just as accurate dimensionally as the graphite plug. (assuming both are done using appropriate machining procedure)
As for burs.
In general terms most modern high performance centerfire rifle cartridges operate in the 50-60k pressure range. That pressure combined with flash chamber temperatures of over 5000 degrees means the probability of any little burr or booger loitering past the 1st or 2nd pull of the trigger is quite small.
Have a great new years.
C
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4Mesh
Guest
You could do it Jerry, but it's not going to be a very interesting case! I'm thinking VERY straight tapered!
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nhkuehl
Guest
Could a cartridge case or dummy round be used as the electrode? Talk about chamber fit! - nhk
Butch Lambert
Active member
NO!! on using a fireformed piece of brass or dummy.
I will agree with Chad, a reamer will do as well as or better than plunge EDM for a chamber.
Butch
I will agree with Chad, a reamer will do as well as or better than plunge EDM for a chamber.
Butch
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Chad
Are you sure about that? Me thinks you have it back wards.
If machining, removed stress, stress relieving would then be mute.
Patents, have become for the most part, worthless pieces of paper to hang on your wall and pad your already inflated ego. With the right amount of money and a creative patent atty you can be granted a patent for, nothing if you wish.
Patents have to be defended to make them worth having, Most things that were patented have expired or the maintenance "FEES" were never paid.
Are you sure about that? Me thinks you have it back wards.
If machining, removed stress, stress relieving would then be mute.
Patents, have become for the most part, worthless pieces of paper to hang on your wall and pad your already inflated ego. With the right amount of money and a creative patent atty you can be granted a patent for, nothing if you wish.
Patents have to be defended to make them worth having, Most things that were patented have expired or the maintenance "FEES" were never paid.
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Butch Lambert
Active member
TRA,
Give me a real reason cutting material induces stress.
Butch
Give me a real reason cutting material induces stress.
Butch
Butch
Give me a real reason cutting a material relieves stress.
Oh....BTW....heat
And there is residual stress and induced stress, although residual stress may be released by a process it can also induce stress.
When you turn, the od of a barrel or shaft it will usually warp. now, you removed material radially, yet the shaft still warped. Stress or not?
Give me a real reason cutting a material relieves stress.
Oh....BTW....heat
And there is residual stress and induced stress, although residual stress may be released by a process it can also induce stress.
When you turn, the od of a barrel or shaft it will usually warp. now, you removed material radially, yet the shaft still warped. Stress or not?
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4Mesh
Guest
The examples were given above. If you want to dispute/discuss them, that's ok. But, I think it's a pretty safe bet the stress is in there and needs relieved. Here's another example.
Piece of metal stock 3" wide. Has stress in it (assumed). Stand it up in front of you and look at it. Left 1.5" has stress pulling the part into a banana toward the left. Right 1.5" has equal stress pulling the part into a banana toward the right. Part looks straight to you.
Cut some material off either side but not both, the part will pull toward the side without material removed. That's what Chad is saying.
What you are saying is that if the part has heat put into it, it could either gain or loose stress (I'm paraphrasing from what I took of your post). I would partially agree that if you do metalwork on that part and your tooling causes the part to get hot, you will ALTER the state of the material and if there is stress involved, odds are you will have a part that is no longer shaped like it was when you began.
But your idea of putting heat in adding stress is counterintuitive (says I). Let's say I turn a part in a lathe with no coolant and it gets up to 250F. That's pretty darn hot. I take the part out of the lathe, lets say it was a long narrow round of some crappy steel. It most likely is not a long narrow STRAIGHT round any more. Ok, now, if I had taken the same part, put it in an oven and heated it ONLY to 250F and then let it cool again, do you think it would have changed in shape as dramatically as some parts you've probably seen come out of a lathe? I bet not. I bet it would barely move, if even measurably. So, one could conclude that the heat did not do the alteration, but the material removal did.
As an experiment. grab a piece of relatively straight 3/4" Cold rolled round stock. Put a center in one end of it. Chuck up quite tightly with 2 or 3" in the chuck. Now bring your live center into the part. Hopefully, the bar is straight enough the center fits up perfectly without help. Now, turn the part down to 1/2". Stop the lathe, and pull the center but let the part in the chuck. If you CAN put the center back in, that is some pretty nice stock you have there cause I'm betting there's times you won't be able to get it back in there. If you could convince me that heating that part to the same temp would have bent it that far, then I'd say you're right. But I don't think it'll ever move that far. I've seen examples of this very thing and the part center sprung ~1/2" from the live center when the tailstock was pulled away.
Butch Lambert
Active member
TRA,
You don't have an answer do you.
Butch
You don't have an answer do you.
Butch
So, however YOU want to interpret the relieving of, or the inducing of stress, the material still warps. That's the rub, and that is all that matters is the removal of the stress, that the processes have altered, in some applications, is still necessary.
I'd be interested in hearing, how you determine that after you machined a part, that the stress was induced or relieved. All I hear you saying is after you removed the stress by machining a part that it now requires "Stress Relieving"
I'd be interested in hearing, how you determine that after you machined a part, that the stress was induced or relieved. All I hear you saying is after you removed the stress by machining a part that it now requires "Stress Relieving"
Butch Lambert
Active member
TRA,
You are kinda tongue tied. What did you say in post #17? Now go back and read my post word for word. What did I say?
Butch
You are kinda tongue tied. What did you say in post #17? Now go back and read my post word for word. What did I say?
Butch
Butch
Sorry for confusing you.
Let's try a more simple version.
When you remove material, you only remove the stress that is now chips.
The remaining material now has induced stresses, plus the residual stress that needs "Stress Relieved, or "Normalized"
Get it now? You only remove the stress that resided in the removed material.
If that's too tough for you, maybe I can drag out my chalk board.
Who really cares if the so-called removal or the release of stress is now laying on the floor or in the chip conveyor? I don't, it's the finished product that matters, and it's more than likely warped....stress or no stress.
Sorry for confusing you.
Let's try a more simple version.
When you remove material, you only remove the stress that is now chips.
The remaining material now has induced stresses, plus the residual stress that needs "Stress Relieved, or "Normalized"
Get it now? You only remove the stress that resided in the removed material.
If that's too tough for you, maybe I can drag out my chalk board.
Who really cares if the so-called removal or the release of stress is now laying on the floor or in the chip conveyor? I don't, it's the finished product that matters, and it's more than likely warped....stress or no stress.