Does any Smith here do that kind of barrel work, similar to the KAC "Dimpled" barrels. I was looking to have an SPR barrel done like that if it is possible. KAC hinted that it is proprietory for their shop. I wasn't sure. Thanks for any help. Jeff
Gunsmithing "Ball Milling" a barrel.
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Re: "Ball Milling" a barrel.
if you want it to look good, it would take a lot of programming on a 4 axis mill so it could be radiused/blended back into the od of the barrel. on a straight barrel it would be easier but on a tapered barrel, whoa!. i think the programing alone would make it cost prohibitive. now just plunging with a ball mill would be easy but personally, i don't think it would look very good.
if you want it to look good, it would take a lot of programming on a 4 axis mill so it could be radiused/blended back into the od of the barrel. on a straight barrel it would be easier but on a tapered barrel, whoa!. i think the programing alone would make it cost prohibitive. now just plunging with a ball mill would be easy but personally, i don't think it would look very good.
Re: "Ball Milling" a barrel.
Should have little or no negative effect. The only purpose is lighter weight and aesthetic looks really. I'll be honest that's my reason. The SPR is a 5.56 18.5" Noveske stainless steel tube, so it has a healthy contour already!
Should have little or no negative effect. The only purpose is lighter weight and aesthetic looks really. I'll be honest that's my reason. The SPR is a 5.56 18.5" Noveske stainless steel tube, so it has a healthy contour already!
Re: "Ball Milling" a barrel.
i was thinking sps and a tapered barrel. if you want a plunged ball mill pattern, i may be able to do it. i could see if i have an old ar barrel around here to try it out on to see how it looks and how difficult it would be. what size ball mill did you have in mind? what is the actual diameter of your barrel?
i was thinking sps and a tapered barrel. if you want a plunged ball mill pattern, i may be able to do it. i could see if i have an old ar barrel around here to try it out on to see how it looks and how difficult it would be. what size ball mill did you have in mind? what is the actual diameter of your barrel?
Re: "Ball Milling" a barrel.
I don't have any calipers, but the O.D. from the chamber is about .825" to the gas block, and then about .75 or .725 from the gas block forward, with a small "step" down just ahead of the muzzle.
I don't have any calipers, but the O.D. from the chamber is about .825" to the gas block, and then about .75 or .725 from the gas block forward, with a small "step" down just ahead of the muzzle.
Re: "Ball Milling" a barrel.
ADCO is now offering it
http://www.ar15.com/forums/topic.html?b=1&f=5&t=991636
ADCO is now offering it
http://www.ar15.com/forums/topic.html?b=1&f=5&t=991636
Re: "Ball Milling" a barrel.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Falar</div><div class="ubbcode-body">ADCO is now offering it
http://www.ar15.com/forums/topic.html?b=1&f=5&t=991636 </div></div>
that's what i was afraid it would look like without some sort of blending back into the od of the barrel. personally, i don't think that looks very good. the tooling marks also don't look like something i would want to pay for. not sure i could get away from leaving them either.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Falar</div><div class="ubbcode-body">ADCO is now offering it
http://www.ar15.com/forums/topic.html?b=1&f=5&t=991636 </div></div>
that's what i was afraid it would look like without some sort of blending back into the od of the barrel. personally, i don't think that looks very good. the tooling marks also don't look like something i would want to pay for. not sure i could get away from leaving them either.
Re: "Ball Milling" a barrel.
Yeah...it looks a little rough...Hmmm. Thanks for the link Falar, the upper was going to them any way for their KAC URX tool help. This might work!
Yeah...it looks a little rough...Hmmm. Thanks for the link Falar, the upper was going to them any way for their KAC URX tool help. This might work!
Re: "Ball Milling" a barrel.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">if you want it to look good, it would take a lot of programming on a 4 axis mill so it could be radiused/blended back into the od of the barrel. on a straight barrel it would be easier but on a tapered barrel, whoa!. i think the programing alone would make it cost prohibitive.</div></div>
Knowing the taper angle of the barrel I could write a macro that would cover the machining in less than 20 lines of code.
Ball endmills don't do well when plunging, Id be a little concerned with stress build-up after machining.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">if you want it to look good, it would take a lot of programming on a 4 axis mill so it could be radiused/blended back into the od of the barrel. on a straight barrel it would be easier but on a tapered barrel, whoa!. i think the programing alone would make it cost prohibitive.</div></div>
Knowing the taper angle of the barrel I could write a macro that would cover the machining in less than 20 lines of code.
Ball endmills don't do well when plunging, Id be a little concerned with stress build-up after machining.
Re: "Ball Milling" a barrel.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AJ300MAG</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">if you want it to look good, it would take a lot of programming on a 4 axis mill so it could be radiused/blended back into the od of the barrel. on a straight barrel it would be easier but on a tapered barrel, whoa!. i think the programing alone would make it cost prohibitive.</div></div>
Knowing the taper angle of the barrel I could write a macro that would cover the machining in less than 20 lines of code.
Ball endmills don't do well when plunging, Id be a little concerned with stress build-up after machining. </div></div>
if i were to do it, i'd probably 90* center drill all the holes almost full depth and then come back and plunge the ball mill. if time wasn't a concern, using a smaller ball mill to machine the holes would probably be the best way.
but yes, just plunging the holes or even interpolating with a smaller ball mill would be cake to program even on a tapered barrel. the part that i think would be tricky would be blending them back into the od of the barrel with either a chamfer or a radius on a tapered barrel.
after looking at some other pictures of barrels with this done, it may look alright with a ball mill not cut full radius deep. say a 5/16" ball mill at .100" deep. it does have my curiosity now and i think i will play with some scrap and see if i can come up with a size, depth and spacing that looks good.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AJ300MAG</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">if you want it to look good, it would take a lot of programming on a 4 axis mill so it could be radiused/blended back into the od of the barrel. on a straight barrel it would be easier but on a tapered barrel, whoa!. i think the programing alone would make it cost prohibitive.</div></div>
Knowing the taper angle of the barrel I could write a macro that would cover the machining in less than 20 lines of code.
Ball endmills don't do well when plunging, Id be a little concerned with stress build-up after machining. </div></div>
if i were to do it, i'd probably 90* center drill all the holes almost full depth and then come back and plunge the ball mill. if time wasn't a concern, using a smaller ball mill to machine the holes would probably be the best way.
but yes, just plunging the holes or even interpolating with a smaller ball mill would be cake to program even on a tapered barrel. the part that i think would be tricky would be blending them back into the od of the barrel with either a chamfer or a radius on a tapered barrel.
after looking at some other pictures of barrels with this done, it may look alright with a ball mill not cut full radius deep. say a 5/16" ball mill at .100" deep. it does have my curiosity now and i think i will play with some scrap and see if i can come up with a size, depth and spacing that looks good.
Re: "Ball Milling" a barrel.
When I fluted one of my barrels (and also a couple of bolts) I used a ball endmill. Instead of plunging it straight down in "Z" I swung and arc in "X" and "Z" to give it a blended appearence (like they were cut with a radius shell mill).
When I fluted one of my barrels (and also a couple of bolts) I used a ball endmill. Instead of plunging it straight down in "Z" I swung and arc in "X" and "Z" to give it a blended appearence (like they were cut with a radius shell mill).
Re: "Ball Milling" a barrel.
i just do a linear ramp in and out of my flutes but an arc wold look really good.
i just do a linear ramp in and out of my flutes but an arc wold look really good.
Re: "Ball Milling" a barrel.
300sniper, what did the chip pile weigh from that?
Fluting........ *sigh*
300sniper, what did the chip pile weigh from that?
Fluting........ *sigh*
Re: "Ball Milling" a barrel.
i didn't weigh it but the math said it was just under half pound. the flutes are only 10.5" long at full depth.
i didn't weigh it but the math said it was just under half pound. the flutes are only 10.5" long at full depth.
Re: "Ball Milling" a barrel.
I always use a .250 radius slitting saw, ramp in and out. I've had great luck with this. The ADCO barrel is very ugly in my opinion, plunging in with for many cuts will always leave tool marks. I have always like the spiral fluting but I only have a 3 axis machine, been thinking about adding a 4th for a rotary head.
I always use a .250 radius slitting saw, ramp in and out. I've had great luck with this. The ADCO barrel is very ugly in my opinion, plunging in with for many cuts will always leave tool marks. I have always like the spiral fluting but I only have a 3 axis machine, been thinking about adding a 4th for a rotary head.
Re: "Ball Milling" a barrel.
I run a Haas 210 Indexer. IIRC it was only a couple of grand when we bought it, can be interfaced with quite a few different controllers.
I run a Haas 210 Indexer. IIRC it was only a couple of grand when we bought it, can be interfaced with quite a few different controllers.
Re: "Ball Milling" a barrel.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">i just do a linear ramp in and out of my flutes but an arc wold look really good.
</div></div>
Very nice job, I'm headed out to the shop to start on mine. I post some pics.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">i just do a linear ramp in and out of my flutes but an arc wold look really good.
Very nice job, I'm headed out to the shop to start on mine. I post some pics.
Re: "Ball Milling" a barrel.
If the barrel is a straight taper, no special programming is needed as long as the barrel is held at an angle so the cut side is parallel to the axis of movement. This can be achieved by offsetting the barrel left or right for sidemilling or up/down for endmilling.
If the barrel is a straight taper, no special programming is needed as long as the barrel is held at an angle so the cut side is parallel to the axis of movement. This can be achieved by offsetting the barrel left or right for sidemilling or up/down for endmilling.
Re: "Ball Milling" a barrel.
maybe i wasn't clear on what i thought would make it look better and take more programming. a chamfer or radius on the top of each dimple. on a flat piece, easy. on a round piece, still easy. on a round piece that is tapered, quite a bit tougher.
maybe i wasn't clear on what i thought would make it look better and take more programming. a chamfer or radius on the top of each dimple. on a flat piece, easy. on a round piece, still easy. on a round piece that is tapered, quite a bit tougher.
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