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ShelleyDavidson
01-14-2008, 08:54 AM
Since Gene has announced his tuner design, I figured I'd talk about the one that I'm building. The design work on this tuner was done by Esten Speers who is a retired vibration engineer with the input and computer modeling of Varmint Al. Also, there was a significant amount of help and input by Ralph Stewart who lent his own brand of high frequency energy and research abilities to the project and made a couple of trips to the Odessa tunnel to test the tuner and effects of DA, all under the watchful eyes of Gene Beggs. Me, I was the machinist on the project and the only real design change that I made was to increase the diameter of the hole and funnel section that extends past the front of the barrel. The increased hole size was to minimize any possible turbulence inside the tuner. And yes, my Oehler 35 chronograph does work quiet well with the tuner. This is the design that was hashed out right here on BR.Com.

I have just finished my first run of 20 tuners and will have the laser engraved weight rings back from the shop later this week. The perceived benefits of the tuner that I make are:

The tuner was engineered so the mass (6 oz.) will assist in dampening the jitters, or wild vibrations, and tune the lower frequency vibrations that are so important to counteract the variances in DA during a day of shooting.

My tuner consists of one cnc'd tuner body that screws on a .9 diameter 32tpi one inch threaded section of the muzzle and two weights that screw over the part of the tuner that hangs off the end of the muzzle. The threaded section, where the weights are is also 32tpi which seems to go through a complete tune cycle or node about every .050" or thereabouts. I assume that different guns and calibers will have slightly different DA formulas and different nodes just like different calibers tune differently when using powder. After all, we are still addressing the exact same dynamics as when using powder to tune.

I didn't farm my tuner out, the body is made on my own cnc lathe and the weights are made on my 16X40 barreling lathe using one set-up from start to finish so they are as concentric as a cnc'd ring. The weight ring's diameter is too big for my cnc which utilizes 5C collets. There is no change in the point of impact using this tuner.

How much is my price? Quiet a bit more than Gene's I'd think. One of the rings has graduations laser etched on it so as to help in setting and getting back to the same spot when needed. For the first batch, the etching is costing me right at $20.00 each. There's a set up charge involved but even after the first time that cost will still be a factor. Then, there's tooling and the time to write and de-bug around 400 lines of code for the tuner. If I knew cad, I could probably use it to write my programs but I don't so I still write in raw G-codes and create my own sub-routines. Oh, yeah, I broke $75.00 worth of mini boring bars before getting the programing right. I didn't say I was a good programmer. (grin) I've actually been working on getting this going for a month and a half.

I can say that my tuners work well. For instance, I was at the range last Saturday. Because it was chilly and really windy I took a break in the heated stat shack and enjoyed a 45 minute BS session. When I returned to the line I checked the DA meter which had risen 500 feet while I was away. I moved my tuner 1/8 turn back towards the rear of the rifle and shot a .150" five shot group. I kinda lucked out on that group as the wind was switchy and gusting to about 20mph. I also shot some wide groups. But I shot the same Harrel's Power Measure setting that I'd used the previous Saturday when it was t-shirt weather, and I stayed in tune all day.

This was kinda interesting because it also tied in with another experiment. I like 30 calibers. I've shot some really small groups with a 30BR using Benchmark, but you can't get enough Benchmark in a BR case to get to the sweet spot muzzle velocity of 2980 fps that the 118 bullets do well at. I've actually shot a .045" group and a .083" group in registered matchs at Tomball using Benchmark. I wanted to try tuning a case to a certain powder.... namely Benchmark. So I had Dave Kiff make a 30BRX reamer that is simply a regular 30BR reamer with the shoulder run forward .100". Nothing new here. Then my testing showed that to chronograph 2980 fps in chilly weather I needed more Benchmark so I ran the reamer in another .025" so I now had a .125" long 30BR. When I got to the sweet spot speed wise I then moved my tuner twice at 1/8 turn per move and was in tune. Neat!!!!

Will my tuner work better or worse than Gene's? Darned if I know. All I know is that I've been dinking around with tuners for several years and they all seemed to work but I had no idea how to use them because I didn't understand the dynamics of how they worked. In a nut shell, here's how it works. When the day warms up and the humidity falls, the air gets lighter/ less dense and your bullet will reach the muzzle a bit quicker. So, you can either decrease your powder load to slow the bullet so it reaches the muzzle at the same point in it's vibration swing or you can turn the tuner so that it's weight moves back towards the rear. This increases the vibration frequency so the muzzle reaches the same sweet spot quicker, when the faster moving bullet reaches it. The tuner weight affects the barrel like the weight on a pendulum. Increase the distance from the fulcrum to the weight on a pendulum and the swing slows down. Go shorter and the pendulum's swing speeds up. It's just that simple.

http://i131.photobucket.com/albums/p313/ShelleyDavidson/IMG_2020.jpg

JerrySharrett
01-14-2008, 09:05 AM
I hope tuners go this time, both in the IBS and NBRSA. In 2005 many of the old guard were really against them.

Wayne Shaw
01-14-2008, 09:14 AM
We'll know this Saturday!

Boyd Allen
01-14-2008, 09:35 AM
Shelly,
What barrel contour and length are you using? Have you played with this aspect of the system to reduce the amount of tuner weight needed? On the thread where Varmint Al showed computer models of several different barrel contours, I asked him to look at a barrel that was reduced in diameter in the middle, and it worked similar to a longer barrel or one with a weight at the muzzle with respect to bullet exit vs barrel swing. For those of us who are already at the weight limit, adding weight to the muzzle means that a like amount has to be removed somewhere else on the rifle. What are your thoughts on this aspect of the problem?

Dusty Stevens
01-14-2008, 09:58 AM
looks good shelley

ShelleyDavidson
01-14-2008, 10:00 AM
The initial 6mm test barrels were all Kriegers in Bruno's special reduced LV taper. We chambered six of the Kriegers for Ralph Stewart's LV. The barrels were all chambered and cut identically and all responded alike to the tuner. Length is 21.8". As always, although all six shot well, there was one that was a bit less wonderful than the other five.

Shilen is in the process of making a test barrel in 6mm that'll be similar to the Bruno reduced taper. A neat thing about the Shilen is that it'll be cut two inches longer than finished length before contouring. In other words, the barrel will be cut to 24" then contoured and then lapped. This will help keep the bore in the middle of the finished blank out at the muzzle end because there will be less length for the gun drill to have wandered. Cool, huh?

The 30 barrel that I'm playing with is a regular Bartlien LV taper. It's one that I have had for awhile and I just used it to experiment with. But since the inside bore is larger than a 6mm were probably dealing with a similar stiffness.

I'd think that any radical change in diameter may affect the ability of the barrel to handle the problems associated with heating. That's just a guess as I have no science to back it up. I'll bet that we'll see lots of tuner configurations over the next year.

hulk
01-14-2008, 10:49 AM
How does one get on the list for one of these?

ShelleyDavidson
01-14-2008, 11:28 AM
e-mail me at shelleyforhire@yahoo.com and I'll send pricing. If you're happy with the price I'll mail one next week. provided you commit in time to get one of the first ones. Although I have 20 bodies made , I only have 9 sets of weights made right now. Seven of those nine are spoken for. If I get orders I'll make more weights.

And.... can someone tell me how to place a classified ad? I need to make sure I'm ok with Wilbur as I really do appreciate this forum.

Shelley

Chisolm
01-14-2008, 01:52 PM
And.... can someone tell me how to place a classified ad? I need to make sure I'm ok with Wilbur as I really do appreciate this forum.

Shelley

Shelley
You will need to go to the classified section and create an account there.
You can use the same username as on the forum or another but you must create a new account as the classified user accounts are seperate from the forum user accounts. I don't know why it's that way but it is.
James

ShelleyDavidson
01-14-2008, 02:05 PM
Placing the ad was easy but I don't see how to add a photo...... help??

I placed the ad under components/barrels.

Shelley

Charles E
01-14-2008, 02:14 PM
A neat thing about the Shilen is that it'll be cut two inches longer than finished length before contouring. In other words, the barrel will be cut to 24" then contoured and then lapped.

Not to hijack the thread, but when I talked to Bill Hull a few years ago, he said that he (Shilen) lapped before contouring. I made sure he meant this, as I was getting an odd contour for a BR rifle. He said yes, he'd take that into account before he lapped it, then it would be contoured.

Did I misunderstand?

ShelleyDavidson
01-14-2008, 02:23 PM
Then was then and now is now. According to Wade Hull, Bill's son and President of Shilen, they are lapping after contouring now. I stand to be corrected but this was what my understanding was as of a couple of weeks ago.

Shelley

Gene Beggs
01-14-2008, 03:37 PM
Hi Shelley,

Congratulations on getting your tuner into production; well done Buddy!

Although my design is simpler, lighter, and uses a different method of adjustment, it was inspired by yours.

Come see us when you can; looking forward to visiting with you.

Later,

Gene Beggs

Larry M
01-14-2008, 03:40 PM
Some manufacturers will lap twice. Once after drilling then again after contouring. To get the correct profile of the bore or lap in a slight choke. When a barrel is contoured the bore opens up on the skinny end.

ShelleyDavidson
01-14-2008, 03:51 PM
I'd have to say that your lessons on density altitude started the whole thing.

Be Well
Shelley

J Conley
01-14-2008, 08:47 PM
Every time I see one of Shelley’s turners on a rifle I’m amazed by the accuracy.
I ordered one to use on my PPC. And now after seeing how well it works with a 30 I can’t wait for the season to start.

Good work Shelley.
Jon

Don
01-17-2008, 07:19 PM
Since Gene has announced his tuner design, I figured I'd talk about the one that I'm building. The design work on this tuner was done by Esten Speers who is a retired vibration engineer with the input and computer modeling of Varmint Al. Also, there was a significant amount of help and input by Ralph Stewart who lent his own brand of high frequency energy and research abilities to the project and made a couple of trips to the Odessa tunnel to test the tuner and effects of DA, all under the watchful eyes of Gene Beggs. Me, I was the machinist on the project and the only real design change that I made was to increase the diameter of the hole and funnel section that extends past the front of the barrel. The increased hole size was to minimize any possible turbulence inside the tuner. And yes, my Oehler 35 chronograph does work quiet well with the tuner. This is the design that was hashed out right here on BR.Com.

I have just finished my first run of 20 tuners and will have the laser engraved weight rings back from the shop later this week. The perceived benefits of the tuner that I make are:

The tuner was engineered so the mass (6 oz.) will assist in dampening the jitters, or wild vibrations, and tune the lower frequency vibrations that are so important to counteract the variances in DA during a day of shooting.

My tuner consists of one cnc'd tuner body that screws on a .9 diameter 32tpi one inch threaded section of the muzzle and two weights that screw over the part of the tuner that hangs off the end of the muzzle. The threaded section, where the weights are is also 32tpi which seems to go through a complete tune cycle or node about every .050" or thereabouts. I assume that different guns and calibers will have slightly different DA formulas and different nodes just like different calibers tune differently when using powder. After all, we are still addressing the exact same dynamics as when using powder to tune.

I didn't farm my tuner out, the body is made on my own cnc lathe and the weights are made on my 16X40 barreling lathe using one set-up from start to finish so they are as concentric as a cnc'd ring. The weight ring's diameter is too big for my cnc which utilizes 5C collets. There is no change in the point of impact using this tuner.

How much is my price? Quiet a bit more than Gene's I'd think. One of the rings has graduations laser etched on it so as to help in setting and getting back to the same spot when needed. For the first batch, the etching is costing me right at $20.00 each. There's a set up charge involved but even after the first time that cost will still be a factor. Then, there's tooling and the time to write and de-bug around 400 lines of code for the tuner. If I knew cad, I could probably use it to write my programs but I don't so I still write in raw G-codes and create my own sub-routines. Oh, yeah, I broke $75.00 worth of mini boring bars before getting the programing right. I didn't say I was a good programmer. (grin) I've actually been working on getting this going for a month and a half.

I can say that my tuners work well. For instance, I was at the range last Saturday. Because it was chilly and really windy I took a break in the heated stat shack and enjoyed a 45 minute BS session. When I returned to the line I checked the DA meter which had risen 500 feet while I was away. I moved my tuner 1/8 turn back towards the rear of the rifle and shot a .150" five shot group. I kinda lucked out on that group as the wind was switchy and gusting to about 20mph. I also shot some wide groups. But I shot the same Harrel's Power Measure setting that I'd used the previous Saturday when it was t-shirt weather, and I stayed in tune all day.

This was kinda interesting because it also tied in with another experiment. I like 30 calibers. I've shot some really small groups with a 30BR using Benchmark, but you can't get enough Benchmark in a BR case to get to the sweet spot muzzle velocity of 2980 fps that the 118 bullets do well at. I've actually shot a .045" group and a .083" group in registered matchs at Tomball using Benchmark. I wanted to try tuning a case to a certain powder.... namely Benchmark. So I had Dave Kiff make a 30BRX reamer that is simply a regular 30BR reamer with the shoulder run forward .100". Nothing new here. Then my testing showed that to chronograph 2980 fps in chilly weather I needed more Benchmark so I ran the reamer in another .025" so I now had a .125" long 30BR. When I got to the sweet spot speed wise I then moved my tuner twice at 1/8 turn per move and was in tune. Neat!!!!

Will my tuner work better or worse than Gene's? Darned if I know. All I know is that I've been dinking around with tuners for several years and they all seemed to work but I had no idea how to use them because I didn't understand the dynamics of how they worked. In a nut shell, here's how it works. When the day warms up and the humidity falls, the air gets lighter/ less dense and your bullet will reach the muzzle a bit quicker. So, you can either decrease your powder load to slow the bullet so it reaches the muzzle at the same point in it's vibration swing or you can turn the tuner so that it's weight moves back towards the rear. This increases the vibration frequency so the muzzle reaches the same sweet spot quicker, when the faster moving bullet reaches it. The tuner weight affects the barrel like the weight on a pendulum. Increase the distance from the fulcrum to the weight on a pendulum and the swing slows down. Go shorter and the pendulum's swing speeds up. It's just that simple.

http://i131.photobucket.com/albums/p313/ShelleyDavidson/IMG_2020.jpg

Hi Shelley,

Ive made and instrumented many of the more common tuner designs, and the one design that I have not analysed is a tuner that uses a very large diameter and thin adjustable mass, much like you are using in the tuner photographed or perhaps even larger and thinner in diameter. This has been on my to-do list for quite awhile.

The reason your large diameter thin mass tuner style intrigues me, and may have greater merit, over other styles is that it concentrates the movable mass to a very specific point along the barrel boreline, or more-so than other designs.

Another reason for its possible merit is the proven design and use of dynamic harmonic balancers in the automobile industry where most common designs use a 10x-15x thickness to diameter specification. I normally loathe to make automobile to firearm vibration comparisons because they are usually apples to oranges, but in this case the general principle of using larger diameter adjustable masses may have some merit..............Don