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All of my testing with the sensors is on my 22lr rifles. With that said, the barrel doesn't get very hot. I did not shoot it rapidly enough to get it hot where it started to affect the elasticity of the barrel. I do notice that 308 are very sensitive to barrel temperature. As it gets hot, the group size gets bigger.

I have. It is done in my previous videos.

@@TunerPlinker yes, now I can find that too. Thanks for pointin out. Very interesting study.

The big recoil is after the bullet exits the barrel. The microscopic movements can have a big impact on POI 50 yards out, depending on the number of nodes in the barrel. Higher number of nodes have larger displacement.

That would be really nice. I was thinking of using Lidar but it would be too expensive for this hobby.

Thanks.

My setup is pretty janky and need some modification before releasing it. I am planning to make modifications and do more prototyping with new sensors.

With the measured speed of the bullet, you can calculate how long it takes to exit the barrel. Since you know the barrel length and final speed of the bullet, you can solve for the time. The inverse of the time is the frequency you want to dampen. I have a spread sheet to does all the calculations. I think the link to the spreadsheet is in the description of this video. If not, then it is in one of my other video

@@TunerPlinker as much as the physics of it exists... accurate readings for such rapid events seem amazing. Of course there is es (extreme spread of velocity) as well. This seems to be the very core of accuracy as per harmonics. Excellent

@@TunerPlinker I can't picture what the inverse of time is. And then relate it to vibration. I guess frequency of vibration decreases with weight...more energy needed to create vibration ..more material to absorb it .. The aim is to Remove vibration Time bullet exit (adjust fps) so it's in the middle of the vibration wobble width. Which the limitations of es may render this impractical..if very sensitive.. My ponderings... probably nothing new

@@misterlewgee8874 To account for ES, you want the notch in frequency to be large to account for the variation. A very stiff barrel is very difficult to tune a wide notch. A carbon fiber barrel on the other hand is much easier to tune for wide variation in fps.

@@TunerPlinker endlessly interesting...I imagined a heavy still barrel would have a lot less necessity to tune...but..tuning it much harder you say.. Keep up the good work. Hope to learn more soon. Thanks.

I tried to make the sensors as light as possible. It's not perfect but was able to get some data.

50 yds

Repeatability seems the statistically significant aspect......

sideshotscopecam.myshopify.com/

Thanks for your advice.

You're welcome

You need to determine the speed of your ammo first. That way you can calculate the acceleration and the time it takes to exit the barrel. The frequency is the inverse of the that time.

Spectroid

ADXL1004BCPZ ?

Senther 540B

The accelerometer sensor spikes violently after the trigger is pulled with a live ammo. Without a live ammo, the sensor data is very quiet.

It should also apply to airguns as well. The tuner is used to adjust the acoustic length off the barrel and hopefully creates a node at the muzzle. The weights were used to adjust the muzzle rise to compensate for vertical dispersion due to variation in ammo velocity. Hopefully with the correct weight and placement, you can reduce the vertical spread due to velocity variation.

I used Matlab to process my sensor data. My sensors are all diy projects. Unless you have an engineering background, it would be hard to replicate it. It still needs some fine tuning and the best sensors to use is just too expensive for me to justify. Unfortunately I am too busy at my full time job to make my gadget compact and available for the general public. Perhaps it maybe a project I can take on when I retire.

@@TunerPlinkerI know I’d contribute!

There were a lot of issues with the sensors clipping. I have since replace with different sensors and resolved the clipping issue. You can see the final results by fast forwarding to part 12 to 14 of the video.

Sorry for the delay. Cold rainy season in NW Pacific. I want to collect more meaniful data before posting another video.

@@TunerPlinker I had an opportunity to work with a couple vibration analysts doing some ODS studies. In all cases we found how to reduce vibrations…. Very coo engineering !

The best accelerometer to use is from Senther Technologies: www.digikey.com/en/products/detail/senther-technology/540B/13574363

@@TunerPlinker Oh nice thank you

Thanks for the suggestion. I will look into it.

Do you know if muzzle flash affects the bullet detection? I have a optical chronograph that won't work unless it is at least 10 ft away from the muzzle. That's the reason I designed my 15MHz solenoid sensor.

Hi Michael, From the gyro sensor data, the highest output peak is just under 2k degrees/sec. I have tried more sensitive sensors but it clips. I am sure that the shockwave also induces peaks in the reading...especially when the bullet exits the muzzle.

My calculations is based on velocity, ballistic coefficient, and barrel deflection. It gather all these information from the sensors and calculate the trajectory and final POI.

@@TunerPlinker yep - i have been eagerly following all the work you have been publishing - i very much appreciate it. My question was about an alternative possible correlation. rather than looking for a correlation between where the barrel is *pointing* at the time of egress and the POI, i'm postulating that there is a correlation between the acceleration or velocity vector of the muzzle at time of egress and the POI. I'm assuming that the radial acceleration vector of the barrel(and bullet) will effect the bullet during its flight time and hence effect its POI ? SO, for example, if the muzzle initially travels horizontally far to the right then swings back and accelerates hard to the left such that the bullet exits just as the barrel is pointing 'straight ahead', will the bullet POI be on the POA or will it be to the left of the POA ? So in this case will the POI correlate with the horizontal acceleration vector or with the final horizontal velocity vector ? My thought is that the bullet must exit the muzzle with the same horizontal velocity as the muzzle and this velocity vector will be a component of its flight trajectory. What do you think ?

@roqcdatamanagement6905 you bring up a very good question. At this point, the projected POI is based on the bullet velocity, ballistic coefficient, gravity, and barrel deflection as calculated from the accelerometer and gyro sensors. I believe based on what I have read is that the barrel vertical velocity or angular rate is important for positive compensation due to variation of bullet velocity. This affects how high the barrel is pointed upward to compensate for slower moving bullet. I am sure that having high acceleration or velocity vector of the barrel deflection can affect the POI. I have some data showing that the barrel acceleration vector is lower with a heavy tuner barrel on the end than without a barrel tuner.

@roqcdatamanagement6905 unfortunately I haven't had much time lately to do more work with my data due to work and family life. There is still more data to collect or work on better sensors to collect better data. I am sure that off axis barrel accelarion and velocity vector affects the point of impact. Having more barrel tuner data will really help with correlating this. I hope to continue working on this when weather and wife permits me time to work on it :) I dread rainy season in the northwest Pacific region.

@@TunerPlinker :-) i really appreciate all the work and time you put into this. Give your wife a hug from me and tell her that there are lots of selfish people out here that want you to spend more time working on this problem ! just think of the glory you (and she) will get from doing the world this service ! .... ah, um, maybe that went a bit far ;-) Seriously though, i really am looking forward to you documenting more of your work on this.

Let's chat via my email bullriderpen@yahoo.com.

Hoping so. Definitely more data and results to collect.

Thanks. More to come. Just been really busy with my full time job.

Yup. Working on it. Just finished printing the sensor mount for the tuner. When I have good data, I will post another video.

No. All the groups with the Norma Match ammo are closely matched to the calculated POI. I did measured the vibration from the firing pin hitting a blank cartridge. The vibration is very small by the time the ammo exits the barrel.

@@TunerPlinker Great info! One thing I have been wondering about, is why the vertical direction has a stronger vibration than the horisontal vibration. There's two obvious candidates. Gravity, and fixtation between stock and mechanism (transfer of force). Do you know the answer? If no, is it possible for you to rotate the rifle 90 degeees, and measure the vibration of some shots?

@sidekickbob7227 Now that I have collected a lot of data, I do not believe that there is less horizontal movement than vertical movement. It all depends on the ammo's speed, concentricity, etc. The spinning of the bullet can create a rocking motion if it is not balanced....just like a washing machine's spin cycle when the clothes are not equally distributed. So depends on the direction of the unbalanced force when the bullet exits the crown, it dictates how the barrel moves (left, right, up, or down).

@@TunerPlinker Thank you for the reply. This information you have managed to collect and published is pure gold! I sincerely hope you continue on this trail. My goal is to try to really understand the process of how and why the vibrations occure, and what the tuner do when tuning it. There's a lot of talking about it, but very few put in the sience at your level. I really preciate your effort.

It makes a big difference. The tuner seems to tighten the groups. Just experimenting with the mid barrel tuner this couple of weeks. The Eley Match was like a shot gun before and now it is one hole.

@@TunerPlinker I'd love to have a version of this to test different powder charges

@mastermoarman You will need an oscilloscope to capture the sensor data....It does not have a microcontroller yet.

@@TunerPlinker how fast of a micro controller would you need? where are you located?

​@mastermoarman The micontroller need to sample at 1MHz per sensor channel. There are a total of 4 channels. I'm located in Washington State.

Glad you are enjoying the contents. There's a lot of still unanswered questions that I am planning to experimentally answer. Some answers to your questions: 1. Tuners do work to an extent. Use good ammo and tuners will definitely help. 2. Cleaning probably affect the friction and vibration. If the ammo has wax, it probably reduce some of the vibration/friction. 3. Not sure about stock bolt tension. 4. Barrel length definitely affect harmonics

Watch this video for how tuner works: th-cam.com/video/OzYbdFGbONU/w-d-xo.html

At least the big visible moments. There are lots of little muzzle movements that the accelerometers picked up that the camera cannot.

You are correct. It is something about the symmetry of the bullet that is causing 4 bullet hole diameter deviations. If we can reduce the harmonic resonance, I believe we can make the groups tighter.

Let's see if we can change that. There is a reason why shot 18 went renegade. The accelerometer readings indicate there may be some imbalance as the bullet spins inside the barrel. Would be great if we can knock that harmonic down.

@@TunerPlinker Hello, I was watching all your videos, and it's interesting what you said here. If it was an imbalance on the bullet, I think if you sorted the ammo first it would be diminished ? (Hard to find any evidence that this works) But with this device, maybe you can not have an aggressive flyer like in the video, can't think of another reason...

I am planning to add an arca vise to my rest that will secure the stock. Afterward, both the forend and stock will be secured to the rest.

in my experience there are no bad shooters, just a few exceptions but generally when you are shooting from a bench with a scope sight it just doesn't make sense, so what i mean is that guns doesn't group as i would like

Had a lot of issues with the sensors. Was working quietly in the background to fix the issues. Lots of progress have been made and I know I haven't update everyone. Didn't feel right to give everyone garbage data till I have sort everything out. I am glad you stuck around. Hopefully it is worth the education as it is for me.

@@TunerPlinker very definitely worth it! You are the only person I know of who is approaching this rationally and publishing your results. That your methodology is very similar to what I would do if I had the time, is just icing on the cake 😊 I'm very interested in seeing if your results show a correlation between the acceleration vector and POI or between displacement/direction at time of exit and POI.

​@@TunerPlinkeryou should get scooped up by Hornady or such

It's a fun project for me. Got a chance to use my electrical engineering skills to solve problems.

@@TunerPlinker I've had the idea to either work out vibration dampening system..passive...active. .will one vibration cancel out another. Or add vibration to modulate it to a preferable frequency ...