Vern juenke machine

alinwa said:
Curiouser and curiouser

alice
Click to expand...

Especially when you go to the Bullet Inspector site and read their caveats. A couple of lifetimes ago I built every piece of electronic test equipment in the Heathkit catalog including an oscilloscope. But I was just an excellent assembler. I remember a quote from a guy who loved to build electronic devices. He said, "My favorite programming language is solder". I'm sure he would love this device.
 
Just got my new PCB in and built.

Did not take all that long. ( A couple of hours to get the board populated and wired into the kit and check some voltages to make sure everything was working )

Works as per the manual instructions.

I now need to get with my buddy that has an original machine and compare readings on mine and his machines with various bullets.

Attached a couple of images. Board_full_view is the original board.

BI_New_Comp is my new board with Components installed.

Went together very easily, and wired into the kit with no issues.
 

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These things are done on very old technology .
The problem is you don't really know what part of the bullet that you are reading. Because it reads more than one thing on a finished bullet.
The meter could be giving you a false reading. There are things you also have to check on the bullet.
To get a better results.
This is not a 5 minute job but I have not given up. I. Need more time.
 
Lou

The circuit components are older, but the theory of operation doesn't change.

The biggest weakness is the temperature sensitivity of the circuit.

Having talked again to some people involved in current Eddy Current technology, I have come to the conclusion based on their knowledge of Eddy Current Sensors that the bullet jacket thickness is what produces the most significant change in the Eddy Current.

Although it will also sense voids and scratches, people in the business have assured me that at the frequency being employed and the materials being sensed, any changes due to voids and scratches would be a magnitude smaller than the change produced by the thickness variation.

Of course to prove that, I would need some known samples to test.

Further development of up to date electronics is ongoing.

Further development of bullet positioning over the coil to get a more uniform distance from the coil to the bullet jacket surface as well as keeping the bullet centered over the coil and being still able to smoothly rotate the bullet at low speed is also ongoing. Also it has to be non-metallic and produce a fixed change in the sensor no matter the position of the bullet holder.

In the mean time the new PCB seems to working out well, will be getting with my buddy that has an original machine to compare his reading and mine with the same bullets this weekend.
 
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Btt for rereading this Christmas morning while waiting for Santa.

He is still delivering isn't he??

Some of the posts in this thread are so funny!

Merry Christmas everyone...
 
What a genious. Vern should start a cult. He could get folks to "believe" way more than jim jones. He could call it juenketown.
 
We put a man on the moon and we can't figure out what Vern was up to?

The Junke I was using, I separated a bunch of bullets and never did tell any difference in the high DU and the low DU's. The thing that makes me really wonder, (about what??) is that each different brand, Hott's, Barts, Connaways, Bradys, Watsons, Fowlers, Cheeks, etc, is they all had different null points???
 
One of the reasons I dispute jacket thickness is what it reads.
I have three bullets all made on the same lot of jackets.
Meter settings aren't even close and same with results.
 
Lou Murdica said:
One of the reasons I dispute jacket thickness is what it reads.
I have three bullets all made on the same lot of jackets.
Meter settings aren't even close and same with results.
Click to expand...

Does this suggest something, like within a given lot there may be significant inconsistencies?

Maybe Vern should have called this thing a smoke grinder...we still don't know much about it do we?

Build us a CMM, Lou, with a laser so we can measure everything about a bullet from its base to its meplat. Measure to 5 or 6 decimal places. I'll bet one thing we will find out is there is great variations in the nose due to the way nose ogives are pointed up.
 
I've been working on developing a digital one of these for a few years now. Yeah digital sucks because you can't "visualise" but it's something that you can get used to if the unit is outputting the right information.

Here's an early prototype in action.
https://www.youtube.com/watch?v=V8MLwajWtRY

I've got some pre-production versions with usb serial data logging connectivity and software temperature compensation. Having more fun developing it than using it :)

As for what they measure...
Depending on the frequency of the signal it's mostly just external diameter variations with a little bit of jacket thickness variation thrown in to keep people happy.
 
If I remember right the object was to measure jacket run out and thickness.
I can't see any use for one now with the great jackets that are being made today.
There was a lot of talk about variations in jacket thickness{wall thickness] back in the 70,s
a lot of people were spinning finished bullets and checking run out then checking run out on loaded round .
some even has tools made to straighten the loaded rounds {came full circle again}
I asked Clyde Hart about spinning bullets His quote is Best way to spin a bullet is down the barrel. LOL
 
Some people just have to do something. You can have 2 side by side measuring different DU then check it next week again to get a better answer if you didnt like that one
 
I have not read the whole post yet, so maybe I am repeating something.

I have noticed that the back of the bullet holder that keeps the bullet from moving forward and back rests against the outer edge of the base of the bullet and not the precise middle. Therefore, if the base is slightly angled, possibly due to a crooked punch, the reading will move, because the distance from the sensor to the bullet ogive will change.

I want to experiment with an adjustable base positioning devise that will move to either the exact center of the base, or any other point on the base. This should help me understand if a bad reading is truly a problem with jacket thickness, or just a base issue. If the point of this devise is in the exact center of the base, I can assume that the bullet is not moving back and forth in the machine, and therefore any deviation would be easier to interpret.
 
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