Your kidding right, one over charge in 50 is a problem?
Turn Your FX-120i into a Prometheus
- Thread starter Sheldon N
- Start date
Oh dear lord, Adam. You used *MATH*... even worse, you used *STATISTICS*
... in an Internet gun forum
Wrong crowd, man. Wrong crowd
lol - Well - having over 30 years in the R&D business I think I might just be able to handle the math and statistics
But to Adams point and of course it is a good one, is anybody here going to be able to see +/- 1 or 2 kernels or fps or .03% difference in MV at 3000fps on the target ? Of course not. However that being said I did some more testing last night and came up with this.
1. I use a Chargemaster next to my Sartorius Entris 64 analytical balance as well as an Omega II trickler
2. I use the Chargemaster to trickle up to 39.8g of H4350 and then transfer the powder in the pan over to the pan on my Sartorius and trickle up to my final target weight of 40.00g or +/- 1 kernel with my Omega II trickler
3. As soon as I pour the powder from the Chargemaster pan to the Sartorius I place the empty pan back on the Chargemaster and it begins to trickle up to 39.8g immediately and will be done before I pour the final charge into the empty case.
4. The time it takes for me to pick up the pan from the Chargemaster with the 39.8g of powder, pour it into the pan on the Sartorius and trickle up to my final weight of 40.00g +/- 1 kernel is approx. 10 seconds.
In looking at Iluvguns video above it takes him approx. 10 seconds to scoop up the powder and achieve his final target weight on the scale. Exactly the same time it takes me to achieve the same task but I have greater resolution (i.e. +/- 1 kernel)
So in conclusion (and this breaks my heart) Adam's new setup
1. Isn't any faster than my present setup
2. Does not have the resolution as my present setup or a Promethius (i.e. +/- 1 kernel)
3. It does somewhat automate my trickling procedure but at a cost of $ 200 and a loss in resolution.
4. Looks to be as fast as a Promethius and considerably cheaper but with less resolution and not able to mount on a reloading press or dump directly into a case
I hope Adam or anyone else doesn't feel that I am being negative here as I am actually a big cheerleader of where this might go but I am just calling it the way I see it and I look forward to further discussion.
That's a really interesting point. Hadn't thought of it in that way before....
I tried something out in Excel to model how powder charge weight variation plays out in actual velocity variation. I used a formula to create a random distribution of hypothetical charge weights (user inputs target weight and standard deviation of weight measuring). I then extrapolated the resulting velocity from that charge weight based on the expected "fps per kernel (.02gr)", and then measured the resulting velocity standard deviation. It's a pretty rough calculation, but it does give an indication of how much additional velocity variation you introduce above your baseline deviation through your powder measuring accuracy.
I then generated a random distribution of velocities based on a baseline SD, and then overlaid the random velocity deviation from average (based on the charge weight) over top of them.
I'll try to attach the spreadsheet to see if others can mess around with it. You need input the powder charge weight, the hypothetical deviation of your measured charge weight, the "fps per kernel" of your load (you'll have to calculate this for your own load), and the baseline SD for your gun (separate from powder measuring). Everything else should fill in for you.
It's pretty enlightening to mess around with the variables. The higher the baseline SD of your load, the less that subtle variations in powder charge matter. They just get lost in the noise. When you get all other factors highly controlled and have a very low baseline SD, then the powder charge weight variations matter a little bit more, but even then they don't have a dramatic effect.
Of course, all this is just looking at velocity... not taking into account POI shifts with powder charge weights, whether you're in a node or not, whether the change in charge weight might push you out of a node, etc.
I'm not doubting you at all but it takes me a lot longer than 10 seconds per charge.
In my case, I trickle to .1 below (you do .2) on a Chargemaster then transfer to another scale (A&D) and drop kernels with an Omega. If you can do 6 charges a minute, my hat's off to you. Over the course of weighing charges for a typical F Class match (I load up about 68 or so), there is no way that I can even come close to having the correct charge every 10 seconds. I wish I could be finished in 11-12 minutes!
I usually end up waiting on the Chargemaster. I then transfer the powder to the A&D and with the Omega say, "There's one kernel, there's two, there's 3, I'm getting close now, there's 4, OK, that looks good." Heck, just that part alone takes me longer than 10 seconds and the worst part of it is that I have to think about it! Lol. Doing that 68 times gets old fast.
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LRTom
Silver $$ Contributor
I use the same setup and wish I could do 10 sec. My hot rodded Chargemaster takes 15+sec or so just to drop 46.4 grains of Varget
I, too, "Chargemaster" low and "Omega" up on the A&D. Takes a while to drop 1 flake.
When I go over it's tweezer time, and my old eyes need magnification to get it right. The operation takes time and effort, and I for one would trade speed for the simplicity of removing a small amount of powder and letting the scale/dispenser try again.
Cujo - I think you are misunderstanding my timing sequence
1. I start with a pan on my Chargemaster that has 39.8g of H4350 in it.
2. I start my stop watch and then remove the pan on the Chargemaster and pour the powder into the pan on my Sartorius
3. I then place the empty pan from the Chargemaster back on the Chargemaster so it can start to fill up again.
4. While the Chargemaster is loading another pan I then use the Omega II to trickle up to my final weight of 40g +/- one kernel
5. Once the final target weight is reached I stop the stop watch which reads 10 sec.
6. I then grab an empty case and funnel and pour the contents of the Sartorius pan into the empty case and then put the filled case into a rack
7. By now the pan on the Chargemaster is filled up to 39.8g and I start the whole process all over again.
It takes approx. 15 sec. for my non turbocharged Chargemaster to trickle 39.8g of H4350 but I am doing other steps as you can see while it is doing it's thing. I didn't mean to say that I can completely load a round in 10 sec. however if you look at the videos above you will see that my timing through the same steps is equal to the videos.
memilanuk
Gold $$ Contributor
Zipollini,
No misunderstanding, just that my (and others) experience with Chargemasters is different from yours. When the initial review camw out on 6mmBR.Com way back when, they cited 8-12 seconds for ~42 gn of 4064. Hot damn, I thought!
Reality for me with 46-47 gn of Varget turned out to be more like 30-45 seconds, even after tweaking the settings (before was more like 50+). I'm on my second Chargemaster; it's a little faster than the first, but not nearly as fast as throwing 0.2-0.3 gn low with my Lee PPM and finishing with the Omega trickler. After loading (many) thousands of rounds both with the Chargemaster and with the thrower, I'm pretty confident of those numbers.
If your Chargemaster really does dispense that fast, congrats... and you're right, this scale mod may not be for you.
No misunderstanding, just that my (and others) experience with Chargemasters is different from yours. When the initial review camw out on 6mmBR.Com way back when, they cited 8-12 seconds for ~42 gn of 4064. Hot damn, I thought!
Reality for me with 46-47 gn of Varget turned out to be more like 30-45 seconds, even after tweaking the settings (before was more like 50+). I'm on my second Chargemaster; it's a little faster than the first, but not nearly as fast as throwing 0.2-0.3 gn low with my Lee PPM and finishing with the Omega trickler. After loading (many) thousands of rounds both with the Chargemaster and with the thrower, I'm pretty confident of those numbers.If your Chargemaster really does dispense that fast, congrats... and you're right, this scale mod may not be for you.
Zipollini,
No misunderstanding, just that my (and others) experience with Chargemasters is different from yours. When the initial review camw out on 6mmBR.Com way back when, they cited 8-12 seconds for ~42 gn of 4064. Hot damn, I thought!
If your Chargemaster really does dispense that fast, congrats... and you're right, this scale mod may not be for you.
I must be living right. I haven't done a thing to my Chargemaster other than the McDonald's straw thing and that doesn't change the timing at all for me. 15 seconds every time for 39.8g H4350.
Why don't you take a timeout here, guys are interested in this system and you're failing to bring anything to the table. Your system sounds impressive, but it's not what this one is about.
For me, it really comes down to automation. A lot of us already have a good scale (A&D, Sartorius, etc.). That money spent has been gone a long time ago. Now, for $200, this "accessory" comes along that makes the scale/powder dispenser work together as a system that a lot of us hoped for. It's now a "faster, more accurate Chargemaster." You're free to use the scale independently for whatever else too.
Is +/- .02 grains good enough? That's for the user to decide. All in, I might be into it for a total of around $650. I appreciate but just don't see the value (me personally) in a machine that costs 5-6 times more whose sole purpose is to throw accurately to a kernel. Even if it was $1K, it's not for me.
If I really wanted to weigh to the kernel, I can go back to the old manual way of just using the Omega.
Is +/- .02 grains good enough? That's for the user to decide. All in, I might be into it for a total of around $650. I appreciate but just don't see the value (me personally) in a machine that costs 5-6 times more whose sole purpose is to throw accurately to a kernel. Even if it was $1K, it's not for me.
If I really wanted to weigh to the kernel, I can go back to the old manual way of just using the Omega.
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Never thought about a DC motor not being linear. Didn't know your stepper motor was AC.
With the omega I'm not sure it matters if it is linear. You just need a fast and slow, like it is now. The big advantage with the omega is it will actually drop one kernel at a time with no clumps.
The point is, I want a unit that will control my omega. Build me one and I'll take it. You would sell a lot of them.
jkl
Silver $$ Contributor
I use an Omega and like it but with some powders it will drop several at some point during a 70 case string. Other powders it is 1 at a time just like you want to see. I am not sure anything is perfect. I purchased one from Adam and happy to see how it does in person. If the speed can be regulated on the trickler it will be even better.
John
John
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Stepper motors work by sending it a digital sequence to make it turn "one step". The time between steps is how you control the speed. Unless there is a mechanical stoppage, the speed control will be exact. More voltage produces higher torque in case you have mechanical resistance.
When comparing rates of weighing charges, ensure that the same steps are included. I usually consider weighing and charging but not seating because I do that at the end. I only have one table and can't touch the press while the scale is working.
It used to take me 45 seconds per charge with the Hornady Autocharge then trickling manually with a 502 beam balance. With two pans going in parallel. That was the reason I built this in the first place. I was literally in physical pain after loading.
The gold pan is RCBS. I like it. Its expensive standalone but available on Midway.
When comparing rates of weighing charges, ensure that the same steps are included. I usually consider weighing and charging but not seating because I do that at the end. I only have one table and can't touch the press while the scale is working.
It used to take me 45 seconds per charge with the Hornady Autocharge then trickling manually with a 502 beam balance. With two pans going in parallel. That was the reason I built this in the first place. I was literally in physical pain after loading.
The gold pan is RCBS. I like it. Its expensive standalone but available on Midway.
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