Home made Shot maker Math problem
I have made a shot maker and want to balance the incoming amount lead with the out going shot. The shot making holes are .0225" in diameter and I have fifteen of them. What size inlet hole will I need to equal them? ... Thanks
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Well simple math would suggest .3375 but I am sure that must be incorrect as it is too simple. will the 15 holes drain faster than the one hole or slower. the weight of molten lead, cooling factor, friction, volume, and the weight of the reservoir may have an effect. What is the diameter of the sieve. perhaps you can try it with a different fluid but I don't know if it correlates to lead. It does sound interesting. 0 -
If you figure the total area of the fifteen holes and try to make one hole with the same area, the circumference of the one hole would be different then the sum of the fifteem smaller holes.
Wouldn't it be simpler to have an adjustable valve or shutter type arrangement where you can regulate the amount of lead going in until it matches the amount pouring out. I would imagine you would need some sort of shut off anyway.0 -
SP45....I did the simple math but like you thought this is too simple which it was. I also came up with .3375 which I think is to large.
rsnyder55.. I tried a screw type gate which worked while cold but once up to 600 degrees + it got to tight to turn. This idea may take some trial and error. Thank you for your input0 -
With due respect, answering this question is FAR more complicated than simple Euclidean geometry would suggest. Its impossible to answer the question simply based on the diameter of your exit holes.
(Well, its impossible to give a GOOD answer).
Factors that might affect the flow rate include temperature of the mix, total height/weight of the input column (eg pressure), specific viscosity of your alloy, surface tension of the drops, etc.
As the exit holes heat up, for example, the rate of flow through them may change a little. Is the input mix temperature going to be absolutely controlled throughout the run? Ambient (eg room) temperature may affect the flow rate. If your alloy composition changes a little bit, that could affect things, etc.
Probably the best way to find this out is to run a typical batch of lead through the exit holes and measure the output volume flow rate. That's going to be the rate-limiting step.
EG: See how long it takes you to ACTUALLY run a liter (or pound) of lead through the holes, then calibrate your input to that flow rate.
Actually, you'd probably want to go a little LESS than that, so things don't back up.
And I agree with Rsnyder. You're going to need a cut-off valve of some sort anyway. So you don't really have to do anything fancy here. Just adjust the flow rate until there is no back up, and then back it off a hair.0 -
I don't think we have enough informatioon to make a definitive answer. rsnyder55's answer seems best to me. 0 -
quote:Originally posted by rsnyder55
If you figure the total area of the fifteen holes and try to make one hole with the same area, the circumference of the one hole would be different then the sum of the fifteem smaller holes.
Naturally.
If you want the math, here you go. Area = Pi x radius^2.
Each hole 0.0225" in diameter yields an area of Pi x (0.0225/2)^2 square inches, or 0.0001265625 x Pi square inches.
15 such holes total 0.0018894375 x Pi square inches
Divide by Pi and take the square root to yield the radius of a single hole with the same area. Double it for the diameter.
So that's ((0.0018894375)^1/2)/2
Or one hole 0.021785" in diameter (equals the area of 15 holes of 0.0225" diameter).
Now, that I've done that constipating arithmetic, the fact is, my answer still probably isn't "right" with respect to the question asked.
The reason is that while the flow rate though a given hole is going to be generally proportionate to its area, in the particular case of a narrow hole (like these), there is "edge" effect that slows down the flow because of adhesion. The greater the amount of "edge", the more friction there is between the moving liquid and the hole, and the greater the slowing effect.
Put a little more simply, for small hole sizes, fluid will generally flow through one big hole with a total area of "X" FASTER than it will flow through 15 separate small holes with the same total area, because the smaller holes will have a lot more "edge" to generate resistance.0 -
I don't understand why you have an inlet hole.Have you looked at the Littleton shotmaker? It's just an electric pan with seven holes for the shot to drip out.Why try to reinvent the wheel? 0 -
Sorry, your math stinks," Or one hole 0.021785" in diameter (equals the area of 15 holes of 0.0225" diameter)." Your answer is smaller than any one of the 15 holes. Now back to the question, as many have posted,'
too many variables to simply go by math alone. I have been to the old
Winchester plant in conn. many,many years ago and toured their "shot tower"
plant. It was amazing how tall it was to let the shot form into perfect
round balls as it fell into the chilled water. Do you use any sort of vibration on the 15 holed sieve plate? bob0 -
You've nailed the correct answer. Unfortunetly, it doesn't seem to be the popular one.
quote:Originally posted by beantownshootah
With due respect, answering this question is FAR more complicated than simple Euclidean geometry would suggest. Its impossible to answer the question simply based on the diameter of your exit holes.
(Well, its impossible to give a GOOD answer).
Factors that might affect the flow rate include temperature of the mix, total height/weight of the input column (eg pressure), specific viscosity of your alloy, surface tension of the drops, etc.
As the exit holes heat up, for example, the rate of flow through them may change a little. Is the input mix temperature going to be absolutely controlled throughout the run? Ambient (eg room) temperature may affect the flow rate. If your alloy composition changes a little bit, that could affect things, etc.
Probably the best way to find this out is to run a typical batch of lead through the exit holes and measure the output volume flow rate. That's going to be the rate-limiting step.
EG: See how long it takes you to ACTUALLY run a liter (or pound) of lead through the holes, then calibrate your input to that flow rate.
Actually, you'd probably want to go a little LESS than that, so things don't back up.
And I agree with Rsnyder. You're going to need a cut-off valve of some sort anyway. So you don't really have to do anything fancy here. Just adjust the flow rate until there is no back up, and then back it off a hair.0 -
The correct answer based on surface area of the 15 holes combined, is one hole that is 0.0871" in diameter.
Best0
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