Strange question of physics in casting

[Cwab]

Casting forum on wsf a good place to research and may hold some answers of sorts, a guy called peter thain could be a start point if no luck here. Best of luck, the truth is out there. edit, no idea now if said man is contactable.

 

[DaveH]

If gravity needs to be factored in I have an equation for that somewhere...

 

[Angrybear]

I've now got most of the equations needed, but have hit the brick wall that the distance the lead flies is an arc, which is further than the distance on the ground (remember all that slack line that flutters down after your lead hits the water).
I'd need to know that distance to get an average velocity from the flight time.

 

[stan m]

You would also need to factor in how many dumps you had in the past month. FFS, in 54 years rod building and selling into 13 countires I have never, ever, feckin` ever been asked to calculate such nonsense and know of no other rod builder who has.

 

[JLD]

Do they also have to take gravity into account ?

 

[nearly70ty]

Line dia.
wind speed and direction
Initiall angle' of projection,
air pressure,
Slope on the field,
Reel resistance
Casters use of his mag.
Even the lifting effect of heat rising off the field.
the variables go on and on

 

[blakdog is back]

John Holden did a very good article in the Sea Angler in the mid-late 80s on the subject ... the figures he came up with were quite interesting regarding speed rpm of the spool etc.

If you want to calculate such things I would suggest you talk to somebody ex-military as they do these calculations all the time for artillery targeting. Likewise the same area of maths is used in electronic navigation (welcome to the world of the logarithm). In fact the first computer (the steam driven "Difference Engine") was invented in the 1820s by Charles Babbage for the purpose of producing tables for the British Government which were apparently to be used for Naval Gunnery ... like many modern projects it was never finished, went over budget and was subject to the Government constantly changing their minds about what they wanted. When I did my Government procurement training in the 90s it was still being used as an example of poor contract management.

I'm sure someone somewhere must host a site that would give you the ballistic calculator that would do the job or would be able to give you the basic of how to calculate some sort of figure that wasn't too far out. Maybe you could combine various results from casting days to come up with a small program, though given the variation of people casting I suspect you would only get anything sensible by basing calculations on a single individual.

 

[blakdog is back]

Something like this?

https://shooterscalculator.com/ballistic-trajectory-chart.php

 

[groundswell]

Something like this?

https://shooterscalculator.com/ballistic-trajectory-chart.php

I think you have mistakenly put an "s" in front of that site

 

[Wolf]

It would be interesting to have a rough idea how fast (mph) the multiplier spool is spinning.

 

[Kine262]

It would be interesting to have a rough idea how fast (mph) the multiplier spool is spinning.

That would be a fairly simple calculation to make and would just involve measuring the line diameter at the start and the end of the cast to reach a median for calculating amount of line per revolution, the time of cast, (a cast where the line going out is stopped before the lead starts to decelerate) and the distance of the cast.
You could discount the very small amount of time at the start of the cast as the spool started to spin to get a reasonably accurate revolution speed.

 

[Angrybear]

You would also need to factor in how many dumps you had in the past month. FFS, in 54 years rod building and selling into 13 countires I have never, ever, feckin` ever been asked to calculate such nonsense and know of no other rod builder who has.

Wonderful, no need for you to bother joining this thread again then is there.

 

[Angrybear]

It would be interesting to have a rough idea how fast (mph) the multiplier spool is spinning.

That would depend on where you measure the spool, working out the rpm might be easier.

Something like this?

https://shooterscalculator.com/ballistic-trajectory-chart.php

Yep, I use that with one of my rifles, the problem is you need to know the velocity the bullet leaves the muzzle,
& that initial velocity of the cast is what I wanted to find.
It's easy with a gun, you shoot over a chronograph & it gives you the velocity.

 

[Angrybear]

That would be a fairly simple calculation to make and would just involve measuring the line diameter at the start and the end of the cast to reach a median for calculating amount of line per revolution, the time of cast, (a cast where the line going out is stopped before the lead starts to decelerate) and the distance of the cast.
You could discount the very small amount of time at the start of the cast as the spool started to spin to get a reasonably accurate revolution speed.

Even easier,
you cast, time the impact, measure the line that is out, (not where the lead landed) then count the revolutions as you wind the line back, (handle turns x gearing)
That gives you; X-yds, in Y-seconds, & X- revs in Y-seconds, so you can work out the mph of the line, & rpm of the spool.

Line dia.
wind speed and direction
Initiall angle' of projection,
air pressure,
Slope on the field,
Reel resistance
Casters use of his mag.
Even the lifting effect of heat rising off the field.
the variables go on and on

No, none of that matters,
just the approximate initial velocity of the lead.

 

[flappy]

Does it matter if you are using monofilament with more stretch.!
The calculation will be different if the line stretches during the launch.
Maybe we should approach NASA for advice..

 

[Kine262]

Even easier,
you cast, time the impact, measure the line that is out, (not where the lead landed) then count the revolutions as you wind the line back, (handle turns x gearing)
That gives you; X-yds, in Y-seconds, & X- revs in Y-seconds, so you can work out the mph of the line, & rpm of the spool.

No, none of that matters,
just the approximate initial velocity of the lead.

That would only give you an average speed, as the lead would be travelling at different speed during flight and as I’ve already explained, you can discount the very small amount of time at the start of the cast as the spool increases speed, but as the lead descends there would be a very noticeable decrease in speed, skewing the result. If it was a 20 or 30 second cast then a second or two deceleration could be discounted, but as most casts in reality are probably less than four or five seconds then it is a good percentage and would considerably affect the average speed.

 

[Valleyboy]

Hi speed camera and graded line. Easier said than done

 

[Cwab]

cannot help but think it’s all been done before, but probably in the states and if so a guy called Tommy farmer will know as a caster and involved in rod development and think is/ was on wsf but just Google for contact details and email.
Am intrigued if chronograph would work or be modified to do so if attached between rugby post wildlife camera style then possibilities nearly endless, cannot believe the American casters have not measured lead speed at max velocity or “muzzle velocity” so to speak.
One thing certain as flappy said if nasa wanted to know they would have found out and cannot be impossible and still think the info regarding lead speed on release is kicking about somewhere. Edit, said Tommy farmer has web site, Carolina cast pro llc suggest an email. The truth is out there

 

[stan m]

Wonderful, no need for you to bother joining this thread again then is there.

I`ll join whichever thread I like. Let`s see, assume a new budget tyre on a 17inch wheel rim. What fraction of a micron of rubber would be lost from the surface of that tyre after travelling on a vehicle, 1.25 miles at 30 mph on a tarmac surface as opposed to what would be lost on a concrete surface. When I have that answer I`ll consider how my life has been improved.

 

[Angrybear]

That would only give you an average speed, as the lead would be travelling at different speed during flight and as I’ve already explained, you can discount the very small amount of time at the start of the cast as the spool increases speed, but as the lead descends there would be a very noticeable decrease in speed, skewing the result. If it was a 20 or 30 second cast then a second or two deceleration could be discounted, but as most casts in reality are probably less than four or five seconds then it is a good percentage and would considerably affect the average speed.

Yes. but with the initial velocity I can get the rest from a ballistics program