Manual Targeting 'Computer'.

[Puster Bill]

After a while using EtchASketch's whizwheel for targeting, I decided to try and find a 'nicer' looking, and perhaps more accurate, solution.

I found a website that gives you the templates to make your own slide rules, both linear and circular. You can find the .pdf files here:

http://www.sphere.bc.ca/test/build.html

Here is, from top to bottom, the following:

1. EtchASketch's 'Whiz Wheel'
2. A cardstock simple 4 scale slide rule
3. A Yokota-based Log-Log made out of the box from a Revell Type XXI model



A couple of observations:

A circular slide rule is probably the way to go if you are using cardboard. The one on the bottom has a pronounced curve to it (but it does work).

I am planning on getting some Lexan from the local Home Depot and making a few of the ones on the website. I'm still learning the theory behind them, so I'm not sure which of them you could use to replicate EtchASketch's design.

Using a stiff plastic would prevent the warping. If you are handy with wood, that would also work well.


Good Luck, and Happy Hunting!

[Meridian]

Great stuff, nice find.

[P_Funk]

Nifty looking. I am definitley gonna download this and fool around with it.

[GreyOctober]

Thank you! ...printing now

[Dantenoc]

No negativity intended, I'm just curious... exactly what calculations are you intending to do with the slide rulers?

I saw a post about them a few months ago, and got very excited about going hardcore and using the slide rulers instead of a calculator... but then I realized, I don't use a calculator for anything either, since the math involved in targeting solutions is simple (adding, subtracting and simple multiplications, no?)

[Puster Bill]

Originally Posted by Dantenoc

No negativity intended, I'm just curious... exactly what calculations are you intending to do with the slide rulers?

I saw a post about them a few months ago, and got very excited about going hardcore and using the slide rulers instead of a calculator... but then I realized, I don't use a calculator for anything either, since the math involved in targeting solutions is simple (adding, subtracting and simple multiplications, no?)

I had been using EtchASketch's WhizWheel to do the calculations, as explained on the instructions for using it. Obviously, this is for manual TDC.

The only real issue I had with using EtchASketch's wheel is that it looks like crap. That isn't really a criticism, as it was obviously made years ago, and he was limited by the technology he had at hand.

So, I decided to look for another alternative to calculate target speed and such. Not that the math is hard, mind you, just that it is quicker to do this sort of thing with a slide rule (either circular or linear). Since I don't 'pause' during an engagement, speed of calculation can be of the essence, especially when your watch crew doesn't spot the target until it is 1200 meters away.

I don't bother to do this for surface attacks, that is what my 1WO is for. But I do handle it myself for submerged attacks.