Thanks, IVV. I used very similar techniques for mine. Except I could never figure out how to make the transparent parts. I tried printing on the heaviest transparency film I could buy, but the resulting pieces were just not stiff enough. (Let us consider the obvious remarks to have been posted, please, and just move on.) I tried to glue the film onto .040' transparent acrylic stock, but I used 3M spray adhesive, and the result was translucent, but not clear. I also tried printing on self-adhesive laminate, but ink-jet ink doesn't adhere to it. I never thought of using multiple layers of laminating material for support. And I make the opaque parts out of multiple layers of card stock. Just never made the connection! Thanks again! I'm going to get some laminating sheets and try it.

BTW, the other face of my wheel is Cap'n Scurvy's AOB Calculator. http://www.subsim.com/radioroom/down...o=file&id=3347. It doesn't have the little "bow" and "stern" protrusions. Instead, the zero bearing is prominently marked. That eliminates the alignment problem between the two faces.

I was concerned about accurately punching the center holes so the disks would align. Instead of using a nut and bolt for the pivot, I stack all the layers on a large carpet tack as I fab them. Then, after the last layer, I glop the protruding point of the tack with Crazy Glue and press a small (1/4") piece of thin foamcore onto the tack and down onto the topmost layer. Then I clip off the protruding point. It is easy to center all the layers on the tack, there is very little runout, and the CA grips the tack well enough to keep it anchored in place. I've used the wheel for about two years and it hasn't tried to come apart.

But now I'm going to have to make another one with transparent index disks!

I wish I'd thought of using a carpet tack. That sounds an order of magnitude better than punching a hole. Until I assembled the thing I had no idea the difference a slight misalignment would make....

As you did, I had to figure out a way to make the thing. Some of my ideas worked well, others not so. At the time, I couldn't find a thread on the subject. There is one now!

A long time ago, I would periodically have to realign my slide rule. (Yeah, that's how old I am!) Amazing how little misalignment it takes to make 5x5 equal 24.8!:D

WOW! What a handy tool to have when playing our beloved Silent Hunter series of video games.

For a person like myself, old, and a bit handicapped with arthritis in both hands makes it difficult to make such a tool. (maybe a little lazy in my old age too. :har:)

Is there someone out there that could make me one?

I would be glad to pay the expense. PM me if you can be of help.

Shipping would be to the USA 77418 zip code.

Thanks

-Clay

:subsim:

I'm one of the slide rule generation too, although I've never had to adjust one. I can remember when calculators started to become available, and weren't allowed in class. I like using a slide rule though because it keeps you involved in the calculation in a way that punching numbers on a keypad doesn't. Also lets not forget that slide rules were good enough to get people to the moon and back....

Yeah - My first attempt at making one of these is sitting in my desk drawer. I had a go at giving it away last week, without any luck. cover the cost of postage and a jiffy bag and you're welcome to it...

PM in transit to you.

-Clay

Hello all

I finally got around to building my own SCAF from the provided download.

However even after reading the documentation I am struggling to understand how to use it.

The only use of it I have understood is the method for finding the AOB from the aspect ratio of the ships length/height.

Would be fantastic if anyone could post other practical uses of the SCAF with some easy to understand examples.


Many thanks

Hi skip, just wanted to point out that SCAF stands for "Ship Centered, Accuracy Fix"....a mod I made years ago to fix the inaccurate mast height measurements found in the Recognition Manual. Those measurements are directly used when taking a Stadimeter reading during game play. Some heights are off by several meters, which will return Range findings off by several 100 meters!

Although....... I've revised many height measurements to be more accurate (then SCAF) with the mod.....Optical Targeting Correction.

One thing I didn't count on during my SCAF making days was the fact that most of the subs don't have the Stadimeter/Periscope as the center point of measurement. This means my corrections with SCAF are good for one particular view bearing......but will be slightly off in another. OTC corrects this off center position, giving reasonably accurate measurements in all view bearings. Correcting not only for the Stadimeter, but also the periscope Telemeter Divisions too (those are the hash marks on the periscope lens).

You mention the length measurements, yet OTC is the only mod that provides length measurements in the Recognition Manual. It's with the accurate Telemeter Divisions scaled to the correct optical view that will provide a good estimate of AoB using only the periscope (as it would in real life).

My apologies for bringing this up in someone else's thread regarding an "Is-Was". However, back in 2007 I also made a similar devise and called it an AoB Calculator (I never knew what an Is-Was was until after making my calculator). I only bring it up because you asked for "other practical uses", which you may find if you download and read "High Realism Tutorial".

Sorry for the Thread Necro, but I was looking for the .pdf files to make on of these for myself and the links seem to be down. Does anyone have the files for this?

Don't be sorry. This is a thread everyone should see.

You can find the files needed here, along with the manual for using it:
http://archive.hnsa.org/doc/attackfinder/index.htm


Note:
If you make one, consider adding an extra cursor to the is-was side. It comes in very useful.

Thank you.

Please explain what you mean? Why, how is this useful? Multiple targets?

It comes in useful if you're needing to keep a temporary result while doing your calculations. It also helps in lining up the inner time dial with the outer speed/range dial. There are also a couple methods you can use the wheel for that involve such things as comparing angles at different ranges. This becomes easier when you have the cursor to track and line up on one of the values, while you use the built in one for the other.

It's not strictly necessary, but it's so useful that I wonder why it wasn't built in.

Construction detail correction
 

As I looked through the description of how to assemble one of the Submarine Attack Course Finder devices from the SubSim site I noticed a variance between what was described for the homemade version versus what is described in the SACF Mk I Mod 3 Manual.

In the manual in the section titled “Description, Course Finder on page 3 it reads:
"A" - Azimuth circle (base disc) represents own ship, for reading relative bearing with periscope pointer.
"B" Compass rose (middle disc) for reading compass course of own and enemy ship.
"C" - Enemy Card (top disc) represents enemy ship, for reading relative bearing on enemy bow and track angle.
Periscope pointers (placed between "B" and "C") represents line of sight, for reading bearings and courses.

According to this, the “P” disc of the SACF is placed between the “B” ring and the “C” ring.

In the description of how to assemble the rings on the SubSim site it says to put the “P” ring on top.
The issue is that putting it on top creates the necessity of adding a handle to the “C” ring so that it can be easily rotated. If the “P” ring is placed beneath the “C” ring as is described in the manual, the handle on the “P” ring protrudes out beyond the “C” ring which eliminates the need for modification to the “C” ring.

If you look closely at the photograph of the front of the SACF you can just tell that the “P” ring is indeed underneath the “C” ring.

Just thought it might be helpful to point this out.

If there are enough people interested in having these made, there are several companies that make all sorts of circular decision and reference devices who could be engaged to make them for us.


Fair winds and following seas!

Is-Was in Use Photo
 

I was poking around at the International Slide Rule Museum website and came across a photo from WW II of 2 officers at the periscope and one was setting up a solution on an Is-Was. I got permission from the museum to share this photo on the forum.

I thought this should be here for the history of it.