this may sound dumb, but do you glue all the wheels back to back to their opposite one? i.e. the big one to the big one and son on?

Doesn't seem to say and I'm a newb :oops:

cheers

-Indy

No. You only glue the two largest wheels back to back. Actually, I used tape. Works almost as well, or you could laminate them together, which is what I did with the US IS-WAS. The smaller wheels and doo-dads have to move freely on the central axis.

still can't figure out how it works lol

-Indy

Anyone?

-Indy

What is exactly what you don't understand? If you have printed them already, you can post a picture and name them with letters (A,B,C,D...) and I will then tell you which ones goes where:hmm:

I can't figure out what the problem is either. You show them together in the .pdf you distributed with the wheels, so it shouldn't really be a problem.

At least, I didn't have any issues, but then again I already had made two other wheels, and a couple of circular slide rules, so maybe I just made assumptions that happened to work well.

Just to help you out, indiana_jones, take a look at the pictures I posted of the wheel I assembled from Hitman's instructions.

To get started, and because you can use it as a stand-alone, and it's easier to assemble, build the backside first.

You will need the big wheel that is graduated from just under 6 to 90 degrees, the medium size wheel that has three scales on it (distance, speed, distance from inner scale to outer), and the small wheel that is marked 'Zeit'. You will also need one of the transparent pointers.

Print them out. I use cardstock, and laminate both sides, including the transparency (it gives it added strength).

Poke a hole in the exact center of each piece (the three wheels and the pointer). I use push-pins to make the holes, because I use push-pins as the axle for the wheels.

Take two push-pins. Using a pair of pliers, pull the actual pin out of the head of one of the pins. If the head breaks, try another one.

First put the smallest wheel on the push-pin that still has the pin in it with the face of it towards the head of the pin. Then put the pointer on the pin. Align the pointer so that it points upwards from the red line on the face of the small wheel. Glue or tape it in place (I use tape. That way I can reposition it if I screwed up).

Then, take the medium sized wheel with the three scales and place it behind the small wheel/pointer combo. Obviously, the face has to be towards the head of the pin. Then do the same with the large wheel.

Take a pair of wire cutters and trim the pointy part of the pin so about 1/2 inch (about a centimeter) sticks up from the back of the wheels. Test the pinless head on it for fit. If it fits reasonably tightly, take it off and put a little (just a little!) glue on the trimmed pin sticking up from the back of the wheels, then put the pinless head back on. If there is a significant gap between the back of the wheel and the bottom of the pinless head when it is assembled, trim the pin a little bit at a time until it fits, then glue it.

Viola!.

Here is how to use it:

Take two observations of your target separated by a reasonable amount of time.

Lets say they were 7000 yards at 60 degrees, and 5000 yards at 47 degrees. The amount of time that lapsed between the two observations was 5 minutes.

First, note the difference in degrees: 60 - 47 = 13 degrees. Align the middle wheel so that there are 13 degrees on the big wheel between the 7000 and 5000 range marks on the middle wheel.

In this example, the 5000 will be underneath the 28 degree mark on the big wheel, and the 7000 will be below the 41 degree mark.

We now have the AOB: At the second observation, it was 41 degrees. (it's kind of counter-intuitive that the AOB for the second observation is above the range mark for the first observation, but trust me, that is how it works).

Now we need to find the distance the target has travelled in between those two observations. Without moving the middle wheel, find the 13 degree mark on the outer wheel. Right below that is the distance the target has travelled, about 2400 meters.

Align the 5 minute mark on the small wheel with the 2400 on the inner scale of the middle wheel. You can now read the target speed, 24 knots, on the middle scale of the middle wheel under the pointer that comes off of the small wheel.

You now have the three things you need to input into the Vohrhaltrechner: Bearing, speed, and AOB.

This procedure works best if you are stopped or moving slowly, say 1 knot. There is a more involved procedure if you are moving, but that should get you started.

I did this exercise with my linear rule, as I happened to leave my KM wheel at home today. :damn:

So if I screwed up, I apologize in advance.

On edit: Yep, I screwed up the speed calculation. Should be 15.6 knots.

Oh no, I have it made, beautiful job you have done Hitman :D . I just can't figure out how to use the damn thing lol

I know I put my true heading at 180 on the outer wheel, and then point the bow part of the long needle to the ship, bearing relative to my sub. then I get a bit lost, well more lost lol

-Indy

Ah I see...it is using it what confuses you:up:

Puster Bill gave you the instructions to use the rear side (Though there are several methods you can use), but the front side is very easy once you know the basics. I will try to do a picture of mine with an example later...

Thanks alot mate :up:

I'm sure it's one of those things where it's easy to do once you've got it, but hard to explain :know:

-Indy

In checking my answer with the actual whiz wheel, the speed should be 15.6 knots.

Seems I always screw it up using the linear rule for my examples, yet I always seem to get it right (mostly) when I'm actually shooting. Must be stage fright. :oops:

Thanks Puster, for the tips.

What you have discribed in using the wheel is the backside? (the one with the Swaztika) in finding a targets speed.

I was after how to use it to find AoB :oops:

-Indy

You get the AOB when you use it. In fact, that is the first bit of data it generates.

In my example above, the AOB is 41 degrees. You just have to resolve it to port or starboard. I just imagine being on the targeted ship. However, some people aren't good at that sort of thing, so here is a little chart in case you need it:

Target is in front of you:
___________________to your port_____________to your starboard
moving to you_______starboard____________________port
moving away___________port_____________________starboard


Target is behind you:
____________________to your port ____________to your starboard
moving to you__________port_____________________starboard
moving away_________starboard_____________________port

If you use that chart, we know that a target that goes from bearing 60 degrees to a bearing of 47 degrees is ahead of us, is to our starboard, and is heading towards us. Looking at the chart we can resolve the port/starboard ambiguity of the 41 degrees AOB from the wheel to 41 port.

You could also use the front of the wheel to resolve it, but I find it quicker to do it in my head. Your mileage may vary.

Hi,

I could understand how both sides of the wheel should work, and I am doing some tests. I usually employ the plotting method (3:15 measurements and so on) but I find that the method using the wheel can be quicker and makes more use of information (e.g. AOB that in the plotting method is not used).

I have a question: in the target speed calculation (rear side of the wheel) I am assuming that own ship must be stationary. But this is a luxury that one can seldom have (need to position better for attack, need to keep depth, etc.).

Is there a way to compensate for own ship movement while computing target's speed (using the rear of the wheel)?

I suppose that (assuming that the submarine has kept constant speed and course) one should make a vector sum of target speed and own ship speed, but I have no idea about how this can be done using the wheel or in another simple way.

I read somewhere that the US wheel could compensate for submarine movement but I have no idea how this was done (I don't have SH4 o I did not study the US wheel)

Thanks

Maraz

The german wheel works exactly like the US wheel, look for the official manual of the MK3 in the hnsa.org web, and you will soon understand it. There are links to it the SH4 forum, in the thread about the MK3:up:

P.S. you can directly get enemy speed by holding constant bearing with any wiz wheel. Do a search for a thread started by don1reed about old fashion method of determining speed.

Thanks a lot, Hitman.
I found the document,
http://www.hnsa.org/doc/attackfinder/index.htm
it showed other ways of using the wheel from the one I knew, so very useful.

I noticed that the KM version does not have the square grid that is useful for calculating the distance of the submarine from the enemy ship's track (i.e. from the best point for firing the torpedo, AOB = 90°). Calculating this distance was the only reason making me still prefer the plotting method. So I have modified (with my limited painting skills) the center disk of the whiz wheel and the cursor, now my wheel is much uglier than yours but has a little more functionality. :D



http://www.webalice.it/antonio.maraz...rad%20copy.jpg

So when I can lie and wait I can use multiple observations to get enemy ship's speed and course, when I am in haste and have to get closer to the ship I can use the matching speed method. I still have to try the speed correction method.
Using the wheel has the advantage (versus plotting) that it makes more efficient use of available information, one is no more restrained in using 3:15 minutes for measuring, etc.

Maraz