Pz III New Build

[Adrian Harris]

Well, no escape hatches makes it either later than an L, which must be an N for Tunisia, or a different hull altogether, which means you've stolen my idea for a Sonderverband 288 vehicle ...

I like your idea of the high fill primer - similar to Clive's method but with a different product. Something else to try when I get round to this model

Adrian.

[Sarah Frazer]

Hi Stephen,

The finish looks great. Are you going to make a new gun as well?


Sarah

[Stephen White]

Sarah, yes, that's the general idea. I've got some good original engineering drawings of the mantlet and mounts.

I've been thinking about how to represent the rifling on a barrel. I can't see any way of machining the lands (the bits that stick up) directly onto a barrel tube. So how about this:

- Bore out the barrel oversize.

- Create a sub-calibre plug and make a reverse pattern on it by sticking strips of brass to represent the rifling.

- Mould a female pattern around it in resin.

- Turn the outside diameter of the female pattern to an interference fit with the barrel sleeve. Insert in the barrel.

- Dress the muzzle end to remove any sign of the join.

What do you think?

Stephen

[Brian Leach]

Stephen,

Hi, another good: you are posting for us to see!

If we are guessing, I would have to say you are building an N







I have been thinking about and researching the rifling problem myself.

The solution I have tenatively come up with is to investment caasting the barrel, Do this so the lands are a bit high, than drill out the barrel on the lathe to get a fine finish. Does this sound reasonable? I have not attempted this yet. I need to get a kiln first. I had looked into putting lands and groves into a long pipe than cutting this to size to use as inserts for the barrel, but this would be very expensive.

Thaks for the great pictures. I was wondering: when you get nearly done, is some one going to snatch your tank so that we may get to see this again, or are you going to do another build?



Cheers!

Brian

[Adrian Harris]

Just as an idle question, how do you get the rifling into a 1:1 barrel

Is it just done on a lathe with a huge amount of force, like a very large pitch thread

Adrian.

[Sarah Frazer]

Hi Stephen,

Your way sounds fine. Another way would be to bore the barrel out oversize but make the insert from a CAD 3D print. This way you could include any specific radii or form for the lands. If you want to do it this way I should be able to do the 3D CAD model for you.

Thanks for the photogrpahs by the way, I'll let you know how it progresses.

If you doing the simplified hull, what will you do with the hull angle brackets?


Regards,

Sarah

[Brian Leach]

Adrian,

To put groves in a real barrel they use a series of "buttons" which are disks with cutters protruding from the side of the "button" which correspond with the number of groves youn want. The twist is added by putting an angle on the cutters so that as it is drawn through the tube, the button twists at rthe correct rate. There are a number of buttons used, each correspondingly larger than the last, until the desired grove depth is reached. As I said, the buttons are drawn throug the tube. The amount of force is more that you or I could exert, but as I understand it, this can be done on a toolroom lathe. In use the draw is done by a screw. As the lathe chuck turns at a given rate, the stationary screw draws the button up the barrel. The difficult part of all this is getting the buttons made at the correct size and angle. (I think)

Did I explain that right?

Sarah,

That is kind of what I would do except that I would use the 3d model to make the pattern so i could cast a metal part. I like metal and the bored out Aluminum barrel would be so shiny

Thanks folks,
Brian

[Stephen White]

I'm glad the barrel rifling bit has generated a debate. It would be great to see some examples, to add that extra bit of detail. After all, the tank is all about the gun, so getting that right is a big part of creating a good model.

As to the choice of an Ausf N, I'd lived with tanks for my professional life and had a view that a proper tank has a decent size barrel. (No comments). I then came across a tank commander who won a Knight's Cross in France, 1940, went through the Greek campaign, spent a short time in Russia and then fought all the way through the Desert camapaign, was at Alamein and won the Deutsches Kreuz in Gold and Oakleaves to his RK, commanding a Panzer Abteilung. All by the age of 26. (He then did some staff training, spent a pleasant few months as Military Assistant to a Finnish General and ended up on the Russian Front. He was wounded, and in trying to return to his family in Austria, was captured by the Russians and was shot trying to escape, a month before the end of the war. Some record). So that's given me the inspiration to do an N, small barrel notwithstanding.

Brian, the answer is Comet next. Don't see myself starting it for a while though.

Sarah - well spotted. Yes, the lower angle brackets need replacing for the plain edged style, so I'll be making those, when I've got some new stock in. At this rate, I'll be taking more bits off the tank than putting on.

Regards

Stephen

[Jim Fowler]

WHile I am by no means an expert, when I was very young I remember my father making black powder pistols and even a rifle or two. The thing is, I remember him putting riffling groves in the barrels by hand. I don't remember all of it, but it was entirely by hand and took a VERY long time. And, I think riffled barrels have been around for a very long time.

But, my point here is that possibly a bit of gunsmithing reasearch could yeild some help, if that detail is important to you - just a suggestion. Also, if the barrel is to be aluminum....well that is a whole lot softer (GRIN!)

Anyway Stephen, your build is awesome and where ever it goes or path it takes, I am very greatful for your willingness to share it.

Best Wishes,

Jim

[Bodo Langbehn]

Hello,
here is the solution I have built for my Panther A.
I have slit a brass tube 32 times on the dividing head with a 0.3 mm circular saw blade and soldered a brass ring with the outer diameter from the barrel on the front and put the bush as an insert in the barrel. It is not so long as I wish, but this handicap disappeared with the muzzle brake.






Kind Regards Bodo

[Stephen White]

Bodo - looks great. On the 75mm, there is no muzzle brake, so the rifling is very visible. I'd want to find a method which makes the lands follow a spiral pattern to represent the rifling. I'm not sure whether you could do that by raising the rotary table to an angle.

This is generating some good ideas, thanks for contributing.

Regards

Stephen

[Brian Leach]

Jim,

I agree with you, doing it in Al would be much easier than iron or steel. I have searched many times over the last six months and I can find no more specfic information than what I related earlier. My gun enthusiast friends tell me the government dosn't want us to rifle at home. I don't know how much of this is paranoia, but from what I gather it is a very technical endever.

There must be a way. Like you said, people have been doing it for a long time at home, or at least in the village.

Maybe some one out there will hear us and help.

Bodo,

That is a great effect! An easy (relative) solution in many cases.
Thanks!


Cheers every one!
Brian

Hello everyone again.

With the help of a friend of mine I found a guy, John Quickenbush, who after explaining what I wanted, told me how I might put 32 lands and groves in a brass or aluminum tube. As he explains it, it should not be too, too difficult for a tube that does not need to shoot a projectile. I am going to play around a bit and see if I can form the barrel insert. if anyone is interested I would be happy to send a pm to them explaining the method as I understand it. It is kind of interesting.

Cheers!
Brian

[Stephen White]

After some abortive attempts to re-profile the roadwheels with a form tool on the lathe some time ago, I can't put it off any longer. Having taken some advice from a very experienced retired machinist, I've had another go with more success. I've posted the profile I got from the Tank Museum on another thread.

Here is the reprofiled wheel being turned:



And here, the mandrel to hold the wheel:



This is the before and after:



There is still more work to do, joining the pairs with 3/32nd brass tube, adding weld detail and installing the bolt heads on the hub caps.

Regards

Stephen

[Derek Attree]

Hi Stephen
That brings back memories. Only another 23 to go!!!

Looking good.


Derek

[Sarah Frazer]

Hi Stephen,

Well done with the wheels, the one you done so far looks very good.

The later Panzer III's have been profiled, but not as much as yours. In a quandary now whether to leave mine or deepen the profile

Enjoy all the rest of the wheels.


Regards,

Sarah