Werfer-Granate 21's

[dodgem37]

I've been plugging away with round 2.

 

Measured the tube diameter with tape, overlaping the tape. Cut the tape within the overlap, which gave me the dimension I needed. Measured that distance against some aluminum sheet, then cut, and rolled it onto a 1/4 inch tube. 21mm x 40.5mm

 

Taped the 1/4 inch diameter aluminum onto the tube, measured the aluminum with tape and repeated the production process. 22mm x 40.5mm. That is the nylon end of a burnishing tool from back in the Letraset/Geotype days.

 

Sanded it down to give it some bite and drilled some holes to glue down the guide rails. This time they are in the location of the fasteners. Center-line is for the hanger base.

 

Rolled it over the tubes, making the diameter a little bit bigger. An even 7mm diameter. The rocket rolls around a bit, so hopefully with the guide rails installed the fit will be better. Photos show the rocket nose closer to the front opening than what the rocket I have offers. I may need to cast it, cut it, and add a spacer. I'll see.

 

Cut a channel into a 1/4 inch tube, made the guide rail, and set the return of the guide rail into the channel.

 

Slipped the 1/4 inch diameter sheet on and underneath the guide rail base. Score lines divide the guide rail base and as such will help me align the outer tube.

 

Then slipped on the other tube. Bad photo, but I think you get the idea. The rail base will be the join point, hiding the seam from within. All of the interior structure will help keep the exterior in the round when I adhere the exterior tube to the rail base. The exterior tube has a bit of spring and can be squeezed shut to abutt. It's not glued as of yet. I'll sand off any residual glue. Epoxy is the front runner.

 

Thanks for looking in.

Sincerely,

Mark

[LSP_Mike]

A lot of evolutions, but I'm sure the result will be astoundifiying.

[dodgem37]

A lot of evolutions is right. I sure hope something positive comes from this effort. But nothing too soon. I've set it aside and have moved back to the K-4 build, to get on with some painting.

 

Sincerely,

Mark

[frankc]

Hey Mark,

 

I found your post a few weeks back and was very curious to see what you would come up with because I too was working on this problem.. Like you, I wanted to work in plastic first but I couldn't figure a way to make a really thin tube of the diameter I needed. I had an idea about heat stretching over a mandrel - but I just couldn't get it to work. The other (and possibly easier) option was to turn the tubes out of brass. But the result needs to be very thin - Im not an expert machinist and that's hard to do for something as large as this is.. So I decided to make them from a sheet of brass

 

I think you ran into some of the same issues I did. One of the most annoying was all kinds of conflicting info about the size of the launchers (length wise). Based on taking ratios of good photos and checking nebelwerfer 42 specifications I decided the launchers were slightly larger (about the same length) as the rockets (just over 3 feet long). I think you will find your launchers match certain drawings - but your rockets won't fit in them right because they are too long! Anyway - If you are interested I have made rockets and launchers for a build I am working on (a Me-109 G) so perhaps you might be interested in how I did it?

 

I saw the Lion's roar rockets! They look pretty nice - I decided to make my own though as you can only see the tip and the end.

 

Here are the finished rockets

 

If you want to see more here is the whole story

http://s362974870.onlinehome.us/forums/air/index.php?showtopic=233944

[dodgem37]

My apologies for taking so long to respond, Frank. I have not been ignoring you or your contribution. I bet at least half of the views are from me looking at your work!

 

What you have done is remarkable. I haven't found that sweet spot necessary to work in brass. Let alone solder it! But it is something I should include in my modelling vocabulary. But brass and I seem to be like oil and water. A difficult mix.

 

After this, that, and the other thing, I've decided to see if I can 3D CAD this thing with a free, and limited, program, then have the stuff printed.

 

This is a scan of a print. I haven't used this program in over 3 years. It needs fine tuning, but it's coming back to me.

 

Thanks for looking in.

Sincerely,

Mark

[Derek B]

Excellent engineering Mark (this goes way beyond mere modelling). Based on what Frank had said, what final overall length did you come up with for the Wgr21?

 

Best regards

 

Derek

 

 

[LSP_Ray]

Ummm...sorry I am so late to this party, I just noticed the thread!

 

I was wondering, if you are going to use the 1/35th Lion Roar rockets anyway, why not use the entire Nebelwerfer kit? Lion Roar Nebelwerfer review.

The tubes are in brass, they provide PE rails, all the little wiring bits and the tubes are even drilled for the fasteners for an extremely detailed build. All you would have to do is cut down the tubes and rails. It is a bit spendy, but it might be possible to get 12 rockets from it, or at least 6.

 

Here is another review with some pics of a real Nebelwerfer that might be handy:

PMMS review.

[dodgem37]

My apologies for not responding sooner. I've been travelling to attend my daughters college graduation, packing up her apartment, and travelliing back.

 

Thank you, Derek. The Rocket is 1260mm long. In 1/32nd it scales to 39.375mm. I'm making it 39.5mm.

 

Thank you, Maru. This is only the beginning!

 

No worries, Ray. Spendy is right. I'm not going to use the Lion Roar set on a model, but I am using it as a reference. The tube and rocket are too small for 1/32nd scale. But the size of the injection molded details is good. I digital caliper measured the Lion Roar rocket and it is 35.9mm high x 5.9mm in diameter at its widest point (out of 36 x 6), with the tube at 7.46mm outside diameter x 37.48mm long (out of 7.5 x 37.5).

 

In 1/32 scale the rocket would be 39.5mm high x 6.875 (7mm) at its widest point, and the tube would be 40.625 (40.5mm). I can't find a tube diameter dimension other than two that states the tube diameter is 2100mm, and we know that's not so because the rocket base diameter is 2140mm and the location where the war head screws into the propellant body flares out. So I'm going to make up the tube diameter to fit the rocket with rails.

 

If I wanted a one-off, I could cast and use a modified Lion Roar rocket because the diameter would fit a modified 5/16" (8mm) brass tube, but I would need to add to the height. But that is not my aim right now. The rocket diameter is about 1/2mm too small. The Lion Roar rails are nice but would be too short, unless they were split. Also, the tube has rings around the outside. The ring is for the location of the 'divider plate'. See below. It's upside down, my apologies.

 

 

A US standard brass tube outside diameter is 5/16" (8mm, .31") with a .014 wall, making the inside diameter = .282. If I can get the wall lathed or lathe the wall to .007 I'll be happy, making the new inside diameter .296 . 1/2mm rail height (.019", make it .020", or .040" to center the rocket in the tube, and that leaves a .256 (or 6-1/2mm+-) for a maximum rocket diameter. The diameter is 1/2mm too small, but I'll keep this method in mind.

 

I can either lathe everything, which would mean I would need to buy a lathe, or I can draw everything up on a program I already have, work out the printing tolerances with the printer, and modify the drawings so the end result would fit together. Which is my direction now.

 

But whatever I do, I just want to be able to solve this problem as accurately as I can with the means at my disposal, and as affordably as I can.

 

This project can be done, as exhibited by Lion Roar's Nebelwerfer and Jerry's earlier rendition, but it will need to be done as a multi-media kit, again, as exhibited by Lion Roar's Nebelwerfer, because to try to resin cast this tube will be extremely difficult. That leaves either latheing tubes or 3D printing tubes. A determination needs to be made as to which is the more affordable.

 

As backup, I've called a local high school that has a metal shop to speak to the teacher, and am awaiting a return call. I would like to get a high school student to turn some tubes so I don't have to buy a lathe, to cut down costs, otherwise I'll contact a pro shop and hear what they have to say. All of the other stuff can be scratchbuilt and resin cast and made from solder, or wire.

 

Right now I'm hoping to stay away from PE. If the printed rails don't pass muster I'll have to draw up and make the rails in PE. But I'll work on that when the time comes. There's alot to do in the meantime.

 

Thanks for looking in.

Sincerely,

Mark

[dodgem37]

Plodding along with the Werfer Granate. A sketch of the part was made, then dimensions were taken off of the Lion Roar part. The renderings are close enough.

 

The Lion Roar part. This is the latch that keeps the rocket from sliding out of the back, I guess.

 

This is my rendering of it.

 

Lion Roar part. The ignition wire from the aircraft would enter the top. The pin enters a hole in the 'divider plate'.

 

Lion Roar part. This part combines with the above part. The pin enters the opposite side of the hole from the above part in the 'divider plate'. The semi-circular ignition rod enters the top.

 

My take. The ignition rod enters the bottom. The wire to the aircraft enters the top.

 

The base. I made a cut-out so it would be easier to sit the 'ignitor'.

 

Lion Roar part. What I call the ignition rod.

 

More in a minute.

Edited December 22, 2011 by dodgem37

[dodgem37]

A little more work is needed to off-center the pin. I extended the opposite end of the pin just in case some play was needed for a good fit. It can be trimmed as needed.

 

This is the hanger base that would be connected to the tube. The hanger, which could be anything from wire twisted around a drill bit, to something made here, goes into the hole. It too is a little long to allow for trim.

 

This is the hook mounting base. It will mount directly onto the aircraft.

 

The hook. 2mm outside diameter modified circle. It would be centrally located on the base above.

 

The anti-sway brace. I made it a little long on both ends. Maybe with a little trimming it can be used for both a '109 and '190.

 

The tube. It has just occurred to me that the tube can be cut in half length-wise and the ends blocked off to make it easier to cast.

 

I'm still plugging away on the rocket. If this escapade works out and materializes, then thru simple multiplication 1/24th scale rockets could be made as well.

 

Thanks for looking in.

Sincerely,

Mark

Edited December 22, 2011 by dodgem37

[Derek B]

Looks good Mark - I was already thinking about a lengthway split of the tube a while ago for casting - that is most likely the way I would go about it, but we'll see what you come up against?

 

Great work so far (and very educational)...Soldier on!...

 

Regards

 

Derek

Edited December 24, 2011 by Derek B

[Thomas Lund]

That is some very fine work you've done here, but are you aware of this:

 

http://www.modellbau-schatton.privat.t-online.de/html/preisliste.html

 

Near the bottom, items 3201 and 3202...

 

I have no idea of how nice they look, though.

[dodgem37]

Thank you, Thomas. I had come across that web page sometime earlier. I don't recall if it was recommended to me, as you have done, by someone else or if it passed by during research. But since it doesn't have an image link I moved on. But I gotta say, if it is anything like what pops up in the other links, what I'm doing is no competition. He's computer driven.

 

This is the 'Igniter', once again, with a modification. While the Nebelwerfer is hard-wired, it didn't make sense to me that the Werfer Granate would be hard-wired as well. I mean, how would the Werfer Granate be removed? The wire would also act as an electrical connection to the gondola guns. So I located a weather-proof neoprene/rubber plug that would be at the end of the wire from the aircraft.

 

Here is just the plug if people don't want to plug the wire into the 'Igniter', but have it just 'hanging around' outside of the aircraft. The wire from the aircraft would go into the opposite end.

 

This is my take on cutting the tube in half. This was an interesting problem. It started out as a hexagon so I could locate the bolt holes 120 degrees apart, which are indents. I think I located the rail backwards. I'll look into that.

 

Anyway, the rail would cover up one inner seam. The rail would act as an up/down mating/alignment guide, and the two blocks (1/2mm deep) at the end of the rail would act as a front/back alignment guide. I'll see if I can draw the other rail. If I can get the rails on I can remove the indents, as they are there to be drilled out to help to glue on the rails, and make them bolt heads.

 

But having the rails in may make cleaning the interior seam difficult. I think it may be easier to clean a couple of mm's of interior seam on either end than tweezering in the rails. We'll see.

 

Almost there! I think.

Holiday Cheers one and all.

Thanks for stopping by.

Sincerely,

Mark

[dodgem37]

I have only been working on this occasionally. There have been loads of chores to do.

 

I have been thinking about how the sway brace fits into the base that is welded to the tube. It needs to be universal to fit in both the Bf109 and Fw190, and it needs to fit differently angled recepters.

 

Therefore I reworked the point of interest and made it an universal joint. The outlying cylinder is welded to the rocket tube and receives the universal joint. I made it 2mm to allow for sanding to fit. 1.5mm probably would do.

 

Trying to figure out how to make the tube so it can be cast and not turned. The rails are .5mm high x 1mm wide, may be a bit on the high side. At the top is an angled cut which will accept the other half.

 

There are no bolts so the edge can be sanded, tho there are indents for bolt alignment. The rectangle is for front to back alignment. It can be sanded off.

 

Thanks for looking in.

Sincerely,

Mark

[Loic]

Modelling engireering at its best