1/48 scale Type VIIC U-201 build

[goshawk823]

Is the stern plane linkage arm premanently sealed in once the hull halves are glued together or you can stlill insert it after?

permanent in my build, as I'm planning on bonding the aft section together.

[goshawk823]

[goshawk823]

Sam,

Where are you at on your build presently? I know you’ve probably had to deal with some of the same fits I’ve been fighting too, but have you committed to bonding any of the hull sections together? I’m still exploring the horizontal split and tabbing with my build but wondering if you might be able to still do it on your build as well. That being said I will most likely bond the aft two lower hull sections together as there is just too much going on there to not. Same goes for the center section as it is less important to separate now with the easier access. The bow lower sections I may only bond one side to the center section and leave the other to be removed due to all the torpedo junk. Curious on your thoughts.

HI Nick, my apologies. I just saw this post and your questions to me.
I have not glued anything up yet...it's basically bolted together and aligned with the pins that on the component pieces. So, all of it can be pulled apart at this time. Since I'm not doing torpedoes, I can permanently bond the forward hull sections, Agree with you about about the center section (nothing much to worry about internally there) and the aft section has so much going on that my plan was to bond all that together too, Ron (R&R Ron) suggested gluing everything together in the lower stern (skeg, rudder support bracket, etc,) there's the two screws there that hold the structure to the hull. I could see scraping the bottom of the pond during a run and having all that rip free. Like you, I had to insert a thin sliver of material (in my case I used styrene) in the skeg to allow the rear planes to travel more freely; I just glued that to one side of the hull half. I have already found that one of the fasteners that is molded into the hull has stripped, so I am really leery of repeatedly taking this thing apart. I am going to try the method you and David have described here. I'm going to have to do it on the Bronco Type XXIII, so in for a penny, in for a pound.
BTW, I have Oto's PE set for this boat, and I was going to use the PE decks, but decided to go with the kit deck (when I was still following the manufacturer recommended assembly/disassembly method). If I cut along the waterline, I don't have to worry about all the attach/detach tabs that Oto has described; the entire PE decks can be permanently bonded to the upper hull. Using your method makes me rethink what I will use deck wise; the PE stuff is really nicely detailed. I already had build the metal fore and aft sections of the deck and basically abandoned them.

[Monahan Steam Models]

Nick? Where did you get the brass props for the Arkmodel kit?

Sam, I got them from Bob. He has them available on his site:

https://www.rc-submarine.com/product-page/brass-propellers-for-submarines

They nice and fit the model very well.

Nick

[redboat219]

Is the stern plane linkage arm premanently sealed in once the hull halves are glued together or you can stlill insert it after?

[goshawk823]

Nick? Where did you get the brass props for the Arkmodel kit?

[Monahan Steam Models]

Drove around town this morning searching for a specific piece of material that I needed for the design that I originally had in mind for the aft dive plane linkage. Struck out left and right.

Decided instead to change the design and just move forward with a simpler design with materials that I had on hand.




Here is what I came up with today.



The new part fits like a glove into the stern planes and the inner machined round journals ride smoothly in the bearings that come installed in the abs moldings. No more slop like the original part had. Small 1/16” pins secured in the aft plane supports will interface with the tubes at the outer ends of the planes.



Planes in the neutral position.



Up angle position.



And down angle position.



Nice and level across both planes.

The gap between the two hull halves where the pushrod linkage will need to run to connect to the aft plane lever arm is .122” in width. Just a gnats ass under 1/8”.

The width of the lever arm is .031”. I’m considering using a very short length of .031” diameter wire bent into a typical Z bend to make the connection to the lever arm. This would give about .028” of space to work with after you add up the material thicknesses filling the .122” width slot in the hull. From the short piece of .031 wire I can quickly step the diameter up to 3/32” and then 1/8” once the pushrod travel clears the narrow slot. Or I can cheat a bit and reduce the thickness in the hull halves in this area to open up the slot and use larger diameter wire to start with for making the connection to the lever arm.

Well that is today’s summary of the small bit of work accomplished.

Nick

[Monahan Steam Models]

bevel gears.

Agreed. Gears have been on the table as an option. Mechanical stuff doesn’t scare me in the least bit. The good news is, there’s lots of options

[He Who Shall Not Be Named]

Thank you!

Yep, there is very little room back there like you said! At the moment in the build, I am less concerned about the rudder control linkages. The rear dive plane linkage has been the main focus. With the addition of the aft tube, I have less vertical room for the dive plane control linkage. I have worked out a plan that I believe will work out well but want to study it a bit more before going with it. Getting the aft tube in place first will allow me to see what room I have to work with.

bevel gears.

[Monahan Steam Models]

Very slick. I have very little clearance for the control linkages for the rudders and planes in my install. I can't even fit the kit supplied plastic part that is the rear tube due to the space needed for the rudders and planes. Can't wait to see how you fit all that in that space back there.

Thank you!

Yep, there is very little room back there like you said! At the moment in the build, I am less concerned about the rudder control linkages. The rear dive plane linkage has been the main focus. With the addition of the aft tube, I have less vertical room for the dive plane control linkage. I have worked out a plan that I believe will work out well but want to study it a bit more before going with it. Getting the aft tube in place first will allow me to see what room I have to work with.

[Monahan Steam Models]

Nice clean job Nick! I like the precision of your work.

Thanks Ken! Much appreciated. I love the work you’ve done on your Marlin!

[goshawk823]

Jumped ahead a couple steps today to focus on the work that needed to be done to the hull for the eventual addition of the aft torpedo tube.



Designed and printed the fixture that will guide the cutting bit that will be used to correct the stern area for the torpedo tube. The fixture uses the rudder shafts as well as tabs molded into the hull to properly set and hold everything centered and parallel to the waterline.



Side view



Fixture with cutting tool guide shaft pressed into it.



Scratch made 1/2” hole saw cutting tool I made for doing the job today.



The holes saw slides over the guide shaft inserted into the fixture.



These molded in hull tabs for the fastener between the rudder supports will need to be cut out.



Removal if the tabs is quick and easy with a razor saw.



Once the hole saw has made the new stern tube opening cut, I wrap self adhesive 320grit sand paper around the cutter and by hand rotate the cutter down the length of the guide shaft to slightly open up the cut diameter.



Again all the work is done slowly by hand to ensure a nice precision job is done.



One of the torpedo tubes I use normally for testing new torpedo designs placed in the newly corrected stern launch tube opening.

Still need to design the aft launch tube components but they will be similar to the bow launch tubes I developed last year. That’s all I have for now.

Nick

Very slick. I have very little clearance for the control linkages for the rudders and planes in my install. I can't even fit the kit supplied plastic part that is the rear tube due to the space needed for the rudders and planes. Can't wait to see how you fit all that in that space back there.

[Ken_NJ]

Nice clean job Nick! I like the precision of your work.

[Monahan Steam Models]

Jumped ahead a couple steps today to focus on the work that needed to be done to the hull for the eventual addition of the aft torpedo tube.



Designed and printed the fixture that will guide the cutting bit that will be used to correct the stern area for the torpedo tube. The fixture uses the rudder shafts as well as tabs molded into the hull to properly set and hold everything centered and parallel to the waterline.



Side view



Fixture with cutting tool guide shaft pressed into it.



Scratch made 1/2” hole saw cutting tool I made for doing the job today.



The holes saw slides over the guide shaft inserted into the fixture.



These molded in hull tabs for the fastener between the rudder supports will need to be cut out.



Removal if the tabs is quick and easy with a razor saw.



Once the hole saw has made the new stern tube opening cut, I wrap self adhesive 320grit sand paper around the cutter and by hand rotate the cutter down the length of the guide shaft to slightly open up the cut diameter.



Again all the work is done slowly by hand to ensure a nice precision job is done.



One of the torpedo tubes I use normally for testing new torpedo designs placed in the newly corrected stern launch tube opening.

Still need to design the aft launch tube components but they will be similar to the bow launch tubes I developed last year. That’s all I have for now.

Nick

[Monahan Steam Models]

Gantu,

Thank you sharing these photos. My prop shafts measure 44.9mm between centerline.

Regards

Nick