1/48 scale Type VIIC U-201 build

[Monahan Steam Models]

The improved access to the lower hull with the waterline cut has made a huge difference. The WTC drops in much easier and the access to the forward and aft sections is much improved. Considering now a fully bonded together lower hull like the above waterline assembly. Will need to modify the forward torpedo tube unit if I do decide to go this route but it looks fairly simple to do.

The staggered tabbing worked well to keep the forward and aft sections aligned great. The area around the saddle tanks because of the angle the tabs had to be mounted at proved more of a hassle for getting the upper and lower halves to click into place, so I removed them. I will be making a different connection/alignment system for that section of the hull. Should be super simple and straightforward from what I’m seeing so far.



One side note. The orange label plastruct solvent cement I’ve been using to bond the styrene strips to the hull is garbage in this application. Parts have very little bonded strength. The white label plastruct bonding cement to bond the the kit’s parts together has been working well.

[Bob Gato]

We all know but I'm going to say it again.. Nick your true engineer I love the way everything in that boat can be accessed to be upgraded or replaced... So many builders in these threads suffer from "get it in the wateritis." They glue the boat together such that it'll never come apart again.. then when something breaks or stops working, and it will - they give up "too much work to fix," then in the dry dock it sits... on the shelf. Your threads are a pleasure to read man -BG

[neitosub]

That WTC is sitting there nice and snug! Can't wait to see her in the water!

Nate

[Monahan Steam Models]

We all know but I'm going to say it again.. Nick your true engineer I love the way everything in that boat can be accessed to be upgraded or replaced... So many builders in these threads suffer from "get it in the wateritis." They glue the boat together such that it'll never come apart again.. then when something breaks or stops working, and it will - they give up "too much work to fix," then in the dry dock it sits... on the shelf. Your threads are a pleasure to read man -BG

Thanks Bob!

Coming from you, your kind compliments mean a lot! Always thankful for your keen well thought out observations and helpful input. Enjoying your meticulous skilled build of the Atlantis. Would be awesome to see your work showed off more on here!

The access in the type VII is much better now. Although the way the original kit is designed is a great boat when built as originally intended, the assembly and access to the hull did not fit in with what I would like to see as a easy to use and serviceable design in the future like you have pointed out. The multiple assembled parts create fitment issues for a clean final finish and many chances of breaking or scratching parts during assembly or disassembly.

Before a build looks good it needs to be mechanically built good and be serviceable. The hull is really a fairing these days. Technology is always changing and upgrades will be inevitable. Like I’ve said in building classic cars, and other technologies, anything is possible, just pick the final shape you like and pour on the work an it will happen.

That being said, enough of us who have built things over the years can agree with what Bob has pointed out, things will break and will need to be repaired or replaced. Make your boat solid but repairable. Don’t lock yourself into a unrepairable design.

Just last week I resurrected a tug boat I built 30 years ago with my father to bring it into running another number of years of operation.

[Monahan Steam Models]

That WTC is sitting there nice and snug! Can't wait to see her in the water!

Nate

Thanks Nate, I really enjoy the work you’ve done on your build recently. Keep up the great work!

Nick

[Monahan Steam Models]

Made a little bit more progress today. Focused attention on the aft section of the boat.



Carefully and gradually enlarged the inner diameter of the areas in the moldings that carry the port and starboard stuffing boxes a few thousands at a time with a series of multi-flute straight cut readers. The 6mm OD nylon tubes provided in the kit were not going to cut it. Replaced these with a set of .250” OD brass tubes with 4mm ID oilite bushings that I made today.



A quick mock up fit and new stuffing boxes fit snug in the hull and while the shaft alignment is perfect and smooth.



I started the design of the “in the wet running” brushless motor, stern planes and rudder servo mount months ago when I took a break from the project. Finished up the design and assembled it today.



Here is it mounted in the hull. It was designed to fit into the profile of the kit’s original mounded bulkhead or frame shapes.



Another view of the same mount assembly fitted into the hull.

The next bit of work will be trying something new with the motor to prop shaft connection. I will be using universal joints to make up for the alignment between the motor centerlines and the shaft centerlines but I’m thinking of designing a center-lined captured magnetic drive interface with the motors. Meaning the connection between the motors and the shafts would be coupled together and driven by magnets. The idea behind this is allowing for the props to be snagged or bound up while allowing for slippage of the motor to shaft connection with out overloading and tripping the main system fuse.

Besides that “what if” experimental nonsense, I’ve been focusing on making the rear dive plane hardware robust and compatible with bonding the two lower hull halves together. Think I finally have something with that. The last orders of business are the rudder mechanisms and last but not least the almighty stern torpedo tube.

Spent a bit of time on figuring out if it would be possible to modify the Arkmodel type VII hull to have a scale size functional aft torpedo tube and the answer is yes. It will require bonding the two hull halves together but the final result will not alter the external molded appearance. Designing a jig and tool for making this modification to the hull. We will see how it goes…. Not really worried

[gantu]

[Monahan Steam Models]

Gantu,

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

Regards

Nick

[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

[Ken_NJ]

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

[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.

[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!

[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.

[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]

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