Japanese Class A 1/16

[MFR1964]

Thanks for the explanation about the socalled silversolder, next time i will pay attention if it's the reall stuff, got me only 10 inch of that wrong stuff, i'll contact the local jewellers shop to get me the real stuff.

Manfred.

[Bob Gato]

"During a few tests the propblades started to bend towards the torpedo-body, you would expect the other way, the other prop simply shattered, i must remark, all blades are silver soldered for strenght, what the hell is going on!!!"

Sorry to see such nice work come apart by a marketing misunderstanding-That wasn't silver solder (noted by the dull gray color seen in the pictures) as is commonly thought of as silver solder- It was probably plumbing solder with silver in it (as found in Home Depot) that usually melts at around 450*F. Its just a little bit stronger then lead solder-True silver solder (now branded and referred to as silver brazing) melts at between 800*F and 1100*F. It is actually stronger than the brass! and will also join steel.
As for the prop blades-bear in mind that the prop is trying to pull the torp forward...the forces on the prop tips are fwd and ultimately in an arc down to the torpedo body-the heat of soldering annealed the brass and probably made it very soft.Example-in airplane accident investigations ...if the prop blades are bent back when the aircraft contacted the ground, it means that the power was reduced or none- but if they were bent forward it means the ground was contacted with power on.

[MFR1964]

Props are refurbished, so ready for some testing, and now another issue, i don't want to run my boat with the torpedo's always inside, leaving the tubes open will give problems with scooping up all the water during driving.



So i made this, a set of plugs to place inside the tubes when i don't run the torps.



They fitt tightly inside the tubes, also added some slots for securing the plugs.



This is inside the plug, by turning the nut at the front you can lock them inside the slots of my tube.



Next stage in the evolution, stuffed as many holes i can get inside the plug, the goal is to get no airbubbles inside, that piece of styrodure at the end is used to get me a neutral bouyency, this way i can trim the boat with plugs inside the tubes.
Why?, most of the time you will drive your boat without the torps, when you use them it will create some positive bouyency, i want to have my boat level after firing the torps and not drive her as some drunken idiot with the nose down, due to loss of bouyency.



So most of the time i will drive her like this, those targets have to take the gamble if she is plugged or armed.

Manfred.

[MFR1964]

As promised the Vid,

https://youtu.be/GVvj7U1DEBk

After this test i decided to molest the tubes even more,



To solve the issue of pressure even more, i decided to drill some holes into the sides of the tubes.



As you can see i now have some inlets to get me a better free waterflow when starting up the torps.

For now i'll dig up the jigg for reparing the old brass props and do some more testing with those props to see if my modifications work.


Manfred.

[MFR1964]

As for the Master thing, i screwed up my torps, that is, props only, the rest is fine.



During a few tests the propblades started to bend towards the torpedo-body, you would expect the other way, the other prop simply shattered, i must remark, all blades are silver soldered for strenght, what the hell is going on!!!



I still want to do some tests this weekend, so i ended up with a slight modification, three blades nylon props, also a bit smaller diameter.



I coocked my brains about the propellor issue, my theory is that starting up those high torque torps sends a pressure wave agains the closed back of my tubes, this would explain the prop blades being bent towards the torpedo-body, the light went on when i was thinking about the tubes of my type XXIII, same method of launching but no shattered blades, the picture shows my solution, drilled as many holes i could into the backplate of my tubes.
Now the pressure wave has a way to get away instead of deflecting, pretty much the same arrangement as on my type XXIII, tomorrow i'll shoot some vids about launching the torps, stay tuned.


Manfred.

[He Who Shall Not Be Named]

Yeah i know, me like complexity, frankly said, i have no idea how they kept their torps inside the tubes, there was no room to use those lockingballs as used on your gastorps, so i ended up with the hook thingy, on the dry it works well.
This week i'll do some testing with launching from the tubes and give the mechanism a rub down to iron out the defects.

Manfred.

I love watching the Master at work (don't tell anyone I just said that!).

David
In Training

[MFR1964]

Yeah i know, me like complexity, frankly said, i have no idea how they kept their torps inside the tubes, there was no room to use those lockingballs as used on your gastorps, so i ended up with the hook thingy, on the dry it works well.
This week i'll do some testing with launching from the tubes and give the mechanism a rub down to iron out the defects.

Manfred.

[He Who Shall Not Be Named]

Oh, man! You've made Rube Goldberg proud, sir!

David

[MFR1964]

It took some weeks to complete the launcher and the mechanics, pictures.



First i had to adapt the torpedo's, so i could use the lockingmechanisms, ended up with some tubes underneath the torpedo's.



Made the hooks which will lock into those tubes.



The hooks will fitt inside the tubes like this.



Took a spare rear-end and made a green led inside, this is done for adjusting the magnets so you will not burn up your motors.



Peeking through the slits i can see when the torpedo is activated by the magnet.



Had to change the magnets because the old configuration was too weak to get me a trusty launch.



Had to find out at which place the locking device had to be placed, an glued them for the time being with some CA.



Those pieces of lead ensure a firm lock inside the topedo's by gravity.

Last step was to make some wires attached to both the controle rods and the lockingdevices.

Made a vid to show how the whole concept works, enjoy

https://youtu.be/Xon6RBoR3u0

Next week i will have some testing inside the tub, which also will be documented, stay tuned


Manfred.

[MFR1964]

Made a vid to show how far i got with the rest, also a small demonstration how the scope and antenna will work, if i remember right Tom had made such a contraption with the scope of his Skipjack.

Enjoy, https://youtu.be/8MHIb8MO2ZI

Manfred.

[MFR1964]

Goofed around this summer with the V80 and the type VII, now it's time to rapport some progress i made last weeks with the Ko Hyoteki.



The loose parts to get me a SAS floater.



Once put together you get this,



Place on the hull at the right position,



To make things easy, it's held on it's place by using neodine magnets, easy job for maintenance.



Another item on the list that had to be made, added some floats to both the scope and antenna.



Had to made some guidingtubes in the upperpart with the hatch.



Once placed back, you get this, i like to have my parts removable, you never know when you need to do this.



Placed both the antenna and the scope inside, those stainless steel rods are needed to restrict the movement of both devices.



I measured up the maximum i could lower the parts untill i reach the SD inside.



Extended to their maximum Heights.



It barely fitts around the SAS float. here you can see the reserved space between both floats.



For now a teaser, working on this contraption to make my two shooter work, iŽll rapport back when there is progress.


Manfred.

[MFR1964]

Yeah, it became a bit of a journey, but at the end i get my reward, that cone gave me some grey hairs, took me some effort to get it right, i ended up with the trusty design you allways use when you have a single shaft propulsion.
I know there is a guy on Youtube which has a working Ko Hyoteki, has some nice underwater video shots,so i know what the result will be, not sure if he has a working two shooter.
Follow the link, https://youtu.be/Hp5wOW73PrU

Manfred.

[He Who Shall Not Be Named]

Slowly, but surely coming together. That cone is a SOB to work in, isn't it?! Man, this is going to be one slick looking boat once you've get it into the water.

David

[MFR1964]

Wanted to build my resquebouye system, but first had to do something else, David stated correctly that the conical shape of the stern would give problems with bouyency, you're not able to get enough foam inside, so i deciced to leave the last part of the stern alone and turned my attention to the second part of the stern.



Stuffed in as much foam as i could, used the old ribs to follow the contours of the hull and glued them down with RTV



The other side of the business end, placed a small spindle inside and added a slidingbar near the hole of the hatch, this is done to give the wire a smooth ride without gettiing stuck.



A better view on the slidingbar and you can see the hook which will hold the bouye on it's place.



At the same time i could add the steeringrods with their guides, marked down the exact positions with the SD inside.



Added the magnets at the last sternpart, this was also done at the second sternpart, when you "magnitize" them together i can control the propellors, rudders, divingplanes and resquebouye.

Next little project will be, building the floats for both the antenna and the scope, i've seen some nice examples on the forum and will follow that road.


Manfred.

[MFR1964]

Blah,blah,blah,blah

Manfred.