Warbird, Yokosuka D4Y-2s, Master style build

leaded50

Legendary member
i found my warbird to build. Yokosuka_D4Y- 2S "judy" . This lines i like. The ordered foamboards needs hurry up be delivered now.. ;).
1150mm wingspan, who is a 1:10 scale.
Two version was made of this, radial engided and this, with a inline. far more superb design.
Enough pictures/drawings found to make it!

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leaded50

Legendary member
starting in wrong end? :D BR2830 1300KV brushless motor, servos, 3 blade props , landing gear w/wheels ordered. Electric retracts & spinner i have from before. I even got a cheap elevator fin from a F4U who is pretty similar to the Yokosuka elevator fin, in correct size.

BR2830 1300KV motor: 11.1v - 9050prop, thrust 1130g 238w
14.8V -1045prop, thrust: 1310g ... that should be ok
 

leaded50

Legendary member
today ive build the front fuselage shape in 280% enlagred papermodel , by size 360mm X 175mm X 110mm (need adjust to to get the size i want, here it got 1320mm wingspan..) ......just to see if the papermodel plans could be used a bit... and yes, it did, the skins seems accurate to get the shape it should. I will try making the parts of fuselage by the papermodelplans, adjusting for foamboard thickness at eg. the formers. If get what i see now, it should be quite possible convert a papermodel plane to foamboard build.

(horrible to get the paper hang together to set some tapebits in place, withouth crunch the whole model .:confused: )
 

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leaded50

Legendary member
well, i did start..... Japanese warbird, the Yokosuka D4Y-2-S - the fastest dive bomber of World War II, even if not many of them was activ
Frontpart of fuselage is made, finish is under work.
 

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leaded50

Legendary member
My experiences at moment to build this from papermodel plans...
I did build some of the fuselage by paper in the size i plan to use foamboards, and it went pretty well with fitness of parts. When do in foamboard things come up..
The fit isnt superb perfect, and parts need adjustments to do it. Mainly it seems because the thickness of a foamboard vs just paper, or irregularity in copying the parts, even if tried taking that in consideration, as eg. the size of formers.. But with the scalesizes worked out, just minor adjustments is needed to get best possible connections. I still havent got connections "much off" and needed put in extra foam, rather cut some away. Specially the fuselage skins 1 - 2 did came "off" with needed minor adjustment to get a "seamless" connection. I tightened the radius in front of skin 2 a touch, and it went well.
I have made original pictures, drawings eg together as the paperplans same scale to fit the size for the build, it helps a lot, for references/measures between, even if need go forth and back between, to check.

All in all, i feel it gets quite ok enough to try further build it from the papermodel plans. Of course internal construction gonna be different.
No, this is not an easy build, not just because the Masterbuild technique, but since most every part needs check for fit, and possible adjusting, and if need make new parts in a bit other shape.
 

leaded50

Legendary member
more experiences...
Well, build from paperplans isnt perfect.. every part needs adjustments. Perhaps if scanned and reworked in 3D to get plans fit to foamboard? Still we wouldnt have all needed to do it...

When building the whole fuselage, it isnt enough to get every section to fit the others...but also to fit the main outer lines of whole fuselage, to get it straight! Every part of fuselage needs measured vertical when fuselage stand at nose at all sides, to get every part correct. A couple of mm off, will be seen later. In this plan it aint formers for each section either.
It neeeds a lot of scratchbuilding "on-the-go" , papermodel plans can be used as a start though, but builder needs skills to measure/adjust accordingly to get it ok. Its not enough to just "follow the plan".
 

leaded50

Legendary member
More work done. Fuselage is complete, and painted! As seen on earlyer pictures, rivets and seems is there... still it is, shown trough the paint, even if more faint, and not as easy seen on pictures. Some is remade too.. Canopy is done too, i was "lucky" find the right plastic bottles to make the sections from.
Center section of canopy is also a hatch to reach electronics/battery. Big nosecone that fit the shape of nose, is shipped. A few 3-blade props versions already in house. Wings are ready planned, approx 3-5% dihedral as the original, and will get retracts.

Personally i feel the build does look as planned, even if not thought it wouldnt be as big it is. ! :)

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leaded50

Legendary member
Gonna do servoless retracts, eg, and thought of making wings detachable. Later i saw this would be some extra work & weight, and need of cutting fuselage in belly fully open again, i decided to not make wings detachable. To get the retracts correct best fit eg, i mountes underwings at fuselage (without the flaps/ailerons) at an incident of 1 degrees, and approx 3.3 degrees dihedral as orginal. Still not got the ordered foamboards and servos though. Scalewise, the wings should even be a touch thicker, i felt it was enough.. Wings are as at orignal placed mid/low.

The servoless retracts was bought cheap on a sale, and more than strong enough for this model. Together with retract wheels/stand of a Spitfire this will be perfect. Even if the stands needed some changes to fit as i wants.

Also made a foam machinegun for rear of cockpit, and pilot "bombsight".

Reinforcing spars in wings is by wooden paintsticks, who is as strong & light as plywood (at least this ones) , glued together with overlapping joints with Gorilla glue. It dont break easy by knowledge!
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leaded50

Legendary member
Servoless electric retracts in place. Reworked Freewing Spitfire land gear to fit is ok. Tail swirling wheel is ok.
....but still no ordered foamboards and servos in mail....
 

BATTLEAXE

Legendary member
Gonna do servoless retracts, eg, and thought of making wings detachable. Later i saw this would be some extra work & weight, and need of cutting fuselage in belly fully open again, i decided to not make wings detachable. To get the retracts correct best fit eg, i mountes underwings at fuselage (without the flaps/ailerons) at an incident of 1 degrees, and approx 3.3 degrees dihedral as orginal. Still not got the ordered foamboards and servos though. Scalewise, the wings should even be a touch thicker, i felt it was enough.. Wings are as at orignal placed mid/low.

The servoless retracts was bought cheap on a sale, and more than strong enough for this model. Together with retract wheels/stand of a Spitfire this will be perfect. Even if the stands needed some changes to fit as i wants.

Also made a foam machinegun for rear of cockpit, and pilot "bombsight".

Reinforcing spars in wings is by wooden paintsticks, who is as strong & light as plywood (at least this ones) , glued together with overlapping joints with Gorilla glue. It dont break easy by knowledge!
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Looking good man you really got this scratch build thing down. So much more satisfying when yo nail a design with no plans, just a couple drawings and some patience. Looks good, can't wait to see the maiden
 

leaded50

Legendary member
Thanks @BATTLEAXE . Patience and measure, measure again, and recontrol measurement.....and a totally sharp knife, and see solution on how adjust to fit, is what does it. If a section get 5mm longer than intended isnt something to care about, as long its consisstent all around in eg. fuselage. When scratchbuilding, you also need adjust to get things fit.Eg because main part of cockpit also is hatch to electronic, battery and such.. the fuselage needs reinforcing against it to hold it shape.. tjhat also give needed changes to the canopy.. not as wide low down as should scalewise. Yes it aint perhaps needed by using other things than easy accesable material, without need order form specialshops. If a RC-shop needed be where everything needs build from, then could easier buy a ready plane. Half of the fun is building, perhaps more!
I had really fun building airplanes out from designs, not done .
Im not a experineced flyer, more or less quite "green" :) but have also freinds excperienced who said willing to be "testpiliots", but i need get all equipment needed. The EDF for the Russian Rocketship came yesterday (gonna be installed today?) but still im missing more servos, and foamboards to get wings ready on the Yokosuka, + a reciver more.. all in shipping but because of the Coronavirus situation, everything is delayed. .
 

JakeTheSloth

Active member
I thought about looking through your feed on account to find this D4Y you were talking about earlier, and I have to admit that I'm very impressed and kind of jealous. It looks great, I wonder how it'll behave in air.
As a little comment to your earlier statements that it'd use some remodelling to be made of foamboard - that's very much true, I've made dozens of cardboard models so far and I figured that after scaling them up or down I had some problems with fit, as they were designed for specific thickness of paper - you can imagine the difference between 0,2mm of paper thickness vs 5mm of foamboard.
The other problem is that paper models are meant just to look nice, not to fly - RC models should have strong internal structure, some kind of rigid frame to keep everything together, one piece elevator and single wing, in this case going through fuselage. I think that it'll use some CF spars.
Anyway I feel like that's not your first model and I'm pretty sure you'll get it done.
Good luck!
 

leaded50

Legendary member
it wasnt totally planned, but when the chance came.... Dynam Beaver floats need minor work to be correct views of typical floats for such Japaneese airplanes of WW2. and a reduced price at $4.5 i couldnt go past them.. :) They do fit correctly in lenght and views with a bit more rounded top on my Yokosuka...
 

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leaded50

Legendary member
Aichi did make the motor for this, and also the Aichi Sensei airplane, who a specialmade attacplane for use from big submarines. The relation ios easy seen in the designs of the Aichi and Yokosuka. Thats reason to use the floats i get, it was an idea to get the warbird even more "universal" in use... by water, snow, or on plain ground. .
Here is a picture of a Aichi Sensei... resemblence is there much.... even in paint origin.
 

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