Tokushu Choban Re-Go and early Japanese helicopter experiments

Hi Guys

Here is very interesting. I was not aware of the fact that the Japanese were experimenting with helicopters.

Check out this link.

http://www.warandgame.info/2007/10/japanese-vtol.html

Regards
Gerhard

Hi! Tokushu choban re go!(特殊蝶番レ号)

http://www2g.biglobe.ne.jp/aviation/jpnhistory.html

Hi!
Source:Japanese internet site

Thank you Blackkite. Are there more info avaiable?

Gerhard

Hi gerhard! Thank you good topic.

The specification of Tokushu Choban Re Go :
Length : 13.3m(including rotors), Breadth : 3.6m(between skids), Height : 2.47m(without rotors), Weight : 633kg, Main rotor diameter : 8.5m(260 r.p.m max), Tail rotor diameter : 4.5m(420 r.p.m max) , Engine : two Kosoku Kikan Kogyo(高速機関工業) KO-60 air cooling engine(55hp each) with 50cm diameter forced cooling fans, connected by V belt and gear each other.
The main rotor and the tail rotor generated lift, rotated inverse direction to cancel anti torque, but the tail rotor's anti torque was small compared with the main rotor, the tail rotor inclined 20 degree. The tail rotor had the flight control function. The mail rotor's hinge(which called Tokushu Choban) had the special mechanism which change the pitch of the main rotor's blades to cancel unbalance of left side and right side rotor lift in forward flight.
There was a No,2 experimental helicopter plan which had a normal single main rotor, vertical tail rotor and more powerful engine planned by the same team based on Sikorsky technical paper. Full scale mock up was made and wind tunnel test was done. But the real helicopter did not completed.

Blackkite san,

Appears that photos of the Tokushu Choban Re Go are from an exhibition which ended sometime last year and some of the photos are from a booklet accompanying the exhibition. Any idea how I can get a copy of that booklet? Thanks

How about contact National Museum of Nature and Science,Ueno Tokyo or Japan Aeronautic Association?
Remaining all data of this helicopter stored in this museum and this association.

Almost technical papers of this helicopter were burned out by students 3 days after the ens of the war.
This helicopter was buried under the ground of the university.

http://www.kahaku.go.jp/english/

http://www.kahaku.go.jp/event/2009/12helicopter/

http://www.aero.or.jp/isan/isan-katsudo/200711kikin-katsudo.htm

http://www.aero.or.jp/english.html

Hi! Enjoy.
http://aeroscale.webs.com/ueno.htm

No.2 helicopter's specification was as follows.
Engine : two Ishikawajima IK2A (air cooling inverse inline 4 cylinders) 100hp(each), Main rotor;diameter:9.0m(3 blades,220r.p.m), Tail rotor;diameter:4.5m(3 blades, 320r.p.m).

New topic split from the old "Japanese Projects before 1945" thread...

The link in the OP is broken, the page (but not the pictures) was archived by the Wayback machine however.

https://web.archive.org/web/20120202214150/http://www.warandgame.info/2007/10/japanese-vtol.html

Hi. I have just started to scratch the surface of this one recently. Would like to share with you what I have found.

First it is claimed that it was made by the Yokohama Higher Technical School (if google translated it correctly, orig: 横浜高等工業学校 >>wiki<<) Even on that wiki page it states the name 特殊蝶番レ号 and directs to >>wiki document on it<<

Second: the works was led by Professor Manri Hirotsu (orig: 廣津萬里). [sometimes I get translations as Masato Hirotsu, which may be more correct]

Also I was able to find one better quality picture:


Finally some interesting URLs:
http://strangemecha.blog59.fc2.com/blog-entry-454.html?sp ← it says among others:

The main highlights of this exhibition are the notebook that summarizes the prototype of the future helicopter devised by Professor Hirotsu, and the materials related to the special butterfly No. 2 that was completed during assembly. It was very interesting to see various interesting ideas. In addition, it seems that some kind of book publication is planned for the issue by the Japan Aeronautic Association, so I would like to wait for that publication, but if possible, I would be grateful if ...

Click to expand...

https://beadsmici.exblog.jp/14623649/ ← description of the booklet mentioned couple of posts above, also the source of pictures for other post.

Looking forward for more details on it.
Does anyone was able to obtain mentioned booklet?

A closer view of the booklet.

According to the wiki page, a more practical design based on the Re-Go's success had a full scale model and was subjected to wind tunnel tests, the design was improved. The section of the page is called Second Prototype, and the last sentence is "A full-scale model was built and wind tunnel experiments were conducted, but the actual machine was incomplete due to the end of the war." I don't know how much that means was done to actually build this thing, though it does raise the question as to the ultimate fate of the model, quite possibly lost to B-29 bombing or deliberate destruction by the Japanese.

Found its source: