JÖRÖ

Hi,
now i have 2 sets 1/4 scale plans, Bates and Manninen's, just need to check which one are more scale. Bates plans are truly a master pcs, drawn beautifully, clear and sharp. Specially very helpful are plans for the retracts. Planning to build upper legs from carbon and maybe some metal castings for lower leg.
mechanism for moving those arms could be as in Bates plans or some strong electrical servos moving those bending arms. Will see what is solution in the end...

Cheers

-Jörö

JÖRÖ

Oh my..
in both plans are major mistakes specially in cowl area. If checking upper view from cowl, both plans are badly wrong. Curvature in cowl starts about 50% from cowl side in real plane. Both plans shows almost straight line. Easy to build but wrong and disturbes cooling. Upper and and bottom profile is straight like it should be, on sides there is huge difference. There should be clear step between cowl and fuse on sides, allowing better cooling for engine. for same reason cowl is shorter like in top of it. so i need to make modifications, there is no option... Just take a peak from upper view from page one, it explanes a lot.

-J-

Kennu

Hi!
Since the starter of this message is from Finland I recommend him to get in touch with the people in Tampere. There are apparently two different projects. One 1/8 scale and the other project is a 1/5 scale. These guys are making fiberglass fuses of the Finnish Brewster.

http://trerc.fi/galleria/brewster/index.html

http://trerc.fi/galleria/iso_brewster/

It sure would be a very cool plane to have!

Greetings from a fellow Finn living in Chile!
Kennu

JÖRÖ

Hi Kennu,
been following those threads,  and their work is absolutely fantastic. And plans on pics look real nice too. It would nice to check those plans too.
Next week going to museum and take pictures from Pekuris brewster.

cheers

-Jörö-

JÖRÖ

Hi,

Decided to figure out the hardest part first.. the landing gear. Been reading many threads and all have same problem to get gear reliable and strong. Taken lots of measurements from struts and movements and believing  founded simplier solution. Angles and struts to outside will be scale but movement inside is much more straight forward, unscale but hey its only few seconds when the gear is moving. Started collecting parts and soon taking some pictures. Can say it wasnt easy to find solution, so many times ended banging head on the wall, there wasnt room for movements, can u believe in fuse with 30cm+ diameter...    -Jörö-

Kostas1

If you start building one,
i'll definately follow your build! [8D]

JÖRÖ

Ok,
just cutted some parts. loosely fitted on Bates plans, so you can see the differences. pic retracted and lowered. Legs will be made from carbon fiber. Bates plans are great for looking for dimensions.
Movement will be with screw and electrical motor. -Jörö-

JÖRÖ

Few words about materials. Main struts where axels will be are 25mmx1,5mm steel, very hard. Slide rails are 12mmx2mm steel, unbreakable i think. All links are iron/steel.  Pushrods are 10mmx1mm alloy (inside those will be epoxied carbon rods).Rail holders and slider are alloy. Holders will be supported 3mm steel angles. And all cunstruc tion will be supported to fuse with ply. Axels will be 8mm steel.
Actuator screw is 300mmx10mm steel. Elecrical motor will be 300-400watts. Should be enough.  Any comments and questions are most welcome. -J-
 

JÖRÖ

Ou, and the rails will be angled 10 degrees like the legs are to forward. This sholud give better operation and more room for rails in fuse. Not much but just enough.   suspensions is still under brain work. Tomorrow i propably go to buy 12mm ply for former/main spar. easier to work, when its mounted properly. -J.

JÖRÖ

Here pics from real mechanism which have problems in real plane and in models also. Its very sensitive for adjusting. And electrical option with screw. These pics are from old rcgroups thread.
-J-

JÖRÖ

JÖRÖ

Going to make shuttle or slider bit wider. Gives more room for motor. I made test with one motor and its too power full!!! I think the force was hundrets of kgs, would break everything.. need to look bit weaker and faster spinning motor. Testing testing.
Sorry bad english.

Experten109/40

My Feedback: (-1)

very nice approach to the problem. you have the skills to pay the bills my friend (erittäin mukava lähestymistavan ongelmaan. Sinulla on taidot maksaa laskuja ystäväni).

JÖRÖ

Shuttle is now wider and there is just enough room for motor. it wasnt easy. there is now about 5-6mm (1/4 or 1/5 inch) extra space for motor.
So problem number one solved. next i need to silver solder screw to motor shaft connector. when thats functional, between shuttle and oleo struts adding pcs of spring steel, that should flex some in hard landings + plus soft air wheels. Estimated 3inch cushioning after that it hits to mechanism and wings.  will see how everything works. -J-

carlbecker

My Feedback: (3)

Here is another top view from the Kagero book. I don't know what Jerry used for documentation and I am not sure where you found the error in the cowl. Would you show us a picture?

JÖRÖ

Here the error.

JÖRÖ

And no plans tell the shape of canopy correctly. Its much more streamlined and bulged than any plans shows. need to shape plug for canopy and cowl with time and patience.
-Jörö-

perttime

In some of the old pics (posted on the first page) the cowl looks pretty straight. Maybe they were not all the same? BW 372 is also a recovered wreck. How accurate are its dimensions after being restored to a "stabilized wreck"?

JÖRÖ

When looking wartime pictures, those curvatures looks like to be same. Its easily seen from the shine, its not straight. Looks like the curvature starts from the screw line. If it would be straight, shine should look totally different. Hope my english isnt so bad. Studing pictures from those 2 books is helpful. Its not huge curvature but its there... Maybe im too anal.. -J-

JÖRÖ

In this picture curvature is clearly visible.

JÖRÖ

Look the canopy, how much its bubble shaped behind front frame. This changes the looks of plane to much ''streamlined'' to my eye.
 

perttime

Or is it more curved near the top and less near the bottom?

carlbecker

My Feedback: (3)

I don't think you are being to anal. Any good discussion on plans can help all. It all depends on what you are trying to do. If it is competition than you will have to follow a three view and certain pictures. If it is to be a personal best scale then a real plane helps greatly. I will be buildiing a F2A-3 and will just have plans and pictures to go from.

Keep up the great work on a plane with great character and history!

JÖRÖ

Pertti, looks like it same at bottom and top. The plane in museum have panels bit ripped off from bottom side and its 'smiling' a bit, and so it looks more straight from there. But watching war time pics, it looks like to be same.

Carlbecker, dont know will i ever go to competition, just want her to be accurate for my own pleasure. Thats me, knowing its impossible to make plans the way it creates 100% scale model. Good photos and eye on real plane are important also.

These are pics from my composite spitfire in 1/8,4 scale. Trying my best.. Hoping the Brewster will be more accurate.

 

JÖRÖ

I might build it like a plug and molding it , havent decided yet.
here small spitty plug with real alloy on it .