Author Topic: Balsa Nose doubler? (Read 3363 times)

Juan Valentin · « **on:** May 09, 2018, 04:44:23 PM »

I`m looking at a kit that came with 1/8 inch balsa sides and it came with 1/16 inch balsa doublers. The engine range is from a .60 to a .75 and I don`t feel sure about it. The plan would be to use a PA.61,which I know is a smooth running engine in this model but I feel that I should use 1/32 ply and would like advice now that I`m getting things together for a future build.

Juan

Air Ministry . · « **Reply #1 on:** May 09, 2018, 07:27:05 PM »

Ive seen them with that , maybe cross grain to sides . Bearers coinciding ( only the sides outside the bearers - doublers stop at them .0

Theory was it absorbed ST 60 Vibration Better . Thinking this over lately , thinking if the nose is FIBREGLASSED ( 3/4 Oz Cloth )
Thered be No Problem .

A lot of the Foam Wing Brigade were F Glass enthusiasts - Cloth at wing joint , wing to fuse ( sometimes in & out ) tailplane to fuse ,
Nose to maybe high point . Outdoors on the cowl . The Resin in the whole cowl / tank bay / engine compartment , of course .
And then theres the undercarrage - if fuselage mounted .

If theres a mag. article , or the Dsg'r did others , theyd be a insight . Or how ' that crowd ' went .

Think Essentially this is How Al's Models later go , as the curvey noses dont lend to doublers much .

Juan Valentin · « **Reply #2 on:** May 09, 2018, 10:28:11 PM »

Hello Matt
This airplane has flat sides and I was not thinking about fiberglassing which is something that I can do. The wood in the kit is excellent the laser work not as much. It will be my first big plane and first with a PA. I still have to decide about pipe or muffler.thank for replying. I`m also starting to work on my 1967 Triumph cafe racer. I did the fiberglass mold for the front fender out of balsa and plywood to look like a Dunstall fender. here are pics.
Juan

Avaiojet · « **Reply #3 on:** May 10, 2018, 03:36:01 PM »

Juan,

I would use the 1/16" ply doublers.

However, I would place 5/8" or 3/4" holes, or smaller, here and there staying away from the area where the rails will be placed.

Charles

RandySmith · « **Reply #4 on:** May 10, 2018, 04:45:10 PM »

Quote from: Juan Valentin on May 09, 2018, 04:44:23 PM

I`m looking at a kit that came with 1/8 inch balsa sides and it came with 1/16 inch balsa doublers. The engine range is from a .60 to a .75 and I don`t feel sure about it. The plan would be to use a PA.61,which I know is a smooth running engine in this model but I feel that I should use 1/32 ply and would like advice now that I`m getting things together for a future build.

Juan

Hi Juan
I developed my technique , of balsa sides balsa doubler with .5 CF mat in between them back in the 1980s , 1/8 inch sides, 1/8 inch doublers, epoxy the .5 cf mat in between makes for a very strong vibration absorbing fuse, and is stiffer than the thin ply plus has a larger edge for the cowling to st on, makes the cowling fit stay better. People have built over 2500 of my planes with this system. ALL of my planes since 1987 have been built this way, no problems
I do not know about 1/16 balsa sides, I would cut new ones out of 1/8 but there is NO problem wth that construction, and as far as I am concerned, it has proven superior

Randy

Juan Valentin · « **Reply #5 on:** May 10, 2018, 05:00:15 PM »

Hello Randy and Charles
Thanks for the advice to you both, I like Randy`s idea that way I will be able to shape the nose better, I know I bought some carbon fiber from you but will have to check what I have.
Juan

Air Ministry . · « **Reply #6 on:** May 10, 2018, 10:11:49 PM »

Quote

1967 Triumph cafe racer.

WELL ! It Should Have THE RIGHT CRANK , ANYWAY .! ( ' pear shape flanks ' , good for GO ( is the ' Thruxton ' item . ))

Was about to mention the carbon veil trip , been beaten to it . .

Use the Norvil / W&S Valve Springs ( From Yam TX 750/550 kit , two for the pice of one , shims caps collets & all .
DO THE SLUDGE TRAP . !!!!!!!!!!!!!!!!!!!!!!!!!!!!! magnaflux the crank . Ball races are FASTER .
68 swing arms stiffer .

11 3/4 pipes , ininya havnt gottem yet , Trim at top fr. to come in tight under ( 1956 headers ) .
Youll need some lead in the front to keep the front down .

Enough of these silly model aeroplanes .

This isnt me , its ' John the Hippie ' , On the way to roll Bob Dylan

in 79 or 80 . ' Sweet Spot ' was 90 mph that day .
A few miles back we'd done a full clamps pull up from 60 to 5 mph , right over left , for a logging truck on the hill .
No Dramas . Second time He'd been on a sickle . Painted his blue helmet black , to suit .

Note the Chain Guard .

If he turned around youd see the black streak ( chain oil ) up his left side .
( actually , looking at His Left Arm , there

)
He mustve sat nice & straight .

Thatd run to 8.100 regularly , with the pipes 271/2 inch , valve float at 8500 in top , Terrys Valve Spings .

Did have the best head on the planet at that time . Many Stories there . You Need a Pre- Unit .

Gutless Wonder. 16.9 @ 80 mph . Couldve Walked Faster . Sounded good tho , 10:1 pistons . A complete miss match .

Note the latest in saftey equipmet . Did have a Bell Star , somewhere .

1981 . inaugural C M R C .

Juan Valentin · « **Reply #7 on:** May 11, 2018, 04:33:27 PM »

Hello Matt
I have been working on this bike for a while,done the header, mini Daytona tail, oil tank and other stuff. Being an aircraft modeler has helped a lot when it has come time to design a part for it. It will be a while before I finish as I work on it a little everyday. Engine is a 650 bumped to 750 with an aluminum billet cylinder,forged pistons,Steel racing con rods,Megacycle cams,Mikunis and a digital ignition by pazon. The crank was magnafluxed and balanced with rods and pistons. I have A whole bunch of new parts. Thanks for posting the photos of the bikes. I have read about Burt Munro and saw the movie,he was a very special kind of guy. Here is a pic at the begining of my project.
Juan

Balsa Butcher · « **Reply #8 on:** May 11, 2018, 04:49:38 PM »

I have made a couple of models using Randy's technique. Follow his instructions and you will have nothing to worry about. Nice bike BTW.

Juan Valentin · « **Reply #9 on:** May 11, 2018, 06:03:32 PM »

I will go with Randys advice,I have the .5 carbon mat. This airplane will be my first try at a big engine and I don`t want to make mistakes. I got some epoxy that I guy I know uses to make carbon fiber paddle boards which is very stiff when cured. I thinking to give it a try,is a 2 to 1 mix. I will be calling on him when I decide to mix it to make sure I don`t mess up.
Juan

Air Ministry . · « **Reply #10 on:** May 11, 2018, 07:14:11 PM »

IF YOU BLOKES WOULD JUST STICK TO THE SUBJECT .

Very Clean Machine, Juan .

This is the Mead & Tompkinson BSA B 50 . A friend worked in a brake shop , had a 72 Lightning & a 62? Humber 80 .
Guess What . The Brake Shoes are THE SAME ! ( Now you Know ). Might be tidyer with internal hydraulics .

Not that the std brake isnt to bad , if its a single run outer cable ( no stop light switch etc ). Also theres longer arm actuators,
cable further from axis , but they fleece you blind . Thus the ' Barcelona ' set up is worth a look.

Hydraulic master cylinder , obviously . Tho some would use the old BMW type cable to master cyl. under seat , for appearances sake .

Juan Valentin · « **Reply #11 on:** May 11, 2018, 09:50:02 PM »

Hello Matt
That is a very interesting set up. would love to see the insides. I will be using conicals with Takasago shouldered Excel Rims. Please send me a PM with your Email. Here are pics of my brakes. I powder coated the rear drum black but I`m thinking about redoing it in silver. I did the vent covers out of 6061 aluminum and used S/S mesh.
Juan

Perry Rose · « **Reply #12 on:** May 13, 2018, 02:56:04 PM »

Juan Valentin · « **Reply #13 on:** May 16, 2018, 11:02:36 AM »

I went ahead and laminated the nose doublers with .5 carbon mat. I drilled holes in the fuse side balsa and doublers together and then glued tooth picks to the fuse side with CA to keep everything aligned when I place weights to make sure all parts bond well and wont slide when the weight is placed. I placed carbon mat under the doubler and using it as a guide I punched holes on the mat with a tooth pick,I enlarged them a little so the mat would slide easy over the tooth picks. I applied epoxy to the fuse sides and slid the carbon mat,applied epoxy to the doubler and using the tooth picks I guided them in. I made sure I had good alignment and using a side cutter I cut the tooth picks flush with the balsa. I always label the parts to make sure I don`t end up with two left sides. Then I applied weights to keep everything straight and make sure all the parts made good contact. Now all I have to do is wait for the slow epoxy to cure. here are pics.
juan

Juan Valentin · « **Reply #14 on:** May 18, 2018, 10:52:52 PM »

Hello Ty
Thanks for posting the photos and keep them coming. I`m working on the fuse every time I have a chance. Can`t find the part that goes on top of F3T will have to improvise that and instrument panel also.
Juan

Juan Valentin · « **Reply #15 on:** May 19, 2018, 06:21:44 PM »

Hello Ty
In this picture I drew two arrows of what I feel are missing in the kit. the F3T I got was a square piece that ended flush with the fuse sides. F2 has a top that sticks out from the fuse sides and has a trapezoidal shape. F3T should had the same shape to provide support to the 1/4 inch balsa pieces for the top of the nose. below the front end of the canopy a bulkhead or instrument panel is shown on the drawing. I just will go ahead and make them for my fuse. I just thought I was missing those parts but is just that they were not included.
Juan

Juan Valentin · « **Reply #16 on:** May 20, 2018, 02:33:41 PM »

Hello Ty
Thanks for the heads up about the wing and L/G will keep it in mind when I build the wing. I will have to cut into the carbon fiber mat to install the wing. bummer.
juan

RandySmith · « **Reply #17 on:** May 20, 2018, 03:39:46 PM »

Quote from: Juan Valentin on May 20, 2018, 02:33:41 PM

Hello Ty
Thanks for the heads up about the wing and L/G will keep it in mind when I build the wing. I will have to cut into the carbon fiber mat to install the wing. bummer.
juan

Hi Juan
You should try cutting the clearing out first before you epoxy the doublers, on ALL my laser cut kits the wing cutout is done in both the Fuse side and in the doubler, I put a thin layer of epoxy on both sdes, then sandwich the CF mat, at that point the fuse side is taped to a piece of glass, the doubler is put on and set perfectly straight, the epoxy will hold it in place or you can tape it down, then I lay a second piece of glass on top, then I look to make sure it is all straight, at that point I add weights on top. I also use this same technique to sheet foam wings

Randy

Juan Valentin · « **Reply #18 on:** May 20, 2018, 09:08:29 PM »

Hello Randy
Thanks for the advice, I was planning on sliding the wing in place thru the sides and since this kit lacks instructions I was not aware that I would have to cut the bottom so I installed the carbon mat all the way to where I thought the spar would be. I`m planning on doing a long diagonal cut in the bottom rear and cutting as close as I can to the spar at the front then I will slide wing in place and use carbon mat and balsa to reinforce the area.
Juan

john e. holliday · « **Reply #19 on:** May 21, 2018, 11:07:22 AM »

Don't forget to insert control horn as you slide the wing in place. Don't ask me how I know about this.

Juan Valentin · « **Reply #20 on:** May 21, 2018, 06:46:26 PM »

Hello John
I will make a note so I don`t forget.
Juan