By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Avoid Building a Banana!!!

straight fuselage sides

All Topics | Latest Posts

Search for:  in Thread Title in  
cymaz06/11/2012 06:08:28
avatar
8912 forum posts
1179 photos

I am just about to glue the fuselage sides to the main body of the superstructure. When I glue the tail end together how do get both fuselage side straight and true and not end up with a bananasad rose???????

This is for my Precedent Stampe build. Thanks

Greybeard06/11/2012 08:01:39
avatar
726 forum posts
6 photos

I would use my building jig or similar. I suppose that you could make something with some shelf brackets. A number of bananas - that are best forgotton - have shown me that this is the way to go.wink

Peter Miller06/11/2012 08:38:00
avatar
10511 forum posts
1246 photos
10 articles

Mark the centre of the bottom of each former . Draw a line along the bench and assemble over that aligning the marks to the line

Ernie06/11/2012 09:10:02
avatar
2517 forum posts
21 photos

Hi cymaz, i'd make a jig from mdf. cut around 6 accurate rectangles, say 150X100 mm. Cut them across the diagonal, and you have the basis of a decent jig. you need a flat building board, and a method of fixing them, but it's not rocket science. I made mine about ten years ago, and am using it as I write this

ernie

Danny Fenton06/11/2012 09:51:51
avatar
9314 forum posts
4125 photos

I am with Peter, build to a straight line drawn on the building board. Use engineers squares to project vertical lines as you go.

I never got on with the jigs.

Cheers

Danny

Tony Bennett06/11/2012 11:40:20
avatar
5081 forum posts
129 photos

Thats my method as well.

just a nice straight line on the bench.

Mike Etheridge 106/11/2012 12:30:16
1536 forum posts
429 photos

I feel I have to state the obvious here,----don't paint it yellow!

MJE

cymaz06/11/2012 13:38:35
avatar
8912 forum posts
1179 photos

The Stampe fus is too long for the building jig. I checked the superstructure and it is square on the diagonals. I will add the sides and glue only to the superstructure. Then clamp the tail end together. If I put a plumb line in the middle of the rear former and mark the middle of the rear post and stretch cotton between the two.

This will give me a striaght line from the front. I mark the fuselage sides down to the rear at equal intervals. If the fuselage is straight the measurement should be the same each side all the way down........

am I correct................would this workquestion

Danny Fenton06/11/2012 14:52:44
avatar
9314 forum posts
4125 photos

I would avoid doing it that way, if I understand you correctly. If the two sides bend differently (almost certainly will) then your plumb line will not be where you want. However forcing the sides in to be centred on your line should work. If thats what you in fact meant?

I would start by positioning over the centre line, bringing the sides together using the marked line and the line in the middle of the bulkheads/cross members that Peter mentions. As you get further back towards the tail, you may need more pressure on one side than the other. I don't clamp them together at the tail until the very end. If you have done it right they will meet perfectly...... thumbs up

Cheers

Danny

Keith Simmons06/11/2012 15:41:29
449 forum posts
9 photos

I always have my sides oversized and then cut to suit after fixing to the model. I found out to my cost never cut the sides beforehand as the wood has other ideas and gaps then appear. embarrassed. It depends on the model if a jig is required and you can do it this way.

Otherwise buld a Buccaneer. wink 2

Dylan Reynolds LaserCraft Services06/11/2012 16:13:20
avatar
1704 forum posts
661 photos

I found that with the Stampe, if the forward formers are true and square you can simply dry clamp the tail post together and it will be spot on, provinding both sides are identical, if they are not, when you centre the tail post the ends will not meet up exactly, i then checked the straightness of the sides with a 1 metre rulemounted onto 3 blocks, purely to check for straight lines, not squareness or central position, try it all dry first and if its all good, get the glupey glue out cheeky

My double check method was to get a 12" rule, tape this to the front former with 7" exactly sticking out, and measure from that point to the centre of the tail post, do the same for the other side and both measurements should be the same if it is in the correct position

ken anderson.06/11/2012 16:40:42
avatar
8523 forum posts
773 photos

a few year ago....i got an award at our AGM for my skills at building things slightly/a lot skew whiff......so if anyone wants any advice how not to do it....let me know...

ken anderson .....ne...1... skew whiff dept.....

Mike Etheridge 106/11/2012 17:02:17
1536 forum posts
429 photos

Many years ago (1961/2) I made a Southern Junior Models 'Southern Dragon'. Whoever designed this kit obviously thought about the 'banana issue' . A balsa 'crutch' was built first around the centre line of the fuselage looking on the plan view. Once the crutch was finished the bulkheads were added to the crutch and then the stringers etc to the bulkheads. A similar arrangement was designed for the polyhedral wing spar which was constructed first. I always thought that if I designed my own plane i would use the crutch method as it ensured there was no distortion. The Southern Dragon was only 42 inches span and was a free flight model. There was the usual warning about putting your name and address on the model which I ignored and hence lost it on it's first flight. The plane /plan is still available through Ben Buckle.

MJE

cymaz07/11/2012 06:10:11
avatar
8912 forum posts
1179 photos

There is always good old Pythagoras and his right angle therum, (that's not a vintage builddisgust). I will do both methods..bringing the tail together over a straight builing line then double check by measuring. The ruler never lies!!!

I have checked my string method and the measurements either side of this all the way down the fus were identicle each side.

I have one chance to get this right. Its more nerve wrecking than a maiden flight.

Dai Fledermaus23/11/2012 13:03:25
avatar
1041 forum posts
52 photos

I Jig

I thought some newbie’s to balsa bashing and born again types like me might be interested in my world patented anti banana jig wot I knocked up, sorry made this morning.

Using the old centre line method it’s an old IKEA shelf I’ve been saving for sometime and some wooden blocks faced with balsa which has been stuck on with double sided tape. The blocks themselves are also stuck in place with double sided tape – it didn’t need anything fancier in the way fixings than that. Just position the fuz over the centre line, position the blocks either side and stick down.

You might just be able to see that the nose is raised so that the tail can sit flat, square as well as centered on the line. Yes, it’s not pretty but it worked a treat

I don't think SLEC will loose any sleep.

cymaz23/11/2012 13:07:56
avatar
8912 forum posts
1179 photos

Good on yeryes

Reno Racer23/11/2012 14:34:54
avatar
1138 forum posts
168 photos

I would start by positioning over the centre line, bringing the sides together using the marked line and the line in the middle of the bulkheads/cross members that Peter mentions. As you get further back towards the tail, you may need more pressure on one side than the other. I don't clamp them together at the tail until the very end. If you have done it right they will meet perfectly...... thumbs up

I follow DF and PM's advice and use this method on all my builds. I've found one of the those cheapo DIY laser levels perfect for this, as they project a red striaght line beam down the centreline of the model (over your original drawn line) and this helps when bringing the tailpost together.

robert chamberlain23/03/2013 06:15:41
138 forum posts

I'm not quite sure what is meant by a "crutch". I've no doubt seen one used in building a fuselage, but have probably called it something else. Bob C

Mike Etheridge 123/03/2013 08:56:58
1536 forum posts
429 photos

Bob C,

just imagine a crutch you would use if you were disabled.You would have one under each armpit. Well the crutch used in the Southern Dragon fuselage construction looks exactly the same and would suit a disabled dwarf!

MJE

Mike Etheridge 123/03/2013 09:00:27
1536 forum posts
429 photos

Here it is Bob--Benbuckle can provide it ,my nephew has / had mine but I bet he has lost it ----can you see the crutch?

MJE

Southern Dragon - Click Image to Close

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Slec
CML
CADMA
Wings & Wheels 2019
electricwingman 2017
Cambridge Gliding Club
Sussex Model Centre
Sarik
Advertise With Us
Latest "For Sale" Ads
Do you use a throttle kill switch?
Q: This refers to electric-powered models but do you use a throttle kill switch?

 Yes
 No
 Sometimes
 Rarely

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us