Finding the right leading edge - retail grumble

[Biggles' Elder Brother - Moderator]

Don't wish to "gang up on you" Simon - but Peter's got a point. For ages I didn't even know you could buy preshaped le - and when I found out I could really see the point because it was never going fit perfectly and you'll end up sanding it anyway!

 

As someone has said the trick is - take your time. Tust to the old "mark one eyeball" - you would be amazed how small a error you can detect if you look hard. It honestly isn't that hard to do. Start with chamfer on each side (bit more on the top than the bottom) then round it off, always rubbing along the length - never chordwise. Just remember you can always take a bit more off but its a bit tricky to put it back on!

 

You'll be amazed at the result - and very pleased with yourself!

 

BEB

[Simon B]

 Messing up a couple of pieces through practice shaping can end up costing more than buying shaped edge.  Anyway, I can't find what I want, so this is most likely going to have to be the route i'm going down.

[Simon B]

By the way, KC, like the idea.  Looks good.

[Biggles' Elder Brother - Moderator]

Posted by Simon B on 07/01/2011 22:26:57:
 Messing up a couple of pieces through practice shaping can end up costing more than buying shaped edge.  Anyway, I can't find what I want, so this is most likely going to have to be the route i'm going down.

 

Ah - but you'll save in the long run not having to buy pre-shaped le

 

BEB

[Augusto]

Hi Simon,

 

You' ld be amazed about how many between us are modellers in a budget man

 

Peter and BEB are very right. 50 years ago we had no money for nothing, We needed to invent our own toys and their accessories, enven the fuel for those diesel engines was made in the back-yard - the paraffin was from candle scraps and the ether was stoled from mum's home pharmacy. Etc...etc... etc!

 

Even today I still use to make a lot of accessories; for instance for the Luton Minor I'm building I made all the bellcranks using scraps of ply:

 

and for the push-rods:

 

BBQ sicks, rests of 14 swg piano wire, tissue scraps from an old shirt and cyano.

 

You can be sure she'll fly (and may be crashed too!) but was made by me! Nowadays there are other fields where it's good to waste more many like Electonics (Radio gear and servos) to intent avoiding the lost of the models.

 

So Simon take the job in your hands and in the end, as BEB said, you'll be amazed with your skills and proud with the resulte.

 

Augusto

 

 

 

 

 

 

[Augusto]

Posted by Simon B on 07/01/2011 22:30:32:
By the way, KC, like the idea.  Looks good.

 

 Whoooo! Glad to hear that from you mate

 

Augusto

 

 

[Alan Cantwell]

razor plane, razor saws, sandpaper, block of wood, 12" ruler, balsa knife, 2 blades, an oilstone, (to sharpen the blades)  box of pins, and all you need is practise,      L.E. section is just roughed out wood,  it never, as has been said, fits your application,  go cover the floor in shavings, and have FUN

[kc]

To be sure you can make the LE with minimum wastage use  the LE shape on the plan and draw on a 1/8 line, then another and so on until you fill the shape.  Then you know the exact widths of pieces that will produce the shape with just a little planing or sanding.  To shape it is handy to attach balsa to a firm base such as the edge of melamine coated chipboard using small pices of double sided Sellotape. Same applies to making trailing edge etc ( saves planing your fingers! )

Lots of real budget aeromodelling in Peter Miller's  books such as High Flying on a Low Budget and Peter Holland's Model Aeroplane Building Sketch by Sketch. Reserve them from your library ( and you will want to buy them later when you are in funds.)

 

 

Edited By kc on 08/01/2011 12:47:55

[Martin Harris - Moderator]

Simon,

 

I'm wondering if you're trying to shape the profile before building the wing?

 

That would be tricky to do accurately...

 

I don't know how the others do it but 'd guess, like me, they would build the wing with appropriate plain strip and plane and sand it in situ - mark a straight line at the most forward projection and smoothly blend to this, finishing that part last to get an even profile.  If you're on a budget, get yourself a balsa stripper and cut your own strips from sheet - buying them pre-cut is a VERY expensive way. For instance, from a randomly selected supplier, a sheet of 1/2 x 3 is £2.42 and a single strip of 1/2 x 1/2 is 75p (L.E. is £1.65) so you could cut 6 strips at a cost of @40p each so a balsa stripper like this (my favourite type) would soon pay for itself - as well as giving you any size you need without delays or wasting petrol or postage!

 

P.S. Don't pay too much attention to the 1/4 inch sheet mentioned in the link - 1/2" is 1/4" from both sides but I'm sure it cuts deeper than this anyway and on thicker sheet still it starts the cut beautifully for finishing with a knife and straight edge.

 

P.P.S. Just checked mine and it goes out to almost 13/16 width and will cut as deep as I can set a scalpel blade - maybe 3/4" although I'd make several cuts for this depth... 

Edited By Martin Harris on 08/01/2011 23:43:39

[Former Member]

[This posting has been removed]

[Simon B]

It's a parallel chord.

 

I'm aware of what the older generation had to do.  My dad is 68 and he did all that back in the day, but he said he'd never want to go back to it and positively welcomes the advances that simplify modelling!

[kiwi g]

Deep fried mars bars , you guys got some strange habits

[Peter Miller]

I believe that deep fried Mars Bars were created by a race whose idea of a delicacy is a sheep's stomach filled with bits of unmentionable offal and anything has to be better than that.

[Peter Miller]

Simon B

 

I bet your dad doesn't moan about not being able to get the exact shape of leading edge that he needs.

[Mowerman]

When I were a lad I got cheesed off with people who kept telling me about when they 'were a lad'

[Pat (rActive) Harbord]

Simon B - Have a go with strip. As Martin says, shape the strip in situ with a guide line drawn centrally along the length of the wing. Getting it into rough shape with a razor lane will only take a couple of minutes. Then switch to sand paper to get to final shape (you will have to do this with preformed l/e anyway to perfectly match the profile of your wing).

 

 

I find shaping leading and traiing edges very satisfying (but then again I like carving propellers for rubber powered free flight models)

[Simon B]

Peter, actually he's found this very frustrating.  He hates shaping leading edge.  Why do I feel like i've done something wrong here? I apologise if my lack of confidence in my abilities has offended.  All i started this thread to do was to find somewhere to buy some leading edge

Edited By Simon B on 09/01/2011 11:29:38

[Simon B]

rActive, many thanks.  I'll give that a go. Thanks to all for the advice

Edited By Simon B on 09/01/2011 11:36:29

[Peter Miller]

You haven't done anything wrong.

 

It is just people are trying to persuade you that trying to find exactly the right shape of L.E. is hopeless and that learning to shape your own is A) cheaper and B) will give you one more skill that will make you a better aeromodeller.

 

It doesn't matter how old we are, we are all still learning new techniques and ideas and shortcuts. Anyone who says that they can't learn any more is an idiot.

 

And, Mowerman, the funny thing is that very often those old ideas get forgotten and one of those "When I were a Lad" types reminds us of brilliant ideas that had been forgotten so don't knock them.

 

And, talking of old ideas and razor planes. Back in those days we used Blue Gillette razor blades in our razor planes because they stayed sharper longer and didn't bend whne we hit a bit of harder wood.

 

You can still find Blue Gillette blades on Ebay. they work a treat in my razor planes and a friend who builds indoor models said that they were the perfect blades for his work. I gave him one of my spare packets.

[Erfolg]

Simon

 

I am offended by your and my lack of skill

 

I know many ways have been suggested.

 

I still think the easiest and quickest the method is the old stunter, combat method.

 

That is a square section turned on edge. It is then a simple process of knocking of the top edge, that becomes the LE. The other two corners to blend into the airfoil contours, or sheeting. Dead simple, as the attached picture, the model built with little skill, care or cost. (less of the agreement and abusive comments please).

 

 

[Simon B]

That's perfect.  Annoyingly though i'm building the Dorschell Kyten and the ribs are pre-cut and i've assembled the rest of the wing now.  Annoyingly also it's a tapered wing, so it would make putting the cut out in harder.

[Erfolg]

I am just started the finishing process, that is painting on a Ta 152H. This wing has quite a taper.

 

Again as has been suggested, it is not as difficult as you may think.

 

In this case i have a false LE, I think PM has advocated this in the past. Onto that is then stuck the real LE, This has the correct plan taper, and an approx right tapers on the front elevation.

 

There after it is just as others have written, it is a case of marking out part shaping, then repeating until finished. Simples. It is all about patience, methodology and slow but steady work. It cannot adequately be done in a single step.

 

[Former Member]

[This posting has been removed]

[Peter Miller]

I am now extremely puzzled.

 

I looked up the Dorschell Kyten  and find that it is a Greenair Designs full kit  (with extremely tapered wings.)

 

If it is the full kit why didn't it come with leading edges?

[Biggles' Elder Brother - Moderator]

Posted by Erfolg on 09/01/2011 13:45:12:

 

 

 

Erfolg - where you clinging to the light fitting on the ceiling when you took this photo?

 

BEB

Edited By Biggles' Elder Brother - Moderator on 09/01/2011 18:37:04