Shaping the leading edge

When it came time to shape the leading edge of my latest project I wanted to do a real good job. That`s when I decided to make a sanding form to do the job and make my life easier. I took two pieces of 1/2 inch plywood one 2 by 6 inch and the other 1.5 by 6 inch and made a right angle then I glued a piece of 3/4 inch triangular stock balsa at the bottom of the Vee.You could use 1/2 inch triangle stock. Using a piece of 1 inch plastic pipe and sandpaper I sanded a radius but it looked too wide. So I sanded some more with a 5/8 dowel and got the radius I wanted for my leading edge. I cut a piece 1 by 6 inch of self adhesive 100 grit sand paper and placed it in the center. At the edge of the sand paper I used 8 layers of 3/4 masking tape on both sides. The idea is that you don`t want to use the form without the masking tape or you will sand a step in the leading edge.Get it looking close to what you want and Then you change the sandpaper to 320 grit and finish.
The masking tape will allow you to feather the leading edge to the top or bottom balsa skins without problem.Hope this is helpful to new guys and retreads like me.Here are some pics.
Juan

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Nice job. Thanks for sharing.

BTW - if you want to bring your nifty tool over to my house and sand my wing, send me a PM and I'll give you directions.

Hello Ron
I would be glad to help you.All I need is a round trip ticket and I would go to your shop and do the sanding.
Juan

Juan
That is such a cool idea to a problem I have always had. I will build you sanding fixture for my next build. Thanks for sharing a really good idea.
Andy

That looks so much simpler than the tool I have for trying to make decent leading edges. I have one of the tools that has layers of hard paper between two hardwood peices. The problem is keeping the sandpaper glued to the form and as stated sanding a step in the leading edge. Thanks,
DOC Holliday

Thanks, Juan! The re-radius with the 5/8" tubing was a good fix!

Th masking tape around the edges is fundamentally and directionally
brilliant.

This is the solution for my Ringmaster leading edges. At last!

Great idea! ...and the masking tape prevents you from scoring the sheeting.
I have one of the Great Planes alum. forms and "One size does NOT fit all".

Nice Idea JV. Does anyone have a suggestion as to how I can accurately sand an I-beamer L.E. that has a constant height for about half its length and then tapers in height toward the tip? Freehand is the only thing I can think of at the moment for the tapered part. Thanks in advance for any advice shared.

Hi Dennis

There is daylight under the right hand side of Juan's tool in the first pic so it should work on your tapered sections. Just go slowly and have a couple of templates of what you want to end with. In fact, after the way I flattened the LE on the first new wing I built some years ago, I make LE templates for all my wings.

Cheers, Geoff

This tool is good, but I much prefer the one you can see here:

http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=82513&mesg_id=82513&listing_type=search#82520

Simply go to post N.9 and open the file.

Dan

Hello Eggy
Other than building some type of bridge work to go over your ribs and guide the sanding form to avoid hitting them I have no Idea.I was thinking that somebody could come out with a lost foam method to keep all ribs aligned and provide support while sanding.It would really make life easier for guys building I beamers.

Juan

Many Thanks, Juan. I made mine last night, and got to use it this morning. Now my LE is like it is supposed to be. Free hand just doesn't cut it. Again, thanks for the idea..

PS, I to have one of those aluminum tools. It never seems to fit my LE. Must have been for RC planes, before they all became ARFS [photo not recovered: sipcof.gif]

I`m glad it worked for you Ty.I find it to be the best I found to shape the leading edge,by adding more strips of masking tape you are able to just hit the leading edge with very little sanding of the wing skins.The way I used really helped me blend the leading edge to the skins without having a flat after the edge. If you are sanding a wing with a smaller radius all you have to do is shape the balsa in the center of the vee to your desired radius and adjust amount of masking tape. the form could be made longer maybe a foot or more for better prescision but if it gets to heavy or bulky might not be as easy to control. I made all kinds of small sanding forms since they allow me to come out with a better finished product.

Juan

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Juan, you need to write an article for Flying Models, Stunt News and Controline World. In fact all three. These forms are a great way to make a good looking model a better looking model and thus a better flying one also

> When it came time to shape the leading edge of my latest
>project I wanted to do a real good job. That`s when I decided
>to make a sanding form to do the job and make my life easier.
>I took two pieces of 1/2 inch plywood one 2 by 6 inch and the
>other 1.5 by 6 inch and made a right angle then I glued a
>piece of 3/4 inch triangular stock balsa at the bottom of the
>Vee.You could use 1/2 inch triangle stock. Using a piece of 1
>inch plastic pipe and sandpaper I sanded a radius but it
>looked too wide. So I sanded some more with a 5/8 dowel and
>got the radius I wanted for my leading edge. I cut a piece 1
>by 6 inch of self adhesive 100 grit sand paper and placed it
>in the center. At the edge of the sand paper I used 8 layers
>of 3/4 masking tape on both sides. The idea is that you don`t
>want to use the form without the masking tape or you will sand
>a step in the leading edge.Get it looking close to what you
>want and Then you change the sandpaper to 320 grit and
>finish.
> The masking tape will allow you to feather the leading
>edge to the top or bottom balsa skins without problem.Hope
>this is helpful to new guys and retreads like me.Here are some
>pics.
> Juan
>
Juan- Thank you for shareing this handy tool information with all of us. I have been doing model building for more years than I care to post and have a lot of home-made tools. This is one I too can use that will cut building time down. We are never too old to learn.....