feeddacat

Hello,
For the first time I'm trying my hand at scratch building a plane and I've a question about the ribs. The plans say I have to cut 32 ribs. Shoot, I'm able to cut two objects that are very close to each other - match perfectly with a little bit of sanding, but 32 copies???

I was wondering if I took a block of balsa, cut it to the shape of the airfoil and then sliced it using a table saw. What kind of table saw blade would cut the balsa and not chew it to shreds?


if that doesn't seem practical, are there people out there that can build a set of wings for cheap? Just supplying the ribs cut would be a major help for me. My skills are modest - and my shop tools are mainly a roto zip, hand drill, hobby knives, sanding tools, scroll saw and various rulers/clamps etc.


Thanks,
Ed

vicman

My Feedback: (10)

I stack mine when I bandsaw them out, then drill two holes for 1/4 dowels and final sand to shape. I keep them in one block even while cutting the spar grooves. I assume you are doing a straight wing. It gets a little trickier for a tapered wing. For a taper you just do matching ribs in smaller stacks.

dr_wogz

My Feedback: (3)

Here's whatr some of us do:

Make a master template out of something hard, liek masonite. Somethign that won't get chewed up by a knife.

Cut them out, with the help of the template, one by one.. then stack them all together and sand them all the same.

or

Make two templates, each with two matching holes. These holes are important. One fore, one aft on teh rib. these are 'locating' holes and must be concentric to each other.

Cut a stack of 'blanks' (roughly teh shape / size you'll need for teh ribs)
stack all teh ribs together.

With a drill press, and one of teh templates, drill teh two holes through all teh blanks.

Attach the other template tot eh 'backside of teh stack (so you have a sandwich of two templates (outside) and a bunch of balsa in teh middle.) Usually threaded rods though the two 'locating' holes, adn secured with nuts Carve and sand to shape.

or

If the plane is popular enough / you have some extra $$, contact a 'kit cutter' and have them cut your parts. If it is a common / well known plan, they might have tegh CAD plans on file. Or, if you can supply the CAD plan, there would be a minimum 'set up' charge

Laser Lizzard is one.. and there are many more..

feeddacat

Thanks for the replies. Money, don't have much of that! So, I'll try what each of you have said.

Thanks again for the advise.


Ed

feeddacat

Thanks for the replies. Money, don't have much of that! So, I'll try what each of you have said.

Thanks again for the advise.


Ed

blw

My Feedback: (3)

A friend of mine did the bandsaw technique for a batch of ribs. He said it worked out very well. He learned it from his father.

Bax

My Feedback: (11)

One way for tapered wings is to copy all of the rib templates at a copy shop, like Kinko's. Then cut them out, but stay about 1/8" outside of the lines. Since you need two of each rib, use 3M's temporary adhesive to glue two sheets of balsa together. Now use the temp adhesive to glue the templates to the balsa. Rough cut them on the bandsaw/scroll saw. Now final cut them close with the scroll saw. Use a sanding disc/belt to take them down to the final outline. Leave about 1/2 of the line on the plans. Peel off the paper templates. Separate the balsa. You can clean off any adhesive residue with lighter fluid (naphtha).

Since many plans are hand-drawn, the ribs won't be exact. When you build the wing, trim them for proper length fore and aft of the spar...use the spar as the reference. Use a long sanding bar to even up all of the ribs to the proper curve and taper. Some may wind up thicker than others. Then you sheet.

bax

vicman

My Feedback: (10)

Bax, I didn't say but that is exactly how I do mine.

toy264

I've used the bandsaw method and it was quick and easy. I clamped a ruler to the table 1/16th of an inch from the blade to act as a guide and make sure all the ribs were the same thickness.
John