Cupertino (oz14209)

 

Cupertino (oz14209) by Julian Beckett 2000 - plan thumbnail

About this Plan

Cupertino. Radio control sport aerobatic model for .15 engines.

Direct submission to Outerzone.

Update 12/1/2024: Added article, thanks to RFJ.

Quote: "Neat R/C aerobatic sports design, to suit .15 motors. Cupertino, by Julian Beckett.

After getting my fingers (and wallet) toasted badly with a couple of recent large scale projects, I needed something to restore the fun factor. Something which was inexpensive to construct, cheap to run and if set up correctly - a real handful!

I dredged the stands at the shows during the summer and couldn't turn anything up that lit the fuse, so to speak: everything was either too large or too expensive, so I got my drawing board revved up, sharpened my pencil (oh alright, mouse then!), and away we went.

I had an OS 15FP kicking around in the workshop: its last home had long since departed to that great hangar in the sky after a spot of finger trouble. That, allied to a Hitec micro receiver, a 600mAh NiMh pack and 4 servos (a mixture of JR 331s and Hitech HS81s) and we were in business.

At this point, I can see you're just about to flip through to the next article, muttering about mini servos, micro receivers, etc as being expensive. Rubbish, you've never had it so good! Around £35-40 for a quality receiver, about £15 each for the servos and a tenner for the battery. To put that into perspective, I spent nearly one hundred pounds covering a one-third scale aerobatic model with a polyester based film covering.

I toyed with some outlines on my Mac to begin with. It was quite literally guesswork. I've no idea about aerodynamics, whatsoever - but I have built an awful lot of models, so I guess I must have developed a feel for what looks right. Within a couple of hours I had an outline that pleased me. The wing section was arrived at by the same method: no fancy section plotting programs for me. I've named the section Ai0001 (Adobe illustrator No.1)!

The beauty of the computer is that you can scale your creation up or down, then print out a copy to get a real 'feel' for its physical size. I actually cut a profile model from foamboard, and that flies as well - just ask my two year old.

From here on in, I simply employed best modelling practice for the construction: D-box wing, balsa box fuselage with 1/44in. ply doublers, a rolled top decking and sheet tail surfaces etc. It couldn't be more simple, so let's begin.

Wing: A good starting point is to select your stock carefully. The ribs should be cut from light but firm C-grain 1/16 balsa. Mine were produced using the sandwich method.

I prefer to work with individual wing panels to avoid hangar rash in the workshop, joining them after assembly. To do this, I used a carefully sanded piece of hard trailing edge stock glued chord-wise between the panels, thus building-in the dihedral, before finishing off with a bandage of 2-3oz glass cloth.

The construction of the two piece wing follows a common sequence with the panels constructed right side up over the plan. Accurately pin down your basswood bottom spars and tack (with cyano) each rib in position. To build in a little washout, take a piece of trailing edge stock and pin it at an angle along the trailing edge marked on the plan, such that a twist can automatically be built into the wing by carefully pinning the rear of each rib to the trailing edge stock (see Figure 1 on plan). Add in the top spars and tack glue all with cyano when satisfied with alignment.

A firm length of 3/16 forms the false trailing edge on both panels. These are pinned to the rear of each rib and spot cyanoed - locking in the twist. Gently sand the false trailing edge flush with the ribs. The leading edges are cut from the same stock, but left slightly oversize in depth, to butt the leading edge sheeting against. Add the soft 16 leading and trailing edge sheeting carefully, so as not to disturb your carefully constructed washout..."

Supplementary file notes

Article.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction

Cupertino (oz14209) by Julian Beckett 2000 - model pic

Datafile:

Cupertino (oz14209) by Julian Beckett 2000 - pic 003.jpg
003.jpg

Do you have a photo you'd like to submit for this page? Then email admin@outerzone.co.uk

User comments

No comments yet for this plan. Got something to say about this one?
Add a comment

 

 
 

Download File(s):
 

Notes

* Credit field

The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.

Scaling

This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.

 

Terms of Use

© Outerzone, 2011-2024.

All content is free to download for personal use.

For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.

Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.