The Rook

Hi all,
I have a Sportster Bipe .40 kit that I am about to start building. These are getting so rare these days, that I knew that if I ever had a total loss, I would scratch build another one as (more than likely) my first scratch building project. I had always wished Great Planes had made a sportster bipe .60, but never made the connection until a friend said, "hey, you should enlarge the plans and make a .60 size!"....sometimes I'm not the sharpest pencil in the drawer...

Anyway, I was looking for advice on what would be the best way to go about this. I would like to take the necessary steps NOW for a future scratch enlarging of this kit before I start building it. Should I trace all the pieces on paper, and then have those AND the plans enlarged to a sixty size?
Or is that too much trouble, and I should just enlarge the plans and trace from there? That same friend has a Super Sportster .60 kit waiting to be built, so I would just reference that as a guide to sizing of spars, stringers, rib and fuse width, etc. I've built the SS .20 and SS .40 monoplanes, and they use the same manual as the sixty. Almost all pieces are the same width/diameter unless otherwise noted. This, and the rather small enlarging (.40 to .60 size) should make for a good introduction to scratch building (although bipes probably aren't the best first timers).

Or....should I be daring and enlarge to a .90/1.20 size??!!!!

Also, how do I pursue getting a canopy and wheel pants, as I'm sure great planes is long since out of .60 parts? What is the best method for shaping cabanes/landing gear wires, etc. when scratch building? Are there companies that can do this for you?

Sorry for so many questions at once, and thank you in advance for the advice/help!

Lake Flyer

My Feedback: (13)

I scaled these plans up to 72". It came out way to big for my taste. At that size I suspect it would need a miminum 45-52 gas engine.

The Rook

Wow!
You did really scale that guy up! Have you flown her yet? I assume you built up the rudder and elevator? How did you form the cabanes?
I would love to see some pictures if you have any.
Thanks,
J

The Rook

I've heard a few options for enlarging plans, ie: Kinkos, blueprint place. My question is, ideally, what is the best (most accurate) method for enlarging plans? Does kinko's really do as good of a job as some of the posts I have read? I did read about distortion at the outer edges of the reproduction.
Thanks
J

BTW, I found the sportster .60 wheel pants and canopy on Tower's website. I guess that was too obvious of a place to look for me to even consider it!

batchelc

My Feedback: (7)

Well the best for scaling plans up os to draw the whole thing in CAD and then plot out full size plans. That way you can change the thicknesses of the formers, etc. When scaling up the wood sizes don't always scale the same. Making copies at Kinkos should work OK.

The Rook

Well I just got back from the blueprint place. The enlargements turned out great. I enlarged the Sportster Bipe 40 plans 112% to match the scale of the SS 40 to SS 60. I took the averages of about 8 measurement differences between the SS 40 and SS 60 and rounded up to get the 112%. The only one that was way out of wack was the difference in airfoil thickness (over 130% if I remember correctly). Obviously the airfoil is disproportionately thicker in the 60 - can anyone savvy with aerodynamics explain to me why this is?

Anyway, I traced the die cut parts from the bipe 40 kit onto rolled paper and had these enlarged with the plans. I also copied a set of SS 60 plans to use as a reference along side a set of SS 40 plans. This should give me a model to follow for enlarging the Bipe 40 to a 60 size. The total was just over $17, so not too bad at all. I'll post some pics of the build as I go along.

J

bmosinski

My Feedback: (6)

Man I have been looking to do the same thing and stumbled on this thread. Anyway to get a copy of your "Enlarged Plans" I would love to build this a long with you.

Thanks, Bob

Roguedog

I was thinking of using the Super Aeromaster wings on a Super Sportster 60 Fuse.

My Super Sportster 60 max wing thickness is 2-3/16". The Super Aeromaster max wing thickness is 1 1/4" across both top and bottom wings.
The Aeromaster also has 3 different wing variations.

1. 48' swept top - 48" straight bottom
2. 52.5" swept top - 48" straight bottom
3. 52.5" swept top - 52.5" swept bottom

I happen to have seen a Sportster Bipe plan (don't have one) and it seems very similar to the Aeromaster.

The Rook

Hey all,
Thanks for the interest. Unfortunately, right after I posted this, I got deployed and haven't touched my RC stuff in almost 2 years. It looks like it will be awhile before I will be able to get to this one