template formula

never posted here before. but here's the question.

I just picked up an old Hot Stuff Single Fin Rabbit Bartholamew (sp.) Model

I'm guessing early 80's anyway. It has a shape like an old McCoy Lazor-zap.

The problem is the length I'm guessing is around 5'3"-5'4". Is there a formula

to expand the dimensions to increase the length to around 6'0" and keep the 

(Nose, Tail, Rocker ect.) in the same proportions as the original. Any help would be

greatly appreciated. Thanks!

Straight proportion.     Desired new length (72''), divided by existing length (64''), equals 1.125 % increase in dimensions.

Apply it to all measurements.    Not a perfect method, but gets you well ''in the ballpark.''

Thanks Bill, Question 2 How do you redraw the template with the new numbers?

Do figure the equation say for every 2" and just connect the dots?

I’m not sure direct scaling is what you are after. If you scale by the same amount on all axis, your 20" wide board becomes 22.5" wide and a 15" tail becomes a 16 7/8" one.

You might be better served by pumping the dims into BoardCAD and using that to scale it.

[quote="$1"]

Thanks Bill, Question 2 How do you redraw the template with the new numbers?

Do figure the equation say for every 2" and just connect the dots?

[/quote]

As stated, ''It's not a perfect method...''    You're going to do OK by increasing the width, and length, and using the template of the shorter board, (the desired curve), to draw the new outline.    The goal is to get the outline curve to ''flow'' in a smooth, clean line.    You may have to spread the nose and tail slightly, to capture a smooth flowing line.   But that's the goal.   To create the smooth line, not chase measurements, and try to connect dots.    I hope that is helpful.

take a straight on photo and i can make you something close and send via email if you’re interested.  I mean a template…i can send you a template via email.

 

Let me know.

Bizgravy, Thanks

Do you need one photo i.e. top view

Are you putting it in a shaping program, if so

would more photos help (rocker, rail profile, tail outline)

Speaking of tail outline, the board has a double bump

soft swallow but the tips of the swallow have been ground down

almost to the stringer. Will this cause a problem with the template design?

Thanks again for your replies, This is a great outlet for people like myself

to have access to people with such a wealth of knowledge.

no i’m not using a shaping program, but i can trace the outline of the board in Illustrator (i do all my templates in Illustrator) and send you a outline template.  Just take a photo of the board straight on leaning up against a wall.  Try to get it standing as straight up as possible.  I’ll take into consideration the ground-down swallow tips when creating the outline. 

Don’t forget a side view (rail on). You’re going to have to play with rocker and foil to scale this up.