# Downsizing?

Discussion in 'Low Power Rocketry (LPR)' started by Crashin J, Oct 29, 2002.

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1. Oct 29, 2002

### Crashin J

#### Member

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Way back many many moons ago like in the early 60's when I was a kid and didn't know any better. My first rocket was a Estes WAC Corpral. Now that you guys are getting me involved with the Micro MAXX movement, (thats alot ). I'd like to do a WAC Corpral but how do you go about downsizing something. I've never tried anything like this. Thanks for your input!

2. Oct 29, 2002

### sandman

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This is where you will wish you paid more attention in math class.

If you are going "downsize" divide the diameter of the new models body tube...let's just say it's 0.32" by the original models body tube size, which is 0.736".

You get 0.4348 (use a calculator or a slide rule hehe!)

http://www.dars.org/jimz/k-11.htm

Take all the dimesions from the original kit plans.

Now multiply every dimension that you will need (as you need it, not all at once) by 0.4348 or 0.44.

I don't know what size body tube you are going to use...I just made the 0.32" size up.

So...recap...divide a known "OLD" dimension by a known "NEW" (body tube you are gonna use) dimesion. THAT is your ratio number...DADAAAH!

It also works going up too!

sandman

3. Oct 29, 2002

### jflis

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another helpful way to do this, if you are creating your design on the computer (i use corel draw, but there are many tools that allow you to do scale drawings)

I select a model that I want to scale up or down and I draw it on the computer full size (no conversions or anything).

Then, when i am done (all my fin patterns are done and everything), THEN i do the math sandman calls out to find out what my scalling factor is (say, .44) and i go into the drawing tool, select the entire drawing and scale it.

done.

course, this only applies if you are using a computer drawing tool to create your design (yea, yea, i know, it's with yer slide rule... *S*)

4. Oct 29, 2002

### rstaff3

#### Oddroc-eteer

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A spreadsheet is a great tool for scaling. You can apply a variable factor to all the pertinent dimensions, and keep a nice record of them too!

5. Oct 29, 2002

### Austin

#### Guest

Hmmm, sometimes the easiest way is the hardest to see...

Here is what I am doing with the MicroMaxx Nike Hercules:

I simply found a graphic of it in Rocksim mode (from Wedge Oldham's website) , copied the picture to Word, resized it until it fit my tube sizes and then I printed it. I have been using this pic for all my fin templates, measurements, lengths and nosecone...NO MATH REQUIRED!!!

So there, the secrets out...I am either lazy or resourceful...maybe a bit of both, but if it works...

Carl

6. Oct 29, 2002

### jflis

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GAWD Carl !!!

you are just so resourc.... reso.....re...

man, just can't say it, ya lazy bum!

7. Oct 29, 2002

### rstaff3

#### Oddroc-eteer

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LOL! Yeah, that Carl sure is lazy. Never spends enough time and effort making his scale models looking like the real thing.

NOT

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