up scale work

[bobby_hamill]

About 2 years ago I took Estes version of the Century Payloader 2 and did an 4 inch diameter up scale with open rocket .
Last night just killing some time with open rocket I did some touch up on the Estes Payloader 2 and did some work
with photo studio function in open rocket .

Here are the results . It will be using 38mm motors and a J 825 redline gave results of 3465 feet apogee .
The "green" section represents the Clear Butyrate tube that is 16.5 inches long and 4 inch outside diameter with a
wall of .062 and an inside diameter of 3.875 inches .

One of these days I will actually get around to building this upscale

Enjoy the photo shot from open rocket

Bobby

 

[Pinetree]

Better get building.

 

[ep29030]

We need build photos, not simulations!

 

[ljwilley]

We need build photos, not simulations!

+1

 

[bjphoenix]

I like doing up-scales and down-scales.
This year I downscaled the best version of the Centuri Aero-Dart to BT-60, the Centuri Javelin to BT-55, the Estes Sprint to BT-55, the Madcow Frenzy to BT-55 and the Wildman Darkstar to BT-60.
If I can find a Rocksim or OpenRocket file I can draw the rocket in CAD and then scale it up or down to the target dimension. If I can find a good photo of the rocket I can pull it into CAD and trace around it, then scale it up or down. I have a couple more ideas for my next batch of builds.

 

[bobby_hamill]

@ bjphoenix

If I am not mistaken open rocket allows you to scale up or down .
By using the outside diameter of the airframe you have and the outside diameter
of the airframe you want open rocket will scale it up or down.

Using Solidworks CAD program you can import a photo and if one measurement is known in
the photo you can trace around the photo and it will give you other measurements
relative to the first measurement.

 

[Hobie1dog]

@ bjphoenix

If I am not mistaken open rocket allows you to scale up or down .
By using the outside diameter of the airframe you have and the outside diameter
of the airframe you want open rocket will scale it up or down.

Using Solidworks CAD program you can import a photo and if one measurement is known in
the photo you can trace around the photo and it will give you other measurements
relative to the first measurement.

I'd like to know how that is done.

 

[bobby_hamill]

@Hobie1dog

ok let me give some details

first of all write down the inside diameter, wall thickness and outside diameter of the rocket present state
second do the same thing but for the airframe measurements you want to upscale to.

When you have done this open the present model up in openrocket and click on the "edit" option and then click on the "scale"
drop-down function . In the scale design box click on entire rocket and on mass and offsets

In the scale design box scale from is the outside diameter of the present airframe in the model, do not change it !

on the other side of scale from is to and change this number to match the outside diameter of the airframe you want to upscale to.
in my case it is a 4 inch tube so I enter 4.024 in the block

then in the scale design box I click on "scale"

Presto your model has been up-scaled from a model with a airframe of 1.17 outside diameter to a 4.024 outside diameter
Now if I click on edit the old 1.17 airframe it will now show the airframe is a 4.024 outside diameter or 4 inch !
the total length of the model changed from 27.934 inches to 96.074 inches

even the fin pattern has been up-scaled

see attached images to help in the description

Hope this is not confusing

Bobby

 

[bjphoenix]

When you have done this open the present model up in openrocket and click on the "edit" option and then click on the "scale"

That's pretty neat, I'll have to try it.
It won't help for designs that I base on photos, I can't find sim files for everything.

 

[OzHybrid]

@Hobie1dog

ok let me give some details

first of all write down the inside diameter, wall thickness and outside diameter of the rocket present state
second do the same thing but for the airframe measurements you want to upscale to.

When you have done this open the present model up in openrocket and click on the "edit" option and then click on the "scale"
drop-down function . In the scale design box click on entire rocket and on mass and offsets

In the scale design box scale from is the outside diameter of the present airframe in the model, do not change it !

on the other side of scale from is to and change this number to match the outside diameter of the airframe you want to upscale to.
in my case it is a 4 inch tube so I enter 4.024 in the block

then in the scale design box I click on "scale"

Presto your model has been up-scaled from a model with a airframe of 1.17 outside diameter to a 4.024 outside diameter
Now if I click on edit the old 1.17 airframe it will now show the airframe is a 4.024 outside diameter or 4 inch !
the total length of the model changed from 27.934 inches to 96.074 inches

even the fin pattern has been up-scaled

see attached images to help in the description

Hope this is not confusing

BobbyView attachment 593210View attachment 593211View attachment 593212View attachment 593213

BEFORE YOU SCALE IT. Save the file as the new name.......

AFTER you scale it, you need to go through all of your components and make sure the materials and thicknesses match the real world values you will use. For example an 1/8" wall thickness cardboard tube would become a 3/8" wall thickness if you scaled it 3:1. But that's not what it would be in the real world. Same for bulkheads, nosecone wall thickness, fin thickness etc
Norm

 

[JohnCoker]

I also have this tool to help up/down scale to available tubing:
http://www.jcrocket.com/upscale-calculator.shtml
And a related tool to find available tubing for a scratch scale project:
http://www.jcrocket.com/scale-spreadsheet.shtml

 

[bobby_hamill]

Thanks guys for pointing that out to me