Trying to get parts for a 3x vector-v.The folks at Semroc say I'll need a 4" tube for the lower section ,I trust them more then I trust my math , and this throws all of my figures out of whack.The 2 tubes I need to upsize are ST-7 to a ST-13. I thought I knew how to do this but apparently I don't. Any help would be greatly appreciated
first upscale
- Thread starter pepe
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Hi pepe,
If you can, download Open Rocket ( https://openrocket.sourceforge.net/ ) It's a freebie! It runs in Java, so you may have to tell your computer to open it with Java.
Then locate the Rocksim file on the web (rocket reviews.com...hint, hint)
Now, I'm a lazy sort, so this is what works for me..... In OR under the 'edit' dropdown you will find a 'scale' button, just enter the applicable sizes and let the program do the math.
Have fun,
Play safe,
Terry
If you can, download Open Rocket ( https://openrocket.sourceforge.net/ ) It's a freebie! It runs in Java, so you may have to tell your computer to open it with Java.
Then locate the Rocksim file on the web (rocket reviews.com...hint, hint)
Now, I'm a lazy sort, so this is what works for me..... In OR under the 'edit' dropdown you will find a 'scale' button, just enter the applicable sizes and let the program do the math.
Have fun,
Play safe,
Terry
Last edited:
Slickwilly
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View attachment Vector V - 3X.rkt
I came up with this design that is very close to 3X scale.
Semroc nose cone - BNC70HAC (9" long)
Upper body tube - BTH70 (18" long)
Balsa transition custom cut - Front dia. 2.247"/2.175" - Rear dia. 3.938"/3.896" - Length 4" with 2" shoulders each end. Hole drilled thru entire transition 1.22" dia. for 29mm motor tube.
Motor mount tube - Semroc LT115 (12.75" long)
Lower body tube - Semroc BT101 (6.75 long) or 4" tube from another vendor and adjust transition size will work.
2 Centering rings - Order 4" rings with 29mm holes from many vendors and sand to fit.
Main fins - 1/8" plywood
Coolant vanes - 3/16" x 3/16" x 1.5" basswood.
The biggest problem is getting the transition made and drilled. Could be expensive. I know BMS will do it, or you can use heavy card stock which is much weaker and would require a different rear end internal design.
I came up with this design that is very close to 3X scale.
Semroc nose cone - BNC70HAC (9" long)
Upper body tube - BTH70 (18" long)
Balsa transition custom cut - Front dia. 2.247"/2.175" - Rear dia. 3.938"/3.896" - Length 4" with 2" shoulders each end. Hole drilled thru entire transition 1.22" dia. for 29mm motor tube.
Motor mount tube - Semroc LT115 (12.75" long)
Lower body tube - Semroc BT101 (6.75 long) or 4" tube from another vendor and adjust transition size will work.
2 Centering rings - Order 4" rings with 29mm holes from many vendors and sand to fit.
Main fins - 1/8" plywood
Coolant vanes - 3/16" x 3/16" x 1.5" basswood.
The biggest problem is getting the transition made and drilled. Could be expensive. I know BMS will do it, or you can use heavy card stock which is much weaker and would require a different rear end internal design.
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