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- Jan 19, 2009
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Agreed - looking good!
Pic 3 would make a neat color scheme!
Maybe on your NEXT version
I found a Peak of Flight newsletter that describes how to modify engine thrust curves to simulate a canted engine(s):
https://www.apogeerockets.com/education/downloads/Newsletter226.pdf
Since it involves modifying only the motor file it should work in OR as well as RockSim.
A bit tedious to crank out the new numbers on the thrust curve, but should give you more accurate sims. Cheers.
Installed the BT-60 over the canted cluster. In order to install it I had to cut it near the bottom of the scallops. Now.... more glue fillets.
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Thanks for the comments fella's.
I've been searching for a material to use for the cargo lifting inserts in the fins. Originally I was going to use 1/8" thick aluminum, but that just seemed like extreme overkill and the weight was considerable also.
I spent about an hour at the local Tractor Supply and True Value Hardware trying to find something that I could use, but didn't have any success.
So I went hunting in my barn and found some body filler applicators... Perfect! They are flexible and are 1/8" thick, same as the balsa for the fins.
I redesigned the size and shape in my CAD model, printed a template and cut the parts, as well as the fin openings on my scroll saw. The design now has the insert trapped inside the balsa, with dowels glued in to hold it all together.
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Also, regarding the canted engines, I remember reading that it is optimal to have the thrust line of each engine go through a point midway between the CP and CG. This supposedly results in the straightest flight if one of the clustered, canted engines doesn't ignite. I don't recall where I read that, it might have been in an Apogee Components Peak of Flight newsletter.
That depends on how asymmetrical your design is and other factors like hanging up on the rod. How high does it get on two of three motors and what is the delay. Some have arced over and recovered . Some have arced over and crashed. One hung up on the rod, worked it's way off and land snaked. Tractor motors won't save you. I have seen the same results from properly canted kits from trusted kit manufactures . Following all the good rules is not going to save you either because there are too many random factors in each launch. When two of three canted motors light all that is left is prayer.Tractor motors, on the other hand, don’t point to the CG because they’re typically forward of it (by definition?)
Hey @Daddyisabar, what happens when all the tractor motors don’t light? Guessing you’ve seen that once or twice...
When two of three canted motors light all that is left is prayer.
Spent some time today on CAD working on a scratch build.... I'm calling it a "Lifting Rocket".
It can be flown with a single 24 mm motor.. or a canted cluster of (3) 18 mm motors.
I'm still working on this... I want to add a payload section at the bottom that locks to the body tube in place of the 24 mm motor.
It would be neat to have multiple motor options and payload configurations.. all retrofitted onto the Lift Rocket
I've added stiffener rings and struts to make it as "durable" as possible.
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