Motor Recommendations for Der Big Red Max with plywood upgrades

[Raymond3457]

I am going to do my first reloadable motors with my Der Big Red Max with the ply upgrades. I will be using the Aerotech 29-40/120 case. I want to keep it fairly low at first. Which motors and time delays would you recommend?

 

[techrat]

F20-4, assuming this delay time comes as RMS, I know they make an F20-7, since I just assembled that into my 29-40/120 for this weekend. I wouldn't go under an F20 for the weight of the Plywood. My DBRM is also heavy as although I kept the balsa fins, they were papered, then doubled up on the Balsa because they warped, and then coated with laminating epoxy, so in the end, my DBRM is probably as heavy if not heavier than the plywood version.

And although it's a 24mm disposable, the F44 absolutely rocks the DBRM -- it flies off the rod/rail but then because the burn is actually just under 1 second, its coasts to a respectable apogee that is recoverable within a reasonable sized field.

Have fun!

 

[K'Tesh]

I'd suggest that you download my sim of the DBRM (9721), update the info with your weights and finishes (rounded fins, etc?) Run it and see what OR recommends.

 

[Raymond3457]

F20-4, assuming this delay time comes as RMS, I know they make an F20-7, since I just assembled that into my 29-40/120 for this weekend. I wouldn't go under an F20 for the weight of the Plywood. My DBRM is also heavy as although I kept the balsa fins, they were papered, then doubled up on the Balsa because they warped, and then coated with laminating epoxy, so in the end, my DBRM is probably as heavy if not heavier than the plywood version.

And although it's a 24mm disposable, the F44 absolutely rocks the DBRM -- it flies off the rod/rail but then because the burn is actually just under 1 second, its coasts to a respectable apogee that is recoverable within a reasonable sized field.

Have fun!

Thank you.

 

[Raymond3457]

I'd suggest that you download my sim of the DBRM (9721), update the info with your weights and finishes (rounded fins, etc?) Run it and see what OR recommends.

View attachment 595143

Thank you. I will.

 

[86mustang408w]

Try a Aerotech F42-4T 29/40 Blue Thunder motor. How much does it weight? Just put up my Leviathan they might not be much different.

 

[dhbarr]

Try simming with the f40 white, 4s delay. Just eyeballing it off the top of my head, and completely depends on your final weight.

 

[John Taylor]

I am going to do my first reloadable motors with my Der Big Red Max with the ply upgrades. I will be using the Aerotech 29-40/120 case. I want to keep it fairly low at first. Which motors and time delays would you recommend?

Check out Thrustcurve.org. put in rocket specs and it will tell you which motors will work and which will not work as well as altitude, delay times, speed off the rod/rail, and peak velocity.
Free, quick, and fun.

 

[SolarYellow]

Check out Thrustcurve.org. put in rocket specs and it will tell you which motors will work and which will not work as well as altitude, delay times, speed off the rod/rail, and peak velocity.
Free, quick, and fun.

Not nearly as detailed or accurate as doing the OpenRocket sim.

 

[86mustang408w]

I just put up one at 500gs without motor on a F23-4FJ. That would work too. I'm not sure what to tell you for reloads.