Sim please?

[DynaSoar]

Could someone please do a quick sim or two for me?

Estes V2 (#1904), motors stick out of motor tube 0.25",
add one ounce at CG (for epoxy and 20/50 ring for engine block),
on:
1. AT F32 (length 5"; engine block 4.75" forward of aft end of motor tube)
2. AT G55 (length 7"; engine block 6.75" forward of aft end of motor tube)

Need to know suggested delay.
Would like to know projected apogee altitude.

Tnx.

(Can't do it myself because until we're moved to Dallas I'm stuck using my wife's test/backup computer for her work, and the company won't allow anything to be installed that they don't approve. And Rocsim and Spacecad don't come in 16 bit Apple IIgs versions.)

 

[cls]

using Estes V2 #1 sim on EMRR (https://www.rocketreviews.com/rocksim/estes_v2_e_version.rkt)
(not a very accurate sim but what the heck)

plus 1oz at CG

E9-4 gives 115 meters altitude, optimal delay is 3.22 seconds - based on my experience with my V2 (built stock) this altitude is optimistic but the delay is about right

F32-5 gives 473 meters altitude, optimal delay is 5.57 seconds

G55-* gives 654 meters altitude, optimal delay is 7.68 seconds.

I wouldn't put a G55 in it.

 

[DynaSoar]

Originally posted by cls
using Estes V2 #1 sim on EMRR (https://www.rocketreviews.com/rocksim/estes_v2_e_version.rkt)
(not a very accurate sim but what the heck)

plus 1oz at CG

E9-4 gives 115 meters altitude, optimal delay is 3.22 seconds - based on my experience with my V2 (built stock) this altitude is optimistic but the delay is about right

F32-5 gives 473 meters altitude, optimal delay is 5.57 seconds

G55-* gives 654 meters altitude, optimal delay is 7.68 seconds.

I wouldn't put a G55 in it.

Thanks Cliff. Normally I wouldn't either. Just wanted to know where to set the thrust ring for the just-in-case case. Chances are I'll set it for 5" for F32, but stick with E9s and F21s max with a spacer ring. I just noticed that the motor tube was 7.75". It could actually hold my G110s. But decided that if I build it I want to keep it. Besides, I may make it a Bumper WAC, and that'll limit the max speed so as not to tear the WAC off.

Hey, I wonder what it'd take to covert it to a Canadian Arrow?

 

[DynaSoar]

Originally posted by DynaSoar
Hey, I wonder what it'd take to covert it to a Canadian Arrow?

Looks like about 3.6" of body tube and a maybe bit shaved off the outer edge of the fins should do it. There's already scale data availble on canadianarrow.com. Both scale models they show were built from V2 kits.

 

[cls]

I'd say, skip the thrust ring, you really don't need it. a couple wraps of masking tape on the aft end of the motor case will provide sufficient friction against the MMT, even up to J420 motors. definitely enough for E/F/G motors.


Canadian Arrow is cool, aren't they going to fly soon?

 

[DynaSoar]

Originally posted by cls
I'd say, skip the thrust ring, you really don't need it. a couple wraps of masking tape on the aft end of the motor case will provide sufficient friction against the MMT, even up to J420 motors. definitely enough for E/F/G motors.


Canadian Arrow is cool, aren't they going to fly soon?

Sorry, I've seen the cases where the tape wasn't enough. And the cases where the fit coming out was more than the fit going in and the rocket got bent to gouged with a rod trying to free it. For 20 cents I'll take the insurance.