Estes E9

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Karl

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Could anyone tell me what the max lift off weight for a Estes E9 is please?
Thanks
Karl
 
All the delays of E9 have a max lift off of 15oz
 
It depends on the rocket, the wind, the rod, etc, but my back of the napkin look says about 6.5oz given the 5:1 rule of thumb. This checks with the graph on InfoCentral so I reckon I'm close.
 
Originally posted by GL-P
All the delays of E9 have a max lift off of 15oz

Estes calculations lead to nice scale flight profiles on their V2s :) Saw one this weekend go off at a 45 deg angle and impact before ejection.
 
All the delays of E9 have a max lift off of 15oz

not exactly, the recomendation changes depending on the delay with any manufacturer including estes

according to estes(in a perfect world)
E9-4 -15oz
E9-6 -12oz
E9-8 -10oz

the lift off weight recomendation changes by delay because-
you have to take into consideration the rocket must have time to deploy the chute before crashing,so not by weight alone, but time as well.(as in,you might lift it ,but will it recover in time)
 
Thanks guys! My rocket ways 19oz so a E9 is out of the question , sureley a Aerotech E15/F21/F72 will throw that thing outta site? (AMRAAM)
 
Originally posted by Karl
Thanks guys! My rocket ways 19oz so a E9 is out of the question , sureley a Aerotech E15/F21/F72 will throw that thing outta site? (AMRAAM)

E15 and E28 will be great. I use the E28 on my PML Tiny Pterodatyl
 
Right , E9's are legal over here , woo hoo! Im gonna finish off my latest project tomorow and get burning some E motors! I've just built the Big Daddy to V2 bash off EMRR , and I only have E9-6's and I dont know if I should CHAD stage her to be on the safe side , D12-0 -> E9-6 ??

Thanks
Karl
 
Karl,

That Big Daddy to V-2 mod should be PERFECT on an E9-6.

Provided you didn't build too heavy.

That motor is absolutely perfect on the 2.6" V-2 so it should work fine.

And where are the pics???
 
Originally posted by Karl
Could anyone tell me what the max lift off weight for a Estes E9 is please?
Thanks
Karl

From the Estes engine chart at

https://www.me.ttu.edu/class-websites/ME4356/projects/engine chart.pdf

E9-4: 15 oz
E9-6: 12 oz
E9-8: 10 oz

The difference between the 5:1 calculations and this is, this takes into account early thrust and its ability to get the bird up to stable flight, then considers the maximum safe coast time that engine will give the weight. The more an engine profile deviates from a constant flat line across its firing time, the less the 5:1 calculation applies. A core burner with a decent early peak like a C5 (MLW 226g) can pop much more weight up to safe speed than an end burner like a C6 (MLW 113g) despite having "less" power.
 
Thanks for the feedback. Well shes made from a normal BD tube. The slots filled with fiberglass & woodfiller and the spirals filled with woodfiller.I dont think the fiberglass added that much weight , it's just a small strip behind each fin slot. The fins is what im worried about. With that 6 second delay , Im going to make the fins from 3mm Ply & The fillets from No More Nails. The centering rings are from 4mm ply (1 flush in the boat tail & 1 in the bodytube.)

Will post pics in the scratch build forum
Karl
 
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