6 replies to this topic

[Hary12]

Hi guys,
I was woundering if anyone had made anything like a estes rocket motor?
becouse they are exellent.
I was also woundering how you can get the end cap to blow out and realese hot gasses to ignite a payload, like the estes motors.

[Stuart]

Simple, have a seperate compartment with loose BP or some other explosive in. Like a break charge without the stars

[chim-chim]

Many people here have made engines like Estes. I sure many people have made shells like Gucci.

To quote BigG from 'To prime or not to prime' -

"well, it's very nice to you to try and reach the estet quality of motors, but really you should not bother. First, the have purer matrials then you. Second, the have better milling facilities then you, third, they have better milling media then you, fourth, the probably mill for much longer then you, fifth, the compress the motors using industrial press, which is better then your press, sixth, the have 80 years of research into those motors - which is longer then you been alive.

In short, Estes motors should not be your bench mark. your bench mark should be the WOW factor your rockets produce, and then to try and make it even a better WOW. "

(note:searching for Estes might have been better than starting a topic)

Estes uses a delay comp (BP with higheer C content) and then a faster BP again at the top to allow the rocket to slow down (while the delay burns) before the quick powder at the top lights, creating enough pressue in the case to burst through the very thin layer of clay at the top.

[StarScream]

Hey Guys

Does anyone know how much BP is used in the ejection charges of the 3 common sizes of Estes motors (13mm, 18mm & 24mm)? If memory serves me, I think the 24mm motors have 0.7g, but I'm not sure about the smaller ones.

[cooperman435]

It would be worth reading the Passfire news letters as recently there was a whole issue dedicated to reproducing them.

[spanner]

He dissected a E9-6 (24mm), said it had ~0.5g ejection charge. He goes on to use 2.0g of homemade ejection charge in his knock-off.

Site is: http://www.skylighte..._..._o=&e=a#ART

[StarScream]

He dissected a E9-6 (24mm), said it had ~0.5g ejection charge. He goes on to use 2.0g of homemade ejection charge in his knock-off.

Thanks Guys

I could have sworn that I read somewhere the 24mm motors use between 0.7-0.85 grams. I always read those Skylighter newsletters... must have forgot about that issue. 2g of polverone seems like a huge amount for an ejection charge, although it's probably ok for a large airframe.