spacer tubes and ejection charges

[rocketsonly]

Hey all. I was wondering how much volume a C engine could pressurize. Is there an online source that tells the volume an ejection charge can pressurize for each motor made? Preferably the Estes (A-E) and Aerotech motors (E-G)?

 

[BlueNinja]

There is something on info central, but you have to know how many grams of BP the charge has.

 

[rocketsonly]

Are there any online sources that display the amounts of BP in each ejection charge for a given motor?

 

[Stymye]

For Estes

D engine =.85 grams
A,B,C,=.5 grams

 

[powderburner]

Originally posted by rocketsonly
Hey all. I was wondering how much volume a C engine could pressurize.

For the Estes-type motors, remember that a single 18mm BP motor will reliably eject the goods from a Big-Bertha-style rocket. That is a BT-60 (1.6 inch diam) where the pressurized volume occupies most of the 18 inch BT length. And B-class motors work just fine in that design also.

If you compare your design to the BB, you should be able to get a semi-quantitative check on how well the ejection system will work.

 

[llickteig1]

This also illustrates why when you launch something like a Wizard on an A8-3 that the ejection charge looks like it's going to blow the rocket to bits, and why I replace short Estes elastic shock cords with tubular Kevlar string at least 3X the length of the rocket.

Sorry to hijack, but it's a design flaw that Estes has had for 40 years that bothers me.

--Lance.

 

[ClusterWiz]

no kidding. I have had countless falures or separations with estes rockets. I just built a Screamin Mimi. it came with a 1/4in. elastic about 14in. long. no way I used that or there SC mount on the side of the tube. Ii used some kevalar and atached it right to the forward CR just like I do on all my HP rockets. really sweet rocket rocket though!