nater Posted March 6, 2012 Posted March 6, 2012 (edited) When building a rocket using 29 mm aerotech type motors, are the threads on the motor retainers on the nozzle end strong enough to prevent the motor from moving forward during the thrust phase, or do I still need to provide a thrust ring in the front of the motor mount as you would on a small model using only a spring clip to hold the motor? Edited March 6, 2012 by nater
TYRONEEZEKIEL Posted March 7, 2012 Posted March 7, 2012 From my experience, the threaded caps work perfect. Im pretty sure you are referring to the black cases with the gold screw on retention. Ive never had problems with the motor coming out of the casing, provided it was assembled correctly. The only trouble I have experienced is the whole casing being ejected from the body at ejection. A good motor retention rig, solved that immediately
nater Posted March 7, 2012 Author Posted March 7, 2012 Yes, I was referring to the black cases with the screw on retention devices that attach on to the motor mount tube. My motor hardware has not come in yet, but it looked like the aft end retention would still prevent the motor from flying through the rocket as well as popping out from the ejection charge. I've built plenty of small models before, but decided to step up to a bigger rocket that could even be capable of a level one flight if I decide to.
TYRONEEZEKIEL Posted March 7, 2012 Posted March 7, 2012 From my experience, you shouldn't face any problems here.
JFeve81 Posted March 7, 2012 Posted March 7, 2012 I've got a mid powered rocket that uses those 29mm motors. Had it for 5 or 6 years and still have yet to fly it. Which rocket did you end up going with?
nater Posted March 8, 2012 Author Posted March 8, 2012 I'm building an Estes D-Region Tomahawk, modified as described on Rocketry Planet. The one thing I am thinking about changing is cutting the nosecone so it is a two piece design and using the space to carry an altimeter
JFeve81 Posted March 8, 2012 Posted March 8, 2012 I'm building an Estes D-Region Tomahawk, modified as described on Rocketry Planet. The one thing I am thinking about changing is cutting the nosecone so it is a two piece design and using the space to carry an altimeter Nice. I just went with the AeroTech Initiator. I think that's the right name anyway. It's been awhile but I've read in a few places it's relatively easy to convert it over as well. Really need to get out and fly it to see what she does.
Nessalco Posted March 8, 2012 Posted March 8, 2012 When building a rocket using 29 mm aerotech type motors, are the threads on the motor retainers on the nozzle end strong enough to prevent the motor from moving forward during the thrust phase, or do I still need to provide a thrust ring in the front of the motor mount as you would on a small model using only a spring clip to hold the motor? The threaded thrust ring is more than adequate. Most mid and high power motors have some sort of thrust ring as part of the system. Don't glue in a forward block - in a given diameter, more power is gained through greater length. If you glue in a block you cannot use any of the longer cases, and thus limit your engine choices. Kevin
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