Stovi Downscale

Hi,

I decided to build a 18-mm version of the LOC Stovi over the winter. Uses a 7 motor cluster. Always liked the design. My intent was to use a altimeter for deployment and the central motor for backup. Then use plugged motors around the outside.

But it now occurs to me that neither Estes nor Quest make a plugged B6 or C6 motor. Seems if I use motors with a delay charge, I have to open them all to recovery compartment. Or vent them all outside to avoid blowing the motors out when the ejection charges fire. What about using the -0 motors? Is there a way to plug them? Can I simply vent the motor tube, or will the heat burn the tube if the motor is held there?

I\'m inclined to just leave all of the motor tubs open them all at the top and use long delays.

Any other suggestions?

Thanks,
David

Recommend doing as you suggest, all seven motor tubes open to the recovery area.

I have two rockets set up that way and it works very well. Select motor delays anywhere from projected apogee up to two seconds afterwards if they are backup.

Motor backup to electronic ejection is very desirable. Because the motor ejections are pressurizing a relatively large body tube, there is no problem with them all ejecting at nearly the same time.

> Is there a way to plug them?

Yes and no.

In the olden-days, BP motors had a paper cap inside the forward end of the motor casing. The cap held the ejection grains in the casing. The cap was held in just by a friction fit. You could easily pop out the cap, pour out the ejection charge, and plug the forward end with a wad followed by epoxy. You could turn a C6-5 into a C6-P in a few minutes.
Look here...you can see the paper cap on the right... www.nasm.si.edu/collections/artifact.cfm?id=A19930513000

Now-a-days, Estes uses a clay plug.

In either case, this procedure goes contrary to the NAR safety code (modification of motors prohibited).

Alternative: There are 18mm re-loadable motors available. Can you use one of those and leave out the ejection grain during assembly?