Lunar Eclipse Jr. post-op

I managed to remove the E9-6 casing from the Lunar Eclipse Jr. motor mount. I also managed to remove the tool I originally tried to remove the casing with, but let’s not go there.

The rear end of the motor mount tube is charred and crumbly. For a black powder motor maybe that wouldn’t matter very much. If you had a motor that normally relied on a rear thrust ring, it wouldn’t be so good.

But why was the casing pushed forward from the rear end of the tube, and why was it so hard to pull out? Well…

When I look down into the motor mount tube I can see the forward end of the motor hook sticking into the tube, and I can see the thrust ring. What’s surprising is that the latter looks to be about half an inch in front of the former. That ain’t right!

The thrust ring should be directly behind the hook. Now, is there any way under the stress of a cato the thrust ring could have been torn loose and shoved forward? Seems less than likely… and it certainly doesn’t feel loose now. The one other scenario I can think of, embarrassingly enough, is that I glued it there in the first place. The motor mount tube is about 6 ½” long so the ring isn’t close to the front end. I don’t remember if I used wood glue or epoxy to install it. If wood glue, I can kind of imagine the ring seizing up and me thinking it’d stopped against the hook.

Apparently the first two times I flew it, or tried to, the hook stopped the motor from going forward, but the cato blew it up to the thrust ring, shoving it past the hook which then made it difficult to pull it back out.

So fixing this rocket would entail… what? All I can think of is cutting about a ½” section of motor casing, with a slot to get it past the motor hook, and gluing that in place between the thrust ring and the hook. Of course it might not adhere all that well: the motor tube has a lot of crud in it. Though arguably it doesn’t have to.

And then there’s still the charred rear end of the tube to consider.

All this assumes the motor mount is not otherwise compromised after the cato (and after my efforts to extract the casing). I don’t see any other problems; doesn’t mean there aren’t any.

I titled this “post-op” and not “post mortem” because I’m not ready to declare this rocket dead yet. But I haven’t decided how much effort, if any, I should put into reviving it. I’m leaning toward none, at the moment.

 

Advertisements

One thought on “Lunar Eclipse Jr. post-op

  1. Pingback: Repairing the Lunar Eclipse Jr. (part 1) | Rich's Rockets

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s