The adventure begins...

[JonathanOtt]

First few layers down on the Mercury Capsule for the my Polecat 5.5" Mercury Redstone clone/scratch build.

I referenced this capsule in another thread, but here's the Thingiverse link: Mercury Capsule for Polecat 5.5" Redstone.

Anyone with any pointers or an unbuilt kit that can help me out with component selection, fin patterns, encouragement or discouragement, please post here (okay, don't post discouragement...only positive vibes here).

I'm actually just printing a test set first, as I have a roll of white that I don't really like and want to test some fit issues first. I'm going to go for throttle up once past 'Max Q' (my little test phase) and commit a roll of black to the capsule and I'll also have a roll of red not far behind it for the LES tower.

 

[JonathanOtt]

Capsule and nose cap printed. The nose cap has a shoulder that slides down the "throat" (for lack of a better word) of the capsule.


I'm gong to have to make adjustments on my wall thickness as the capsule is printed at four (4) walls and there is a substantial gap between the cap shoulder and the top of the capsule.


I also printed a short part of the top of the capsule at eight (8) walls thick, and it's still not thick enough.



Instead of spending 10+ hours printing additional capsules, I'll print representative samples of the mating parts to get the wall thickness dialed in.

Stay tuned!

 

[Adam3836]

Very cool this will be interesting to follow
Good luck !!!!

 

[JonathanOtt]

Quick update, the wall thickness at four (4) perimeters might be okay. I forgot about the AVBay that is INSIDE the capsule...the testing continues...

I can't pull the capsule into Tinkercad...probably too many faces.

 

[JonathanOtt]

Capsule parts all printed out. This was an expensive test run, as I'm not perfectly happy with the results. I printed the shoulder (with the red trim ring) at too high of infill...I'm going to re-print it at something like 10% infill, and make sure I turn the top layers back on (no idea why I had the top layers turned off); the tower itself turned out great, other than I broke one of the pipes taking the supports off. You can see where I glued it back together in the bottom photo, look on the right most vertical tower pipe, between the first and second horizontal and you'll see a dark line. Apparently cyanoacrylate glue discolors red PLA. Who knew? Also, I want to print the tower at a finer resolution, like maybe .12 layer height. You can really see the .20 layers.

I still need to figure out what I'm going to do for recovery and hardware on the pointy end. No hurry though.

 

[JonathanOtt]

This is the "Capsule floor" which sits on top of the shoulder like so...



It has four holes with for captive nuts. I have to chat with the designer, but I'm thinking a U-bolt to connect the shock cord and parachute, but I'm not really sure why there are four holes. Sure, I could run one U-bolt and a couple eye bolts...maybe put a drogue on an eye bolt and the main on the U-bolt...I dunno.

 

[JonathanOtt]

The AV Bay goes on top of the capsule floor, and has vent holes. I'll glue theAV Bay tube and it's support shoulder to the capsule floor once I get the captive nuts seated in place.



The capsule shell then slides down over the AV Bay.



Looking down into the AV Bay from the top.



The nose cap has a hole in the bottom to take a screw. I'm planning on drilling it out a little then tapping to maybe 6-32 and running a length of all thread from there, through the AV bay, through the hole in the center of the capsule floor and then securing it with a nut, or maybe a wing nut on the bottom to cinch it all together for flight. I'd like y'alls thoughts on that.

This is where I'm at so far. I have to finish my drawings for the fins, and finalize the design for through-wall capturing to the centering rings. That'll be another post here in this thread sometime soon. Still scribbling on napkins and staring at the ceiling thinking things through.

 

[Spacemo]

Jonathon,
That is my rocket in the picture on Thingiverse so I have at least one tip for you. You will need a considerable amount of nose weight. Here is my solution. Also, if you fly with your tower attached, it will break on landing so it is an expendable piece.

 

[JonathanOtt]

Jonathon,
That is my rocket in the picture on Thingiverse so I have at least one tip for you. You will need a considerable amount of nose weight. Here is my solution. Also, if you fly with your tower attached, it will break on landing so it is an expendable piece.

Thanks! At this point in my build, I'd never thought that it would take that much nose weight. Wow.

Also, as for the tower being expendable, I've almost resigned myself to that fact; and flying with out it is almost sacrilege. I'll be sure to print up an extra or two. I also figure that this will be a yearly flyer, and display most of the time. I'll even go so far as to print up a "nice" nose cap and tower for display, and a separate nose cap and towers for flying. I know I'll have to open the inner diameter of the tower base to allow it to slide on the nose cap easier, as I had to trim a lot to get it to slide all the way home...maybe even drill a couple small holes to add some screws to secure the tower in place for flight and allow easy replacements.

What (if you know) is your flying weight, and what is your motor of choice?

I'll probably hit you with more questions as I progress along.

Jon

 

[Spacemo]

I flew it on a K540 Metal Storm. It weights in about ten pounds without motor and chutes. Here's a good photo of the lift off.

 

[JonathanOtt]

I flew it on a K540 Metal Storm. It weights in about ten pounds without motor and chutes. Here's a good photo of the lift off.View attachment 455779

Sweet!!!

 

[JonathanOtt]

It's for sale.

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