Penguin 1: Supersonic Ice Cream Sandwich (Build Thread)

[Nytrunner]

Ah! That's simpler, but time consuming. A rough paint job will still get pushed past Mach. But it sounds like you want every ft/s you can get.

The trick is surface preparation. If you can feel it, you'll see it when painted. Sanding starts at 220, prime, fill indents/divots/scratches/pinholes (bondo spot and glazing putty, the red stuff not the 2 part), sand ~320 or 400 grit now, repeat till smooth. When primed surface is as flat as you're willing to get it, paint. Follow the instructions to the letter as far as recoat times and environmental conditions. Spray cans or airbrush is up to your skill/resources. When fully cured, wetsand increasing grits 600, 1000, 2000. Some folks use a polishing compound at this stage.

 

[Pariah Zero]

Spray cans or airbrush is up to your skill/resources. When fully cured, wetsand increasing grits 600, 1000, 2000. Some folks use a polishing compound at this stage.

For super sharp taped lines, get some fine line tape (used for auto paint). Great stuff.

One trick (though a bit thicker & heavier): spray a light coat of clear over the masking tape between colors. Read the directions, make sure the clear works with the color. The clear will seep into any cracks/crevices in the mask you missed, and when you remove the masking, the lines will be sharp.

You could also use a clear coat when all finished - the process is similar to prime/sand cycles, but with clear coat. Shoot clear, sand it flatter (but not into the color), shoot more clear, sand... That way you aren’t cutting into the paint as you sand over masked lines. The trick there: is the extra smoothness of the clear worth extra weight? Your call.

Unless you intend to pay a pro to spray clearcoat, stay away from automotive “2k” clear. That stuff is pure poison in liquid/spray form. Pros have the safety gear. It’s expensive.

 

[Nodroc]

Again, I appreciate all the advice!

Today's update involves some renderings of the GoPro securement system I've got going on for the AV bay.

As I had said before, I wanted to develop a system such that I didn't need to take the rocket apart to put in my GoPro Hero5 Session.


Here we can see generally how this system will work. With cuts in the coupler and switchband, the GoPro will be inserted into the housing attached to the AV sled. Once the camera is inserted, a cap is placed on top of the GoPro face and screwed in (screw holes have not as of yet been included in the model but will be in each corner).



Here you can see the cap that will be placed to hold the GoPro in place. My initial design of the cap only had fillets trailing up to the top and down to the bottom. As I thought about the design however, I imagined there would likely be better airflow if the entirety of the cap were filleted. So, accordingly, I added fillets around the entire region as seen below.



I'm curious as to what this will do to the aerodynamics of the rocket. Am I correct in saying the last design would better? Would it be beneficial to create a dummy cap to place on the other side of the coupler for more even air flow? Let me know your thoughts!

 

[ebruce1361]

Any updates to this project? I fear the ice cream may have melted by now.

 

[Nodroc]

Update on the project! I'm finally getting back into it and its definitely go time to start cranking things out. What with COVID and becoming the team lead for one of the high power teams at my university, this project got swept under the rug a bit. In any case, here is the rocket my team and I built in the meantime:



I'll take some pictures of Penguin 1's current progress and upload it later. I've got the fins on and filleted and I'm going to be doing a bunch of work in getting the avionics bay up and running today. I hope to use an Eggtimer TRS as my main deployment and a stratologger as my backup. Though I have some concerns about GPS capabilities inside of the avionics bays with the metal all thread rods. Is attaching the antenna on the outside of the rocket a viable solution?

 

[Grog6]

I bought some of the pin-locks from MSC
That you push the button to release; glued one if these switches to a matching piece of tubing
You can chuck up the tubing in a cordless and flare the mouth of the tubing to accept the pin lock. making it easier to put the pin into.
I used a pair of needlenose to flare it out, while spinning it with the drill,
I'll try to get some pix later.

 

[Nodroc]

I bought some of the pin-locks from MSC
That you push the button to release; glued one if these switches to a matching piece of tubing
You can chuck up the tubing in a cordless and flare the mouth of the tubing to accept the pin lock. making it easier to put the pin into.
I used a pair of needlenose to flare it out, while spinning it with the drill,
I'll try to get some pix later.

Not sure I'm following what you're saying.

 

[Grog6]

OK, pix always help:

 

[Grog6]

You can see the flared tubing here, there is a small hole in the tubing for the button on the switch,and the large "remove before flight " banner came from aerotek.