Jump to content

Sound Barrier Rockets (SBR) - Rocket Season 7/4/17 - 2/28/18


Recommended Posts

  • 3 weeks later...
  • 2 months later...

@The Raging Sandwich, it sounds like you live in the U.S. I just wanna make sure you are complaint with all faa restrictions. I think your rocket may be too heavy to launch with out a launch permit.

These are the requirements for no paperwork involved rockets:

  1. Uses no more than 125 grams (4.4 ounces) of propellant;
  2. Uses a slow-burning propellant;
  3. Is made of paper, wood, or breakable plastic;
  4. Contains no substantial metal parts; and
  5. Weighs no more than 1,500 grams (53 ounces), including the propellant

http://www.nar.org/high-power-rocketry-info/filing-for-faa-launch-authorization/filing-for-faa-waiver/

Link to comment
Share on other sites

14 hours ago, Aperture Science said:

So uh, any updates? It's been a while.

Also, me and some friends are making a model rocket as well. I'll make a thread later.

Well, I accidentally broke a fin off of the smaller rocket but it can be fixed, and I'll be gluing the window to the camera platform of the larger rocket soon. I've had no time really to do much of this because I have Track at school, but I have some time on the weekends. Also, I'll be making changes to the engine of the larger one.

Link to comment
Share on other sites

On 11/23/2016 at 6:34 PM, Aperture Science said:

I was also thinking of doing this, but if I decide to do this I'll do it in December/January.

So far, what I've thought is:

Use PVC pipes as structure, use sugar+KNO3+aluminium powder as propellant, maybe try to make a nozzle with copper. Use delayed sugar+KNO3+baking soda mixture for automatic chute deploy.

Copper nozzle is a bad idea. If a chunk of the propellant breaks free during launch and plugs the nozzle, the PVC will overpressure and turn to shrapnel. PVC shrapnel can kill you.

If the casing is made out of a frangible material like PVC or aluminum, then the nozzle should be made out of pressed or rammed clay with the nozzle bored/ground out of it. If you want a copper nozzle, the casing needs to be made out of cardboard. You can do a composite overwrap design if you want a higher chamber pressure, as long as no part of the casing is frangible.

Finally, many US jurisdictions require that you follow NAR rules in launching rockets, and NAR rules require a license for launching any homemade motors.

Link to comment
Share on other sites

I seem to remember there's a plastic with more benign overpressure behaviour than PVC. ABS maybe? Something that's less likely to cause shrapnel. It came up in discussions of homemade water guns, which usually include an air-filled pressure chamber.

Link to comment
Share on other sites

23 minutes ago, sevenperforce said:

Copper nozzle is a bad idea. If a chunk of the propellant breaks free during launch and plugs the nozzle, the PVC will overpressure and turn to shrapnel. PVC shrapnel can kill you.

If the casing is made out of a frangible material like PVC or aluminum, then the nozzle should be made out of pressed or rammed clay with the nozzle bored/ground out of it. If you want a copper nozzle, the casing needs to be made out of cardboard. You can do a composite overwrap design if you want a higher chamber pressure, as long as no part of the casing is frangible.

Finally, many US jurisdictions require that you follow NAR rules in launching rockets, and NAR rules require a license for launching any homemade motors.

Yeah, we've started working on it, our nozzle was made out of epoxy. The casing is going to be made out of PVC, and we're getting help from an aerospace engineer that has made motors before. I think I'll make a thread with pictures, but right now there isn't much to see except for the nozzle and throat.

Also, we live in Brazil. We launch it from a farm, nothing happens.

Link to comment
Share on other sites

34 minutes ago, sevenperforce said:
On November 23, 2016 at 6:34 PM, Aperture Science said:

 

Copper nozzle is a bad idea. If a chunk of the propellant breaks free during launch and plugs the nozzle, the PVC will overpressure and turn to shrapnel. PVC shrapnel can kill you

35 minutes ago, sevenperforce said:

Copper nozzle is a bad idea. If a chunk of the propellant breaks free during launch and plugs the nozzle, the PVC will overpressure and turn to shrapnel. PVC shrapnel can kill you

It is also illegal to use metal as a nozzle. Yeah, pvc is pretty deadly.

4 minutes ago, Aperture Science said:

Yeah, we've started working on it, our nozzle was made out of epoxy

Clay is better. Or cheep kitty litter.

Link to comment
Share on other sites

@munlander1 @sevenperforce

Here's the nozzle, top view:

L59YHfd.jpg

What you see there is the converging part of the nozzle, that silver thing is a flat metal ring, then below it is the diverging part of the nozzle. It'll be glued to that PVC cap next to it, which will be glued to the rocket's casing.

We're going to work on it again this weekend, I'll let you guys know more about it. If you want to see us making the nozzle, let me know and I'll go search for footage/images (likely images).

Edited by Guest
Link to comment
Share on other sites

1 hour ago, munlander1 said:

@The Raging Sandwich ? You gonna have full life support?

Well, I'm going to do something like Adam Savage did on his Mercury suit and put a fan into a sort-of oxygen blower that blows air into the back of the helmet. The helmet I ordered has holes in the back so it would be a good place to do that.

Link to comment
Share on other sites

23 minutes ago, Spaceception said:

It better have life support :)

Well heating, cooling, waste management, that stuff. Did the Gemini suits have all of those?

2 minutes ago, The Raging Sandwich said:

Well, I'm going to do something like Adam Savage did on his Mercury suit and put a fan into a sort-of oxygen blower that blows air into the back of the helmet. The helmet I ordered has holes in the back so it would be a good place to do that.

Oh, so costume. I thought you were thinking about a full on Eva space suit.

Link to comment
Share on other sites

1 minute ago, munlander1 said:

Well heating, cooling, waste management, that stuff. Did the Gemini suits have all of those?

Oh, so costume. I thought you were thinking about a full on Eva space suit.

They probably did. I don't really want to go uber-realistic and have to order size small adult diapers.

Link to comment
Share on other sites

  • 2 weeks later...

So the helmet I ordered came in yesterday. It comes with a neck-guard sort of thing that can be attached to the helmet for cold weather. I'll leave it on and attach a sealing ring to the bottom of it that connects to another sealing ring on the suit, sort of like on the Mercury suit. Ill probably post a picture of the suit so far later today.

Also, should I put the mission patch on the left shoulder or where the Apollo suit had their mission patches?

 

Link to comment
Share on other sites

  • 3 months later...
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...