High power 2 stage rocket build thread!

[cwbullet]

I know how to bevel fins, I just want to know if there is an easier way than holding it to a belt sander.

Put a small wood dowel through 2-3 holes in the TTW portion of the fin. This will also provide an area for the glue to drip. If there is no TTW portion of the fin, use tape.

[blackbrandt]

I don't get what you are saying. Is this for beveling or cutting?

Put a small wood dowel through 2-3 holes in the TTW portion of the fin. This will also provide an area for the glue to drip. If there is no TTW portion of the fin, use tape.

[grouch]

It's for cutting. It ensures all fins are cut the same since they are all cut at the same time. Personally I just tack them together with M77 and then glue the template on one side and cut them out. There is some merit to having the holes at the root of the fin for glue to rung through but I'd rather have a solid fin root.

[CarVac]

He wanted to know about beveling, not plain cutting.

[blackbrandt]

I am starting to use a scroll saw to cut the fins, and yes, I will stack sand them. I ran out of 3/16 inch birch plywood, so my question is, what other materials can be used as fins? What thicknesses, what materials? G10, honeycomb, and Lexan are out. I am looking for wood.

[CarVac]

You could perhaps fiberglass reinforce balsa, if the design is such that landing damage is not going to be a big problem. It wouldn't be as strong as end-grain balsa layups because of reduced shear strength of balsa parallel to the grain, but the strength would be easily sufficient.

[kruland]

You could just build the sustainer and fly it and cert. Then build the booster later.

[blackbrandt]

I was hoping to fly both of them the same day.

[qquake2k]

Is 1/4" birch plywood too thick? I get mine from Michael's. I've actually gotten some nice pieces there. They don't have 3/16", unfortunately, just 1/8" and 1/4".

[ClayD]

i have gotten 3/16 birch ply from hobby lobby, they have a MIDWEST stand...
R/c shops almost always have the larger sheets of 3/16"

for L1 type rockets, 1/8" is fine....

[Aksrockets]

I like 1/8in glassed plywood. It's been the only thing Ive been using for most of my 2in-3in rockets recently. Great stuff to work with, plenty strong and dirt cheap.
(you did receive a few free yards of FG recently didnt you?)

Alex

[blackbrandt]

I like 1/8in glassed plywood. It's been the only thing Ive been using for most of my 2in-3in rockets recently. Great stuff to work with, plenty strong and dirt cheap.
(you did receive a few free yards of FG recently didnt you?)

Alex

Yep! Got it today, and my sis opened the box and got it all over herself. I nearly burst out Laughing.

[qquake2k]

Yep! Got it today, and my sis opened the box and got it all over herself. I nearly burst out Laughing.

Got fiberglass all over her? Man, that's brutal.

[blackbrandt]

Yep, and then she got it all over me!

[blackbrandt]

OK, so I got the big white box (really big, like 30 inches long), and in it were the following:
(6) 1/4 inch lugs for the E-Bay
1 27 inch long 29mm tubing
and 2 BT80 couplers for the av-bay


I took a piece of BT-80 tubing, and then coupled the couplers together using the BT80 as a sleeve. The bay ends up being 8 inches long. I then proceeded to attach the following to the end of each bulkhead.

(1) 1/4-20 U-Bolt
(1) 10/24 allthread that holds 2 wingnuts that tighten down to hold the E-Bay in place.

It is pretty tight, especially considering that I still have to cram an ejection canister and 2 wires on one of the bulkheads, and 1 wire on the other.

Pics to come.

[Aksrockets]

OK, so I got the big white box (really big, like 30 inches long), and in it were the following:
(6) 1/4 inch lugs for the E-Bay
1 27 inch long 29mm tubing
and 2 BT80 couplers for the av-bay


I took a piece of BT-80 tubing, and then coupled the couplers together using the BT80 as a sleeve. The bay ends up being 8 inches long. I then proceeded to attach the following to the end of each bulkhead.

(1) 1/4-20 U-Bolt
(1) 10/24 allthread that holds 2 wingnuts that tighten down to hold the E-Bay in place.

It is pretty tight, especially considering that I still have to cram an ejection canister and 2 wires on one of the bulkheads, and 1 wire on the other.

Pics to come.

Now THAT is a post.THAT is what we like to see. Keep it going and good luck with the Jr. L1.

Alex

[blackbrandt]

I am still scratching from the FG cloth, especially since I had to pick up all of the threads that had fallen off into the carpet. Not fun. Not fun at all.

[Jiffycoil]

Fiberglass itch relief, now that's a thread in itself. I look forward to your build. It's fun seeing your excitement in your posts. I'm 52 and still feel that excitement.

[blackbrandt]

Argh!!!!! How hard is it to cut a circle? I have tried 6 times to cut a circle with a jigsaw. I can cut a bulkhead with any diameter except 2.56 inches! I always cut ovals on this diameter! ! Also, how do I cram a terminal block, a U-Bolt, and a piece of all-thread onto this tiny bulkhead!?!? My head is about to explode!!!!!!!!!!!!!!!!

[Salvage-1]

instead of using a terminal block, you can put a pair of thin bolts through the bulkhead and use them as connections. Connect the wires to the inside of the bulkhead with nuts, do the same on the outside. - edit - if you do this, check that the resistance of the bolts doesnt mess with the firing of your matches - end edit -

Do you have access to a drill press? If so, check out circle cutters

Also, for thin diameter tubes, when the bulkhead is tiny, make a loop of kevlar, pass it through the hole in the center of the bulkhead, where the eye-bolt usually goes. Tie a large knot in the non loop end, which will sit inside the AV Bay, and epoxy it to the inside of the bulkhead.

[blackbrandt]

instead of using a terminal block, you can put a pair of thin bolts through the bulkhead and use them as connections. Connect the wires to the inside of the bulkhead with nuts, do the same on the outside. - edit - if you do this, check that the resistance of the bolts doesnt mess with the firing of your matches - end edit -

Do you have access to a drill press? If so, check out circle cutters

Also, for thin diameter tubes, when the bulkhead is tiny, make a loop of kevlar, pass it through the hole in the center of the bulkhead, where the eye-bolt usually goes. Tie a large knot in the non loop end, which will sit inside the AV Bay, and epoxy it to the inside of the bulkhead.

FINALLY! Afteer much plywood, swearing, and sweating, I figured it out. I got two circular bulkheads, and space for an eyebolt and a terminal block on each. One of the bulkheads will be permanently epoxied in, the other one will be removable.

[blackbrandt]

Now, I come back into the house after I get back from church, and...
What's this?
A nose cone!!!



Yes, it is a 2.56 inch LOC nose cone that I got on ebay for $17, including shipping!!! I also built the E-Bay, I will post pics as soon as my dad can get this virus off our computer!

[qquake2k]

Argh!!!!! How hard is it to cut a circle? I have tried 6 times to cut a circle with a jigsaw. I can cut a bulkhead with any diameter except 2.56 inches! I always cut ovals on this diameter!

What kind of blade are you using? A wider blade won't cut a tight radius. Do you have a scroll blade?

http://www.sears.com/craftsman-4-in-...p-00964361000P

[o1d_dude]

1. The basic principles
   • Draw an appropriately sized circle on the plywood.
   • Keep the saw blade outside the lines.
   • Sand the profile down to the lines.
2. Step by step description: How to cut a perfect circle with a jigsaw
3. Video

[blackbrandt]

1. The basic principles
   
   • Draw an appropriately sized circle on the plywood.
   • Keep the saw blade outside the lines.
   • Sand the profile down to the lines.
   
   
2. Step by step description: How to cut a perfect circle with a jigsaw
3. Video

Thanks! Instead of using a compass, I use a bulkhead that I got cut from GLR. Then I sand it with a belt sander. My problem was, the belt sander's belt was new in one spot, and really used in another, so it didn't sand at the right rate. I finally got it though. Next, the fins...

[blackbrandt]

Sorry for the delay, this build won't continue until September 5 for personal reasons. Punishment made me lose rocketry privileges for a month, so this build will continue on September 5.
Thanks for watching
Blackbrandt

[qquake2k]

Sorry for the delay, this build won't continue until September 5 for personal reasons. Punishment made me lose rocketry privileges for a month, so this build will continue on September 5.
Thanks for watching
Blackbrandt

Okay, you have to tell us what you did.

[blackbrandt]

Looking at rocket stuff when I was supposed to be working on school.... I know, I am an idiot...

[qquake2k]

Looking at rocket stuff when I was supposed to be working on school.... I know, I am an idiot...

I wouldn't call you an idiot, I'd call you a normal kid. But let that be a lesson to you, school comes first!

[blackbrandt]

Arghh!!!!!!!!! One more day! And naturally, during this time, my mom has had me clean up my entire workshop. "NO BUILDING", her words exactly! This is misery!
Build will continue on Saturday, I am too busy on Wednesday and today.