High power 2 stage rocket build thread!

[blackbrandt]

Here is the build thread for my super-modified Estes Optima. This rocket will have a 29mm motor mount in both the booster and sustainer. The booster will house a CTI H410, and the top stage will house a G80 single use motor (even though a G138 would give a heck of a flight). This rocket will use Dual Deployment by a Raven3 altimeter. Before I get comments about how I am not allowed to use Electronics for any recovery or airstart purpose, I am getting a L3 flier to fly this rocket for me. The Raven will also control the airstart and an alarm. Anyway, I started this rocket today.


I started with the sustainer part.
In this photo, you see the dry fit of the motor mount. The aluminium tubing on the side is for the wiring for the airstart. The centering rings are made of 3/16 inch birch 3 ply plywood. The tubing is LOC 1.14 mmt tubing. I am still working on the positioning of the rings for the fins.








Yes, I know, my workbench is messy.

More pics to come.

[blackbrandt]

This is a pic of the centering ring template that i got off of payloadbay.com



Here is a ring before I cut the middle out.



Here is me sanding the ring on a belt sander.

[blackbrandt]

I should be getting a package from semroc and from scotty dog in the next couple of days. The next part of the build will be the ebay that will house a Raven3. What is coming from scotty dog, well, I don't know...

[sodmeister]

Hey ,some guys do their best work on a messy work table ,you should have seen Robert Goddards and Wernher von Braun`s ......total chaos !

Boy oh boy ,I`ve skinned many a good knuckle on a belt sander doing that

Cheers

Paul T

[blackbrandt]

List of stuff to tell my dad:
I need a drill press
My workbench isn't that messy
a Raven Altimeter is on my wish list

And more...

[DRAGON64]

List of stuff to tell my dad:
I need a drill press
My workbench isn't that messy
a Raven Altimeter is on my wish list

And more...

I picked up a drill press from Harbor Freight for $39 a number of years back... I'd check there first. It is basic, but I have made centering rings, bulkheads, and drilled many a hole to build my own launch pads... worth every penny.

[blackbrandt]

My dad thinks Harbor Fright is only "single use tools".

[DRAGON64]

My dad thinks Harbor Fright is only "single use tools".

In most cases, yes, your dad is correct. The small drill press has been a gem though.

Looks like the price has gone up a bit in recent years: http://www.harborfreight.com/garage-...ess-38119.html

I paid only $39 for the same press, the difference was, mine was painted red.

[blackbrandt]

OK, the big white box should come in either today or tomorrow... The big white semroc box, that is.

[blackbrandt]

I need some help designing the Avionics Bay. It will house a Raven3 on a G10 sled. The bay will be similar to the "Altimeter bay 1" in modern High power rocketry 2. My question is, where can you get sleds, and how do I put a switch in there?

Also, I got some FG cloth (6oz) for attaching the fins. Is this overkill?

[blackbrandt]

Should I use a rod or a rail for this? I have both 1010 rail buttons, and 1/4 inch lugs.

[qquake2k]

Should I use a rod or a rail for this? I have both 1010 rail buttons, and 1/4 inch lugs.

I use rail buttons on all my HP builds, and all the MP builds that the design lets me. I think a rail is always better, since there is no "rod whip". Plus, rails are usually longer.

[blackbrandt]

How long is a typical 1010 rail?

[CarVac]

You cannot buy sleds. If you don't have the facilities to cut G10, which is very likely true, you should make it out of thin plywood.

Depending on what your fin design is like, the fiberglass may or may not be overkill; there is little harm in doing it unless you really want max performance out of it.

[qquake2k]

How long is a typical 1010 rail?

All of the rails at both clubs I'm a member of are 8ft long. The longest 1/4" rod I've seen there is 6ft.

[blackbrandt]

The OR file is saying about 125 miles an hour off an 8 foot rail. Oh sweet. The name of the rocket is still in debate, but I am thinking "Whiplash"

[cwbullet]

I use rail buttons on all my HP builds, and all the MP builds that the design lets me. I think a rail is always better, since there is no "rod whip". Plus, rails are usually longer.

Imagine the force required to cause rail whip. +1 rail.

[blackbrandt]

OK. Acme or delrin?

[qquake2k]

The OR file is saying about 60 miles an hour off an 8 foot rail. Oh sweet. The name of the rocket is still in debate, but I am thinking "Whiplash"

I like the name!

[qquake2k]

OK. Acme or delrin?

I prefer Delrin. Less alignment issues.

[blackbrandt]

How do I mount those in a 3/16 inch ring?

[CarVac]

I prefer Acme or the public missiles urethane ones. Alignment is not so hard a challenge, especially with Acme.

[qquake2k]

How do I mount those in a 3/16 inch ring?

I epoxy pieces of 1/4" plywood to the centering rings for the rail buttons to screw into.

http://www.rocketryforum.com/showthr...931#post311931

[DRAGON64]

Two Delrin buttons and a rail gets my vote.

[blackbrandt]

OK, sweet, I just found the 1010 buttons that I ordered from Apogee a year or two ago.

[blackbrandt]

Should I use G10 fins or 3/16 inch birch plywood fins? I will not do FG fins for all of the fins ($81 from GLR total). However, I do have FG cloth (6oz). What is y'all's opinion on this?

[blackbrandt]

You cannot buy sleds. If you don't have the facilities to cut G10, which is very likely true, you should make it out of thin plywood.

Depending on what your fin design is like, the fiberglass may or may not be overkill; there is little harm in doing it unless you really want max performance out of it.

Since this isn't high-performance (even though max acceleration is over 1000fps^2), I am thinking birch plywood fins. There is one minor problem. I completely stink at cutting fins out of plywood. Is there anyone who is actually decent at cutting fins out of birch plywood?
Also, doesn't GLR cut sleds?

[qquake2k]

I prefer Acme or the public missiles urethane ones. Alignment is not so hard a challenge, especially with Acme.

I haven't used Acme guides yet, but I have a couple pair. I do know that as long as you mount them along a straight line, no other alignment is required for rail buttons. And as long as you screw them into blocks like I do, you don't need to epoxy them. This allows you to remove them if it's ever necessary, which I've had to do a couple times.

[qquake2k]

Since this isn't high-performance (even though max acceleration is over 1000fps^2), I am thinking birch plywood fins. There is one minor problem. I completely stink at cutting fins out of plywood. Is there anyone who is actually decent at cutting fins out of birch plywood?
Also, doesn't GLR cut sleds?

Do you have access to a bandsaw? I cut all my plywood fins with a bandsaw.

[blackbrandt]

Umm, I have access to a Saber Saw, which looks like this. Soon I will be getting a scroll saw, which looks like this. What should I use?