Hi and welcome to another episode of Bernardo's Tech Blog. Today I have a project to show you
This is a rocket that I built from scratch
just from household materials I had laying around. It has 3 "D" size engines
as a cluster so all of them fire at once. That should make it a pretty powerful rocket
I'm going to give you an overview of the construction process, and then we're
head to the launch pad and we're gonna
give it its first test flight. I built this rocket entirely from
household materials I didn't buy anything for it except for the engines themselves.
I used a cardboard tube that
is actually pretty heavy for a model rocket - it has thick sides and is very strong
and I hope that with a
3-engine cluster I won't have any trouble getting this thing into the air.
I did check the weight and checked the specs of a D engine and what they're supposed to be able to
launch
and I think it should work. The fins actually are just
corrugated cardboard - I laminated two layers
of corrugated cardboard together and used that for fins.
Now these probably won't last. Ifthis thing survived the first flight
I'll probably switch them out to something a little better.
The nose cone is also something I rigged up. Believe it or not, it is a
peanut butter jar with the bottom cut off and it just happened to fit
perfectly in there and and it doesn't go down in - it has
a little lip right here that catches so it works out really well.
Now if you notice there's no recovery system and that's because this is
actually
a rear reject rocket. I've never built one of these before - hopefully I've done it right
the engine mount comes out and then there's the recovery system and I really
hate to pull this completely out
but maybe I will just so I can show it to you. Here's the whole thing
I got a parachute in there
I have a piece of cardboard up there that blocks
the body tube just at the top of the engine mount
and that way it'll actually push that out the bottom
along with the recovery system and so
hopefully that'll work - I know you can build them this way - other people have done it
and I just thought I'd give it a try. So this is very much experimental
this first flight that we're going to do
if it survives the first flight I'll probably do a little more to it probably
paint it, put better fins on it, put a better nose cone on it
but for now I'm just gonna see if it flies and then we'll go from there
so stay with us as we head out to the launch pad
and we'll see what happens. For this rocket
I didn't think I could use just a standard launch controller I was afraid
it wouldn't have enough power to fire all the engines off at once
sometimes when you press a button on a launch controller it takes a bit
for it to ignite the engines and I have to be sure that these all ignite
immediately and at the same time and so
what I did is just took .. cut off an extension cord
and made three bare spots on the wire
and I'll attach these
basically I'll be attaching the igniters
in parallel as opposed to in a series -. I don't believe you can do that with the
Estes igniter
they need to be attached in parallel. Then I'll plug this into a longer extension
cord
and then I'll simply attach that extension cord to
either vehicle battery or something like that or plugged into an outlet
and that should have plenty of voltage to fire it off.
my first indication of trouble came when I tried to put the rocket
on to the launch pad. The launch pad was small enough and the rocket heavy enough
that it had trouble keeping it pointed up right. however after some work I got
everything ready
I had my onboard camera strapped on I had the igniters attached
and I had it precariously balanced on the launch pad so it would fly straight up
but just as I was ready to touch the rocket of
I had yet another problem and that was the launch lug came loose from the side
and the rocket fell over. so the only thing to do at that point was to launch
directly from the ground so I took several sheets of flame proof recovery
wadding and laid those on the ground
and simply set the rocket on top
Eldon: Oh! Crystal: Parachute didn't come out.
Well, here's the snap swivel and it appears just fine but
I wonder if something happened to the the shock cord that it was
holding on to
OK, here's the engine, or the engine pod I should say
looks like all three engines fired, so that part works
that's largely intact. One of the engines
got punched up in a little further than it should have
The rear ejection seemed to work too but the problem of course was
the parachute.. oh yeah, I see. The shock cord
might not be able to see it but the shock cord down in there
looks like melted or burned up. Apparently I didn't choose the
the best material for shock cord - I just used what I had laying around the house
and
that cord must of
melted and that's what allowed the parachute and the
engine pod to detach and the rocket came straight down
and impaled itself into the ground.
there must be
I wonder if the nose cone got jammed up in there
the makeshift nose cone that I had that you probably saw earlier on the video
I won't be able to tell tell until I dig that dirt out of there and find out
well back to the drawing board
The take-off worked pretty good - it was the landing that
didn't the work out too well