3d printed rocket motor

[Jerry Isdale]

Buried in this (http://vimeo.com/19829560) video of a roadtrip to the FAR launch site in Mojave Desert is a bit of info on (and vid of test fire of) Unreasonable Rocket's (http://unreasonablerocket.blogspot.com/) 3D Printed rocket motor. Laser sintered aluminum was used on previous test. This test used LS Stainless.

So now 3d printing is part rocket science.

Jerry Isdale
http://MauiMakers.com

[James]

Actually, I bought a Makerbot for just that reason!

One of my primary reasons for getting a Makerbot was to print small
unique parts for my motors, (things like apogee detection system
parts as well as generate nozzle designs and fin slots etc..).

I just got it up and operational about 3 weeks ago, but I believe that
the Makerbot is perfect for development of single use motor parts.. I
plan to do some validation tests within the next 2-3 months.

[Conrad Farnsworth]

http://www.thingiverse.com/thing:4224 Try these...they fly...ok. They're my friend and I's designs. I did a video on the ordeal.

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Conrad Farnsworth
Lead electronic and technological engineer of project SAM

[James]

Very cool. I love the notched wing design with the ring, excellent
idea. I use formica for my wings, and plan to use the Makerbot to
manufuacture tracks that install on the side of the fusilage.

I am doing slightly bigger rockets, mostly over I-K size or low
pressure motors for land travel..

Here is a cute video that some friends put together from last year.

http://www.youtube.com/watch?v=Jocr5RdtutI

One of the guys at this event was actually making a Makerbot onsight.

In any event, I have started designs for a number of interal motor
components. The main one I am working on right now is an ignition and
delay reentry charge containment structure. (Big words for something
that will allow me to both start the motor and keep the motor
"together" for 3.6 seconds before a delay charge can ignite.)

On Feb 13, 5:37 pm, Conrad Farnsworth <robot.lig...@gmail.com> wrote:
> http://www.thingiverse.com/thing:4224Try these...they fly...ok. They're my

> Lead electronic and technological engineer of project SAM- Hide quoted text -
>
> - Show quoted text -

[beverageexpert]

this is awesome

On Feb 23, 5:00 pm, James <lru...@yahoo.com> wrote:
> Very cool.  I love the notched wing design with the ring, excellent
> idea.  I use formica for my wings, and plan to use the Makerbot to
> manufuacture tracks that install on the side of the fusilage.
>
> I am doing slightly bigger rockets, mostly over I-K size or low
> pressure motors for land travel..
>
> Here is a cute video that some friends put together from last year.
>
> http://www.youtube.com/watch?v=Jocr5RdtutI
>
> One of the guys at this event was actually making a Makerbot onsight.
>
> In any event, I have started designs for a number of interal motor
> components.  The main one I am working on right now is an ignition and
> delay reentry charge containment structure.  (Big words for something
> that will allow me to both start the motor and keep the motor
> "together" for 3.6 seconds before a delay charge can ignite.)
>
> On Feb 13, 5:37 pm, Conrad Farnsworth <robot.lig...@gmail.com> wrote:
>

> >http://www.thingiverse.com/thing:4224Trythese...they fly...ok. They're my

[Oren Beck]

The unexplored to my reading elements are printing whole engines or
just "fuel sticks" for metal/composite chambers.Let alone a whole
rocket. Using the proper materials as opposed to just what's either
easy,cheap, or expedient in some other way is what separates the great
builds from not good enough. Staying in one of the Goldilocks Zones
for materials spec- 3D printing's a tool I see as barely even into
infancy. Making solid propellant sticks with gradient density ratios
of fuel/oxidant seems to have been done several different ways. The
melt extrude points for several propellants I can think of seem not
far outside what we use for plastics. I had some time ago wondered
about using 'bot extruder tech for casting propellant and looking at
this site may show why.

http://www.jacobsrocketry.com/aer/caramel_candy_propellant.htm

Why would someone "bother" using a fab bot to extrude sugar
propellant? Remote control safety comes to mind first. IF you've ever
seen someone mess up while making the sugar/saltpeter rocket variants?
A sacrificial 'bot's a lot cheaper than skin grafts or worse. I'm one
of the most risk reality balanced people you may meet in that I'm not
either blissfully ignorant nor stupidly overcareful in either extreme-
usually.

There's a different everything for man rated rocketry and hobby gear
too. Someday- we may print man rated rockets. We won't get there
unless we get hobby stuff perfected. I fly Estes shrinkwrapped stuff
with my Grankids. Because they're boringly reliable. And fail "less
dangerous" than some stuff Tripoli rightly forbids. No- I'm not a
member of any rocketry org. So I can be neutral for now.

I'd LOVE to see a whole rocket printed by 'bot including "copter
wing" recovery as printing plastic sheet's edgy for now. but? As a use
for PVA support material dissolved after a built that uses it? taking
as reuse example- PVA used for the support material while making an
integrated fin/motor shell like the RTF solid kits use?

Dissolve the PVA, decant the solute into a shallow pan and dewater etc
forming into a sheet for parachute film?

On Feb 24, 4:27 am, beverageexpert <beermake...@gmail.com> wrote:
> this is awesome
>
> On Feb 23, 5:00 pm, James <lru...@yahoo.com> wrote:
>
> > Very cool.  I love the notched wing design with the ring, excellent
> > idea.  I use formica for my wings, and plan to use the Makerbot to
> > manufuacture tracks that install on the side of the fusilage.
>
> > I am doing slightly bigger rockets, mostly over I-K size or low
> > pressure motors for land travel..
>
> > Here is a cute video that some friends put together from last year.
>
> >http://www.youtube.com/watch?v=Jocr5RdtutI
>
> > One of the guys at this event was actually making a Makerbot onsight.
>
> > In any event, I have started designs for a number of interal motor
> > components.  The main one I am working on right now is an ignition and
> > delay reentry charge containment structure.  (Big words for something
> > that will allow me to both start the motor and keep the motor
> > "together" for 3.6 seconds before a delay charge can ignite.)
>
> > On Feb 13, 5:37 pm, Conrad Farnsworth <robot.lig...@gmail.com> wrote:
>

> > >http://www.thingiverse.com/thing:4224Trythese...theyfly...ok. They're my

[James]

I use to be a member of Tripoli, there down right hatred of PVC motors
for the silliest of reasons is one of the reasons why I dropped my
membership.

I have been doing Kno3/Sugar motors for years, I love the simpleness
of the mixture and its low burn rate makes it pretty forgiving. The
largest challenge with manufacture of propellant grains (the chunks of
fuel that you would put into a chamber) is introducing cracks,
fissures or imperfections that can increase the surface area, which in
tern creates more burn surface, leading to over pressurization, which
chain reacts, (higher pressure, faster burning) and potentially
catostrophic results. There are many ways that you can create them,
form the video, you can see that I make them in a wok, but I don't
think that the current methods of 3d printing would be effective for
manufacturing the propellant grains. Only because the risk of surface
area exposure would be too great if there were any imperfections in
the structure, or weaknesses in the bonds between layers when exposed
to the pressures.

> > > > - Show quoted text -- Hide quoted text -