I have a lot of articles and videos on HPR modeling, mostly specific
techniques. Here's a video on sport-scale modeling for example:
http://jcrocket.com/sport-scale-modeling.shtml
John
On Fri, Jun 26, 2015 at 2:05 PM, Adrian P. Bailey <adrian@xxxxxxxxxxxxxxx>
wrote:
Thanks Mike! We’re frugal, too, so this is great advice, thank you! This
is all about teaching Max that we can build cool things that don’t arrive
in a glossy box from Denmark with step by step instructions… ;)
I doubt we’ll be fabricating our own parts (at least not the main ones)
but that’s something to consider for the next project.
*From:* roc-chat-bounce@xxxxxxxxxxxxx [mailto:
roc-chat-bounce@xxxxxxxxxxxxx] *On Behalf Of *Mike Riss
*Sent:* Friday, June 26, 2015 1:43 PM
*To:* roc-chat@xxxxxxxxxxxxx
*Subject:* [roc-chat] Re: Scratch build tips
Adrian and Max,
I'm "frugal". So, I decided that rather than buying a kit of a rocket I
really wanted (LOC Expediter), I would build one from scratch. I'd suggest
the same principle (using an existing design, not the frugal part) for your
first attempt.
- Pick a rocket you really like.
- Then, find a sim file for it. Most manufacturers provide them, and
there are some online sources as well (rocketreviews.com for example).
- Use the sim file to get a list of parts.
- Then, source the parts from either online vendors if you need it right
away (or it's the only source), or keep in mind another back-yard source --
the vendors that attend our launches.
- Use the instructions from the kits you've assembled as a guide. Modify
them with the knowledge you've gleaned from your experience so far.
- One thing to consider is upsizing the motor mount, so the rocket stays
active in your fleet as you progress through the hobby -- you can always
adapt down, but it's harder to make the motor mount bigger once the
rocket's built.
Also, there's scratch, and then there's "scratch", where you fabricate
parts yourself. For instance, with a big rocket, you might use "sonotube"
or something similar for the rocket body. However, it doesn't always match
up in size with available nose cones. So, you make the cone yourself.
Bryce had an interesting method for his L3 Squat :-) Using composites,
you can even make the tubes yourself, as well as make flat stock for fins,
centering rings, etc. You can also adapt "trash", like carpet tubes you
find (for free!) in a dumpster.
Check out some of the online resources like John Coker's site (
jcrocket.com), or The Rocketry Forum (rocketryforum.com), which has a
section devoted to scratch builds (but there's lots of scratch projects in
the other sections too).
Take advantage of the Tripoli TAPs and NAR L3CCs. Most people think of
them only for certification, primarily L3, but they have a wealth of
knowledge that anyone can use. They can be especially helpful if for
example you're trying to upscale a model rocket design but aren't sure what
material/size/thickness/etc. is appropriate for your rocket and intended
motors.
Most of all . . . have fun!!!
Mike
On Friday, June 26, 2015 12:00 PM, Adrian P. Bailey <
adrian@xxxxxxxxxxxxxxx> wrote:
LOL, we’re new to rocketry but I have been using McMaster-Carr for
decades. And they are in our back yard… ;)
*From:* roc-chat-bounce@xxxxxxxxxxxxx [
mailto:roc-chat-bounce@xxxxxxxxxxxxx <roc-chat-bounce@xxxxxxxxxxxxx>] *On
Behalf Of *Allen Farrington
*Sent:* Friday, June 26, 2015 11:51 AM
*To:* roc-chat@xxxxxxxxxxxxx
*Subject:* [roc-chat] Re: Scratch build tips
Excellent! I get components from Public Missiles, Giant Leap, and Madcow,
depending on what I'm up to. I'm sure others have good sources as well. Oh,
and I use McMaster-Carr for hardware.
Allen
Terseness and mis-spelling courtesy of my iPhone
On Jun 26, 2015, at 11:38 AM, Adrian P. Bailey <adrian@xxxxxxxxxxxxxxx>
wrote:
Thank you!
We modified our Mirage to take an I motor with some help from David Reese.
For the next project we want a big, fat, low and slow rocket.
Any suggestions on where to source the parts?
*From:* roc-chat-bounce@xxxxxxxxxxxxx [
mailto:roc-chat-bounce@xxxxxxxxxxxxx <roc-chat-bounce@xxxxxxxxxxxxx>] *On
Behalf Of *Allen Farrington
*Sent:* Friday, June 26, 2015 11:32 AM
*To:* roc-chat@xxxxxxxxxxxxx
*Subject:* [roc-chat] Re: Scratch build tips
My first experience was that I modified a few kits, then later went to
full-scratch. I converted a L1 rocket into a dual deploy by adding a
payload section and electronics bay. Next I modified a LOC Magnum to change
the motor mounts and add air-start wiring as well as an extended payload
section. The nice thing about modifying a kit is that you get most of what
you need component-wise, and then you can order other components, usually
from the kit manufacturer. One common thing to do is to purchase a kit with
a 29mm motor mount and then find and order the parts to upgrade the mount
to 38mm. You’ll have to modify the fins to do this so it’s a good way to
start getting used to doing the types of modifications required to do a
full scratch build. I would stay away from minimum diameter for your first
scratch build as it adds a bit of complexity to the fin attachments.
Before you know it, you’ll start getting familiar with the different sizes
of the different types of tubing. For example, 3” cardboard is not the same
as 3” phenolic or 3” fiberglass. Couplers and bulkheads and centering rings
all have to be ordered or modified if you change tubing and modifying kits
is a safe way to step into that world.
Good luck!
Allen
--------------------------------------------------------------------
Allen H. Farrington
http://www.allenfarrington.org
818-653-2284
On Jun 26, 2015, at 11:14 AM, Adrian P. Bailey <adrian@xxxxxxxxxxxxxxx>
wrote:
Max and I are exploring the options for a project for November’s ROCstock
that we will start working on together over his summer break. Any tips on
how to get started building from scratch? We have been playing with
OpenRocket (thank you Chis and Phil) and I see that Apogee Components has a
lot of parts available.
