The pipe for the barrel is 1 1/4 in. 24 in. long. The end caps for the
projectile are 3/4 in. so there is not to much of a loose fit. I haven't
made one myself but a friend of mine has & it does just like the article
say's, use with caution & safety. I'm interested how it works with a tennis
ball, that sounds real neat. Howard K0ACF
"John Ferrell" wrote in message
...
On Fri, 27 Nov 2009 17:13:50 -0800 (PST), Gary
wrote:

On Nov 27, 11:27?am, John Ferrell wrote:
There is an artical by W4SSY in the March 2009 QST Magazine. I am
planning to duplicate it for use at my QTH. I am interested in any
comments, especially from anyone who may have already built one.

My available trees may be about 80 feet so that is my minimum
expectations!

There is a lot of Google information available but I am trying to
focus on this example.

John Ferrell W8CCW

Hi John, I have not built one yet but am contemplating. Mine will
use a Rain Bird 1" Auto Sprinkler Valve, electrically actuated (24 VAC
or DC). I plan to use a Harbor Freigth 5 in one power source for the
air compressor, the pressure gage, and the 24 VAC actuator supply.
The power source is $60-$90 depending on the sale going on, it is also
handy for lots of other stuff.

This will be my first shot because I have this available. As far as
the PVC, tire valve, fishing reel, ect. don't have that much
experience. As far as line, I have had one break on me after a nice
launch with a sling shot. Make sure your line is of good quality.
Happy launching.

Gary N4AST
I bought most of the supplies last night at Home Depot. The Orbit
sprinkler valve was only about $12. It is an inline type valve like
the one in the artical. I was thinking I would use a long piece of
pipe as the accumulator but after doing the math I have decided to go
back and get a piece of 3 inch pipe to use. BTW, the cement and primer
is available in a single package for about $6.50. I am a little
concerned about the loose fit of the projectile in the 1-1/2 inch
barrel.

I will report back as I continue.
John Ferrell W8CCW

"Howard K0ACF" wrote in message
...
The pipe for the barrel is 1 1/4 in. 24 in. long. The end caps for the
projectile are 3/4 in. so there is not to much of a loose fit. I haven't
made one myself but a friend of mine has & it does just like the article
say's, use with caution & safety. I'm interested how it works with a
tennis ball, that sounds real neat. Howard K0ACF
"John Ferrell" wrote in message

I don't have that QST but I built one like this:
http://www.qsl.net/k5lxp/projects/La.../Launcher.html

I did wrap a couple of layers of electrical tape over the end caps I used.
Found some orange electrical tape that I thought would make it easier to
see..
Still sort of loose in the pipe. At 35 psi it will shoot them to about 60
feet or more. My first trial shot put it over my triband beam that is about
55 feet up. Did not mean to do that but just wanted to get the feel of how
much psi I should use. I have found 45 psi will put it over the tops of the
trees here that are over 70 feet tall.

On Sun, 29 Nov 2009 10:17:37 -0500, "Ralph Mowery"
wrote:


"Howard K0ACF" wrote in message
.. .
The pipe for the barrel is 1 1/4 in. 24 in. long. The end caps for the
projectile are 3/4 in. so there is not to much of a loose fit. I haven't
made one myself but a friend of mine has & it does just like the article
say's, use with caution & safety. I'm interested how it works with a
tennis ball, that sounds real neat. Howard K0ACF
"John Ferrell" wrote in message

I don't have that QST but I built one like this:
http://www.qsl.net/k5lxp/projects/La.../Launcher.html

I did wrap a couple of layers of electrical tape over the end caps I used.
Found some orange electrical tape that I thought would make it easier to
see..
Still sort of loose in the pipe. At 35 psi it will shoot them to about 60
feet or more. My first trial shot put it over my triband beam that is about
55 feet up. Did not mean to do that but just wanted to get the feel of how
much psi I should use. I have found 45 psi will put it over the tops of the
trees here that are over 70 feet tall.


That is the model that I planned to use if the available Sprinkler
valve had that particular configuration. I was concerned about this
model because of the barrel and the tank being of equal volume. It is
good to have the testimony that it works as well! I be live it would
be easier to build and cost a little less as well. I would lean toward
the 1-1/4" barrel bore and the 3/4" tubing projectiles because I have
yet to see the 1" end caps described locally.

I may get to try a paper towel for a "patch" as used in Black powder
fire arms tomorrow. I am anxious to get up the 160 meter inverted L.

John Ferrell W8CCW