[Robotgroup] Ponginator work night

[Richard Abbott]

  I appreciate all of Ed's hard work and thinking that have gone into this project. I didn't think it would be a piece of cake. Too bad you couldn't make it to the meeting last night. The surprise strippers were a real hit. Anyway, I just cleared it with the owner and he agreed to let us come to my work tonight and do our experimenting here. He is concerned about injury and legal issuse so I am going to draft some sort of " If I am injured, it's my own fault and I will not sue" document to ease his mind somewhat. I know we are a careful bunch, but stuff happens. So anybody who is interested in this and wants to throw their $.02 in, can come to my shop tonight from 7:00 till we decide to call it. The address is Randolph Austin Company, 2119 FM 1626, Manchaca

Ed Xavier Gonzalez <ohlaser at swbell.net> wrote:
  Well . . . I hate to send bad news, but, the results this evening 
(actually, Friday morning at 01:00 AM) were a bit less than stellar (I've 
been reviewing various websites to see if there is more to learn, so the 
time is MUCH later than the actual start time of this note).

Connecting the valve directly to the compressor, then the 1.5" pipe to the 
valve and cranking the pressure up to 120psig+, the most I got was a measly 
six feet before the ball hit the floor. I think the reason for the 
lackluster performance is the total VOLUME of air, not the air PRESSURE 
going through the valve body.

After reviewing some of the designs previously sent, they all seem to 
prefer a straight-through valve with a 90 degree shutoff directly connected 
to an air bladder with the inside diameter of the valve that is the same as 
the inside diameter as the pipe, or a MUCH larger valve body so there's no 
internal flow limitations such as a water sprinkler valve. Of course, 
everything needs to be as close to the maximum size of the output diameter 
of the pipe as is feasible to minimize constrictions of the air flow. This 
results in a full release of air with no restriction and an immediate 
impulse of the entire volume of whatever storage cylinder is 
installed. That's how they can get such incredible distances from all 
their designs. A limitation they don't discuss is the 'single fire' nature 
of their plans, so doing this multiple times will require multiple barrels 
and lots of loading. Since I don't have a specific 1/2" to 3/4" pipe 
adapter, I wasn't able to try the 24VAC sprinkler valve that's in the box, 
Vern.

I'd like to bring what I've tried to Vern's house Friday evening (if he and 
all of you are available and interested), so you can see what I've 
done. The only thing I'd ask is that we restrict our happy band to persons 
over twenty years old so we can stick to accomplishing the goal rather than 
children playing games and wasting time (I get REALLY grumpy when I work 
until 2:20AM, huh?).

Maybe I'm missing something in the simple connections I've made, so I plan 
on getting the adapter previously mentioned and possibly a straight through 
1.5" diameter shutoff valve if I can afford it, and stick each of them 
inline without the existing electrical valve body. The manual valve will 
make controlling the release essentially a manual process rather than 
computer controlled, so the sprinkler valve might still be a viable option, 
but it will require a 24VAC doorbell transformer to power it.

I'd still like to consider trying the spring-steel/motor and the spinning 
wheel designs if the sprinkler design doesn't work, so if someone else 
would like to take over the pneumatic design so there can be parallel 
attempts, now is the time to jump up and wave.

Hey, Vern? You up to another group of people wandering aimlessly around 
your garage late in the day? How about Saturday? You guys up for another 
adventure at Vern's if he's up to it?



Ed Xavier Gonzalez
Oak Hill Laser
ohlaser at swbell.net
(512) 288-5243