SpudFiles

i got ggdt to open on vista thanks to the other posts and now get a run-time error 5 90% of the time i use it i have vista home and ggdt v4.6

This is likely caused by the fact you've given the barrel diameter as 100cm.

just changed it and still happend

edit: i changed it from cm to inch and it works

Possibly the fact the piston seat diameter and piston diameter are so close together.

You do know what each of those means, right?

EDIT: Alternatively, that pilot volume is very low, but GGDT has a feature that'll cover that.

I had something abit like that, does it just close the window down?

i drill press lathed my piston with a oring and put a moded schrader valve in it as a check valve.
and my pilot is full of hot glue it follows the d/4 rule

all the number in my ggdt screen shot are measured with digital calipers

yeah when i click ok it close

edit i downloaded it again and it works but only in inchs

-_- wrote:all the number in my ggdt screen shot are measured with digital calipers

So the diameter of the valve orifice (i.e. the hole the air flows through to get to the barrel) on your cannon is 19.7mm? With a 20mm diameter piston? Well, I can tell you right off, in the real world, that cannon wouldn't work.

What I think you've done is put the diameter of the piston in the seat diameter, and put the diameter of the tube it sits in under "piston diameter".

While the latter is acceptable, the former is a mistake - and if you've not made a mistake with the numbers you've put in, you need to fix that cannon.

no its 1.97cm is where the piston seals aganst and the piston is 2cm wide and i put a grove in the piston so that air can push it back since there isent much around the barrel port

Um... yeah, that just isn't going to work.

That groove - it does nothing. Air pressure acts in all directions. It will push on the back of your groove - but it will also push on the front of the groove completely equally.

Want a demonstration? Put the piston down on a table - it is now in a isobaric system like the chamber (namely, the atmosphere). Is it experiencing any acceleration as a result of unequal forces on that groove?

It isn't? Bummer. Well, it isn't going to experience any in the chamber either.

The problem here isn't with GGDT, the problem is with your launcher.

I had the same thing happen to me you just have to load it up a few times.

i know my gun works
i just downloaded it and it works now only in inchs
thanks for that rag i thought it would help, makes it lighter now

-_- wrote:i know my gun works

Well, if the launcher works, then you're clearly putting the wrong numbers into GGDT. If those numbers were genuinely the right ones, I have absolutely no doubt the launcher would completely fail to work.

my sealing face is a bit bigger than my piston(about 1mm on each side) that i did not acount for so your right

but still if i set my gun up in inches it work then set it to cm and i get run time error

ill try see if a bigger piston fixes it