Page 1 of 1

Part Ghetto First Combustion 75mm Mortar

Posted: Thu Mar 27, 2008 9:51 am
by MaxuS the 2nd
Well this is my very first combustion in all my experience with Spudguns, it took a bit over an hour to complete and just seems quite ghetto with all the tape and whatnot. It will definately be my last combustion.
The bore is actually closer to 68mm than 75mm.

The shots were in order of Crap - Best.


[youtube][/youtube]

Posted: Thu Mar 27, 2008 10:20 am
by potatoflinger
That isn't a bad looking gun, but as you said the performance wasn't too great, although the shots were getting progressively better, so I guess you were getting better at measuring the fuel.

Unless you go all out and build an advanced combustion, the performance of a combustion gun won't really be too amazing.

Posted: Thu Mar 27, 2008 10:56 am
by Tom
It doesn't look that bad :D . I don't now if it's possible but when you don't have a bigger chamber the barrel I would use a powerful fuel like hydrogen :twisted: . I'm not sure the PVC will hold that amount of pressure :!:
Tom

Posted: Thu Mar 27, 2008 11:21 am
by MaxuS the 2nd
Lol, well thanks guys..It's probably going to rot in my shed now. :D

I'm a pneumatic man, I like them far more than combustions mostly due to the reliability.

Posted: Thu Mar 27, 2008 12:04 pm
by Carlman
what is your ammo for that thing?

and also a simple propane meter would work wonders for this thing :D

Posted: Thu Mar 27, 2008 12:10 pm
by MaxuS the 2nd
I'm using very loosely fitting tennis balls and whatever else I can shove down the barrel. This cost almost nothing to make, the end plug is custom made from a piece of wood and bolted into the end. I'm using a schrader for supplying new air to the chamber.

I can't be arsed to make a propane meter for this beast, all efforts are going into my rather huge spud gun instead (it's yet another pneumatic).

Posted: Thu Mar 27, 2008 12:12 pm
by Carlman
mmmmmmm k, i still love it though :D

Posted: Thu Mar 27, 2008 12:13 pm
by MaxuS the 2nd
Lol, doesn't even produce a muzzle flash. :(

Posted: Thu Mar 27, 2008 12:28 pm
by Carlman
what is the ratio you using?, spose you could control and change that by moving the position of the stop...

Posted: Thu Mar 27, 2008 1:46 pm
by MaxuS the 2nd
C:B Ratio was about 0.5:1. Yeah, I thought about moving the stop.

I did a dry fire earlier and it sure does require ear protection when standing right next to it.

Posted: Thu Mar 27, 2008 2:07 pm
by Tom
What is the maximum pressure of the PVC your using?

Posted: Thu Mar 27, 2008 3:21 pm
by MaxuS the 2nd
It is rated for 10 bar (147.5psi). I'm doubtful it will fracture under such low pressures.