Simple Pump Action Design

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
jean
Specialist
Specialist
Germany
Posts: 125
Joined: Thu Dec 13, 2007 12:23 pm

Wed Sep 28, 2016 1:55 pm

Hi,
i am a rookie with cad, but it will be enough to understand the whole concept.
Hopefully your will leave a comment or critique

The design comes up with only a few parts.
1. The blue one is the moving part. Built of butane reservoir, outer part of the meter and a piston (with one-way-oring).
2. The green one - barrel and endplug, for the combustion chamber.
3. The red one - inner part of the meter, endplug (with one-way-oring).

Remenber .. green part and red part are "static" parts.

1.By moving the blue part to left...
-the piston suck fresh air in (right side)
-the piston push the (old) gases (left side of piston) out into the enviroment
-the butane-reservoir shut up
-the meter-pipe open (meter-pipe to chamber)


2.By moving the blue part, from left to right (front to back),
-the piston will displace the air/fuel from the right side of the piston to the left side of the piston (passing the lose oring)
-the meter-pipe shut up (meter-pipe to chamber)
-the butane-reservoir get open

ready to ignite..

:)
Sorry for bad english..
Attachments
picture1.jpg
picture2.jpg
picture3.jpg
User avatar
mark.f
Sergeant Major 4
Sergeant Major 4
Eritrea
Posts: 3634
Joined: Sat May 06, 2006 11:18 am
Location: The Big Steezy
Has thanked: 57 times
Been thanked: 57 times
Contact:

Donating Members

Thu Sep 29, 2016 11:47 am

I had a similar idea that I never got around to implementing here. Essentially it's the same operating principle although yours is a lot better.

Hopefully we can see something like this in action. :D
jean
Specialist
Specialist
Germany
Posts: 125
Joined: Thu Dec 13, 2007 12:23 pm

Thu Sep 29, 2016 5:23 pm

Thanks for you reply:)
Nice design.
And yes i hope it to :mrgreen:

So i just ordered some aluminium pipe 3"x8" (80mmx2mmx200mm).

Orings are the next on my list but i have some trouble to decide the dimensions and materials...some help is very welcome.
Should i skip the orings and go with a flap-check-valve design..?

Some of the parts will be 3d-printed in ABS :idea:, there no problems with oring grooves or something like that.
Ordered a spool of flexible TPU-filament to try printable seal.
Ideas are welcome:)
User avatar
mark.f
Sergeant Major 4
Sergeant Major 4
Eritrea
Posts: 3634
Joined: Sat May 06, 2006 11:18 am
Location: The Big Steezy
Has thanked: 57 times
Been thanked: 57 times
Contact:

Donating Members

Thu Sep 29, 2016 8:34 pm

I had to deal with the build constraints I had personally. If you can print o-ring grooves they would probably be more reliable and safer.
jean
Specialist
Specialist
Germany
Posts: 125
Joined: Thu Dec 13, 2007 12:23 pm

Wed Oct 05, 2016 11:30 am

Today some orings arrived. Still waiting for the al-pipe.

The orings are 66mmx5mm and 2x2mm in dimension.
Attachments
20161005_180907.jpg
jean
Specialist
Specialist
Germany
Posts: 125
Joined: Thu Dec 13, 2007 12:23 pm

Thu Oct 13, 2016 12:42 pm

Hi :)

I got the aluminium tubes and printed the first parts.
Changed the meter in size (6mm diameter to 13mm dia.), also got new orings 7.8mmx2.4mm (insted of 2mmx2mm)
Attachments
IMG_20161013_193332.jpg
jean
Specialist
Specialist
Germany
Posts: 125
Joined: Thu Dec 13, 2007 12:23 pm

Fri Oct 21, 2016 8:21 am

So yeah redesigned red part and printed in pla. Some parts will be glued together..because of some warping issues i sliced the piece.
Attachments
Clipboard01.jpg
Clipboard01.jpg (28.74 KiB) Viewed 5797 times
IMG_20161015_225141.jpg
User avatar
Alanstone
Private 4
Private 4
Posts: 61
Joined: Wed Dec 14, 2011 3:11 am
Location: South Africa

Sat Oct 22, 2016 4:15 pm

Hi Jean. Good luck with your project. You say you are printing the parts in pla and then going to glue them together. What glue are you going to use for that?
jean
Specialist
Specialist
Germany
Posts: 125
Joined: Thu Dec 13, 2007 12:23 pm

Sat Oct 22, 2016 9:23 pm

Thanks Alanstone
Glue for PLA is Dichloromethane.
jean
Specialist
Specialist
Germany
Posts: 125
Joined: Thu Dec 13, 2007 12:23 pm

Tue Nov 01, 2016 12:13 pm

Slowly getting in shape.
Attachments
IMG_20161101_180056.jpg
User avatar
Alanstone
Private 4
Private 4
Posts: 61
Joined: Wed Dec 14, 2011 3:11 am
Location: South Africa

Tue Nov 01, 2016 1:35 pm

Looking good. It's coming along nicely. I am looking forward to how your project works out.
Post Reply