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Newbie on Stirling Engines [Need HELP plz...]

Posted: Mon Apr 05, 2010 9:31 am
by empty
Hi Guyz!!!

I'm 3rd Year High School student here in the Philippenes...

and i was wondering if you guyz could help me with my research...

It's a stirling engine for charcoal stoves....

I got my diagram for the device and i just need help with the materials needed....

And some corrections on my diagram if it will work or not....

I'll post it tommorow, haha... forgot to copy it from my laptop... its late night now...

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Mon Apr 05, 2010 8:32 pm
by empty
here it is....


Image



Description...

The Area with red paint, is where it gets heat... (through charcoal...)
that area is where the charcoal stove is....

The piston with pink/violet paint needs to be on the other side at first....

So is the piston with blue paint....


Please suggest things.... Thnx :D

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Tue Apr 06, 2010 4:33 am
by Junkie
Hi,
I'm not sure why you have so many pistons. You only need two.

I changed your diagram. See if you can get hold/make of a graphite piston for the power piston they are really
smooth and perfect for this engine.

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Tue Apr 06, 2010 5:00 pm
by empty
Junkie wrote:Hi,
I'm not sure why you have so many pistons. You only need two.

I changed your diagram. See if you can get hold/make of a graphite piston for the power piston they are really
smooth and perfect for this engine.


It is becuase, the fan is used to give air unto the charcoal [the heat source].....


My research is called... Modified Charcoal Stove with Built-in heat powered fan....
So basically, i need to get the heat source from the charcoal in order to run the fan, at the same time the fan gives/produces air and the air goes to the charcoal.... So the expected reaction would be that the charcoal would increase in temperature, burn more....

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Tue Apr 06, 2010 7:59 pm
by empty
im kinda like 15 years old... in the Philippines...

Where/How to make a graphite piston?

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Sun Apr 11, 2010 1:36 pm
by Junkie
I think it would be better to connect the fan via a belt / chain etc rather than have all those piston. I don't think the engine would be able to overcome the friction from those extra pistons. It's best to keep it as simple as possible if the stove depends on it to run.

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Tue Apr 13, 2010 5:07 am
by robertvi
I agree that you should try to make do with only 2 pistons (one power piston and one displacer piston). A little air will leak out for each piston - if you have too many the machine will leak too much, or else have too much friction to work.

I don't know where to get graphite pistons - they would probably be best. Alternatively you may be able to get hold of some high temperature epoxy glue called JB Weld. It is possible to make a piston by pouring this epoxy into the power piston tube and letting it set. Be careful - it contains some nasty chemicals. Here is a video showing how to do this:

http://www.youtube.com/watch?v=RbhTKQKcH1c

Good luck!

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Tue May 04, 2010 6:09 pm
by empty
Thanks guys! I've got the engine almost done..

Please help me make the crankshaft please..

The parts of the crankshaft i need to build it.. < This confuses me..

And I've tried placing u-joints and knuckle join on the connecting rods before connecting it to the crankshaft.. but no store in our country sells them.. please.. i need help badly..

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Fri May 07, 2010 8:09 pm
by robertvi
one way to make the crank shaft is to get some wire that you can just about bend using tools (like a coat hanger), and bend it into the shape you need

i also tried making one out of flat aluminium pieces and bolts, screwed together very tight - it sort of worked, but the problem is the shaft ended up not quite straight. see the picture for a small part of the crank i made (sorry i didn't photograph the whole thing!)

you can also avoid having a complicated crankshaft altogether is you use a rocking bend design, but you need to arrange the power piston at 90 degrees to the displacer piston:
http://www.boydhouse.com/stirling/

hope this helps

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Sat May 08, 2010 2:37 am
by Junkie
The easiest way is to just bend brass or copper rod say around 2 - 4mm. You can use a gas torch to soften the bends

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Mon May 31, 2010 12:07 am
by empty
Image



will this engine work? the red spot indicates the heat source.. and thats the placement of the engine.. not vertically. but horizontally..

i got confused wether it will work because the displacer cylinder and power cylinder are open on the other end.. but the pistons are about the same size/circumference as the cylinders...

will it work?

edit* forgot to draw the water box... anywats my problem is if it will work with the cylinder open? as stated above..

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Mon May 31, 2010 5:28 am
by Junkie
No it won't work, you need the displacer cylinder to be sealed at both ends, then it will work :cool:

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Wed Jun 02, 2010 6:30 am
by empty
i cant help but notice...

http://www.youtube.com/watch?v=x4LIO_xs ... re=related

this engine also runs w/o the top covered...

damn it, gonna test this out first.. and consult with our adviser...
then do the editing... thnx guys!

gonna post pictures of the real deal a week from now..
and updates,,

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Wed Jun 02, 2010 8:10 am
by Junkie
I think the hog engine is an alpha type engine ? Not clear but it looks like it. Those don't have displacers, they have two pistons that are hot and cold. A displacer type engine won't work if it's not airtight.

Re: Newbie on Stirling Engines [Need HELP plz...]

Posted: Thu Jun 03, 2010 7:54 pm
by empty
Image

here, what if i remove the hose.. then replace the water box with a cold plate.. and attach the both cylinders at differend ends? make it like an alpha type stirling engine.. will it work?