Volum alfa model

Discussion on Stirling or "hot air" engines (all types)
Horex
Posts: 13
Joined: Sat Apr 08, 2017 8:48 pm

Re: Volum alfa model

Postby Horex » Sat Apr 22, 2017 9:12 am

Here is the drawing:

Horex
Posts: 13
Joined: Sat Apr 08, 2017 8:48 pm

Re: Volum alfa model

Postby Horex » Sat Apr 22, 2017 9:14 am

Here is the drawing:
Attachments
HC.jpg
HC.jpg (52.89 KiB) Viewed 533 times

Horex
Posts: 13
Joined: Sat Apr 08, 2017 8:48 pm

Re: Volum alfa model

Postby Horex » Sun Apr 23, 2017 8:09 pm

A technical question to the group:
(Take a look to my last drawing: HC.jpg)
I have made a new piston and a Heylandt Crown for the warm cylinder.Both are 29 mm long, The warm piston is 16 mm in diameter and HC is 14 mm diameter.
How big shall the HOTCAP inner-cylinder be ?
Shall HOTCAP have thin or thick wall ?
/johannes

Ian S C
Posts: 1941
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Volum alfa model

Postby Ian S C » Sun Apr 23, 2017 11:12 pm

The hot cap should be thin, to allow heat transfer, I think the hot cap on my motor is just over .25 mm thick. the end is made of the same material TIG welded on the end of the piece of tube that forms the cylinder.
Ian S C

MikeB
Posts: 8
Joined: Fri Jun 26, 2015 7:50 am

Re: Volum alfa model

Postby MikeB » Tue Apr 25, 2017 4:59 am

That picture shows the cylinder being vented at the right hand side - is that a mistake in the drawing, or how you've built it??

Horex
Posts: 13
Joined: Sat Apr 08, 2017 8:48 pm

Re: Volum alfa model

Postby Horex » Tue Apr 25, 2017 4:48 pm

Hi Mike
Sorry, this is bad drawing from my side.
The "ventilation" is output to the cold cylinder.
See S24.jpg how it was made first. The horizontal cylinder is the warm one.
I am working now to add Heylandt Crown to my warm cylinder. I keep the old cylinder, but are making a bigger Hotcap
The Heylandt Crown piston have the same length as the warm piston, but have ca 1 mm less diameter.
But how much free space shall I make ?

ps: can I do something with old drawing/picture ?
or just make new correct one?

Ian S C
Posts: 1941
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Volum alfa model

Postby Ian S C » Wed Apr 26, 2017 3:02 am

The only change I would make to your hot cylinder drawing is to out line the hot cap section at a similar profile and thickness to the Heylandt Crown. On the finished item it could be up to .75 mm/1 MM, or even a fraction thicker.
Ian S C

Horex
Posts: 13
Joined: Sat Apr 08, 2017 8:48 pm

Re: Volum alfa model

Postby Horex » Mon May 01, 2017 9:21 am

Hi Ian and all Stirling builders.

My motor will still not run even with a"regenerator".
Take a look to my “Paint” ( Stir-1) , is there any measurement I can adjust?
The "regenerator" is filled up with steel fiber stolen from the kitchen.
Cylinder stroke volume 0,8 x 0,8 x 1,9 = 1,9 ccm

/johannes
Attachments
Stir-1.jpg
Stir-1.jpg (102.32 KiB) Viewed 483 times

Horex
Posts: 13
Joined: Sat Apr 08, 2017 8:48 pm

Re: Volum alfa model

Postby Horex » Mon May 01, 2017 9:23 am

Here is a photo :
/johannes
Attachments
Stirling motor.jpg
Stirling motor.jpg (239.22 KiB) Viewed 483 times

Ian S C
Posts: 1941
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Volum alfa model

Postby Ian S C » Tue May 02, 2017 8:20 am

First thing to look at is friction, how well do the pistons fit, they need to be a close fit, but loose enough that if the piston is placed in an open cylinder it drops through, but if you seal one end(with your hand) the piston should slow almost to a stop.. Make sure there are no leaks. Maybe try to run the motor with a tube between the cylinders instead of the one with the regenerator (my motor has no regenerator). Are both the cylinders the same volume, the cold cylinder seems very tall in the photo, but that may be deceptive.
Ian S C

Horex
Posts: 13
Joined: Sat Apr 08, 2017 8:48 pm

Re: Volum alfa model

Postby Horex » Tue May 02, 2017 7:26 pm

Hi Ian and all Stirling enthusiastic people.

My motor have same diameter of the pistons diameter, so connected to same axel weave, the stroke volume would be the same. (2,4 ccm)
But how much can a closed volume be between the cylinders without it makes trouble for the compression or transportation?
The pistons shall press a “lot” of air between each other.
One piston stroke-volume is 2,4 ccm. (0,8 x 0,8 x (1,9 x 2) = 2,4 ccm) (The numbers in drawing Stir-1 are wrong!!!)

But how much volume of air is between?
Heylandt Crown has 0,2 ccm free space, Regenerator 1,3 ccm and the pipes make ca 1 ccm. Total ca 2,5 ccm
Total so is the volume between cylinder nearly same as one piston stroke-volume. But here I need a physicist that can tell me about transportation of air with different temperature in a closed system.

The friction is low, but the “compression” is good in a cylinder. I have done the “hand” test.
I will try to find a plastic tube to have between cylinders. The transportation-volume will be low and the plastic will heat- isolates the cylinders.

PS.
I am new in this group, so I don’t know how you like my big PAINT drawings. They are not technical correct, but the give me a visual ide what a problem is. I have problem to describe and to understand with only text.

Best wishes from
Johannes

Ian S C
Posts: 1941
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Volum alfa model

Postby Ian S C » Wed May 03, 2017 12:38 am

A GAMMA motor of similar shape has been run with a 6ft rubber hose between the cylinders with little or no lose of power. How good are the crankshaft, and con rod bearings.
Ian S C


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