LTD Stirling engine

[Powder keg]

I'm planing on using plastic for the con rod bearings. I was going to machine some tubes with a groove on the outside. These would be screwed to the crank and not turn. The wire would just spin on the plastic. This should work good right?

Thanks, Wes

 

[BobWarfield]

I'm getting curious about machining some graphite while reading this thread. I know it is very commonly used with EDM machines. I'm wondering if there are grades or sources of graphite that is especially machinable. I've never messed with a very big chunk of the stuff.

Best,

BW

 

[Davyboy]

Hi Wes, I had the bearings on my Simple Simon too tight, and it wouldn't work. My crankshaft was made from hand-straightened wire, so it had a bit of runout. The crankshaft bearings were rigid in the frame, they worked only after I let them "float" with the crank. (Slopped'em out a bit ) This guy has to turn over easily with no binding. As for the weight of the con rod wire, I believe that balancing the weight is more important than mass, at a reasonable scale of course. Just my .02c

 

[Powder keg]

I've made a couple graphite pistons. The best way I've found to get a good size is to turn the piston down to a thou. bigger then file it down to with in a couple tenths. Then sand it down with newspaper. This will give a really good finish.

I was planing on making the bushings a running fit in the con rods.

I think that the less rotating mass you have the less weight there will be on the graphite bushings. This will mean less friction.

Wes

 

[Powder keg]

I started night school to learn CNC's and I am thinking of making some of the parts there. That would partially void the weekend engine idea, but I'd have another engine:O) I'll still post the plans for download:O) I have the top and bottom plate drawn up and will try and machine them soon. I am also drawing some of the pieces.

Wes

 

[Powder keg]

I have a couple pictures drawn up on Mastercam and I would like to make them into Jpegs or something that everyone can look at. Is this possible?

I figured out a way to hide the bolt's that goes through the center to hold the two half's together also. I about have this drawn up. I am planing on cutting this part out on the CNC. I'll tke some pictures and hopefully some video:O)

Wes

 

[1Kenny]

Hey Wes,

Is there something like a Mastercam reader we can down load?

kenny

 

[Brass_Machine]

I have a couple pictures drawn up on Mastercam and I would like to make them into Jpegs or something that everyone can look at. Is this possible?

I figured out a way to hide the bolt's that goes through the center to hold the two half's together also. I about have this drawn up. I am planing on cutting this part out on the CNC. I'll tke some pictures and hopefully some video:O)

Wes

Wes... I am not familiar with mastercam, what is the file type when you save it? I may be able to convert it for you. OR look to see if the is an export option OR take a screenshot with mastercam open.

Eric

 

[Powder keg]

I'm fairly new at this. How do you do a screenshot? I can save the files as DWG's if that helps? I've only had one night class so far on cad and I have a lot to learn. Mastercam is a program made to design a part and then machine it. From what I've seen, It's not a super Cad program, but what it does on the CNC end is awesome! I can machine a part on my computer before I even get the mill warmed up.

Later, Wes

 

[Brass_Machine]

Sent ya a PM

Eric

 

[Powder keg]

Anyone have any ideas on holding the styrofoam displacer cylinder, without smashing the crap out of it?

Thanks, Wes

 

[Powder keg]

I'll give that a try. Should there be something in the middle to reinforce where the displacer shaft enters the foam?

Wes

 

[Kactiguy]

Wes, I built a displacer out of that blue insulation foam that they put on houses. It was very lightweight and very easy to shape with sandpaper. I stuck some on a mandrel once and spun it on the lathe, then shaped it with sandpaper. Seemed to work fine for me.

 

[Powder keg]

I have most of the pieces drawn up now. Once I figure out how to post them here I will. I have the displacer cylinder done. I've decided to CNC some of the parts. The top and bottom plate, The flywheel support, and the flywheel will be cut out on the CNC. I'll start to post pictures in the build log section of this engine.

Wes

 

[Brass_Machine]

There ya go Wes

 

[Brass_Machine]

Posted for Wes

 

[Powder keg]

Thanks! I have all the toolpaths figured out for the flywheel pedistal. I should be able to machine it at school on Tuesday. I'll try and get a video:O)

Wes