Stirling powered fan

[daz]

After much deliberation on whether or not it would be too complex for a relative beginner I have decided to grow a pair and just do it!
I fitted a new QCTP the other day and fitted some nice sharp tooling to the holders, then read over the drawings half a dozen times. I still don't "get" fractions, I was born too late! So everything is being converted by way of a vernier and my now falling apart Zeus book.
I am not doing this in the same order as the plans and instructions, but doing the bits I already have the materials and skills for. I hope to learn along the way and as my skills and confidence grow I can tackle the more complex parts. Some of them I can't do due to lack of tooling and work holding, so I will shop a couple of bits out to a local firm who I have been dealing with for quite a few years. These two guys are the busiest company anywhere close to where I live, we no longer have any "propper" machinists round here apart from these two so their services are very sought after, they can be grumpy, cantankerous, bad mouthed, and even down right rude, but when it comes to machining they are sh*t hot

Don't worry some pics are coming in the next post, but first I have to find out how to put text between the pics so they are not all joined together with one big explanation at the bottom. If someone knows where I can read about this I would be greatful.

cheers
daz

[sparky961]

When posting, I usually use IMG tags that link to remote pictures (PhotoBucket in my case, but could be anywhere online).  This is probably the most common method that people use here.

When you insert it, the forum translates it into showing just the picture but when you are editing your post, you would see something like:
[I MG]http://i296.photobucket.com/albums/mm185/sparky961/IMG_4883.jpg[/I MG]

(Except without the space in "IMG" - otherwise you'd see a picture where I put that in )

To put text between pics, just add the "tags" as indicated above, and type your explanations between

If I typed something like this:

Code: [Select]

This is an example of the kind of setup needed with my mill/drill/lathe combo:
[IMG]http://i296.photobucket.com/albums/mm185/sparky961/IMG_4884.jpg[/IMG]

I was a bit nervous the setup might come apart, so I put a board under the spinning parts and didn't stand inline!
[IMG]http://i296.photobucket.com/albums/mm185/sparky961/IMG_4883.jpg[/IMG]

I would get the results exactly as shown after this....
-----------------------------
This is an example of the kind of setup needed with my mill/drill/lathe combo:


I was a bit nervous the setup might come apart, so I put a board under the spinning parts and didn't stand inline!



-Sparky

[Bernd]

Nice explination Sparky. 

Would you like a job as a Moderator?       

Just kidding.

Bernd

[daz]

Thanks for the tip sparky, lets hope I get this right.

These are not the first parts for my Stirling powered fan as I managed to leave the others at work, but hopefully these will give you a wee taster.

This is the cylinder for the power piston being turned down, the instructions said it should be bronze. But alas I had none and managed to find a bit of brass that had been used as a (rather large) punch. I also didnt have a piece big enough to make the cylinder and its base from one piece so I am planning on making it in two parts and soldering them together, can anyone see a problem with this?


The next part was to bore it out to 0.7500 and pollish the tooling marks to ensure a nice snug fit for the piston. I was a bit nervous doing this as I had only ever done it once before and that was just two days ago!


Next up is the piston and cylinder together. I am really pleased to say that they fit perfectly I taped the hole in the piston and one end of the cylinder and tried to push one inside the other, on letting go the piston sprung back just as it should. With the tape removed the piston slides right on through. Just a wee bit of pollishing and they are done.


As mentioned above I didn't have a big enough piece of brass to make the piston and its base in one go, but I did find a nice piece of copper from a bus bar, albeit a little bent! So in the mill it went.


Yes the mill and vice are straight, but the copper bus bar link isn't.......................yet.


Now it is cut to 1/4" thick and given a bit of a pollish before going back in to be cut down to size and have its perimeter squared off.


once it is down to size I need to drill a hole at each end for securing it to the engine base, find a way of boring a large hole in the centre and then brazing it on to the cylinder part. What I am thinking of doing is securing it to the milling table, putting the cylinder in the hole and using a centre in the mill to keep it square and true. Then get the gas torch out and braze or silver solder the two parts together.
It's desperately slow progress as I am learning as I machine, but hey, Rome wasn't built in a day and I would rather take it slow and easy to ensure I get things right first time.

Cheers
daz

[daz]

The forgotten pictures.

This is the power piston being turned. Again I really took my time over this, especially the outside. It was made from a short piece of steel I found lying under a workbench and didn't need much taken off to get it down to size.

Down to OD of 0.7500

Parted off and faced, I'm so glad I got a new parting tool and holder, it makes life so much easier.

Drilled out and ready for boring to 0.0625

Already centre drilled, and opening up for yoke to fit through

And just for my own satisfaction at getting something right



 
Hoping to get some more done today, hopefully some materials will turn up in the post.

cheers
daz

[Stilldrillin]

Hi Daz.
Nice parts, accurately machined..... 

Hope your cylinder doesn't distort, during soldering........   

Good luck! 

David D

[daz]

Do you honestly think there is a good chance of happening? Plain solder doesn't need that high a temp so I thought it would be ok, but I am always willing to listen to the more experienced. The other way I thought of doing it was with grub screws and loctite, as long as I get a nice tight fit it should be ok, fingers crossed

Cheers
Daz

[sparky961]

Seems like you've got the posting of pictures and text down.  You're also off to a good start with machining!

Although I'm sure you'll get quicker as you get more practice, one thing I've learned with hobby and professional fabrication is that things take WAY longer to make than most people would expect.  Don't rush it, and enjoy the process!

-Sparky