Graphite

[slowcoach]

Hello all,

Can anyone please direct me to a good source of Graphite. I don't want much, 3/4" diameter by say 6 or 12" long. I fancy having a go at building a little Ringbom engine and need some for the power piston and cold end bushing. Also whilst i'm on the subject of Graphite, has anyone got any tips on machining the stuff on a lathe, speeds, lathe tool shape etc

Cheers
Rob

[Bluechip]

Rob

Only one I know, apart from a commercial supplier ...

http://www.nogginend.com/product/Graphite-Round-Bar

Never had stuff from him, nor ever machined graphite ..

Just know he does it ..

BC

EDIT ----- Just remembered the Industrial Co.-------  .pdf on this page ..

http://www.olmec.co.uk/graphite_rods.htm

[PTsideshow]

I have never used this place, I don't know if they ship world wide.graphite store
This one is supposed to be good also, graphite
They do have a link for jerry howell sterling engines pages. It is a supplier to makers of home shop rocket engines.

Another source closer to home maybe a glass working store for beads and glass blowing. As graphite slabs,paddles and rods are used for flattening and shaping the hot glass. They are called marvers

Here is one of the larger hot glass working suppliers, again I don't know if they ship world wide. I have dealt with them for bead making supplies and the safety UV glasses. wale apparatus
They currently have the rods on sale 3/4"x12 $16.58 USD
Hope this will give you some ideas or help.
Will say that with the limited working I have done with graphite solid and powder. It is messy and will get everywhere. I have only used hand tools, and did it out side might be an idea to machine with a good vacuum near the cutting action if on the lathe,mill etc.
 

[David Jupp]

This company specialises in graphite machined parts (near York), not sure if they'd be able to help.

http://www.coidan.com/

also

http://www.gpescientific.co.uk/view-categories.php?catID=68&mastercatID=6

Some on e-bay at the moment
http://www.ebay.co.uk/itm/Graphite-Bar-/200757756171?pt=UK_BOI_Metalworking_Milling_Welding_Metalworking_Supplies_ET&hash=item2ebe18410b

[krv3000]

is it graphite yarn you is after for packing the glands if so try Stuart tuner they sell it

[raynerd]

Just a thought - every single year at the ME shows, I am blown away with the Sterling Engine stand and the chap from Cornwall always spends a long time talking to me. These are his engines:



Although he has used graphite, he uses many highly polished aluminium pistons. He drills them out so thay are just a shell and then polishes to a perfect fit. He also uses many sterlings with diaphrams which is another option.

I used graphite for mine but if I attempt another, I`ll use aluminium or a diaphram.

Chris

[slowcoach]

Thanks for taking the time to answer my questions guys, really appreciate it  I never considered aluminium Chris, you got me thinking now 

I will let you know how it goes.

Cheers
Rob 

[raynerd]

Hi Rob
Glad it helped. I used graphite in mine and of course it is nice but heavy and I didn`t enjoy machining it that much. The aluminium power pistons he makes are basically hollowed out bar to leave just a nice light shell and they are super polished to fit the precision glass tube he uses for the cylinder. He has anodised some at home (which is fairly easy to do!) but he assured me that anodising isn`t necessary. You can see in my picture that all the ringboms he has on display are using aluminium if not a diaphram. For what it is worth - he says that a diaphram is by far the best way to go... low fricition and dirt cheap to make! He told me he uses white latex from gloves.

Chris