Search found 144 matches

by vile_fly
Sat Jan 03, 2015 4:55 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Boron Nitride as a lubricant
Replies: 33
Views: 19608

Re: Boron Nitride as a lubricant

I think the coarsest size is about 14 micron, so if used, I don't anticipate a big problem. I really haven't worked with the stuff, but I do my homework. From what I have seen, it is alot like talcum powder--greasy, forms ultrafine dust, and technically can be hot formed into spongy, sintered-like s...
by vile_fly
Sat Jan 03, 2015 8:30 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Boron Nitride as a lubricant
Replies: 33
Views: 19608

Re: Boron Nitride as a lubricant

Well, if you compress and sinter it, it becomes something much harder.....just like graphite. Except in this case, it is about 0.25 softer than diamond. The compressed, hardened form will cut even silicon carbide grinding wheels, and is used to dress them to refresh the surface. The powdered form is...
by vile_fly
Fri Jan 02, 2015 5:54 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Boron Nitride as a lubricant
Replies: 33
Views: 19608

Boron Nitride as a lubricant

Has anyone tried using boron nitride powder (amphorous, not compressed)? PHYSICAL FORM: Solid metal COLOR: White ODOR: None MELT POINT: 2700 SOLUBILITY IN WATER: Insoluble SPECIFIC GRAVITY: N/A VOLATILE BY WEIGHT: Essentially zero VAPOR PRESSURE: N/A DENSITY: 2.25 g/cm Its nickname is "white graphit...
by vile_fly
Fri Jan 02, 2015 6:17 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Design for the beta tye stirling engine
Replies: 4
Views: 4104

Re: Design for the beta tye stirling engine

Pretty design. What is the bore and stroke of the unit and the diameter of the heater tubes? Basically I am looking for dead volume calculation data. Having the inside of the heater tubes threaded will help to increase internal surface area and efficiency. Not sure how easy that will be, though. I r...
by vile_fly
Thu Jan 01, 2015 10:04 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Website Links Area and Magazine Articles..
Replies: 71
Views: 62896

Re: Website Links Area

This is a link to a "amateur work" vintage magazine on the construction of a hot air engine with 2.5 inch diameter pistons. The blueprint is shown as well with dimensions in inches. The title is "a hot air engine", and is worth a look. http://chestofbooks.com/crafts/popular-mechanics/Amateur-Work-3/...
by vile_fly
Thu Jan 01, 2015 9:48 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Website Links Area and Magazine Articles..
Replies: 71
Views: 62896

Re: Website Links Area

This is a link to NASA's "Stirling Engine Design Manual" PDF file. Worth a read for anyone who wants to understand stirling engines. What works and what doesn't. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&uact=8&ved=0CE0QFjAK&url=http%3A%2F%2Fntrs.nasa.gov%2Farchive%2Fna...
by vile_fly
Thu Jan 01, 2015 9:14 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Website Links Area and Magazine Articles..
Replies: 71
Views: 62896

Re: Website Links Area

This site shows you how to build a poor man's dynamic balancer for anything you should need to balance. Having a engine out of balance can really can rob you of potential power output, so here's the link. http://www.antiqueautoranch.com/montana ... page4.html
by vile_fly
Mon Apr 23, 2012 6:59 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling 'first run'
Replies: 19
Views: 10283

Re: Stirling 'first run'

Wow....super pretty engine and it works well, too! Wish I could make pretty ones like that. Ugly and functional is usually what my projects look like.
Introducing the fly seal of approval.
by vile_fly
Sat Mar 17, 2012 9:30 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Ian Bradley Electrically Heated Heinrici (ME 84/85)
Replies: 8
Views: 4564

Re: Ian Bradley Electrically Heated Heinrici (ME 84/85)

Is the "ME" an abbreviation for mechanical engineer? I suppose it is a magazine or publication of some kind, but I have never heard of it.
by vile_fly
Sat Mar 17, 2012 6:33 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Turning point?
Replies: 4
Views: 4898

Re: Turning point?

I found a very cheap supply of aerosol boron nitride powder as well as raw bulk powder. $15.00 per 13oz can. here is the link: http://www.lowerfriction.com/product-page.php?categoryID=24# The powder is available from 5 micron to 70nm form. It ranges from $54.00 to $108.00 per pound, depending on mic...
by vile_fly
Sat Mar 17, 2012 6:29 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Turning point?
Replies: 4
Views: 4898

Re: Turning point?

What I think would be interesting use of ceramic......casting a stirling engine block with regular castable ceramic, use castable foam ceramic for the displacer, a ceramic filter for the regenerator, and possibly a graphite power piston. All of this might be possible with the high temp boron nitride...
by vile_fly
Wed Mar 14, 2012 6:54 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: another displacer material--aerogel.
Replies: 13
Views: 9129

Re: another displacer material--aerogel.

Thanks for the link, Ferraccio. These newer ceramic materials are better than what I had found, and priced better, too. The idea of casting foam ceramic is very appealing, and cost effective. The boron nitride lubricant that Cotronics.com sells also caught my eye. 1500°F Boron Nitride Spray on Coati...
by vile_fly
Sun Mar 11, 2012 9:24 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: another displacer material--aerogel.
Replies: 13
Views: 9129

Re: another displacer material--aerogel.

Well, I decided to renew my search and found a site that sells hydrophobic aerogel as well as hydrophillic aerogel. hydrophobic is preferred, by the way. The site is http://www.buyaerogel.com/ one disk is 26mm x 7mm another is 1.5cm x 1cm the hydrophobic disc is 26mm x 4mm. They have other great aer...
by vile_fly
Sun Mar 11, 2012 8:57 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: another displacer material--aerogel.
Replies: 13
Views: 9129

Re: another displacer material--aerogel.

The NASA website is how I found out about the space shuttle tiles for sale. Unfortunately, I had to be a teaching institution in order to buy a 2" x 2" square section of a tile for the bargain price of $220.00. Not such a great deal after all.....because I am cheap. Anyways, that sale was about a ye...
by vile_fly
Sat Mar 10, 2012 10:31 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Power piston sideloading: possible solutions
Replies: 2
Views: 2851

Power piston sideloading: possible solutions

I was wondering if anyone had tried this on a large engine. Using a u-joint type coupling to the power piston. The picture is that of a cylinder hone, but you get the idea. It was meant to prevent sideloading and insure a smooth movement. This way, the power piston can stay concentric in the bore an...