Search found 80 matches

by cudabean
Wed Nov 19, 2003 8:57 pm
Forum: Tools and Construction
Topic: Sintering, porosity & combustion synthesis
Replies: 20
Views: 13469

Sintering, porosity & combustion synthesis

This discussion about sintering and porosity of various materials reminds me of some other material and net-shape manufacturing techniques that I've studied. My friend worked at a scientific glass-blowing shop and used to be involved in making sintered glass filters. Temperature control allowed them...
by cudabean
Tue Nov 18, 2003 9:46 pm
Forum: Tools and Construction
Topic: Hydroforming
Replies: 21
Views: 16045

Perhaps worthy of experimentation? * Carve a foam male part into the shape you want for your hydroformed part. * Suspend the foam in a waterproof vessel. * Pour slip-casting clay into the vessel around male mold * Once clay has hardened, remove male mold and relieve regions in female mold as require...
by cudabean
Tue Nov 18, 2003 6:52 pm
Forum: Tools and Construction
Topic: Hydroforming
Replies: 21
Views: 16045

Hydroforming

Bruno mentioned Hydroforming, touting it as an inexpensive way to create metal parts. It seems to me like it would be feasible to use it for small run or even one-off manufacturing like making aluminum ribs for a homebuilt, etc. In any case, this process had slipped past my radar (that typically hom...
by cudabean
Tue Nov 18, 2003 5:26 am
Forum: Tools and Construction
Topic: Liquid fuel vaporizer
Replies: 22
Views: 15582

Another thing--aerosol manufacturers are looking at this as a non-disposable aerosol can replacement. Definitely the potential for high-volume cheap consumer-grade stuff here.

cudabean
by cudabean
Mon Nov 17, 2003 5:25 am
Forum: Tools and Construction
Topic: Liquid fuel vaporizer
Replies: 22
Views: 15582

Liquid fuel vaporizer

Vapore http://www.vapore.com/ has developed a little unit that vaporizes liquid fuels. It's the size of an altoid, requires no pressure--just a little bit of heat and Vapore claims it works better than carburation. Vapore sells to other businesses, so if you want to try to get ahold of one, you'll h...
by cudabean
Sat Nov 15, 2003 5:49 am
Forum: Pulse detonation engine forum
Topic: PJ Alternators and Microwave PDE
Replies: 56
Views: 57870

I believe it is ionized while it is burning, I'm trying to find out. At the very least there are a lot of free electrons in there. Typically in ion engines for spacecraft attitude control, they use magnets to bend or focus the stream, and electric potential to accelerate the ions (typically the ion...
by cudabean
Sat Nov 15, 2003 5:37 am
Forum: Pulse detonation engine forum
Topic: PJ Alternators and Microwave PDE
Replies: 56
Views: 57870

I'm not sure. It's mass flow @ 50 cfm is kind of unimpressive. It is kind of intriguing though, but I'm not sure I want to pay $65 to satisfy my curiosity. Further thoughts on compressors: A friend pointed out that another way to stage centrifugal compressors is to take two turbo units and route the...
by cudabean
Fri Nov 14, 2003 11:15 pm
Forum: Pulse detonation engine forum
Topic: PJ Alternators and Microwave PDE
Replies: 56
Views: 57870

About this ionization... So what's the deal, does heating of gases cause ionization? Positive or negative? If that's so, you might conceivably be able to use pulsating combustion strictly for ionizing the gases and use waves of moving magnetism after the combustion zone sort of like an afterburner t...
by cudabean
Wed Nov 12, 2003 6:58 pm
Forum: Off topic forum
Topic: Alternate propeller designs
Replies: 14
Views: 10348

Thanks for the responses. Another problem, besides efficiency, with small area velocity greatly exceeding the flight speed is noise.

One possibility for alternate forms of thrust generation is a squirrel cage blower.

cudabean
by cudabean
Tue Nov 11, 2003 10:45 pm
Forum: Off topic forum
Topic: Alternate propeller designs
Replies: 14
Views: 10348

Alternate propeller designs

All aircraft propellers that I've seen revolve around a drive shaft aligned with the longitudinal axis. Has anyone seen a propeller that operates more-or-less like a sternwheeler paddle? I've seen windmills that revolve around a vertical axis, but I suppose the problem with using that type of design...
by cudabean
Mon Nov 10, 2003 9:21 pm
Forum: Gas turbine forum
Topic: Multi-staging radial compressors
Replies: 7
Views: 8210

Mike, Thanks for the response. I wasn't expecting such a good one in this somewhat dormant forum. I never thought of the dynamic balancing issues of radial compressors. However, the auto manufacturers and small gas turbine builders seem to favor the radial compressor for their small units. A larger ...
by cudabean
Mon Nov 10, 2003 5:36 pm
Forum: Gas turbine forum
Topic: Multi-staging radial compressors
Replies: 7
Views: 8210

Multi-staging radial compressors

Any one know why there aren't many multi-stage radial or centrifugal compressors out there? I think I've seen two stagers, but even those are rare. It seems to me like you could reduce complexity of a high-efficiency fanjet by eliminating the ten or more axial flow stages and replace them with, perh...
by cudabean
Wed Nov 05, 2003 11:50 pm
Forum: Rocket forum
Topic: Huge sucrose rockets
Replies: 6
Views: 5179

Huge sucrose rockets and sugar bombs

182.5 m/s = 657 k.p.h., which is pretty fast in my book. I think you could probably get usable thrust out of a ramjet operating at 200 k.p.h. which is still suitable for runway speed. It won't be running efficiently, but you are developing thrust. Another consideration: In the U.S., aircraft operati...
by cudabean
Wed Oct 29, 2003 9:18 pm
Forum: Tools and Construction
Topic: poliester resin question
Replies: 15
Views: 12892

You don't have to be strongly allergic to become sensitised to the amine hardeners used in epoxies. try to avoid skin contact as much as possible. But i agree epoxy is much better than polyester. Proper mix ratios are essential with epoxy excess harderner or resin can effect the cured product prope...
by cudabean
Thu Oct 23, 2003 4:53 pm
Forum: Off topic forum
Topic: Rand Cam engine
Replies: 9
Views: 7681

Yes, I've been keeping my eye on that one. Here's another rotary that's interesting as well. Invented by a Turkish guy: http://www.idolmotor.8m.com/ It's a little hard to comprehend--even with the animations, which may ultimately be detrimental to acceptance of an otherwise workable design. The neat...