Search found 539 matches

by skyfrog
Wed May 03, 2006 2:35 pm
Forum: Off topic forum
Topic: Big ups to Ben
Replies: 5
Views: 2246

re: Big ups to Ben

Thumb up too Ben, Thanks!
by skyfrog
Wed Apr 19, 2006 5:30 am
Forum: Tools and Construction
Topic: Spinning or drawing
Replies: 7
Views: 4551

re: Spinning or drawing

Hi Viv, Forming limit of sheet metal is strain-rate sensitive. Under quasi-static condition (for example hydraulic bulging ) we cannot bulge the tube too much, as forming limits are easily reached, then necking occurs and leads to failure. But under high strain rate it is different story. In high st...
by skyfrog
Tue Apr 18, 2006 9:58 am
Forum: Tools and Construction
Topic: Spinning or drawing
Replies: 7
Views: 4551

re: Spinning or drawing

Have you ever tried high strain rate forming. Use a concrete mold, place the tube inside, and put in some black gun powder, ignite it and the tube will be deformed in high strain rate to the desired shape, this is a no welds design :-)
by skyfrog
Fri Apr 14, 2006 2:31 am
Forum: Valved pulsejet forum
Topic: Animé of a Modeled PC
Replies: 4
Views: 3685

re: Animé of a Modeled PC

Excellent job, Forrest. If the modelled trend is correct, I mean at least we did see the combustion resonates inside the CC, I think the "compressibilty" is probably not so important a factor for a pulse combustor. However one thing still confuses me, how did you put into account the gas expansion d...
by skyfrog
Wed Apr 12, 2006 3:42 pm
Forum: Gas turbine forum
Topic: good priced turbine for model r/c plane?
Replies: 5
Views: 4656

re: good priced turbine for model r/c plane?

Hi,

Here is a link of jetjoe, but I don't recommend it :

http://www.jetjoe.com/main.php

You can try WASP too, 20lbf, designed by Phill Heward, not too expensive and the design is superb, smaller, lighter than KJ66, yet it is more powerful.

http://www.heward-microjets.co.uk/
by skyfrog
Tue Apr 04, 2006 10:21 am
Forum: Off topic forum
Topic: We should be able to beat this, right?
Replies: 18
Views: 7409

re: We should be able to beat this, right?

Bruno, nothing was implied. They are producing engines with their own design, I might have provided a little help, that's all, Hehe
by skyfrog
Tue Apr 04, 2006 10:05 am
Forum: Off topic forum
Topic: We should be able to beat this, right?
Replies: 18
Views: 7409

re: We should be able to beat this, right?

We should be able to beat this, right?

No you can't. Jetbeetle inside. heee
by skyfrog
Fri Mar 24, 2006 11:26 am
Forum: Tools and Construction
Topic: DIY furnace for melting Aluminum
Replies: 0
Views: 1752

DIY furnace for melting Aluminum

This is not copyrighted I think, because it is moe than 50 years old. Remove it if I am wrong.
by skyfrog
Tue Mar 21, 2006 5:33 am
Forum: Gas turbine forum
Topic: Electric Hybrid Turbine
Replies: 11
Views: 9305

Re: re: Electric Hybrid Turbine

Here's a diagram of what I'm talking about. Each stage is mounted on a stationary central spindle and rotates on it's own set of bearings. Does that clear up what I'm talking about Horace? Marlin Hi Marlin, Thanks, now it's clearer for my perception your idea. I do hope any new innovative ideas can...
by skyfrog
Mon Mar 20, 2006 2:35 pm
Forum: Gas turbine forum
Topic: Electric Hybrid Turbine
Replies: 11
Views: 9305

re: Electric Hybrid Turbine

Other features--no stators, just counter-rotating stages for compressors and turbines. Advantages of multi-spool turbines can be realized without the complexity of multiple spools operating concentrically. Hi Marlin, Could you sketch some drawings to illustrate your idea, as a picture is worth a th...
by skyfrog
Tue Mar 14, 2006 5:00 am
Forum: Off topic forum
Topic: Theory of Gravitation
Replies: 127
Views: 57137

re: Theory of Gravitation

Hi Forrest, Yeah, I suppose you must have been very busy. Don't put aside the topic of weight reduction yet, I found it very interesting, and had decided to take a look at it more seriously. I now have a new project to investigate theoretically the possibility of weight reduction by using Einstein's...
by skyfrog
Sat Mar 11, 2006 3:40 am
Forum: Off topic forum
Topic: Autodesk Inventor 11 Soon to be Reality
Replies: 1
Views: 1722

re: Autodesk Inventor 11 Soon to be Reality

I am a little bit confused as to what will be happening to MDT ? Will it become obsolete ?

Many R&D centers in here use Solidworks more often.

Edit : OK, I've got the answer, IV is included "free" with MDT, you buy IV, you get MDT too. poor MDT !
by skyfrog
Sat Mar 11, 2006 2:15 am
Forum: Valved pulsejet forum
Topic: Turboprop PJ experiment update
Replies: 119
Views: 63265

re: Turboprop PJ experiment update

Hi John, Thanks for your postings, the info is very helpful. I was more or less on the sidelines as a spectator, just been curious as to what will be happening. A quick question, did you use any nozzle guide vanes, you need to direct the production gas normal to the turbine blades before impinging t...
by skyfrog
Thu Mar 09, 2006 1:38 pm
Forum: Off topic forum
Topic: map surveying question
Replies: 7
Views: 4031

re: map surveying question

Hi,

You can use this equation to calculate the length of any sides. Yes it holds for irregular triangles.

A/sina = B/sinb = C/sinc

where A, B, C = length of sides,
a,b,c = corresponding angle of side which length is A, B, C respectively
by skyfrog
Fri Mar 03, 2006 9:32 am
Forum: Gas turbine forum
Topic: help in designing a small turbine
Replies: 48
Views: 29782

Re: re: help in designing a small turbine

its going to be at least a 5 stage, that is 5 layers of blades on the cone and 5 on the shell, this should give me the comrpession i need for it to self sustain. Excuse me for my lame English in both reading and writing, when articles get too long I'll just skip it. Are you refering to an axial com...