Home Built Jet Engings



http://www.tech-domain.com/thread-30110-1-1.html






http://www.tech-domain.com/thread-30111-1-1.html






http://www.tech-domain.com/thread-30109-1-1.html






http://www.tech-domain.com/thread-30108-1-1.html

I would classify them as for home assembly rather than building.

Unless you get them as kit parts, you must have to give one some credit even if he get such crucial part fabricated from someone in the country.

You just cannot design turbine parts on AutoCad and go to nearby Lathe shop for milling. The material science for such engine is much demanding. Remember, esteemed organizations like NAL/HAL are still struggling to find alloy to manufacture indigenousness 'Kaveri' jet engine for the LCA type projects. Getting the right raw material and then getting machine for casting/milling them would be near to impossible in the country.

In the West/China, its a totally different story.

I bet every one here would be eager to see some one following the text from these books and build such engines entirely in India.

Have I spoken about the ECU yet ?

I totally agree, material would be a problem, thats what preveen said.

What gives you an idea that the NAL/HAL is struggling to find materials for the Kaveri engines?
Trust me they are not, have spent enough time in HAL uniform to know what exactly was going on when it was.
BTW there are  various firms in India who would happily mill your turbine blades and rotor discs for the right price. HAL routinely subcontracts such jobs to these firms.
 

"Getting the right raw material and then getting machine for casting/milling them would be near to impossible in the country."

I would assume that this would be a problem for a "one off" in ANY country. Kits ARE available though and a local modeller did get one from a branded manufacturer in Bangkok, I think. It works fine.

Manish

I doubt that one could find suitable guys for the small sizes of blades, ceramic bearings, etc. that one would need for a model jet engine.

Susheel,
A guy in business, would do that for the right price.
You should sometimes see the gearboxes on the full size MiG's.These have lot of intircate and minature machiningand these are handled in India. Yes there is economy of scale, but I am sure the same guy would do a one off if the price is right and the guy is interested
Do not know about ceramic bearings though. The full size bearings for some MiG Variants did come direct from Russia though
And btw the cast blades for R 11 engine (atleast till 6 years back) were still ground manualy by hand by an operator sitting on a grinding wheel station with mutiple templates to ensure correct profile on the plades  

So atleast 6 years ago,The blades COULD have had imperfections to a slight level?Or were they within accepted tolerances?

I do agree when you refer to a guy in business etc. But my point is that I am not sure there are such guys for the small parts needed.
The machining may well be manual but the casting has to be right. So one would need to locate several of the
"guys in their - respective - business"! Possible but the probabilities are low, in my opinion. BTW these model engines idle at 50,000 RPM + and rev up to 150,000, though I am sure you know that already.

I read it long back in the news about problem faced in developing GTX-35VS Kaveri engine. The engine is still under final test in Moscow, as I last read in about it.
The LCA Tejas just given IOC yesterday, was supposed to have the Kaveri engine, but is been fitted with a GE  F404-GE-F2J3 for the meanwhile before Kaveri is ready for it.

A full history of the Kaveri development could be found at http://en.wikipedia.org/wiki/GTRE_GTX-35VS_Kaveri

Its nothing new to face such problem while developing the first indigenous engine by a country. All the western country had similar stories. I have absolutely no itention undermining the might of Indian engineers/scientists. I was just highlighting how demanding these engines are, that sometimes a country like India has to reinvent so many things to complete the project.

Just to give analogy, Sharma have been selling Glow engine for almost half a century. You even have Micro BL motors being exported from Bangalore. But have you ever heard about some Indian company building such Jet engine here? Even I would love to hear that. But I know the multitude of infrastructural challenges to get everything locally.

Yes, there have been multiple problems, issues with the engine development, but finding the right alloy for turbine or blade was not the problem. It was that they were looking for something even better and lighter so the performances could be improved/increased along with weight reduction. Even established long running designs have inherent issues, including material problems. To overcome these there is a compromise, in terms of compensating controlsetc and at the same time the engineers continue to research ways to overcome these inherent flaws.

And BTW again a small correction Sharma never built a glow engine in 1960's, per my infortmation thier glow came much later may be in late 80's (will call Vivek and find out exactly when they started)

As for an Indian company building a jet engine that would happen when we have a market. Sharma stepped in to fill the NCC market. So imagine if there was no NCC market for Sharma engines, would the company survive on selling to hand full of flyers in India or collectors/diesel lovers abroad. I am sure the aeromodelling business is not soemthing the Sharma's do for a living but more for the love of it

I stand corrected on my last post.
Just got off the phone with Mr Vivek from Sharma Models and the first ever engine which they made was indeed a glow, and this was in 60's.
So it does make it half a century (almost)

flyingboxcar is right - technology for model jet engines is there
reason why you don't see any is due to the perceived market and
largish investment required.

just to give you an example - the turbocharger impellers in diesel engines
rotate at similar speed..... manufactured in at least six plants in India

also most model jet engine turbines are manufactured to less exacting specs


 

Sharma engines are like HMT to watches, they bought pride of using indigenous products though made with imported technology.
Both brings nostalgia, and are sought after by collectors and tech.lovers world over.
I had flown CL model made by Sharmas, in early 80s with my uncle and I still remember, we were guided by Mr. Saini, an ex ncc. We used to mix fuel in the noons to go flying in evenings.

I have read the book by Thomas Kamps and I should say the techniques are pretty much straight forward. There is a detailed plan for a jet engine and its proven to work. Anyone with some intermediate skills on a lathe machine and metal works should be able to make one. I agree its not easy but not impossible either.

The toughest part is the combustion chamber... its like keeping a candle burning while wind is blowing at high speed.

Some of the components could be purchased from auto mobile market while others need to be fabricated. The steel used for the NGV and the turbine regions needs to be of high temperature grade. All these are discussed in detail in Kamp's book. I would give a  for this book.