Reverse Engineering OEM Turbine Blades or Vanes?

• Mar 24, 2012

• #2

MikeHalloran

Mechanical

Aug 29, 2003

14,450

US

I've been on a tour of an outfit that reverse engineers blades. I'm not sure what CAD app they use, but they've been doing it for decades, so they started with graphite. They were doing it before any fancy reverse engineering apps existed.

For accuracy, they've got a CMM and a crew that knows how to use it, and a vibration table. They validate that their blades fall within the measured geometrical range of a good sample of OEM blades, and that they resonate at the same frequencies with the same mode shapes and displacements, again when compared to a range of OEM blades.

For each OEM replacement blade they decide to reproduce, they generate a drawing that's at least as detailed as the OEM's drawing. It has to take months; they are deadly serious about making parts that cannot be distinguished from OEM except for the markings.




Mike Halloran
Pembroke Pines, FL, USA

 

Upvote 0 Downvote

• Mar 24, 2012

• Thread starter
• #3

REDesigner09

Aerospace

Nov 19, 2010

227

US

Hi MikeHalloran & Others,

This appears to be the type of precision that I’m seeking. I deal with a company that despite its 40+ years of “reverse engineering” expertise, still has difficulties proving full traceability. I’ve asked for Characterization Matrix, Characterization Tree (kind of like a sports brackets, such as for the March Madness breakdown) or Characterization Map(s). The company Reverse Engineers can give me a partial story, although they think they are giving the full story at times. When asked to fully document their processes, it gets lost.

Does anyone develop Characterization Matrix, Characterization Tree or Characterization Map(s) to prove full traceability & to use that towards validation processes?

Thanks

 

Upvote 0 Downvote

• Mar 24, 2012

• #4

IRstuff

Aerospace

Jun 3, 2002

44,889

US

I can't seem to find much information about what you're asking, but it sounds like a bit much to me. These guys are reverse engineering, after all, and the best they could possibly do is to mimic the physical and structural characteristics to the best that they can; given the lack of OEM input.

TTFN
faq731-376

 

Upvote 0 Downvote

• Mar 24, 2012

• #5

GregLocock

Automotive

Apr 10, 2001

23,885

Orbiting a small yellow star

Make that two experienced engineers and one reverse engineering company who don't understand /your/ jargon. They sound like some consultant has taken standard TQM tools and renamed them.

Try googling Characterization Tree if you want a laugh.







Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

Upvote 0 Downvote

• Mar 25, 2012

• #6

tbuelna

Aerospace

Aug 10, 2002

4,026

US

REDesigner09,

Take a look here:

http://www.ttl-solutions.com/aerofoils.html

These guys use NX for what they call "adaptive machining". Not specifically RE, but very similar in principle.

Terry

 

Upvote 0 Downvote

• Apr 2, 2012

• #7

Airsporter1st

Mechanical

Aug 3, 2011

44

ES

It sounds to me as if you are looking for some kind of statistical analyses to support the dimensional tolerances being applied in reverse engineering.

That being the case, I guess that the company involved have the raw data, but don't know how to manipulate it to provide you with the confidence levels you are seeking. In fairness to them, why should they? - they are are presumably engineers, not mathematicians!

Perhaps you need to get together with them to review the data they have and then manipulate it in a way which will satisfy your requirements?

 

Upvote 0 Downvote