New Oberursel Ur2 - Page 13

AAC Cadet Leader · 4 April 2008, 11:04 PM

Quote:

Originally Posted by franzkait

it is not so easy to be a pioneer , after some unsuccessful tests , the wings get extended .

my, how your boy pioneer aviator is growing, udo!

hope you'll allow me to share a pic i took of my own pioneer aviator testing one of his own creations three years ago. our boys should meet someday.

Machinbird · 5 April 2008, 07:29 AM

Franzkait. I have really enjoyed seeing the processes you have had to use to make this engine(s). Great craftsmanship! Thank you for putting this information on the forum.

There are a couple of posts that seem to conflict so I thought I would repeat them here and ask a question. Is there some sort of mis-statement here between these two quotes, or just something I don't fully understand?

Cast iron liners and cast iron rings? I would normally expect metal of two different hardnesses to be used in a sliding application.

Quote:

Originally Posted by franzkait

the left piston is a Oberursel made bevor 1918 , the other one is a Le Rhone made after the war . The Oberursel is the better piston . Oberursel piston rings are made from cast iron like a modern engine ,Le Rhone rings are made from steel . Oberursel had 3 different type of piston pins , I use the later ones .
So how do the lightening holes look like at the late ones ?

Quote:

Originally Posted by franzkait

this cylinders have cast iron liners , after I press them in , I hone them.
all this parts look like Le Rhone , but the Oberursel is the better engine . for example Le Rhone liners 1mm Oberursel 1,5mm .
original the engine had many parts made from Chrome Nickel , I use Chrome Molly . ignition , carburetor , lubrication , all original .
no heavy bending oil , just oil

franzkait · 5 April 2008, 02:57 PM

a cast iron cylinder liner with cast iron piston rings is normal for the last 100 years of piston engines .

Machinbird · 5 April 2008, 04:12 PM

Thanks Franzkait. I found an interesting paper on the subject which shows me I didn't understand the issues.

The need for rapid break in of the cylinder is one of the driving factors. No wonder I've had such good luck breaking piston rings in the past when rebuilding engines!

Here is an article on cylinder tribology:
http://www.vtt.fi/inf/pdf/tiedotteet/2002/T2178.pdf

jumpinjan · 5 April 2008, 05:43 PM

Good Article....Thanks
Jan

franzkait · 5 April 2008, 07:22 PM

Martha, we can start a kids pioneer competition , foto is 2 weeks old , first version .

AAC Cadet Leader · 5 April 2008, 07:32 PM

Quote:

Originally Posted by franzkait

Martha, we can start a kids pioneer competition , foto is 2 weeks old , first version .

standby, udo. i'll dig for another one.

AAC Cadet Leader · 5 April 2008, 08:21 PM

okay, here's my son's first test flight for his prototype design from standing atop of a six foot high fence. year 2001 at age 10. wing is heavy plastic sheeting, stapled to the main spar which is a 12' long carpet tube. control stick is a wooden croquet stake. long, yellow rubber bands fasten the contraption to him. completely his own - no help from me or anyone else.

AAC Cadet Leader · 5 April 2008, 08:37 PM

and here's another view of the glider he created from paper, bamboo, thread and ingenuity in 2004 at age 12.

womenfly2 · 6 April 2008, 05:15 AM

... nice pictures, maybe worth starting another thread just for Young Aviators and move these there. Would not like to see this thread veer to much off topic. I have a few I would like to post in it too when my son was the same age.

This thread is one of a kind on new rotary engines, ground breaking in fact.

Where are all the engines destined for? Can you say?

WF2