2014 - The progress page has moved to my FaceBook site.
May 2013 - After a long hiatus, I will soon be back working on the airplane. I am moving to St. Louis, MO this month and will set up a new shop and begin working again. Find, and like my FaceBook page! Search for CranePlanes!
3 January 2009 - Ran the engine again with a re-worked arrangement of one of the pillow blocks. I turned it around so that now it butts up against the driven pulley and this arrangement stops the forward and aft movement of the jack shaft. The problem is still the idler pulley movement. It resonates at about 2000 RPM and really gets moving. I need to damped it somehow or find a different one that is already dampened. I have a video, but I can't upload it using this web provider. E-mail me if you'd like to see it.
26 December 2008 – Website updated. I got a space heater for Christmas, so I can keep working on the plane even though the garage is 35 F. It's COLD outside (at least for the Seattle area).
13 December 2008 - Hirth engine ran for the first time on the engine test stand! Two and a half years in the making, the engine finally ran! It started right up and ran great. Idle at around 2050 RPM gave the smoothest running characteristics, and man was it smooth. I ran it for about 15 minutes before shutting down. The only problem was excessive idler pulley movement. It really took up the vibrations (I could run it down at 1300 RPM), but it was jumping back and forth so fast, it was hard to see with the naked eye. It also had a little forward and aft movement and was rubbing against the vertical drive support.
Engine Test Stand - Left Side Engine Test Stand - Back
1 December 2008 - Started wiring in the engine on the test stand. The Odyssey battery still had 12V after sitting on the shelf for 2.5 years!. I wired in the MGL Engine E-1 Maxi Single for my engine gages. The MGL is highly recommended and was very easy to wire in with the pre-built wiring harnesses that come standard with the instruments.
MGL Engine E-1
20 November 2008 - Started construction on an engine test stand. If the new drive system vibrates itself to death, I don’t want it taking out the back half of the airplane. I will run the engine with the propeller from the KFM engine, in case it throws it. I don’t want to damage the new Prince Prop (not very expensive, but took too long to get).
October 2008 - Found and integrated an idler pulley on the slack side of the belt. I chose a spring-loaded version where the idler pulley sits on a small (4-inch) arm that is tightened by means of a torsion spring. The idler pulley is necessary because the 14-inches between the drive and driven pulleys will cause excessive belt “whip” at low RPM. It will also be the method for setting and maintaining the proper belt tightness. As the belt stretches, the spring will take up the extra slack. This was a common problem with the belts on the KFM engine.
Idler pulley can be seen on slack side of belt. The round black object in the middle is the housing for the torsion spring. The pulley itself is the original driven pulley that I had made, but it was the wrong size.
July 2008 - Designed and built the vertical drive supports. I just used 6061-T6 Aluminum L-shaped channel and had my local A&P friend do the welding (I don’t know how to weld yet). I built sort-of an A-frame type structure and the pillow blocks that will hold the jack-shaft will sit on top. The jack-shaft is 1-inch chromalloy steel (I took the idea off ultralight aircraft running 50-HP Rotax engines). Maybe someday I’ll spring for the money to get a titanium jack-shaft. It would save about 4-pounds and be just as strong.
October 2007 - June 2008 - Moved to Washington State. Did some training then on deployment with USS NIMITZ (CVN 68) (Yes, I have a day job that involves airplanes too.). Spent most of my time missing my family and mentally designing the next stages of the plane.
October 2007 - Designed and had built the driven pulley. Man, I want a milling machine!
June 2007 - Designed and fabricated the exhaust system. The Hirth F23 uses two separate exhaust systems with two expansion chambers. This takes up precious room in the boom of the airplane and does not leave much room for insulation and cooling. I think I will test the engine with both one and two expansion chambers to see how much power a single chamber will give me.
June 2006 - June 2007 - Worked on overall concept design and research. Did trade-off studies on where to place the engine and exhaust. Roughed out designs for drive system. Issue: The Hirth engine is roughly 40-lbs heavier than the KFM engine: where do I put it to maintain the weight and balance (well, just balance, really)? Issue: the propeller needs to be 14-inches higher and 8-inches back from the power output of the engine. How do I get the power from the engine to the propeller?