Posted by frank (220.127.116.11) on November 08, 2005 at 19:55:54:
In Reply to: Re: Frank, I have a question posted by frank on November 08, 2005 at 19:07:00:
Posted by frank (18.104.22.168) on November 14, 2004 at 23:24:17:
In Reply to: Re: Frank's picture posted by Kevin on November 14, 2004 at 22:22:35:
You are very perceptive - yes there is a slight pre-bend in the Ti rod just after the middle bracket.
My son Kevin did the design and the work at his Maintenance shop.
3/4" Ti rod was bought from a Canadian source for around $35. Tailwheel is lightweight single post AirProducts from ACS. Rod pre-bent perhaps 10 degrees in a hydraulic press. Two bolt holes drilled and upper end beveled at a speciality machine shop. (Titanium is tough to cut!!) Aluminum sleeve of the T/W was drilled out to accept the 3/4 rod. He made the two brackets from 4130 round and square tubing - gas welded. Toughest part of the job was getting the correct number of links in each side of the steering chains. Took 3 of us compressing springs with channel locks, etc.
The pic shown is with 210# in the rear cockpit. Spring rates and dampening when we bounce the tail seem very similar to the leaf springs just removed. Won't be able to test hop for a week or two when the annual is finished.
Net result is exactly 5# less at the tail. (4.5 # versus 9.5 # for the leaf spring setup.) We calculate this will exactly compensate the W&B change for the 21# lost up front when we changed from Hartzell to an MTV-12 prop.
BTW, lots of acro birds such as the Extra similar setups.
As soon as we are happy with this setup we will install out new 5" spring aluminum main gear with 5" wheels and brakes - another 40# saved - but very close to the CG! Including the prop, this and other changes like an EIS in place of round engine guages and a lighter ELT will net us at least 80# saved. That's like leaving 13 gals of fuel on the ground = better performance, or some would say - equivalent to adding 13 HP!
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