N9648 B

A forum about all aspects of the construction and maintenance of the Billy Dawson inspired modified Hatz Classic biplane. Here is the place to ask your questions and get the answers from the real experts.
RSouthard
Posts: 48
Joined: Tue Mar 16, 2010 9:40 pm
Location: Seaford Delaware

Re: N9648 B

Post by RSouthard »

Congratulations Michael, great job!! Thank you for sharing..
M Lightsey
Posts: 112
Joined: Tue Jun 15, 2010 3:10 pm

Re: N9648 B

Post by M Lightsey »

Michael,
Congratulations, looks great.
If your tailwheel isn't breaking loose, you might need softer springs. It shouldn't unlock just from full rudder travel, but only when the springs stretch past the point of full travel.
Mark
mmcgrew
Posts: 154
Joined: Thu Mar 18, 2010 8:03 pm

Re: N9648 B

Post by mmcgrew »

Mark please explain more . I have fairly stiff springs and there is very little slack. Do I need weaker springs? and how much slack?

TKS

michael
M Lightsey
Posts: 112
Joined: Tue Jun 15, 2010 3:10 pm

Re: N9648 B

Post by M Lightsey »

Hatz's are pretty light on the tail. If the steering springs are too stiff, the tailwheel will just slide before the steering springs stretch enough to allow it to go full swivel.
You don't want it kicking out from full rudder travel, but rather just when you apply brakes in conjunction with full rudder travel. That should stretch the springs just enough to allow it to go full swivel.
3200's are used on some pretty large airplanes that have a lot more weight on the tail than a Hatz, so you might just need to reduce the steering spring stiffness. Personally, I'm not a fan of slack in the steering system.
Mark
PoconoJohn
Posts: 133
Joined: Tue Mar 06, 2012 3:57 pm

Re: N9648 B

Post by PoconoJohn »

Congratulation!
John Cronin
HC 149
painless
Posts: 98
Joined: Fri Apr 09, 2010 7:39 pm

Re: N9648 B

Post by painless »

Congratulations Mike. Looks like you did an awesome job. Very inspirational for us still in the building trenches! Oshkosh-bound this summer??
Jeff Orear
Hatz Classic #138
Peshtigo,WI
https://eaabuilderslog.org/?s=Patients
stearmoth
Posts: 234
Joined: Mon Apr 26, 2010 12:47 pm

Re: N9648 B

Post by stearmoth »

Congratulations for a very nice job, Michael! Please keep us posted on your flight results. 130 mph is a very high speed for a Hatz! Hope to see you in Brodhead next year!

Kindest regards from overseas

Hans & Sam, H.C. #78, Switzerland
mmcgrew
Posts: 154
Joined: Thu Mar 18, 2010 8:03 pm

Re: N9648B

Post by mmcgrew »

I know - 130 mph was a little wild. Did a left base descending approach for a low fly by - certainly not a cruise speed. As a side note - No vibrations. I am running an Ellison Throttle Body and have only been able to get 2500 RPM - which kind of surprises me. I have a wood 74-58 prop so I am not over proped. Called Ellison but can not get a call back. Very disappointed in their customer support. I have gone through the required set up (twice). The motor runs smooth and strong at 2500 - so I not sure if this (low rpm) is a concern. Still working on the tailwheel problem. I may change to a lighter MATCO tailwheel.

Michael
N 9648B
mmcgrew
Posts: 154
Joined: Thu Mar 18, 2010 8:03 pm

Re: Hatz Classic Speeds

Post by mmcgrew »

PS - The Stearman hits 150 mph in a dive for a loop. I do not know for sure, but I would guess the Hatz Classic would need to be around 130 mph for the same loop. Anyone have some experience on this?

Michael
9648B
hatz215
Posts: 110
Joined: Tue Mar 23, 2010 3:29 pm

Re: N9648 B

Post by hatz215 »

It will do a fine loop at 120. 130 gives you a little cushion. I didn't know a stock Stearman could get to 150. It doesn't need that to loop.

Steve
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