Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Go Back   VAF Forums > Model Specific > RV-4
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Thread Tools Search this Thread Display Modes
Old 10-07-2017, 06:32 AM
DanH's Avatar
DanH DanH is offline
Join Date: Oct 2005
Location: 08A
Posts: 7,804

Originally Posted by tgmillso View Post
I presume that you can move your rudder to both stops by hand without the tailwheel unlocking using the new bolt positions in the rudder horn, so is the only way you can unlock your tail by standing on one brake?
Tom, amazingly enough, I actually remembered to check...

If I stand behind the slowly rolling airplane and move the rudder to the stops, the yoke remains locked. However, if I add some lateral force (i.e. shove the tail sideways), enough to stretch a spring, the additional angular deflection of the yoke will allow it to pop into full swivel.

Note two possible adjustments. Moving the rudder arm connection points inboard decreases yoke deflection for any given rudder deflection. Set that ratio so full rudder deflection doesn't deflect the yoke quite far enough to reach its unlock angle. Now, the additional lateral force necessary to unlock is a function of spring stiffness.
Dan Horton
Barrett IO-390
Reply With Quote
Old 10-07-2017, 04:04 PM
tgmillso tgmillso is offline
Join Date: Nov 2012
Location: Launceston, Tasmania, Australia
Posts: 620

Thanks for checking Dan. I also remembered to give Jason at JD Air Parts a call and ask him for his position on things, given that there must be hundreds of these setups out there with the with the prescribed drilling positions. He said that what ends up happening is because the contact point of the tailwheel is aft of the pivot point, the tail wheel tends to pull straight a little even at full rudder deflection, so he said it would probably still be necessary to stamp on a brake to get the thing to unlock. He also said the internal geometry setup was almost identical to the Van's tailwheel, so the unlock angles should be similar, however my thoughts now are that this will only apply in the unloaded condition or if the arm length between the contact point and pivot point center are the same, and of course only when the tailwheel is on the ground. In a nutshell, I'm going to give it a crack as it is for now. If I don't like it during taxi tests, I'll drill that next hole inboard. I'll let the guy who is performing the initial test flight know what the deal is and if he wants either the chain length adjusting or another hole inboard drilling, I'll have the gear ready to do it.

Last edited by tgmillso : 10-07-2017 at 04:07 PM.
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 06:35 AM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.