The Biplane Forum > Biplane Builder's Forums > Starduster > SA300 tailwheel stress



Help Support Biplane Forum by donating using the link above or becoming a Supporting Member.
Reply
 
Thread Tools Display Modes
Old 10-10-2017, 05:26 PM   #1
mreinh3233
Registered Users
 
mreinh3233's Avatar
 
Join Date: Jun 2014
Posts: 217
Liked 54 Times on 35 Posts
Likes Given: 216

Default SA300 tailwheel stress

I know the aircraft is stressed for 9g's but the tailwheel spring and mounting assembly should not need to be stressed for that much should it. I mean if you do a landing that induces 9g's the least of your worries would be if you stressed the tailwheel spring. What should it be stressed for I guess is the question. 500 to 600lbs, a 1000?. I don't like the way mine is set up, it doesn't look right, compared to auto springs I'm familiar with. (All three leafs secured at both ends). Shouldn't one end be free to move allowing flex? (Like on a Champ). Anyone with input jump in, I don't have plans so I don't know if it was done to plans or not. Dave do you have a picture of how your's is set up?


mreinh3233 is offline  
 
Reply With Quote
Old 10-10-2017, 06:01 PM   #2
Larry Lyons
Registered Users
BiP_LIFETIMESUPPORTER.png
 
Larry Lyons's Avatar
 
Join Date: Oct 2012
Location: Stockton, IL.
Posts: 3,407
Liked 787 Times on 603 Posts
Likes Given: 1427

Default

What's your look like?


__________________
Larry Lyons
Rebuilt:
Smith Mini, flying
Taylorcraft, almost flying
and on going Taylorcraft project

In dog beers I've only had one!
Larry Lyons is offline  
 
Reply With Quote
Old 10-10-2017, 07:10 PM   #3
Timbob
BiP_SUPPORTER.png
 
Join Date: Oct 2008
Location: Socorro, NM USA
Posts: 473
Liked 84 Times on 61 Posts
Likes Given: 4

Send a message via MSN to Timbob
Default

Here is a pic of a Dave supplied tailwheel spring, it has a slot in the second spring instead of a hole where it binds on the tailwheel mount..if I remember right?
Cielo - 1.jpg  
__________________
Tim
Timbob is offline  
 
Reply With Quote
Old 10-10-2017, 07:25 PM   #4
mreinh3233
Registered Users
 
mreinh3233's Avatar
 
Join Date: Jun 2014
Posts: 217
Liked 54 Times on 35 Posts
Likes Given: 216

Default

Quote:
Originally Posted by Timbob View Post
Here is a pic of a Dave supplied tailwheel spring, it has a slot in the second spring instead of a hole where it binds on the tailwheel mount..if I remember right?
If I did this right you should see that my leafs don't taper and they are bolted at both ends. Makes for a very stiff spring...
IMG_0411.jpg  
mreinh3233 is offline  
 
Reply With Quote
Old 10-10-2017, 08:19 PM   #5
Timbob
BiP_SUPPORTER.png
 
Join Date: Oct 2008
Location: Socorro, NM USA
Posts: 473
Liked 84 Times on 61 Posts
Likes Given: 4

Send a message via MSN to Timbob
Default No wonder its stiff!

Its needs to be longer?!
IMG_0411 copy.jpg  
__________________
Tim
Timbob is offline  
 
Reply With Quote
Old 10-10-2017, 08:28 PM   #6
StinsonPilot
BiP_LIFETIMESUPPORTER.png
 
StinsonPilot's Avatar
 
Join Date: Nov 2007
Location: North Bend, WA 1WA6
Posts: 3,081
Liked 620 Times on 446 Posts
Likes Given: 204

Default

Looks like that spring was cut off to make it shorter.
__________________
Doug

Flying is the answer...What was the question?

Steen Skybolt
Stinson 108-2
StinsonPilot is offline  
 
Reply With Quote
Old 10-10-2017, 08:52 PM   #7
Dave Baxter
BiP_LIFETIMESUPPORTER.png
 
Join Date: Nov 2007
Location: St. Helens, Oregon
Posts: 1,218
Liked 476 Times on 280 Posts
Likes Given: 1

Default

Mike there are quite a number of threads on this subject, and this is only one. if reading all of this you will find more than one opinion, it is up to you to determine what is best for your situation? Basically 60# lbs on the tail in level flight attitude is what you want. With the tail down 100# to 120# lbs is good, when tail weights are more that 85 # lbs such as 120 or more in level flight with the tail down that weight can increase to well over 200# lbs, and about the only wheel that will survive back there at those weights are the 3200! And the 1 1/2" spring as most airplanes have will flatten out slowly or quicker at the higher weights.

http://www.biplaneforum.com/showthre...l+wheel+shimmy

Please check out this thread, and if you have any questions pvt msg me with your ph # and best time to call. Dave
__________________
Dave Baxter
O-540 powered Skybolt Flying sold with 63 hrs on the clock.
Finished Two Stardusters, 180 and 540 Also built a Marquart MA-4 and have an SA-100 Starduster project

Last edited by Dave Baxter; 10-10-2017 at 08:54 PM.
Dave Baxter is offline  
 
Reply With Quote
Old 10-10-2017, 10:15 PM   #8
TFF1
Registered Users
 
Join Date: Apr 2010
Location: Memphis,TN
Posts: 2,707
Liked 457 Times on 354 Posts

Default

If you do a 9 g landing, you will have no back to go along with your wrecked airplane. I think certified is around 3 Gs. I don't think you could do 9 Gs without planting the nose or tail. Tail slide at 50 ft above the runway might do it. Remember you have to hold in the slide, don't let the nose drop. Smoke on?
TFF1 is offline  
Uhoh Likes This 
Reply With Quote
Old 10-10-2017, 10:23 PM   #9
planebuilder
Registered Users
 
planebuilder's Avatar
 
Join Date: Jan 2010
Location: Midland, Ontario Canada
Posts: 626
Liked 196 Times on 133 Posts
Likes Given: 234

Default

That spring looks too short and yes, one end should be allowed to slide, not both ends bolted tight.
__________________
Morgan
Starduster Too
planebuilder is offline  
 
Reply With Quote
Old 10-10-2017, 10:29 PM   #10
Lotahp1
BiP_SUPPORTER.png
 
Lotahp1's Avatar
 
Join Date: May 2012
Posts: 3,540
Liked 669 Times on 482 Posts

Default SA300 tailwheel stress

The end that the tailwheel bolts to ,that bolt should only be tight enough so the slop is gone it should allow for the spring with the slot slide a little. That's why that bolt needs to be a cotter keyed bolt not just a lock nut.


Lotahp1 is offline  
 
Reply With Quote
Reply


Thread Tools
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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Stress analyis vintagehatz Pitts 19 03-04-2015 11:58 AM
Starduster Stress Analysis DCWest Starduster 50 01-06-2015 11:56 AM
Stress risers in cracks christopher Hangar Talk 10 03-25-2013 05:55 AM
Stress, Safety & Rod Ends an8pilot Pitts Fuselage & Empennage 28 11-04-2012 12:01 AM
Bi-Plane Stress Analysis decathlondriver Smith Mini Plane 3 03-04-2011 06:16 PM