• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction).

Torque tube build. pt 1

scottly

Well-Known Member
*
Joined
Sep 13, 2006
Messages
1,639
Reaction score
4
There has been discussion on this board about plans stick vs. bearing stick. The manual shows a great build of a plans stick, but I have chosen a bearing control assembly for my project. This is very similar to the setup shown in the December 1976 MacKenzie newsletter, with some slight changes.
The newsletters are full of different ideas, but I have found that they are sometimes not clear at explaining how to do something. The control sticks are one of those, in my opinion. I'll try to explain construction better than the newsletters,without repeating the steps in the newsletters.


First step is drawing and cutting out all the parts listed. This is easy, but the letter never tells you how these parts go together. It shows you a poor quality photo of the finished item, but that is all.


After cutting out the parts, you will bend two of them as shown in the newsletter. You want to drill small pilot holes where the .250 holes will eventually be. The pilot holes will be needed later, when welding.


The instructions tell you to bend the end of the stick socket with a mallet, but I just used a vice. When held in the vice, I applied a litle heat to relax the metal and avoid springback. I used a propane torch so that it would not get it too hot.


20071110_224207_c&



Next step is to weld the pieces you bent with the 5/8" bending block onto the control stick sockets. The newsletters don't tell you this nor show you this. the socket you squashed to 3/4" dimension fits perfectly on top of the bent piece and gets welded, like so:


20071110_224400_c&





Now the pilot holes come in handy....use them for the clecos that will hold the parts together while you weld them to the stick sockets....like so:


20071110_224539_c&



When you are done welding the pieces together, around the edges and to the stick, you should end up with something like this:


20071110_224722_c&





This episode brought to you by Wendy's....




Now you can drill and ream to final size of .250.




Instead of installing Oilite bushings as the newsletters direct you, I decided to use a bearing set up using RZ44 bearings. Using a lathe, I cut a bearing sleevethe same length as the newsletters direct you to. Cut an internal support sleeve .364 shorter and press in place (see thread on aileron bellcrank). I then drilled my stick socket to fit the bearing sleeve and welded it in place.


20071110_225033_c&







When you are done, you'll have this:


20071110_225158_c&





I'll post part 2, bearing collar, soon. Edited by: scottly
 

Latest posts

Top