Building a Cozy MK IV Elevators


Chapter 11 Elevators



 

I started this chapter by hotwiring the cores. I did this at the same time that we hotwired the cores for the canard. I cut my elevators about an inch shorter than the plans because I am planning on making fairings where the elevators meet the fuselage. This seems to be a common plans deviation.

 I next epoxy the elevator cores to the torque tubes and twisted the tubes to the right location using the gauges. Below is a picture of this. 





    


I then epoxy the cores to my work bench and fiber glassed the bottom of the elevators.
The unidirectional fiberglass used on this part is cut to a 30 degree angle in relation to the fiber orientation and the fiber orientation is altered back and forth from layer to layer. It is the same for the top of the elevators.
I kept this a dry layup per plans. With a squeegee I worked as much epoxy out of the layup as possible. The plans say to do this or else you might have a hard time balancing the elevators.
I next trimmed the excess fiberglass off and sanded the trailing edge straight. I turned the elevators over. I then bonded the elevators to the workbench to prepare for the fiberglass on the top of the elevators.

I sanded the foam cores, checked the shape of the elevator with the gauge and vacuumed the dust off of the cores. I applied thick micro to any damaged areas and slurry to the rest of the cores. Then I fiber glassed the elevators the same as the bottoms. I then microed the trailing edge to blend it in with the contour of the elevator.

After sanding, this is what it looks like.







I next installed the torque tube that join the two elevators together along with the

torque tube offsets and the pit trim bellcrank. Below is what that looks like.

  






           

          










Then positioned the elevator on the canard in the proper position using the templates.







I next cut the slots into the bottom of the canard to attach the hinges to the canard.


   Wing tip upside down.




I then made wing tips. You start out with a piece of foam attached with micro to the wing. The plans give you a rough idea on the shape but you basically sand the block of foam until it follows the shape of the wing with a curl up on the tip. This is my translation of the plans. Wing tips are different on every Cozy. After you get the shape they get covered with two layers of unidirectional fiberglass. Below is a picture of the bottom of the wing tip.







You will also need to make a hole through the wing tip to enable you to remove the elevator hinge pins. To do this I drilled a hole through the foam before attaching it to the wing with my drill press, to get the hole square with the wing. I then used a drinking straw and with micro I attached the straw to the wing tip.



 




You then cut two pockets into the bottom of the wing for the elevator counter weights to pass into. These pockets get bidirectional fiberglass in them. My pockets are cut a little bit larger than needed but I am going to put ice guard covers over them later. 

Now you fill in the low areas and finish out the wing. To do this I will be using West Systems 205/105 epoxy with micro. I am using a sanding block that is about two feet long in order to keep everything straight. This process also fills in the fiberglass cloth so that it will have a smooth finish. Below are the sanding blocks.









This completes chapter 11. This brings the project to 22% complete. This chapter weighed  lbs. On to Chapter 12.


 





If you have any questions, comments or concerns, feel free to email me at Jfisher59@gci.net