Posts: 2084
Joined: 8/1/2005 From: Vancouver,
WA, USA Status: online
quote:
ORIGINAL: pt40crasher
It is subjected to shear loads every time you make a control input. While mine has also not shown any wear, the 1/8" dowel is not very confidence inspiring and I've heard of a few SSE's lost from this pin moving or breaking. Mine is epoxied in and I'll be leaving it as is. Just sayin'.
CA that pin in place. I had this drift on me during a flight and was lucky to land it in once piece after one of the wings began to rotate.
somegeek
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Fly safe, have fun. Measure three times, cut once. The man who makes no mistakes does not usually make anything.
Posts: 1506
Joined: 9/4/2002 From: Bruce,
MS, USA Status: offline
The antirotation dowel is what put my last SSE into the ground. Glue it well with exopy! It is plenty strong enough as is but must be glued well. I was trying to save weight and never tought about vibration over time.
Posts: 1125
Joined: 7/15/2004 From: Middleboro, MA, USA Status: offline
I used ca to secure the dowel in place when I set the wing alignment before I installed the lower fuselage piece. I wanted to make sure it was glued both to the sides and to the bottom of the servo tray where it seemed that that was a design consideration as it dowel in combination would absorb most of the inward force of the wing root. The servo tray adds most of the rigidity to the wing center structure, and I did not think it would be all that easy to secure afterwards. And it is a going to be a bit of a pain when I finish the fuselage sides, but I wanted to make sure about it bing fastened well. I will also need it for a reference for the fairings that I am going to use to blend the wing into the fuselage with, as well as the wing tube. The wing is going to slide into a 3/4 inch pocket on the side of the fuselage.
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The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185
Posts: 1125
Joined: 7/15/2004 From: Middleboro, MA, USA Status: offline
Some small progress made…
I managed to reduce the weight of the plywood base for the canopy hatch from .6 oz to .4 oz so that is another .2 oz to add to the total weight reduction. That now puts the total amount of weight reduction at 3.7 oz thus far. After that I installed the two formers three stringers to the hatch assembly and am now ready to start adding sheathing to the hatch.
Now a bit more about this build regarding weight… I have estimated the weight of the balsa sheathing for the cowl, cooling duct, fuselage and tail along with the carbon fiber veil for the entire fuselage and control surfaces at 3.4 oz (not including adhesives or finish). Normally it would take roughly 1.5 yards of monocoat to cover the plane, the weight of that monocoat would be around 2.7 oz (not including adhesives or finish). So worst case I am adding .7 oz to the extra weight of the airplane at this point (estimated) to add a full cowl, cooling duct, sheathing to do the stressed skin finish of the plane (not including adhesives or finish). That stressed skin, along with some added composites will allow for some further weight reduction when I do the tail feathers, by eliminating the weight of the screws, dowels, fittings wire and solder used to make up the flying wires used to strengthening the tail feathers. So with that being said the stressed skin finish will have a three fold benefits of strength, reduced drag, and reduced weight (hopefully) of the finished plane to allow for all of the modifications I am adding to blend the fuselage and wing into each another.
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The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185
Posts: 1125
Joined: 7/15/2004 From: Middleboro, MA, USA Status: offline
Got the canopy hatch sheathed, and built and sheathed the tank hatch. Got the skin to sheath the turtle deck glued up other than that not much progress other than taking a hard look at the tail feathers and how they are going to be modified. I have not finished the sanding on either hatch as of yet, I will do the finish sanding after the cowl is shaped and the rest of the fuselage sheathed.
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The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185
Posts: 1125
Joined: 7/15/2004 From: Middleboro, MA, USA Status: offline
Thanks for the compliment but the canopy hatch has some filler on it, thank goodness for microballoons … The wood was a bit stiff and I cracked on that side as I bent it, and it was soaked down fairly well. The forward hatch was planked on the sides and then skinned, lots of sanding on that but not much filler. Basically sand away anything that doesn’t look like an airplane…
As far as progress.. I have been working on the plans for the horizontal stabilizer and vertical fin modifications I intend to do and plan to start putting them together in the near future.
I have the turtle deck sheathed and one side of the fuselage sheathed just sanded out the skins for the other side tonight after our club meeting. I hope to have it done tomorrow night and will try to post some photos as an update then.
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The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185
Posts: 1125
Joined: 7/15/2004 From: Middleboro, MA, USA Status: offline
Just a quick note and some pictures to update my progress thus far.
The first picture shows the turtle deck sheathed and the second shows the sheathing applied to the sides of the fuselage. You may make note the sides are sheathed with the grain vertical as you would do a shear web for the same reason. This along with the carbon fiber veil should add a lot of strength to the airframe. And allow me to add a radius to the bottom of the fuselage to clean up the airflow a bit.
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The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185
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RE: Yet another Sig Something Extra Build - 
