Dave's SS7

[alexM]

Same kind of tape is sold by a company that calls it Rescue Tape.

I once met someone with a great Rescue Tape story. They were motoring a sailboat through the Panama Canal when they had a coolant hose start leaking. One doesn't just pull aside and fix things while transiting the Panama Canal. It requires meeting a very tight timing schedule with no room for having issues.

They were able to wrap the leaking hose with the engine still running, and it worked perfectly. I haven't done anything quite as crazy as that but I always have some around.

[Pushboy]

Just curious if anyone knows if the control column bearing for a series 7 is made of UHMW?

I may have buggered mine up and I have some UHMW around the shop.

Thought I might make a new one rather than wait for a part in the mail.

Thanks.


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[jiott]

I'm pretty sure the factory calls it a Delrin bearing block. Delrin is a brand name for acetel plastic. It has better creep resistance (long term deformation) than UHMW but still has the low friction properties. Its probably no big deal, but I would try to get a block of Delrin; should not be hard to find.

[Pushboy]

I'm pretty sure the factory calls it a Delrin bearing block. Delrin is a brand name for acetel plastic. It has better creep resistance (long term deformation) than UHMW but still has the low friction properties. Its probably no big deal, but I would try to get a block of Delrin; should not be hard to find.

Hey Jim -- thanks for the info. I'll touch base with the factory and ask. I'm sure you are right that Delrin would work well. I think that the block that came with my kit is UHMW though. From what I understand UHMW has a specific gravity (density) of 0.94-0.98 so it should float in water -- which mine does. Delrin if I recall correctly has a density of 1.45ish - so it should sink. When I tried the bearings for the rudder pedals, they in fact sink -- I'm "fairly" certain these are Delrin.

Dave.

[efwd]

I used that tape to fix a garden hose only to have it become a water balloon tumor on the hose. I guess its good for low pressure, below city water pressure levels? Also, I was surprised to find a location or two on my plane where the wire tie simply cut through it over time. Don't overtighten.

[jrevens]

Yeah, it is very soft material and it “cold flows”. Really not a very good choice for every “rescue”.

[Pushboy]

So I have updated my build in a while, so here goes.

Over Christmas/New Year I was working on my balsa end caps for the tail/rudder and horizontal/elevator. I probably spent too much time on these, but it was an enjoyable process in the end, and I finally got them to where I was happy — but I’m no sculptor!





I then moved on to the aluminum flanges for the tail access cover and the forward bulkhead.






Initially I was going to continue with the access panels and fit them, but I went down a bit of a rabbit hole about all the different kinds of hardware combos. I gave myself some analysis paralysis, so to starve of the inevitable insanity I decided to move on to something totally different.

I chose the control column… I found this quite a lot of fun, although not without its own challenges.




I got over eager on sanding the column block and created some play in the column, so I fabricated a new column block out of some UHMW I had in the shop. After I had done this, it occurred to me that I could have likely shaved down the “legs” on each side of the large hole of the block — this would have effectively made the vertical diameter of the hole smaller, which is where the play was. Oh- well, I guess I have a spare now.
I did use the technique of the steel sleeves inside the block to prevent excessive cold flow of theUHMW.


I continued to work on the control linkages following them rearward.
I don’t have many photos of this stage. I had the usual issues — things not quite fitting right and having to make adjustments to get things to move right. Again I spent more time than I like to admit on getting the controls to glide smoothly in all directions.
I did have considerable trouble with installing my flaperon mixer. In conversation with Brandon at the factory and some creativity I was able to get things aligned and moving freely. That old advice “If things aren’t working…. Maybe take a step back… and start fresh on a new day…”


Next I turned my attention to the floorboards and center console.
This involved the flap handle and adjustable rudder pedal handles. I was glad to see my kit came with the 1/16 holes already drilled in the detent pins. I do wish the factory had sent some extra roll pins though, as the longest part of that assembly was looking for that tiny pin on the shop floor after I inevitably dropped it. There was the associated stress that came with that situation which also meant I did not take any photos.

The floorboards were back to woodworking, and a better level of skill/comfort.


Then the center console and sides. I’m not finished this step, but well on my way. I gotta admit, this was pretty cool — to see the project go from looking like some broken dune buggy frame to some semblance of a cockpit was quite rewarding.



Also somewhere in there I put the rudder pedal and flap detent brackets together. I haven’t installed them in the console yet as I’m waiting for a counter sink bit for the rivets. I also modified the flap bracket for 2 extra notches.


That pretty much brings things up to date.

Thanks to Harlan, Jason, Keith, Patrick, John and anyone else I’m forgetting… But most of all to Brandon - without his constant cheerful advice I would not be this far along— nor this happy.

[jiott]

What you have done so far looks like very good craftsmanship to me.
One small suggestion: On the very aft part of the tail access panel opening I recommend bonding (Hysol) a thin aluminum strip to the back side of the fiberglass tailpost fairing. There will be several screws securing the access panels to that fiberglass fairing. Trust me, they will soon strip out if they only have thin fiberglass to bite into. The aluminum will give the self-tapping screws something much more solid to bite.

[Geek]

Agree with Jim- awesome work Dave. Another suggestion I did on my console side panels was to bend a slight crease inboard at the front end. It moved the front of the console away from the rudder pedals just a bit but mainly did it to add some stiffness to the end of the panel. Doesn't take much. Apologize that the pic isn't really clear but the red line is where I creased it and you can see it's not much.

Keep on it man - great progress and outstanding job.

G

Console.jpg

[bbs428]

Those surface tips look really smooth and nicely shaped. I like how your project is going. Great workmanship!

Keep at it every day - eat that elephant one bite at a time. Lol.

You'll get to the finish line with a plane you'll be proud of!