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-   -   a couple printed ideas (https://vansairforce.net/community/showthread.php?t=147771)

jliltd 06-30-2020 11:40 PM

Deadline schmedline. You're doing great stuff.

Steve Melton 07-01-2020 12:30 PM

Garmin 760 Panel Dock
 
contact is made. hopefully, it prints well.




Steve Melton 07-03-2020 11:26 PM

a finding
 
several weeks ago I posted some strength test results of a RV12 rudder pedal extension made of nylon / carbon fiber. the results were 320 lb across the weakest axis. before I broke the test setup down I tested a 2 month old development part and it was 20% stronger. how could this be unless some of the residual stress had relaxed or just test scatter? that made me wonder if I annealed some fresh parts to completely eliminate the residual stress would it made a difference. yes, it did. I annealed these two parts for two hours at 200F and tested one of them. I was afraid to test the second part because of the high loading and broken parts flying around the hangar. the annealed part failed at 620 lb. I believe these parts will relieve some of the printed residual stress over time at room temperature but annealing does it faster and probably more completely. I went down the rabbet hole and actually found something this time. :) not too bad for a 44 gram printed part.

BEFORE ANNEALING, 320 lb .... a test several weeks ago on a fresh part


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AFTER ANNEALING, 620 lb ... a recent test on a fresh annealed part




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I could not find the other half.


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I did not test the second part because of the danger. Maybe I'll do it tomorrow and put a blanket over it.

Steve Melton 07-04-2020 12:01 AM

Garmin 760 Panel Dock
 
this 760 dock is the first dock printed and I am having trouble finding anything to adjust but I'll keep checking over the next several days during first article inspection. this one has the .25 inch raised edge that serves to stabilize the hand. for a touch screen, I believe it is essential to stabilized the hand against a surface in order to even be able to operate the GPS. this dock finished a couple days ago but is still lacking a spring to install in the release slide. I don't believe I will receive the spring since this is a holiday weekend, but hopefully by Monday and ship on Tuesday. so, that's a 10 day turn around time from receipt of the GPS. missed the week turn by 3 days but it turned out very well. this dock will far outlast the GPS. BTW: you don't need all these side screws I just put them in to show where they are located. you only need either the long side or the short side screws installed. if you are making these at home, I used a .060 inch gap all around from the GPS and the spring is 1.5 inch long. the latch release slide is not installed in the photos, awaiting the spring.













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inspected at 74 deg F

************* design, measured
short side (inch) 5.662, 5.661
long side (inch ) 7.810, 7.810





Bill Boyd 07-04-2020 07:31 AM

Those RV-9 aileron bracket fairings look sharp! How are the ones for the -10 coming along?

Snowflake 07-04-2020 10:37 AM

Quote:

Originally Posted by Steve Melton (Post 1443857)
I was afraid to test the second part because of the high loading and broken parts flying around the hangar.

I note in your test photos that you have hard points, rigid equipment, and then nylon (?) rope in the tension path. I recommend adding a section of steel chain. Rope stretches like an elastic and rebounds when it releases, giving you the flying parts. Chain doesn't rebound, it just collapses.

Steve Melton 07-05-2020 09:08 AM

Quote:

Originally Posted by Bill Boyd (Post 1443890)
Those RV-9 aileron bracket fairings look sharp! How are the ones for the -10 coming along?

working to achieve a better blended surface transition on the sides then need to do a fit check.

Steve Melton 07-05-2020 09:09 AM

Quote:

Originally Posted by Snowflake (Post 1443944)
I note in your test photos that you have hard points, rigid equipment, and then nylon (?) rope in the tension path. I recommend adding a section of steel chain. Rope stretches like an elastic and rebounds when it releases, giving you the flying parts. Chain doesn't rebound, it just collapses.

good suggestion, the rope acts like a bow string. parts flying and banging off the sides of the hangar walls. I may try putting a blanket on it.

Steve Melton 07-05-2020 06:05 PM

prop gov
 
getting a new prop gov. group buy. using magnetic drain cups, two at a time, one also at the filter. very strong magnet, actually five individual small magnets in there, locked with epoxy resin. didn't spill a drop of oil.




Steve Melton 07-06-2020 08:48 AM

Magnet fully recessed - drain cup
 
another option to test today. it may find a use for getting close. using multiple magnets and having the texture of the print with the epoxy bonding locks the magnets in place. the magnets are very secure.



*******

iteration 2, allows the drain tube to be outboard from center to gain clearance



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