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

Steve Melton 09-13-2019 10:33 AM

Quote:

Originally Posted by FlyingBanker (Post 1373355)
Steve, are these A20 holders available for sale? I don't see them on your website.

Amanda will upload them by this weekend. We became consumed last night trying to join copper, nickel and silver for a metals art class project.

And also, if anyone needs a different control module mount developed, send Amanda your headset and we will make you one for free and return it to you in a week. This has been a good training project for Amanda using lofting and she's got it now and can churn them out.

We currently have:
A20
AHX-32-01

Bill Boyd 09-13-2019 01:09 PM

Steve, have you thought about doing an intake bell mouth for the SCAT connections on the rear baffles, for heat and oil cooler air? Those square shoulders on the VA-187 can't be good for maximizing air flow.

How about your own version of rear baffle hole covers where the Lord mounts protrude through?

I'm sure I can lay this stuff up over clay plugs with lightweight cloth and epoxy, but it seems like a natural application for 3D printing in appropriate material.

cderk 09-13-2019 05:02 PM

Quote:

Originally Posted by Bill Boyd (Post 1373395)
Steve, have you thought about doing an intake bell mouth for the SCAT connections on the rear baffles, for heat and oil cooler air? Those square shoulders on the VA-187 can't be good for maximizing air flow.

How about your own version of rear baffle hole covers where the Lord mounts protrude through?

I'm sure I can lay this stuff up over clay plugs with lightweight cloth and epoxy, but it seems like a natural application for 3D printing in appropriate material.

Now that you mention intakes on SCAT tubes, a bug screen holder that you can slide in there would be nice too. I guess the user would have to supply their own material. There is a write up in the July2018 Sport Aviation magazine that shows how to make one using 2? tubing. I was thinking of something like this for the -10 to keep out the bees :)

Steve Melton 09-14-2019 07:54 AM

Quote:

Originally Posted by Bill Boyd (Post 1373395)
Steve, have you thought about doing an intake bell mouth for the SCAT connections on the rear baffles, for heat and oil cooler air? Those square shoulders on the VA-187 can't be good for maximizing air flow.

How about your own version of rear baffle hole covers where the Lord mounts protrude through?

I'm sure I can lay this stuff up over clay plugs with lightweight cloth and epoxy, but it seems like a natural application for 3D printing in appropriate material.

I've thought about it but the temperatures under the cowl are too high for ABS and ASA. I am planning to experiment with graphite/nylon to understand it's temperature capability. The filament I have has a Tg of 147C and you want operate 25C below that so that's 122C (250F)max. The next part I am planning for is the spark plug lead pass thru wire mount to test on my aircraft. Peak soak back maximum temperatures usually occur at around 6 minutes after shutdown so I will be able to connect a thermocouple to the parts and check after landing.

Steve Melton 09-15-2019 08:01 AM

Bose A20 for Velcro
 
I'm sure these will make someone happy.


Steve Melton 09-17-2019 06:29 AM

under cowl temperature after shutdown
 
max reading = 208F at 8 minutes after shutdown on a 75 degree day. if ambient temperature was higher the reading would obviously be higher. I'll try to find my ambient temperature correction equation but for now I'll just add the delta to 115F day of 115-75 = 40. So, 208 + 40 = 248F. That just just under the 250F max operating temp for my graphite/nylon (-25C of the nylon Tg), so I'll proceed with the spark plug lead pass through grommet. note: under cowl engine temperatures can vary depending on the engine. my engine is 0-320 with a standard oil cooler. PLA, ABS or ASA material does not have sufficient temp capability for this location.



to look something like this


Bill Boyd 09-17-2019 10:01 AM

You're on the right track
 
Now do the -540 (3 holes):D

Steve Melton 09-18-2019 10:36 PM

plodding along
 
thinking of this design and how best to print..... kicking it around.


Snowflake 09-19-2019 08:52 AM

Make it in three pieces... Make the two halves for the cable holders, but put a flange around the outside that would sit on the baffle. Those pieces can be printed with the split plane (through the center holes) on the print bed. Make a third piece for the mounting flange, that fits around the cable holders, but has a recess to fit around the flange as well. Print that with the front (face we're looking at in your photo) on the bed. The recess won't need supports that way. It will also allow the cable holders to "float" a little bit, which may help with alignment/installation.

Steve Melton 09-19-2019 06:43 PM

Three pieces is a thought but prefer to be minimum parts. I'll try this and see how it goes with carbon/nylon, two pieces. They are mirror pieces like the Slick but the pins are not mirrored. I'll print a couple of these to determine if it is possible and if so, then tweak it to close the gaps.







**
**

carbon/nylon

first print, some work to do but encouraging.



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