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

Steve Melton 03-18-2017 12:07 PM

a couple printed ideas
 
rocker switch protector. use small velcro on each end to secure.




infinity stick cover. first trial.



looks goofy, works great. no more snagged switches when climbing in. that could ruin your day. just drop it on and it finds the home. done.







label embossed



print with multiple colors and glow in the dark plastic?




label recessed

Steve Melton 03-20-2017 08:33 PM

fuel drain fairing
 
maybe a little proseal on the cylinder is enough to adhere. weight = 16 grams. first trial, size is not final. plastic cost = $ 0.42. may also improve the life of the o-ring since it will eliminate vortex shedding vibration of the stem that is in the airstream.




crabandy 03-20-2017 09:11 PM

Sweet, I will take 2 of the fuel drain fairings, where do I send the $0.84?:D
How about a smaller fairing for the fuel vents on the belly?

rockwoodrv9 03-20-2017 09:12 PM

Steve, you are having way too much fun there!

Steve Melton 03-20-2017 09:12 PM

I'll throw a couple of these in a back for Oshkosh. Fly away with a "faster" airplane.

PilotjohnS 03-20-2017 09:38 PM

Fuel drain lock
 
On the fuel drain fairings could you put a hole in it such that a small lock can be inserted so that it will prevent someone from stealing fuel? I dont know why this occurred to me, not that i live in LA or anything like that.

Steve Melton 03-20-2017 09:41 PM

John, I wouldn't do that for anyone except you. Let me know when you need it. Steve

Steve Melton 03-21-2017 04:50 AM

From concept to holding in the hand in about two hours and I had to watch a youtube video for training. I am still amazed by this technology.

I see Solidworks can complete CFD airflow analysis. I'll post a couple slides of that. Not that this simple fairing needs any analysis but just to share. Maybe someone can chime in on that.

My youngest daughter, 9th grade, runs circles around in solid modeling and is beginning to talk about stress analysis. Now we have something to discuss!






GalinHdz 03-21-2017 05:37 AM

Nice work!!

:cool:

rzbill 03-21-2017 05:38 PM

PLA or ABS and are they hollow?

Fly2KiteSurf 03-21-2017 06:45 PM

?
 
http://www.jdair.com/fuel-drain-fair...s-rv-aircraft/

rocketman1988 03-21-2017 07:03 PM

What plastic?
 
What plastic did you print in...

Hopefully not PLA because if you did, they won't last long as it is biodegradeable...ABS would be better but not sure of its resistance to gasoline. If your printer can get to 235 degrees, you can print in a nylon blend which I have used before and works pretty well...

Steve Melton 03-21-2017 07:28 PM

Quote:

Originally Posted by Fly2KiteSurf (Post 1159722)

I have these currently installed and recommend them, however with my paint they don't engage as fully as before paint. I thought I would try similar in plastic. The ABS plastic will not scratch paint. These are printed hollow, 4 cover layers, 40% in-fill, weight = 16 grams. I believe the weight could be reduced to 13 grams. Fit check and final tweaking still needed since I sketched these from memory.

kaweeka 03-22-2017 08:02 AM

Amazing!!!!

Lynnb 03-22-2017 12:19 PM

Are you going to try and smooth them any with an acetone wash or fuming? Any chance you want to share some files? ;)

Lynn

dwranda 03-22-2017 03:41 PM

I had my son design me one of those last semester when he wasn't too busy with school work. Came out pretty good, but he wants to tweak it a little.

Steve Melton 03-22-2017 08:11 PM

Quote:

Originally Posted by Lynnb (Post 1159884)
Are you going to try and smooth them any with an acetone wash or fuming? Any chance you want to share some files? ;)

Lynn

no, they are smooth enough for me. yes, I'll drop the files out to a shared location when completed.

Lynnb 03-24-2017 07:08 AM

Quote:

Originally Posted by Steve Melton (Post 1159999)
no, they are smooth enough for me. yes, I'll drop the files out to a shared location when completed.

Cool, thanks.

Lynn

N941WR 03-24-2017 07:23 AM

Can you incorporate a small piece of screening material in it to keep the bugs out? (Mud daubers are a real pain in the South and will build a nest in any opening they can find.)

Quote:

Originally Posted by Steve Melton (Post 1159479)
maybe a little proseal on the cylinder is enough to adhere. weight = 16 grams. first trial, size is not final. plastic cost = $ 0.42. may also improve the life of the o-ring since it will eliminate vortex shedding vibration of the stem that is in the airstream.





Steve Melton 03-25-2017 09:03 PM

Bill, I attempted to make the fairing removable if needed for access or to clean out mud.... I used the same idea as the JD fairing because it's good, a set screw at the fwd edge.

JD fairing didn't seat fully because of paint. I've been flying with this for a year, no problems.


printed fairing, Eppler 863 airfoil, thickness increased from my first prototype made from memory, my memory wasn't very good. it's a solid fit. I like it. the ABS plastic will not scratch the paint.












Tram 03-26-2017 04:05 AM

Just when I was looking for another reason to get a 3D printer.. I guess I should go ahead and order it..

Any of you guys using the Maker Select V2?

YvesCH 03-26-2017 06:27 AM

I also just started to try out 3D printing as we used it a lot in my old job and there it worked great. I had two problems where I was looking for a solution:

1: Mounting the CO Guardian remote co monitor: I have to remove it periodically and the factory mounting only on one side did not satisfy me totally. So I decided to print a attachment bracket whereas the co monitor will be clipped in and secured with lockwire on top.




2: CB Panel: I wanted a solution to attach my cables from the CB panel so they make a nice turn towards the hole in the gear Towers (RV-8). The Solution will clip in the copper bus bars and the cables will be secured with a zip tie.



Now I ordered the parts at Shapeways and I hope they come soon :)

Lets see....

Steve Melton 03-26-2017 06:31 AM

nice design. what do you pay to have that part printed?

plastic cost for the fuel drain fairing = $0.58. weight = 19 grams as installed.

scard 03-26-2017 07:59 AM

Quote:

Originally Posted by Steve Melton (Post 1159999)
no, they are smooth enough for me. yes, I'll drop the files out to a shared location when completed.

Steve, Please do share your files when you're ready. They look real nice.

Steve Melton 03-26-2017 08:39 AM

Quote:

Originally Posted by scard (Post 1160756)
Steve, Please do share your files when you're ready. They look real nice.

Well, having thought about that some more. I prefer to send the model direct to the user because of legal concerns.

I think these set screws will be nice because they have a nylon tip. I'll give it a try.


Snowflake 03-26-2017 11:27 AM

Quote:

Originally Posted by Steve Melton (Post 1160760)
Well, having thought about that some more. I prefer to send the model direct to the user because of legal concerns.

I hate this society sometimes. I would be interested in the files though.

Quote:

I think these set screws will be nice because they have a nylon tip. I'll give it a try.
Less removable, but have you considered using something like a molding adhesive tape, like they use to attach car emblems and trim pieces? If the fairing is designed with enough clearance for a 1/2" socket to get in there to pull the plug to replace the o-rings, then the fairing should never need to come off?

Also, could you comment on the choice of shape? Both yours and the JD Air ones have a nice profile that ends with a "flat" section (closest to the wing). Since you're 3-D printing, why not make a profile that looks like the pressure recovery wheelpant, that curves right down (or up) to the wing surface?

I have the original JD Air fairings that are held on by the drains... I always waste more time getting my drains to stop dripping by working and turning the plunger, when I should just pull the plug and change the O-ring, because changing it *and* holding the fairing in place at the same time is such a recipe for gas-soaked clothing... I have access to a 3-D printer so this solution seems promising to me!

Steve Melton 03-26-2017 12:06 PM

maybe a profile like this? about 7 degree.


1001001 03-26-2017 12:37 PM

Steve,

I love what you're doing with 3D printing.

A few years ago (nearing 10!) I started fiddling around with CFD analysis. I was working in the power industry at the time and was looking for ways to analyze and improve the operation of some equipment I was responsible for. I built a CFD box out of what was at the time some awesome hardware and ran OpenFOAM on it.

Fast forward, I am in a new job that doesn't have the same concerns and have left CFD behind, but not the desire to play around with it. I might consider re-equipping and getting up to speed with OpenFOAM again. I understand it has advanced quite a bit since the old days.

Now being into airplane building I have thought a lot about the possibilities for customized 3D printed solutions for fairings and covers and such, and the ability to test them out in a CFD environment. What have you found about the capabilities of SolidWorks for CFD? Does it approach the capabilities of the dedicated CFD packages?

YvesCH 03-26-2017 01:22 PM

Quote:

Originally Posted by Steve Melton (Post 1160750)
nice design. what do you pay to have that part printed?

plastic cost for the fuel drain fairing = $0.58. weight = 19 grams as installed.

I pay around 11$ for the cable holder and 12$ for the other parts. I also made some smaller parts to tidy up my static/pitot tubes and other cables.. Those are around 2$ each. Ist quite cool as you just upload your STL file and see immediately the Prices. This keeps you improving the design to make it even lighter :) Also ist cool to just try out 3D printing without buying one. The other Advantage is the possibility to print in different materials and colours.

As soon as I will receive those parts (shipping estimate 7th of April) I will post the result here.

I use ZW3D as a CAD tool as it is the software I have at work.

Snowflake 03-26-2017 04:29 PM

Quote:

Originally Posted by Steve Melton (Post 1160793)
maybe a profile like this? about 7 degree.


Not bad, but I was thinking more rounded at the nose, and even thinner at the back. Think a pressure recovery wheelpant cut in half across a plane parallel to the ground, and scaled down so the maximum height is the same as the protrusion of the drain.

Steve Melton 03-26-2017 05:51 PM

a 7 degree taper is typically a good free stream diffusion angle for maximum pressure recovery. I don't know the wheel pant's angle. the nose needs to be fairly large to allow the plastic ample area. the alum part from JD can be thinner.

note: I did a check fit on a neighbor's RV-4 that has a significant proseal build up around the flange to wing skin and the fairing would not fit flush. I will make a custom enlarged flange recess area for his.

one flight test today had positive result, light rain. the fairing was secure.



avgas test. after one hour it was same as before testing. we will leave it for a week. ABS plastic.


Steve Melton 03-26-2017 06:02 PM

Quote:

Originally Posted by 1001001 (Post 1160799)
Steve,

I love what you're doing with 3D printing.

A few years ago (nearing 10!) I started fiddling around with CFD analysis. I was working in the power industry at the time and was looking for ways to analyze and improve the operation of some equipment I was responsible for. I built a CFD box out of what was at the time some awesome hardware and ran OpenFOAM on it.

Fast forward, I am in a new job that doesn't have the same concerns and have left CFD behind, but not the desire to play around with it. I might consider re-equipping and getting up to speed with OpenFOAM again. I understand it has advanced quite a bit since the old days.

Now being into airplane building I have thought a lot about the possibilities for customized 3D printed solutions for fairings and covers and such, and the ability to test them out in a CFD environment. What have you found about the capabilities of SolidWorks for CFD? Does it approach the capabilities of the dedicated CFD packages?

I thought the EAA version of Solidworks had CFD analysis but it does not. There are two different versions of student Solidworks. EAA has the lowest version that does not include CFD.

rocketman1988 03-27-2017 09:28 AM

ABS and Gasoline
 
Here is an engineering reference on chemical resistance:

http://www.gilsoneng.com/reference/ChemRes.pdf

Checking ABS and Gasoline yields a rating of 3 which means it is not recommended. Hate to see that really nice 3D printed part melt into a pile of goo...

Print it in Nylon, it has great gasoline resistance and is 3D printable...

Steve Melton 03-27-2017 10:37 AM

Quote:

Originally Posted by rocketman1988 (Post 1161059)
Here is an engineering reference on chemical resistance:

http://www.gilsoneng.com/reference/ChemRes.pdf

Checking ABS and Gasoline yields a rating of 3 which means it is not recommended. Hate to see that really nice 3D printed part melt into a pile of goo...

Print it in Nylon, it has great gasoline resistance and is 3D printable...

after soaking for a week, we may find a pile of goo at the bottom.... or not. :)

donaziza 03-27-2017 10:56 AM

First--your "subject" matter before the 3D printer.
 
I've been following this 3D printing thread with great interest, having never known anything about it before. I've Googled enough where I've got the concept of how the "printer" works and what you can do with it, but I can't seem to really find anything on Google, that explains how to get the "concept" either from your head, or from an actual object "Whatchamajinger" you want to reproduce into the printer's computer, so that the printer knows "what to print"?:confused:

Like Steve Melton, you made that scoop, others were talking about making antenna's---between the idea in your head, and actually creating it on the printer, what happens, and how do you do it?

rv8ch 03-27-2017 02:02 PM

Solidworks
 
Quote:

Originally Posted by donaziza (Post 1161091)
I've been following this 3D printing thread with great interest, having never known anything about it before. I've Googled enough where I've got the concept of how the "printer" works and what you can do with it, but I can't seem to really find anything on Google, that explains how to get the "concept" either from your head, or from an actual object "Whatchamajinger" you want to reproduce into the printer's computer, so that the printer knows "what to print"?:confused:

Like Steve Melton, you made that scoop, others were talking about making antenna's---between the idea in your head, and actually creating it on the printer, what happens, and how do you do it?

It seems a lot of people are using Solidworks, which if you are an EAA member, is "free".

https://www.eaa.org/en/eaa/eaa-membe...esource-center

It's a kind of 3d drawing program. Be psychologically prepared to invest some time learning it if you are not already used to CAD programs.

rocketman1988 03-28-2017 11:21 AM

Interesting on the Gas test...
 
That is really interesting that gas doesn't seem to be affecting the
ABS. Let us know after a week...

One thing I did find out about ABS is not to get blue loctite on it. I 3D printed an arm for my flap position sensor and used blue loctite to secure the ball for a ball and socket attachment. Less than a week later, the ABS literally crumbled in my hand...then I read the warning label on the loctite...:D

Snowflake 03-28-2017 05:51 PM

Quote:

Originally Posted by Steve Melton (Post 1160860)
a 7 degree taper is typically a good free stream diffusion angle for maximum pressure recovery. I don't know the wheel pant's angle. the nose needs to be fairly large to allow the plastic ample area. the alum part from JD can be thinner.

Here's a quick model done with TLAR measurements... "sort of" to the shape of the PR wheelpant. A piece of double-sided 3M Body Molding Adhesive tape
front and back, and it would stick nicely. Tape at either end and none in the middle would also help account for the curve of the bottom of the wing... The tape is about 3/32 thick.

https://lh3.googleusercontent.com/wZ...PRks4XiQk?.jpg

https://lh3.googleusercontent.com/QC...YXze8VQ8M?.jpg

https://lh3.googleusercontent.com/d_...q9Yezzvow?.jpg

Steve Melton 03-28-2017 08:04 PM

Rob, trying to incorporate your ideas tonight before releasing it to the group. I think it looks better. I can't see your pictures.






Snowflake 03-29-2017 07:45 AM

Sorry, complain to Doug for not allowing photo uploads. I already have.

Here's a link to a Google Photos Album, which should be visible to all:
https://goo.gl/photos/819NY1dPewsJaNkG6


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