Giant scale OV-10A

[daveculp]

It looks like the new design main landing gear will survive the stress test, so I'm printing a new right main gear.  Here is a photo of the old design compared with the new design currently being printed.  The thicker walls and more solid infill will hopefully hold up even when the model is jostled or moved around a bit.

 

 

 

 

[Out2gtcha]

2 hours ago, daveculp said:

It looks like the new design main landing gear will survive the stress test, so I'm printing a new right main gear.  Here is a photo of the old design compared with the new design currently being printed.  The thicker walls and more solid infill will hopefully hold up even when the model is jostled or moved around a bit.

 

 

 

 

 

 

hrmmmm, cant seem to see that pic Dave.

[daveculp]

I'm working on the cockpit last.  The design work is being done on a spare fuselage section.  First step is to cut away the nose gear mounts in order to get a full-depth cockpit.  Next step is to cut the foam canopy rails off leaving the forward and aft cockpit sections separated for now.  I want this process to be repeatable, so that requires that I cut the parts off in a simple way with minimal "carving".  My goal is to print up a cockpit tub that slips in to the foam fuselage as one piece.  For this reason I'm leaving the foam side wall thickness as is.  The foam walls are thicker than scale so I'll just have to work around that limitation.

 

 

 

 

In order to get the cockpit floor at the right height I first need to make seats.  I'll then use the seats as my guide for setting the cockpit depth.  The seats are printed in two main pieces on the FDM printer.  Like all my FDM printed parts these will need bondo/sanding/primer treatments to get a nice surface finish.  Other seat components will be printed on the resin printer, except for the cushions and belts.  The cushions will be made from clay (which means they are individually sculpted - thus not "repeatable").  I haven't decided how I'll make the belts/harnesses yet.

 

 

 

 

Today's job is to design the survival kit.

 

Edited February 8, 2021 by daveculp
grammer

[daveculp]

Some progress on the seats.  First a photo of the printed parts before any surface treatment.  One change I made after taking this photo is printing the seat bottom using my resin printer rather than the FDM printer.  The part comes out smoother but is also heavier.

 

 

 

 

Surface prep and painting continue:

 

 

 

 

A couple close-ups showing two sides of the pilot's seat:

 

 

 

 

 

Painting the yellow/black striped handles is a pain even at 1/9 scale!  I'm always amazed at the results people get at the smaller scales.  I plan to make the seat cushions from clay, and I'll try to 3D print the harnesses.

[allthumbs]

Looking good Dave. You’ve become a 3D printing maestro!

[daveculp]

On 3/1/2021 at 5:05 PM, allthumbs said:

Looking good Dave. You’ve become a 3D printing maestro!

 

Thanks, Rich.  Printing at 1/9 scale gives me a chance to learn more about FDM printing.  At smaller scales all the printing is with resin.  One thing I've learned is that the FDM prints are much lighter than resin prints.  In this case it's not a big deal because the cockpit is going to be a non-flyer anyway - in fact the static display cockpit could use the extra resin weight to hold the nose down.  These seats are going to be heavy even with the seat back and armor plate being FDM printed.  So far I'm at 115 grams per seat, and I haven't even started the cushions yet:

 

 

For people using the google browser:  https://urlb.us/diCtNQng

 

 

3D printing lends itself to repeatability so I'm starting to think and act more like a kit maker than a craftsman.  That might not be a good thing.

 

Dave

Edited April 16, 2021 by daveculp
added new photo link for google browsers

[RLWP]

On 1/23/2021 at 10:11 PM, Out2gtcha said:

 

 

hrmmmm, cant seem to see that pic Dave.

 

Neither can I - I can't see any of the pictures in this thread

 

Richard

[daveculp]

8 hours ago, RLWP said:

 

Neither can I - I can't see any of the pictures in this thread

 

Richard

 

 

The issue was addressed by Roman on page 4 of this thread.  Basically your browser is set to assume that my photos are a security risk.  I can fix this by buying an SSL certificate for my website, but I'd rather not.  You can always change a setting in your browser to allow the HTTP content to be viewed within HTTPS pages (this is called "mixed content").  Until recently the mixed content has not been considered a problem, but the newest browser releases come out of the box with a "strict" setting in regards to mixed content.  Supposedly this is done for security.  I believe the real reason is to "encourage" everyone to use the HTTPS protocol so that all content delivered can be associated with a home or business address.  So if I buy an SSL certificate (annual fee, forever)  from GoDaddy, my hosting service, then I'll be paying extra to have my home address associated with my photos.

[RLWP]

I decided on taking the other route, and shifted my website to https - I thought it would be best for me to change to match the world rather than expect them to change. It costs me about £1 a week, which I think is worth it

 

Richard

 

 

[daveculp]

It took a long time to get the cushions done.  This was my first time using poly clay, in this case I used Fimo Soft.  Getting the folds right required adding small string-shaped bits of clay and then blending them in.  After baking I did some sanding and Bondo treatments to get it looking good, then primer and paint.  The paint color, Vallejo Model Air 71.044, is called "Grey" but looks a lot like a grey-green to me - just right for the cushions.  I made some decals for the back cushions, but after applying them they looked too thick with a plainly visible edge, so I sanded them off, resurfaced, reprimed and repainted.  I think the problem with the decals may have been a too-thick coat of clear to seal them.  I'll try again with a thinner air-brushed coat (if I dare).

 

The parachute risers were 3D printed on a resin printer.  I've been doing CAD work on the seat belts and harnesses, but now I think it's best to just print the hardware, i.e. buckles and such, and then use some fabric material for the webbing.

 

Also, I found a site that shortens URL's, and it also converts the original http to https, so this may be a solution for those using google browsers who can't view the photos.  Let me know if this solves the problem for you.  I can't test it here.

 

 

For those using google browsers:  https://urlb.us/_kqYEe38

 

 

[RLWP]

Unfortunately, I still can't see the images

 

I can see the 'Google' links as long as I click them, then click 'proceed'. Which is a bit of a faff

 

Richard

Edited April 16, 2021 by RLWP

[daveculp]

After a few months all three of my original landing gear cracked.  The cracking is not preceded by any bending - the breakage is sudden after a few months of holding up the airplane.  I've since printed up a new set, this time with wall thickness set to 4 and infill percentage of 40.  Here's a cross section of the nose gear showing the thicker construction:

 

 

 

If this doesn't solve the problem I'll have to switch to a different material, maybe PETG.  The stress test has begun, and I'll know in a few months if the gear will hold.

 

 

 

 

NOTE:  Images are delivered using the HTTP protocol.  If your browser blocks this protocol you might consider using a different browser.  The Dissenter and Firefox browsers still accept HTTP protocol.

[dodgem37]

Nice.  Honeycomb may be a better interior structure than cross-hatching.

 

Sincerely,

Mark

[seiran01]

Looks superb!  Dunno how I missed this thread until now.

I wish they had released this before I stopped flying R/C. I had Motion RC's TA-152 and loved flying that

 

[allthumbs]

Great work Dave...coming together nicely!

Rich