3D Printing 4x mars lander

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alexzogh

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Just finished re-modeling and printing a 4x upscale of the Mars Lander. Over a week's worth of printing. About 16" diameter, and over 4 feet tall. I had to re-revolve the entire ascent stage to ensure it could handle the stress. I also had to redo the descent stage to match the thickness changes in the ascent stage. Completely removed the rod port. Attached in the zipfile are the fusion 360 files for the ascent and descent stage in case anyone wants to make more modifications. This isn't the version I printed, as I integrated two AV bay's; one specific to the featherweight GPS tracker, and the other specific to an altimeter of my own design. I Still need to do a lot of sanding, and some laminating for reinforcement. I'll re-export everything as STL's and upload to Thingiverse sometime next week.

I ordered decals from stickershock, and they should be in this week. I plan on flying this at mini midwest power at the end of the month. Depending on the final weight, it will likely go up on a CTI 98mm M520, which has a great 13-second burn. Below is the 4x, with the 2x to the right of it, and surrounded by 3 regular mars landers

The photo's really don't the size of this thing justice. For perspective, the diameter of the 4x landing gear pads is about the same as the the body diameter of the regular mars lander.

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ThirstyBarbarian

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That is a badass Mars Lander! Awesome!

I’d love to see this fly, and you picked a really cool motor for it. I like fat rockets with lots of drag on long burn motors. That will probably reach its maximum velocity after about 4 seconds and spend the next 10 seconds just chugging along to Mars orbit, slowing down under thrust the whole way. Do you have a plot of the flight profile?

What does it weigh?
 

neil_w

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Wow. I'd pay admission to watch that thing fly.

How much does it weigh, and how long did it take to print?
 

AfterBurners

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I'm not real familiar with 3D printing but understand the basic concepts. I'm assuming its similar to those car programs you see on Velocity where if the shop needs a part they design it on a computer and feed the information into a high pressure water cutting and it does the rest. Like making custom wheels. Now is that just one large piece of plastic or is t done in sections and assembled later with adhesives??
 

alexzogh

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Thanks. Sanding is done, and decals have arrived, but the weather has not been cooperating. We've had 10 inches of rain in the last few days - my cul-de-sac is now officially a small lake.

Final weight came in at just under 15 lbs. I will be adding an additional 4.5 lbs of weight up top, add a thin coating of epoxy resin to the outside and some fiberglass reinforcement on the inside in key areas.

total print time was about 140 hours on two printers. A lot less time than the Saturn V.

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Hopefully, I'll get a day or two this week to finish it up in time for mini midwest power.
 

jd2cylman

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Alex, are you going to need something special to launch this? Besides balls of steel??? :D I remember the one at Bong.... :eek:
 

ThirstyBarbarian

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Just need 1010 rail, and maybe a trashcan post launch :p
I mentioned this project and the M520 motor choices with the 14 second burn to a few friends. The quote that stood out for me was, “No matter what, it will be amazing!“ lol!

If it flies straight, it should be awesome. But it seems like the wide stance of the legs and the size of the landing foot pads might cause some asymmetrical drag that could cause an arc or tumble. Also, the legs seem like a weak spot for 14 seconds of M power. Will they hold up? Whatever happens, it should be spectacular!
 

alexzogh

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I mentioned this project and the M520 motor choices with the 14 second burn to a few friends. The quote that stood out for me was, “No matter what, it will be amazing!“ lol!

If it flies straight, it should be awesome. But it seems like the wide stance of the legs and the size of the landing foot pads might cause some asymmetrical drag that could cause an arc or tumble. Also, the legs seem like a weak spot for 14 seconds of M power. Will they hold up? Whatever happens, it should be spectacular!

All good thoughts. If you look closely at the photos above, I didn't glue in the footpads and it won't fly with them. Legs should be ok as they were printed with 100% infill, and I printed them upright, which is much more difficult to ensure the filament alignment would have the maximum vertical adhesion.
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Legs are mechanically resistant to folding inward any more than they are so air resistance shouldn't change their angle of attack. The springs they are attached to, despite being exactly the same seem to have differing resistance. If I replace the springs with something rigid, they will be in place, but will likely break at touchdown if there is no give. Any thoughts would be appreciated.
 

AfterBurners

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Thanks. Sanding is done, and decals have arrived, but the weather has not been cooperating. We've had 10 inches of rain in the last few days - my cul-de-sac is now officially a small lake.

Final weight came in at just under 15 lbs. I will be adding an additional 4.5 lbs of weight up top, add a thin coating of epoxy resin to the outside and some fiberglass reinforcement on the inside in key areas.

total print time was about 140 hours on two printers. A lot less time than the Saturn V.

View attachment 417113

Hopefully, I'll get a day or two this week to finish it up in time for mini midwest power.
Beautiful area...where do you live?
 

cwbullet

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That is pretty slick!
 

alexzogh

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Beautiful day here in Chicago. I've been prepping my rockets for mini midwest power tomorrow. To solve my leg "problem", I bought very stiff custom springs - https://www.springsfast.com/part_detail_extension.php?part=344 . I guess they were too stiff.....

When I was installing one of them today, the spring tension was so strong, when I pulled on it to clip it to the internal mounting, I actually cracked the leg mount! Can't believe it did that much damage. I guess the good news is the leg itself is unharmed, so it can withstand some serious pressure. I will have to redesign, and reprint the descent stage.

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Luckily, I didn't put on the decals yet, so it's not a total wash
 
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