So my 11 year old bought a 3d printer...

Actually, I did, and she's paying installments. I've never messed around with one until now, and I'm already hooked.

I've seen these cool little paracord rope lock things, and found a design online, scaled it up, and tried it out for some quick adjustable tie downs. I'm pleased with how they came out. I reinforced a bit from the original, but I don't know if that was necessary.

I made another couple hat were more like the rope cinches you'd see on a tent. I'm gonna use both and see how they work out...but pretty cool what can be done with some time and a couple of dollars worth of stuff that looks like weed eater line!









(I don't have to get on my knees to test them out on dads 182... )

A little more engineering needed...

An unscientific break test had the figure 9 doohickey break at an estimated 150lb steady pull (not a "snatch").

I'll do some playing and see if I can make it stronger and more viable.

This 3d printer sure is something else, if nothing else than for seeing models of "real" machined stuff without spending the money to machine until you know it's gonna work.

Could you share which model you bought? I am thinking about getting one as well.

Chris

Scott, depending on the capabilities of the printer, different filament material (as well as print infill settings) will change your part strength.

Things to check is whether the printer capable of printing PETG? ABS? Nylon?

I recently acquired a Purusa i3 MK2 kit; great reviews on print quality and easy to assemble. Great thing is you can print your own spare/replacement parts. Software apps included are excellent. Even has an option to automatically use up to four different filaments when printing a part.

I have printed a few parts like zip tie mounts from 3D parts files available in the builders forum at https://electricmotorglider.com/. Found the site through EAA/Brian Carpenter's Hints for Home builders videos on 3D printer parts. Still experimenting with layer thickness vs quality vs print speed, bed and nozzle temps, etc. Finally getting the hang of printing with PLA, no luck on my ABS attempts so far.

John Salak
RV-12 N896HS

My new 3D printer is also a Prusa i3 MK2. Warning - There's about a 7-8 week lead time just for the kit version of this printer. Add 2-3 weeks for a fully assembled one. It was the top rated 3D printer in the last Make Magazine shootout. It works great, and was cheap. Anyone who builds or maintains RV's should have no trouble assembling one, it'll take you most of a day.

The goal would be to have it break above 800 pounds, which appears to be around what RV-3B tiedowns will see in a 70 mph wind.

An additional concern is whether there is any possibility at all that in a highly gusty and dynamic environment, the rope can possibly slip or lose tension. I've been in strong conditions and have seen aircraft destroyed because of that. So far, I haven't seen anything better than good rope and several half-hitches.

Good luck with the development!

Dave
RV-3B now skinning the tailcone

Answers and guesses

In extreme winds, I'd tie it off (or get it the heck out of there...) I wouldn't depend on any extraneous stuff, especially not something I made with a technology I am just learning. My paint may not be show quality, but I try not to leave my airplane out much more than overnight for a visit somewhere.

I'm looking for something that is reasonably reliable and easy, especially for my folks to use on their aircraft for basic nice day tie down when they fly somewhere for breakfast or lunch...and mostly just toying around with the printer.

I've got some ABS filament inbound, so I'll try that, and I'm going to try to modify the fill shape to triangles and up the fill content. (Didn't know I could do all that until today)

I (she) got the Lulzbot Mini...they are about $1250 (!!) on Amazon and she's been saving. When I saw she was serious I started lurking craigslist...eventually I found a guy with more toys than money who seemed legit, and I paid $450 for it with a roll of PLA filament.

Lulzbot is located just 30 minutes or so from my house, I understand they will service stuff, and many of their machine parts are actually printed on a 3d printer.

I'll check the link posted above--if anyone else has links with aviation themed printing info (besides here of course), I'd love to see what folks are dreaming up.

You've got a great printer with the Lulzbot Mini.

The printer uses 3mm (most often its 2.85mm) filament. That printer can print nylon. We used a Mini to print nylon sprockets for a FRC robot and even at 20% infill, those things took an incredible beating and kept working.

The Lulzbot edition of Cura with the breadth of Lulzbot profiles makes it easy to use a wide range of filament material. With those profiles, nylon is as easy to print as ABS.

Your 11yo has good taste in technology!

Taulman 3d has a wide variety of copolymers (PET and Nylon) that fill a wide bill of applications requiring ductility and strength. I also use Polycarbonate where absolute toughness is needed.

These aren't as simple to print with as ABS or PLA but they are worth the effort. Bottle holder and strap shown below are polycarbonate:



Don

My nephew gets the credit...it's what he taught her how to use. Of course, I'm sure with some brilliant marketing, the fact that the Lulzbot units are what some of the schools around here is not a simple afterthought...

humptybump said:

You've got a great printer with the Lulzbot Mini.

The printer uses 3mm (most often its 2.85mm) filament. That printer can print nylon. We used a Mini to print nylon sprockets for a FRC robot and even at 20% infill, those things took an incredible beating and kept working.

The Lulzbot edition of Cura with the breadth of Lulzbot profiles makes it easy to use a wide range of filament material. With those profiles, nylon is as easy to print as ABS.

Your 11yo has good taste in technology!

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I have been "about" to buy one for a couple of years now. What always stops me is the fog of descriptions of the products. For instance this seems to be a great printer: ALUNAR 3D Desktop Printer Prusa i3 DIY High Accuracy CNC Self Assembly
down in the 2-4 hundred dollar range. But then comes along the comment that spending $1500 will get you a Lulzbot mini, and I have absolutely no idea what that extra$1300 actually buys me (besides being assembled)
Can someone with experience throw some light on my confusion please? Are there model options within the "PRUSA i3" printers, or are they all the same printer with different prices?
Help me out here guys!

DonFromTX said:

Prusa i3 DIY Self Assembly
down in the 2-4 hundred dollar range [vs] spending $1500 will get you a Lulzbot mini ... are they all the same printer with different prices?

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I started to write my perspective and it turned out to be tl;dr. You can read it here - 3D Printers - low cost kits, high cost kits, low cost manufactured, and high cost manufactured

The short answer is "it's a lot like airplanes". There are cheap kits, more expensive kits, affordable certified airplanes, and expensive ones. Are you a builder or a flyer? What's your mission?

So then, saying you bought a "ALUNAR 3D Desktop Printer Prusa i3 DIY High Accuracy CNC Self Assembly" is kinda like saying you bought an airplane with wings and a motor. What "brand" did you who bought a Prusa i3 get and how do you like it? What is the next step up from that, something like going from the engine and wings plane to one with two engines or a jet engine?

In the case of the Purusa i3, it is an open source developed 3D printer, which is why you can replicate the parts yourself. As I understand the situation, there are versions of the Purusa i3 offered by some companies that use lower quality parts, such as stepper motors that may not be durable or very accurate, open frame power supplies that do not have protective covers on exposed power lugs/wires, low quality extruders, etc. The original was designed by Josef Purusa and his company's version is called the "Original Purusa i3 MK2". I purchased mine directly from their web site and waited 8 weeks to get it (lead time was clearly stated on the site). Check out the video of a room full of Purusa i3's making parts for more Purusa i3s. The filament listing is also interesting, including carbon fiber reinforced filament and several embedded metals.


John Salak
RV-12 N896HS

DonFromTX said:

a "ALUNAR 3D Desktop Printer Prusa i3 DIY High Accuracy CNC Self Assembly" is kinda like an airplane with wings and a motor

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Perhaps a better analogy is if you could get a J-3 Cub kit from Cab Crafters vs from Wu Express. Each may have all of the same parts but the instructions, support, and quality of parts may be significantly different.

If you find a kit printer you are interested in, then read the reviews, do a few internet searches (looking for good and bad), and see if there are any forums where you can get help. If you find the necessary positive feedback and available support, then you have a higher probability of success with the kit.

BTW: If you find a Lulzbot for $450, let me know

ADDENDUM: Lulzbot promotes open source. If you are up for a scratch build project, you can download the entire bill-of-materials and assembly instructions for both the Lulzbot Mini and the latest Lulzbot TAZ 6.

Lulzbot

I usually check the markets I get to often on craigslist to see regional variations...for me that's usually Colorado and Fort Worth area -- interesting that there were no Lulzbots for sale in TX when I looked, but a number of them here -- I guess it's the local name recognition.

There's two other mini's on Craigs right now for $600 -- the one I bought was listed at $550 and had been listed for 2 months. The guy lived up out of town in an inconvenient place, but agreed to meet me 1/2 way and take $450. I'm assuming his location hurt his ability to sell.

Check out boulder or fort collins craigslist if you are looking for a reasonable deal on the Lulzbot machines, they seem to come and go...

For the poor

If you are poor, you can get a Tevo Tarantula DIY kit for between $200 and $300 from Gearbest. Not for the faint of heart, but hey, if you can build an airplane, this is a cake walk. I have had one for a few months now. It's a blast, but getting in the way of my build time.

This one is currently $195.

OK, you convinced me, I have one of these on order.
I never did figure out why they get $50 for a 15 cent plug,
but figured it was for a 120 volt power supply, and decided to go for it.
Looks like it should do for me what I need done (which is absolutely nothing). Thanks to all for the help!

cdeerinck said:

If you are poor, you can get a Tevo Tarantula DIY kit for between $200 and $300 from Gearbest. Not for the faint of heart, but hey, if you can build an airplane, this is a cake walk. I have had one for a few months now. It's a blast, but getting in the way of my build time.

This one is currently $195.

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