Looking for Ideas for 3D Printed Jets

[Mr Man]

sorry for hijacking your thread Telnar 😂😂

 

[Houndpup Rc]

sorry for hijacking your thread Telnar 😂😂

Whoops, I forgot! 😂 (Sorry @telnar1236!)

 

[telnar1236]

You're both good - I made both this thread and the experimental jet design threads to discuss new design ideas more than any one of my designs in particular - all this discussion is very much in keeping with the spirit of the thread which is figuring out new ideas to try

 

[Mr Man]

You're both good - I made both this thread and the experimental jet design threads to discuss new design ideas more than any one of my designs in particular - all this discussion is very much in keeping with the spirit of the thread which is figuring out new ideas to try

👍👍👍

 

[Houndpup Rc]

You're both good - I made both this thread and the experimental jet design threads to discuss new design ideas more than any one of my designs in particular - all this discussion is very much in keeping with the spirit of the thread which is figuring out new ideas to try

Okay cool! 😁

 

[telnar1236]

In the interceptor you just print it so the control horn is on the bed and set the bottom layers upto like 7 and you get a solid control horn but the infill can still be 4%

That's a cool technique. Good way to reduce the number of parts you need to assemble. It still doesn't give you as much control over the geometry though - for example if you want to use different materials for the control horn or even make it a different color. I also like to include a fillet at the base of my control horns to increase the strength for out of plane loads, especially because of the limits of 3D printing. And it gives you the freedom to put the control horns wherever you want.

My general approach is to include a triangular cutout in whichever control surface so it still prints well, but I can also glue the control horn in there.

I've only ever had control horns fail when I've crashed them into the ground, so it seems to work pretty well. It also scales up well and I've used it on my almost 6-foot-long F-106 where the control horns are 2.4 mm thick on quite large control surfaces.

 

[telnar1236]

Wings for the boundary layer ingesting flying wing. They're LW-PLA without any spar, but they should still be strong enough for a 3s 50mm design. Wingspan is 36" so it should hand launch easily too due to the low wing loading. Each wing only weighs 68 g at the moment (although this will increase with the addition of control surfaces and servos) which is almost as light as foam board.

 

[Mr Man]

Wings for the boundary layer ingesting flying wing. They're LW-PLA without any spar, but they should still be strong enough for a 3s 50mm design. Wingspan is 36" so it should hand launch easily too due to the low wing loading. Each wing only weighs 68 g at the moment (although this will increase with the addition of control surfaces and servos) which is almost as light as foam board.
View attachment 254523

Cool! I love the upswept wingtips 👍

 

[Houndpup Rc]

Wings for the boundary layer ingesting flying wing. They're LW-PLA without any spar, but they should still be strong enough for a 3s 50mm design. Wingspan is 36" so it should hand launch easily too due to the low wing loading. Each wing only weighs 68 g at the moment (although this will increase with the addition of control surfaces and servos) which is almost as light as foam board.
View attachment 254523

Nice!! 👍 BTW is LW PLA more filament conservative being that it foams? Or do you just sallow the price...

 

[quorneng]

Houndpup Rc
In theory yes as the required flow rate for LW-PLA can be as low as 40% but to achieve the same strength/stiffness as ordinary PLA does require more "structure" to be printed reducing the weight advantage.

 

[tomlogan1]

I'm looking for ideas for 3D printed jets that people might be interested in building - I have way too many power systems and rolls of filament sitting around, so I need to do something with them, or get rid of them.

I think I'm going to make it my goal this winter to try and get as many of the power systems I have as possible into flyable airframes. As one of the few people who designs and builds his own planes at my local rc club, people tend to give me old power systems they no longer want, so I have quite the collection of outdated (and a couple modern) EDFs and even a couple motor/prop combinations. I also have too many rolls of filament from different projects where I bought the roll and then didn't use the whole thing and I need to get rid of them. It's also looking like I'll be able to design parts for the F-100 look-alike (thinking about calling it the Super Duper Sabre) faster than I'll be able to test them between TFRs and the weather, so while the experimental jet will remain my main project, I'll be able to work on some simpler designs in between.

A couple of ideas I'm thinking of are a 64mm 4s sport jet, a twin 50mm 4s blown wing design for bush flying (because I like making EDFs do dumb stuff), and some version of the boundary layer ingesting flying wing concept (the laminar flow wing and improved streamlining of the more conventional designs I'm working on combined with the inability to use flaps on a flying wing mean it isn't really a good fit for my experimental high performance EDF project anymore). However, none of these is set in stone.
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But I also have a significant number more EDFs than this and a few prop systems as well, so I still need ideas. The goal will be to give any planes that fly well enough to be fairly manageable to younger/newer flyers at my club and to put anything that is more difficult to fly up for grabs for anyone at the club, since I really don't need more planes either - though I suspect I might keep a couple for myself if I like them enough. And then of course to post the STLs for any designs on here as resources if they fly well enough.

So please, give me ideas, preferably geared more towards the intermediate side than the very advanced in terms of flight characteristics. Also, I'm not going to be trying to make anything mechanically complicated or all that fast. These will all be fixed gear designs using plastic gear servos, since I don't have a ton of metal gear servos and don't want to need to buy new parts for any of these.

How about something that will print and fly made out of regular PLA? I've tried and failed on so many rolls of LW-PLA that I've pretty much abandoned trying to 3d print planes. I started with an Ender 3 Pro and now have a Anycubic Kobra 3 which makes GREAT prints on regular PLA but LW-PLA prints are so stringy that it is not worth the effort to try to clean them up. LW PLA on the Ender never completed. The same planes, printed in regular PLA, look great but are too heavy to fly consistently.

Off my soap box.

 

[Houndpup Rc]

How about something that will print and fly made out of regular PLA? I've tried and failed on so many rolls of LW-PLA that I've pretty much abandoned trying to 3d print planes. I started with an Ender 3 Pro and now have a Anycubic Kobra 3 which makes GREAT prints on regular PLA but LW-PLA prints are so stringy that it is not worth the effort to try to clean them up. LW PLA on the Ender never completed. The same planes, printed in regular PLA, look great but are too heavy to fly consistently.

Off my soap box.

Hmmm, you tried lowering your print temp? I was getting a little stringing with PETG and then I realized I had the temp too high...That also can kill the look of the print. (BTW, a trick I found for getting rid if the string, is the just to take a wind proof lighter and just give it a quick shot of heat which will melt the strands in, giving you a very clean nice looking print! 👍 )

 

[tomlogan1]

Hmmm, you tried lowering your print temp? I was getting a little stringing with PETG and then I realized I had the temp too high...That also can kill the look of the print. (BTW, a trick I found for getting rid if the string, is the just to take a wind proof lighter and just give it a quick shot of heat which will melt the strands in, giving you a very clean nice looking print! 👍 )

Tried the lighter it was like napalm . My Anycubic printer is pretty fast but I can build a foam board airplane that will fly AND survive crashes in less time and in most cases for about the same or less than 3d printed. The 3d printed DO look better and more accurate but this is a hobby for enjoyment not anguish.

 

[tomlogan1]

Some of my 3d printed before Terra Firma. They do look nice until they leave the bench

 

[telnar1236]

Cool! I love the upswept wingtips 👍

Winglets are pretty much the perfect use case for 3D printing - pretty difficult to do without and effortless to do with

 

[Houndpup Rc]

How about something that will print and fly made out of regular PLA? I've tried and failed on so many rolls of LW-PLA that I've pretty much abandoned trying to 3d print planes. I started with an Ender 3 Pro and now have a Anycubic Kobra 3 which makes GREAT prints on regular PLA but LW-PLA prints are so stringy that it is not worth the effort to try to clean them up. LW PLA on the Ender never completed. The same planes, printed in regular PLA, look great but are too heavy to fly consistently.

Off my soap box.

I wonder if being a bed slinger doesn't help...

 

[Houndpup Rc]

Some of my 3d printed before Terra Firma. They do look nice until they leave the bench

They look really good! (Is that a Interceptor you have there?)

 

[telnar1236]

Nice!! 👍 BTW is LW PLA more filament conservative being that it foams? Or do you just sallow the price...

Pretty much what Quorneng said - LW-PLA is somewhat lighter in some use cases. For this 50mm design, I can print with 1 wall and 3% infill since it doesn't require that much strength and it is legitimately 60% of the weight of PLA. However, in my sport jet, I started out with LW-PLA, but when I went through and sliced everything for ABS it actually came out 50g lighter since the heavier plane and stronger structure meant that the higher strength to weight ratio of ABS was a bigger factor. Even PLA would work out to be only barely heavier than LW-PLA for the sport jet.

In terms of filaments, if you can print ABS, it's the best for most planes over about 700g in my opinion. It's cheap, tough, and resists heat which means you have more flexibility in transporting your planes. LW-PLA is good for smaller lighter planes that don't need much structure. PLA is mostly good if you can't do either of the others and works fine but is nothing special. PETG isn't great due to its higher weight, but if you need the heat resistance and can't use ABS (for example in motor mounts) it's useful there.

Overall, 3D printing is best used for heavier faster planes, ideally flying off a runway, and for slower, lighter, easier to fly planes, foam board is better.

 

[Houndpup Rc]

Pretty much what Quorneng said - LW-PLA is somewhat lighter in some use cases. For this 50mm design, I can print with 1 wall and 3% infill since it doesn't require that much strength and it is legitimately 60% of the weight of PLA. However, in my sport jet, I started out with LW-PLA, but when I went through and sliced everything for ABS it actually came out 50g lighter since the heavier plane and stronger structure meant that the higher strength to weight ratio of ABS was a bigger factor. Even PLA would work out to be only barely heavier than LW-PLA for the sport jet.

In terms of filaments, if you can print ABS, it's the best for most planes over about 700g in my opinion. It's cheap, tough, and resists heat which means you have more flexibility in transporting your planes. LW-PLA is good for smaller lighter planes that don't need much structure. PLA is mostly good if you can't do either of the others and works fine but is nothing special. PETG isn't great due to its higher weight, but if you need the heat resistance and can't use ABS (for example in motor mounts) it's useful there.

Overall, 3D printing is best used for heavier faster planes, ideally flying off a runway, and for slower, lighter, easier to fly planes, foam board is better.

I should get some ABS and give it a try....I must say, I am REALLY impressed at how well, and fast the K1 SE prints, and if I need to have a warmer chamber I can just tape foam board around as it retains the heat VERY well!

 

[telnar1236]

How about something that will print and fly made out of regular PLA? I've tried and failed on so many rolls of LW-PLA that I've pretty much abandoned trying to 3d print planes. I started with an Ender 3 Pro and now have a Anycubic Kobra 3 which makes GREAT prints on regular PLA but LW-PLA prints are so stringy that it is not worth the effort to try to clean them up. LW PLA on the Ender never completed. The same planes, printed in regular PLA, look great but are too heavy to fly consistently.

Off my soap box.

Most of my designs are normal PLA. You can check out my 50mm jet trainer if you want something that will fly well without needing to resort to LW filament and my sport jet design and Saab 105 will also work well in normal PLA or ABS once I get around to releasing them. You do need a pretty strong hand launch with normal PLA planes and there is unfortunately a lower limit to the weight. My F-104 will also work well in PLA, but the build is notably worse since I had less experience when I designed it.

I'm using LW-PLA on the 3s 50mm design because it simply won't fly well with PLA or ABS and because I have some that I haven't been using and want to get rid of. I don't do much with normal PLA since I live in Florida where if you leave it in the sun for more than 5 minutes it starts to warp which very much limits the life of those planes. LW-PLA is more resistant and ABS is immune to this.

With LW-PLA, the stringing is just part of life for any non vase-mode parts unfortunately. I try to design anything using LW-PLA to reduce it, but there will be some. You can also improve it by telling your printer to only move within printed perimeters - you still get the stringing but it's in the infill so you can't see it.