36" Northern Pike - 3D Printed Cuda Clone (It Flies & STL's are Posted!)

rockyboy

Skill Collector
Mentor
For orientation purposes I'm planning to do one wing / wing tip in a different color. Maybe an opaque white bit out on the end. If I can't tell up from down, at least I'll know right from left :p
 

localfiend

I like 3D printers...
Mentor
For orientation purposes I'm planning to do one wing / wing tip in a different color. Maybe an opaque white bit out on the end. If I can't tell up from down, at least I'll know right from left :p

Hah. That should work. And if your vertical stabilizers are both black or something, that should help with up and down. We'll see how it goes on the maiden. Everything is clear lol. Maybe I should hit some parts with a bit of paint.

I've got a RS2306-2400kv motor coming in for this. Lightweight, but I'm thinking it should still pack a punch. Only issue is, I think the only good batteries I have in the right size are 3s. Might need to find some 7 inch props.

https://www.miniquadtestbench.com/assets/components/motordata/motorinfo.php?uid=136
 

JimCR120

Got Lobstah?
Site Moderator
Ooh the excitement builds. When do you expect the first flight? Can we expect some video with all these teasers?
 

localfiend

I like 3D printers...
Mentor
Ooh the excitement builds. When do you expect the first flight? Can we expect some video with all these teasers?

All depends on if I can get the fuselage bits all worked out this evening and on the printer. So far, everything I've printed has come out pretty well.

Printed Parts.jpg


I have everything printed except for the forward fuselage. Only a few of these parts will need some printability tweaks, so far they should all work for the prototype. If I can get the rest of the parts printing tonight, and they all work, and the plane balances like I hope it will, I may be able to fly this weekend.

And of course I'll video the maiden. Gonna need to find my gopro, otherwise it'l be cell phone footage. It disappeared before flitefest and hasn't shown itself since.
 

cjspecial

Member
Hah. I wouldn't make you figure it out on your own. Could make a short video showing what has to happen. It's basically only 4 steps. Make a sketch plane along a spar, add a sketch to that plane, draw circles on said sketch, then extrude the circles through the spar. You just have to do it over, and over, and over again.

However, that may not even be needed. We'll see after I get the plane done and can figure out what the weights should be. What would probably be needed are motor and servo specs and sizes. The firewall arrangement would have to be adjusted, as well as resizing the servo cutouts. Did you have electronics in mind when you picked 24 inches?

Printers finished up the stuff I had drawn this morning.

UVyUcWK.jpg


You can see the tongue and groove assembly I settled on. This lets you easily just slot the wing together without having to mess with alignment tabs for gluing. This will make getting perfect CA joints very easy, and the tongue and groove material doubles as an additional heavy duty spar right where it's needed. Should be easier to assemble than most of the 3D lab prints stuff.

PRwLyVw.jpg


SlbSrAH.jpg


YBMneon.jpg
Awesome to see someone else designing 3D printed planes! I've built a few from 3Dlabprints and I'm always looking to try others designs. My printer is currently without any projects at the moment! Hint, Hint... LOL
 

localfiend

I like 3D printers...
Mentor
Got the rest of the main parts printed last night. Firewall bits are going now in polycarbonate.

I think the mouth and eyes printed out pretty darned well. Didn't have any paint, so the prototype got the sharpie and china marker treatment.

0DyL7Uj.jpg


tUPgDEy.jpg


a9WfXnk.jpg


0n6hda4.jpg


There are a few things I need to fix. The V-stabs don't have quite enough spars, and you can see the surface warp/bubble in a couple spots. Was hoping to get away with it being lightweight. I'll add a couple more to keep the skin tension up. Also, a few bits on the fuselage need work. Some of the internal structure pushes printable overhangs too far, and they come out ugly and broken. All in all, not that bad. Just gotta tweak the files a bit and they should be ready for release. If it flies that is.
 

localfiend

I like 3D printers...
Mentor
So, I've got a motor bolted on. RS2306-2400kv. Lightweight race quad motor, but it'l put out something like 1700 grams of thrust with a 6045 prop. Oh, and the motor only weighs 34 grams. So yay for motor tech advancement. Now that I have a motor on the back, I'm working on making sure I balance.


Here's the wing dimensions:

kTBLEXk.png


Here's the info plugged into an online CG calculator.

rJ7AQw1.png


And here's what it takes to balance out:

pRZXGmd.jpg


That's 2x 1300mah 3s batteries. That's about the size of what I planned on, but they're further forward than I would have liked. I think I have a 2800mah 4S battery that should do the trick for the maiden.

Anyone know much about Forward Swept wing CG? Do my numbers look right?
 

localfiend

I like 3D printers...
Mentor
So here was Sunday's outcome:

SeJlsgr.jpg


Kersplat lol. Bad toss, my hand slipped. The fuselage is just too wide too hold easily and still release overhand without getting your fingers in the prop.

I've got no problem palming a basketball, so if this gives me trouble, I think the fuse needs to shrink in width.

AvjzU74.jpg


Added 50 mm (~2"), and narrowed the fuse considerably.

oIpcvAU.png


After some thinking about things a little more, I'm adding even more. So 90mm total length increase.

eylmjQf.jpg


I don't think that will detract from the overall look of the plane, and the increased length will help out a lot with motor and battery choices. You'll be able to run a bigger motor, and smaller battery back without issues this way. If it's not narrow enough, and is still awkward, I'll consider adding some cutouts for finger holds on the underside of the fuse near the leading edge of the wings.

I've salvaged the elevons from the wreck, and am re-printing the rest of the wing bits that remain unchanged. The wing pieces that are part of the fuse, and the fuselage it'self need to have all the spars, holes, and fiddly bits redone. I'll hopefully have time tonight too re-add all that stuff in, and we'll see how far I get on lightening holes.
 

willsonman

Builder Extraordinare
Mentor
I think if you moulded in a proper hand grip like the Eflite RearBear, it would make things very easy for a good toss every time. Have a look at the third picture on that HH page and it will give you a good idea of how it looks. If you still need additional pics, send me a message and I can snap some for you on mine. I can even get measurements for you.
 

localfiend

I like 3D printers...
Mentor
I think if you moulded in a proper hand grip like the Eflite RearBear, it would make things very easy for a good toss every time. Have a look at the third picture on that HH page and it will give you a good idea of how it looks. If you still need additional pics, send me a message and I can snap some for you on mine. I can even get measurements for you.

I may have to think outside the box a bit, or make the handgrip area a separate printable part. That grip shape won't be printable in the orientation of the rest of the integrated fuse/wing pieces, and the spars inside won't be printable if I swapped directions.

After typing that, I think it could be doable, but it will have to be entirely separate, with it's own spar structure. Will add some to the weight, but that will be worth it. I'd be interested in knowing how wide it is at the narrowest point.
 

cjspecial

Member
I may have to think outside the box a bit, or make the handgrip area a separate printable part. That grip shape won't be printable in the orientation of the rest of the integrated fuse/wing pieces, and the spars inside won't be printable if I swapped directions.

After typing that, I think it could be doable, but it will have to be entirely separate, with it's own spar structure. Will add some to the weight, but that will be worth it. I'd be interested in knowing how wide it is at the narrowest point.

Have you considered a discus type launch? I use to launch my wings like a traditional hand toss, but discovered that the discus method seemed to have better results and higher launch speed. I will admit it takes a bit of practice because every plane is a bit different and the weight difference between planes also changed how much force was needed. Just a thought...
 

localfiend

I like 3D printers...
Mentor
Have you considered a discus type launch? I use to launch my wings like a traditional hand toss, but discovered that the discus method seemed to have better results and higher launch speed. I will admit it takes a bit of practice because every plane is a bit different and the weight difference between planes also changed how much force was needed. Just a thought...

I normally wing tip launch most flying wings and pushers. I know some people don't like that method though, and a plane you spend effort on printing out is probably the wrong plane to practice with. I'd rather it be easy and repeatable for everybody though, so a good grip spot seems like the best overall idea. Same thing for a catapult, too big of a pain.
 

cjspecial

Member
I normally wing tip launch most flying wings and pushers. I know some people don't like that method though, and a plane you spend effort on printing out is probably the wrong plane to practice with. I'd rather it be easy and repeatable for everybody though, so a good grip spot seems like the best overall idea. Same thing for a catapult, too big of a pain.

I didn't take the 3D printed aspect into consideration when launching. I've printed about 6 planes so far but all of them have landing gear so launching them isn't really needed. Curious to see what type of grip you come up with because I would like to print one and try it out!

On a side note, what are the chances of adding some type of landing gear either designed into the fuselage or adding afterwards? I'm asking because I don't have any grassy fields to land on, only dirt, rocks and asphalt LOL.