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3D Printed / Foamboard Auto-gyros

localfiend

High Alpha!
Mentor
#21
Thought I already posted these, oh well. 3D printed rotor blade leading edges:

Rotor Blade - 1.png

Rotor Blade - 2.png

Print out the edges, CA them together, then hot glue to a rectangle of dollar tree foam. Fast and really light weight.

I've also designed a set of full airfoil 3D printed blades to try. Gonna start that printing in just a bit before I head to work.

Still need to make the rotor head, been distracted with the blades. Once I get the rotor head done I can do some spin up tests and see if everything holds together or sends bits of foam and plastic everywhere. :cool:
 

LitterBug

Troll Spammer
#22
3D printed leading and trialing edges might be good for all foamies. Excellent idea!

Printed up the BB ratchet clutch and it works flawless. $1.99 for a tube of 350 BBs. I actually got carded for buying a tube of 4.5mm metal balls. WTH?

Cheers!
LitterBug
 

localfiend

High Alpha!
Mentor
#23
3D printed leading and trialing edges might be good for all foamies. Excellent idea!

Printed up the BB ratchet clutch and it works flawless. $1.99 for a tube of 350 BBs. I actually got carded for buying a tube of 4.5mm metal balls. WTH?

Cheers!
LitterBug
Awesome and lol. I'll have to take the BB idea and adapt it to fit. If it ends up lower friction that my clutch it will be a nice upgrade.

I got carded at Walmart buying a case of brake cleaner of all things not that long ago. I've got an 8" or so full beard so that was rather funny. :D

Hopefully my printer will soon be able to extrude multiple materials. Being able to print a leading edge with rubber exterior surfaces would be awesome for a combat plane.
 

LitterBug

Troll Spammer
#24
I've seen other people use skewers on the leading edges, but some 3D printed single wall leading edges on my FT Viggen would really look good. Couple that with the 3D printed Thrust tube, I'm kinda doin the same angle of mixed foam/3D only on a fixed wing....

ThrustTubeCorrected.jpg
SingleWallThrustTubeFlexTest.jpg

Half tempted to work on a 3D printed EDF.... I have some pieces to spin up in a wide open space to see if they self destruct. Not sure 3D printed blades spinning at high RPM are really a good idea. There's got to be some serious stress risers and imbalance inherent in grown parts. Willing to sacrifice a cheap camera out at remote corner of the field to get some good footage.
LetsDoThis.jpg

Not going to sacrifice a frame, but you get the idea..... Remote controlled spin test.

Cheers!
LitterBug
 
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localfiend

High Alpha!
Mentor
#25
I've seen other people use skewers on the leading edges, but some 3D printed single wall leading edges on my FT Viggen would really look good. Couple that with the 3D printed Thrust tube, I'm kinda doin the same angle of mixed foam/3D only on a fixed wing....
The 3D printed thrust tube is pretty cool. I've only designed and flown one EDF plane so far (top secret project. :cool:) but I used a paper tube. Maybe I should print myself up a thrust test machine and do some comparing. More power and speed would be great.

I'm pretty sure the printed blades will self destruct, but it would be cool to watch lol.


After a ton of trial and error I finally figured out how to make an STL that would print with true thin walls. Been experimenting with different spar designs but I think I've run up against a wall when it comes to sketchup and complex compound curves. It generates too many errors no matter how careful you are. The spars need to be a very specific distance from the outer shell. Time to learn Fusion 360.

thinwallblades.png

thinwallblades2.png

I think using the above pictured method will get me 3D printed blades that only weigh around 20 grams a piece. Hopefully stuff ends up strong enough.
 

PsyBorg

Fly Angry
Mentor
#26
3D printed leading and trialing edges might be good for all foamies. Excellent idea!

Printed up the BB ratchet clutch and it works flawless. $1.99 for a tube of 350 BBs. I actually got carded for buying a tube of 4.5mm metal balls. WTH?

Cheers!
LitterBug
You never saw the opening scene to the movie "Swordfish" I take it?
 

localfiend

High Alpha!
Mentor
#27
Got Fusion 360 figured out enough to get a set of Blades drawn up and printed. Took me a lot of revisions but I got there in the end.

8h12rotorbladetest1.png

8h12rotorbladetest2.png

8h12rotorbladetest3.png

I've got a thread going over at RCGroups to discuss the best airfoil and blade style if anyone is interested in that kind of thing. It's sounding like I'll get the most gains from adding a twist to the blade, so that will be the next challenge to tackle.

https://www.rcgroups.com/forums/sho...plexity-are-no-object-what-s-the-best-airfoil

Of course, I really want to test out my clutch and gearbox with a set of blades, so I'm going to draw up the rotor head with Fusion 360 (I'm really liking it now that I've gotten over the first learning curve hurdle). Hopefully I'll be able to do all that this evening and get a test print started before going to bed.
 

localfiend

High Alpha!
Mentor
#28
Rotor Hub and shims for blade angle are drawn up and printing. I've got multiple shim angles, apparently it can take a bit of tuning. Though I hope with 3D printed parts things will be consistent enough that when I find the correct angle it should be reproducible without tuning.

rotorhubandshims.png
 

localfiend

High Alpha!
Mentor
#29
Got the rest of the parts drawn and printed and was able to do a quick runup test.

Rotor Head and blade tips.png

It get's kinda scary lol. Winds are supposed to be 8-10 mph and I'm getting around 700 RPM if my digital tach is reading correctly. Don't know if that's good or bad, but it's fast enough for being so close to my face.

 

localfiend

High Alpha!
Mentor
#30
This is quite possibly the ugliest FT Explorer ever. I hacked the V-Stab down a bit early on as I thought I'd have the blades spinning over it. It balanced better this way though. Also just took an assembled power pod with a 2212 1400kv motor and 8x4.7 SF carbon prop, and slid it into the nose.

Auto-E.jpg

If this thing doesn't crash and burn like I expect it to, maybe I'll make an actual AutoGyro pod that can be hooked to the explorer that looks good.
 

localfiend

High Alpha!
Mentor
#32
So cool to see the real progress you are making!

Cheers!
LitterBug

Real progress and real explosions lol.


It was dead calm, and that runway has too many cracks for long takeoff runs. Couldn't get auto rotation going in those conditions so I decided to gun it and see what would happen. On the bright side, the airframe was fine, and I just glued the blades back together. Probably not something that could have been done with wood lol.

Next attempt I will use the autostart, or I'll just go for it if the day is windy.
 

PsyBorg

Fly Angry
Mentor
#33
Are the blades just attached by a shaft thru a hole? It looked like it had some wobble in the spin up video that produced some binding. If you don't have bearings in that blade grip assembly to the shaft I think you might want to do that and some thrust washers to keep everything aligned. With out bearings it can also end up in that scenario we discussed with the clutch and possibly heat weld itself.
 

localfiend

High Alpha!
Mentor
#34
Are the blades just attached by a shaft thru a hole? It looked like it had some wobble in the spin up video that produced some binding. If you don't have bearings in that blade grip assembly to the shaft I think you might want to do that and some thrust washers to keep everything aligned. With out bearings it can also end up in that scenario we discussed with the clutch and possibly heat weld itself.
There is a 623zz bearing in the head unit. The wobble you were seeing was from me not having it tight, I tighted things up a bit when I put it on the explorer frame. I figured things would stabilize just fine when you're in the air, as the lift from the blades would pull the stop/driveline up against the bearing and the slop would be gone.

headbearing1.png

headbearing2.png

I've considered adding a second bearing to the top so that I could do like you suggested with thrust washers. If it has problems I'll do so, just didn't want to increase the weight or complexity too much.
 

PsyBorg

Fly Angry
Mentor
#35
Seems like you may have to widen the gear out quite a bit to counter the shifting weight of the blades at lower rpm so it doesn't waddle down the runway until head speed build enough to be an actual disk or "Wing" If you look at real auto's they have a wide stance too.

How well are them blades balanced hot off the printer?
 

localfiend

High Alpha!
Mentor
#36
Seems like you may have to widen the gear out quite a bit to counter the shifting weight of the blades at lower rpm so it doesn't waddle down the runway until head speed build enough to be an actual disk or "Wing" If you look at real auto's they have a wide stance too.

How well are them blades balanced hot off the printer?
I widened things a good bit more, but I think I could go even wider.

Blades seem to be perfectly balanced right off the printer. They're identical in weight and plastic doesn't have he same variations that wood and such do. Vertical spin test shows no heavy blades, so I'm very happy.
 
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ElectriSean

Eternal Student
Mentor
#38
Very cool project :) I just ordered the same printer, I'm pretty excited... Waiting the 7-8 weeks might just kill me. This is definitely going on the list, assuming I survive the wait ;)
 

localfiend

High Alpha!
Mentor
#39
Very cool project :) I just ordered the same printer, I'm pretty excited... Waiting the 7-8 weeks might just kill me. This is definitely going on the list, assuming I survive the wait ;)
Yeah, it's a long wait. I'm on the list for another one... One printer can't keep up with all the things I need to print and test lol.

:cool: Repeat-ability is a key to success on things like blades so that's a huge plus. :applause:
That's one of the nice thing about 3D printing. It may not be the fastest technology in the world, but if your printer is tuned well, you get the same quality and consistency for every part.


So, my widened out landing gear would have worked well if I could have stayed on the airstrip. I had wind this time, a little too much of it, and gusts from random directions. Checked after the fact and saw the gusts were hitting 17mph. A bit fast for an auto-gyro with this power level.


Blades seem to be quite tough, which is another plus. I'm not worried about them falling apart while spinning anymore. Of course, no blades would have survived that last crash. :D

I'm building another air-frame for round two of testing. I already had a Mighty Mini version of the FT Explorer drawn up from this winter:

View attachment 84545

View attachment 84546 f

So I'm taking that with a few tweaks to make a clone of the Hobbyking Auto-G. I'll also be integrating the start assist into the mast for a clean build. All critical control surfaces and parts will be placed as close to the Auto-G locations as I can get them. I think that will get me the best opportunity for success.

You can see the MM Explorer Conversion with Auto-G sized and styled tail feathers:

View attachment 84547

That servo is in an odd spot, but after I figure out how things will balance it will be able to be moved. To start, this will be a tractor setup, but I'd like to keep the option open for pusher as well.
 

ElectriSean

Eternal Student
Mentor
#40
Yeah, it's a long wait. I'm on the list for another one... One printer can't keep up with all the things I need to print and test lol.
I'm hoping that one day they'll offer a hardware package, everything but the printed parts. Should cut the wait times down, and I bet they'd sell a ton of them.