Decided to make something fun for my daughter this weekend. Have had my eye on a few similar designs but finally decided to print this one for her: https://www.thingiverse.com/thing:51489
Just printed the 5 blade prop first - came out quite nice and flys impressively well!
At least for me. With a good solid tug I can get what I'd estimate as 80'-100' of altitude in calm air. But my daughter with her little 7 year old arms can't quite get that good of a tug on it. She gets maybe 10'-15' of altitude on her best tries. One of her friends was able to get about 20'-30' but still not as good as I could.
I tried printing a few of the other prop designs, 3 bade, 6 blade, and the remixed 5 blade lightweight version. She got really excited trying to predict which would do better - would more blades do better? Or Would ones with fewer blades to better because they were lighter? She guessed all by herself that the ones with more blades would be "stronger" and should be able to go higher...but they weighed more. She was really into trying to figure out which would be better and I loved watching/listening to her reason out her hypothesis!
I could have left it there. It's a great fun toy and we're having a blast with it. But I'm me. I can't leave well enough alone. And I want her to have the fun of launching a really high flight all by herself.
I also couldn't help but notice that the top of the handle looks to be about the perfect size to fit a 2204 or 2205 motor...and I have quite a few of those laying around from my multirotors....the original designer was also kind enough to share his Solidworks files which Onshape can open....hmmmm.
Only took a few minutes to open the file for the "hub" in Onshape and make a few quick adjustments:
First I removed most of the hub since I didn't need the shaft and spool.
Then I made a new sketch on the bottom face and drew a 5mm circle in the center which I did a remove extrusion "through all" to fit a 5mm motor shaft. (It's actually 5.4mm to fit easily but 5mm is easier to say.)
I'm using a spare CCW emax 2204 2300kv motor so it should self-tighten...but figured I'd use a nyloc for safety...except...the only nylocs I saw on my desk had a large flange on them and would require removing too much material from the hub. So instead I just used the stock prop nut.
I made another sketch on the top surface and added a 6 sided inscribed polygon on a 10.3mm circle to fit the stock prop nut.
It actually took me four revisions to get the sizes "just right", thankfully this is a quick 25 minute print
Finally I had a hub that fits my motor and holds the nut. Since it's a CCW rotation it self tightens and all is good with the world:
To test it I grabbed a spare KISS esc....then realized it would be a lot easier to use an ESC with a built in BEC for this so swapped to a spare emax 12a "simon series" I had laying around. Mounted the motor on a spare arm for my hexacopter (which I don't plan on using because this hybrid plywood/CF arm proved to be too weak.) wrapped the ESC in some kapton to keep it from shorting out on the arm then added some heat shrink to keep it all in place.
Hooked up a servo tester and took it outside with a 450mah 2s pack from my 90mm quad. Spun it up to full throttle...and got to enjoy some nice failure. :black_eyed:
I had grabbed the 3 blade prop to test with first figuring it would be the lowest stress on the motor. But...the 3 blade prop was damaged. One of the blades had broken at the hub. Still flew fine human powered but the power of the 2204 on 2s was more than it could take and it blew apart before it could launch. Also, I had forgotten to tighten the mounting screws on the 2204 so it almost fell off and was shaking like crazy.
Oh well, 1st tries seldom succeed!
Snugged up the motor, grabbed the 6 blade prop...inspected it for damage...and went out for another try.
Worked great On 2s it didn't seem to get quite as high as my manual pulls...but these "simon series" ESC's have slow FET's and can't do active braking. So the launch is a little sub-optimal. And it's a lot windier today than it was yesterday so I had a lot of lateral drift that probably ate some energy.
Well....let's channel my inner Tim Taylor and give it "more power!" time to try 3s.
It's kind of scary how it sounds at full throttle...but it works quite well Think I'm getting a bit more altitude than my hand launches now...but again the wind today makes that hard to judge.
Still it's proved the concept enough to take it another step:
Handle modified to mount a 220x motor! It's printing now, still has about 30 minutes to go.
Oh, BTW OnShape project is here if anyone wants to play with it:
https://cad.onshape.com/documents/1...8f83c0697b2e8aff1b/e/799261b008764e4709b70116
And STL for the motor hub is shared on Thingiverse here: https://www.thingiverse.com/thing:2404022
I was thinking about modifying the handle to hold some 18650 batteries...but hooked up my watt meter and found this thing is pulling 22amps with the 6 blade prop (and 21 with the 5 blade) on 3s...no wonder my little 12a esc is getting kind of warm 18650's won't deliver those amps...so I'll have to stick with a lipo pack which won't fit in the handle very cleanly. I have a few ideas though.
Also going to swap my 12a simon series esc for a 25amp afro since it can do better braking to release the prop faster. And going to replace the servo tester with an arduino setup so you just push a button and it then spins the motor at full throttle for a few seconds and then cuts it to 0. (Could get fancy and add a tach function so it stops when the props stops accelerating...but I'm too lazy to tackle that right now.)
Fun project well worth trying if you're got a 3D printer!
Just printed the 5 blade prop first - came out quite nice and flys impressively well!
At least for me. With a good solid tug I can get what I'd estimate as 80'-100' of altitude in calm air. But my daughter with her little 7 year old arms can't quite get that good of a tug on it. She gets maybe 10'-15' of altitude on her best tries. One of her friends was able to get about 20'-30' but still not as good as I could.
I tried printing a few of the other prop designs, 3 bade, 6 blade, and the remixed 5 blade lightweight version. She got really excited trying to predict which would do better - would more blades do better? Or Would ones with fewer blades to better because they were lighter? She guessed all by herself that the ones with more blades would be "stronger" and should be able to go higher...but they weighed more. She was really into trying to figure out which would be better and I loved watching/listening to her reason out her hypothesis!
I could have left it there. It's a great fun toy and we're having a blast with it. But I'm me. I can't leave well enough alone. And I want her to have the fun of launching a really high flight all by herself.
I also couldn't help but notice that the top of the handle looks to be about the perfect size to fit a 2204 or 2205 motor...and I have quite a few of those laying around from my multirotors....the original designer was also kind enough to share his Solidworks files which Onshape can open....hmmmm.
Only took a few minutes to open the file for the "hub" in Onshape and make a few quick adjustments:
First I removed most of the hub since I didn't need the shaft and spool.
Then I made a new sketch on the bottom face and drew a 5mm circle in the center which I did a remove extrusion "through all" to fit a 5mm motor shaft. (It's actually 5.4mm to fit easily but 5mm is easier to say.)
I'm using a spare CCW emax 2204 2300kv motor so it should self-tighten...but figured I'd use a nyloc for safety...except...the only nylocs I saw on my desk had a large flange on them and would require removing too much material from the hub. So instead I just used the stock prop nut.
I made another sketch on the top surface and added a 6 sided inscribed polygon on a 10.3mm circle to fit the stock prop nut.
It actually took me four revisions to get the sizes "just right", thankfully this is a quick 25 minute print
Finally I had a hub that fits my motor and holds the nut. Since it's a CCW rotation it self tightens and all is good with the world:
To test it I grabbed a spare KISS esc....then realized it would be a lot easier to use an ESC with a built in BEC for this so swapped to a spare emax 12a "simon series" I had laying around. Mounted the motor on a spare arm for my hexacopter (which I don't plan on using because this hybrid plywood/CF arm proved to be too weak.) wrapped the ESC in some kapton to keep it from shorting out on the arm then added some heat shrink to keep it all in place.
Hooked up a servo tester and took it outside with a 450mah 2s pack from my 90mm quad. Spun it up to full throttle...and got to enjoy some nice failure. :black_eyed:
I had grabbed the 3 blade prop to test with first figuring it would be the lowest stress on the motor. But...the 3 blade prop was damaged. One of the blades had broken at the hub. Still flew fine human powered but the power of the 2204 on 2s was more than it could take and it blew apart before it could launch. Also, I had forgotten to tighten the mounting screws on the 2204 so it almost fell off and was shaking like crazy.
Oh well, 1st tries seldom succeed!
Snugged up the motor, grabbed the 6 blade prop...inspected it for damage...and went out for another try.
Worked great On 2s it didn't seem to get quite as high as my manual pulls...but these "simon series" ESC's have slow FET's and can't do active braking. So the launch is a little sub-optimal. And it's a lot windier today than it was yesterday so I had a lot of lateral drift that probably ate some energy.
Well....let's channel my inner Tim Taylor and give it "more power!" time to try 3s.
It's kind of scary how it sounds at full throttle...but it works quite well Think I'm getting a bit more altitude than my hand launches now...but again the wind today makes that hard to judge.
Still it's proved the concept enough to take it another step:
Handle modified to mount a 220x motor! It's printing now, still has about 30 minutes to go.
Oh, BTW OnShape project is here if anyone wants to play with it:
https://cad.onshape.com/documents/1...8f83c0697b2e8aff1b/e/799261b008764e4709b70116
And STL for the motor hub is shared on Thingiverse here: https://www.thingiverse.com/thing:2404022
I was thinking about modifying the handle to hold some 18650 batteries...but hooked up my watt meter and found this thing is pulling 22amps with the 6 blade prop (and 21 with the 5 blade) on 3s...no wonder my little 12a esc is getting kind of warm 18650's won't deliver those amps...so I'll have to stick with a lipo pack which won't fit in the handle very cleanly. I have a few ideas though.
Also going to swap my 12a simon series esc for a 25amp afro since it can do better braking to release the prop faster. And going to replace the servo tester with an arduino setup so you just push a button and it then spins the motor at full throttle for a few seconds and then cuts it to 0. (Could get fancy and add a tach function so it stops when the props stops accelerating...but I'm too lazy to tackle that right now.)
Fun project well worth trying if you're got a 3D printer!