3D resin printed Draco RC 2500mm
- Thread starter chaos23
- Start date
GrizWiz
Elite member
Yesssss
william Metge
Well-known member
Awesome!!!!
Pieliker96
Elite member
Here's another reference for variable pitch as implemented on a full scale aircraft. This implementation electrically is probably a tad too complex for RC because it requires brushes and conductive tracks to transfer power to the variable pitch servo in the spinner. It might be possible to do with a PCB on the backside of the spinner and preloaded brushes on the plane itself.
chaos23
Senior Member
Yeah, just a tad to complex, I am subbed to dark aero, my dream is to one day have a workshop where i can build a full size aircraft. Maybe at some point in the future i will do a tech demonstrator of this type of VPP at RC scale.
chaos23
Senior Member
Working on the front end assembly in preparation for the VPP, decided to go all out and hide all the VPP and RC componants inside a faux turbo prop engine case, since it will all fit. lol this 500kv heli motor looks so small. It should be powerful enough to swing the 20inch prop to 6.5k rpm. If i need to up the motor rpm and make an inline planetary gear reduction box then that is still an option. 80cc-100cc equavilent electric motors that normally are used for 20+inch props are just way too expensive.
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chaos23
Senior Member
So this motor business aint sitting right with me, so I googled the motor and its not a 500KV motor its an 1800KV motor.... so I will most definitely be doing some serious gear reduction to to convert RPM to torque. I just spent the last 2 hours looking online for a suitable motor around the $100 mark that can swing a 4 blade 20inch prop.... forget the price i can not find a damn thing or im just looking in the wrong places....
So please help, anybody know of a reasonably priced motor in the 8s power range that has the guts to spin this prop? I would like to avoid spending more money on a motor and esc, so I will be doing the gear reduction, but i have my doubts on how well that will work ( its just more complexity and parts that can fail). So a back up plan (the correct motor for the job) is a very good idea.
1800kv on 8s 100amps... 60% throtle (17.76v) --> 31968rpm lets call it 30krpm under load.. so target constant rpm is 6.5krpm means I need a 4.6ish to 1 gear reduction. That's possible with a single stage planetary gearbox, now i just need to make it, btw i will use a stationary carrier for the planet gears.
ps. I love the internet
http://www.thecatalystis.com/gears/
chaos23
Senior Member
I am not 100% happy with the way I'm implementing this idea, will probably redo it down the road, but the idea is starting to take shape. Going to take a break for a few hours now thow, seriously hurt my wrist working in the garden yesterday, so working with the mouse atm is a struggle. but my goal is to have the gearbox done by tonight. At least the gear profiles, as for having it all mechanically functional ill see how a go. I am hoping to at least be started on the VPP mechanism by the 1st of Jan.
And oh yeah, I dont think i showed you all how I did the wing root sockets, its very light at the moment, i will come back in with more structure later when i decide how ill be sectioning the fuselage.
And oh yeah, I dont think i showed you all how I did the wing root sockets, its very light at the moment, i will come back in with more structure later when i decide how ill be sectioning the fuselage.
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the rc project
Well-known member
I must say this is some of the finest rc modelling I have really ever seen. You must be doing this kind of stuff for a living right?(CAD)
I might need to buy a resin printer myself to build this beauty
I might need to buy a resin printer myself to build this beauty
william Metge
Well-known member
I am not too sure, but the Freewing 8S 4075-1390kV Brushless Inrunner Motor looks like it fits most of the specs given.
chaos23
Senior Member
Thanks, yes I do CAD full time, no I dont make any money from it atm lol, Im working full time on my youtube channel, Which is growing steadily.
The Freewing is for 90mm EDF, the motor im looking for would be a chonker of a thing with a kv between 150 and 800. Anything above 800kv will need a reduction gear to convert rpm into torque. The motor im using is a high RPM heli motor, they generally have a high torque as well as rpm.
chaos23
Senior Member
and its done, I now have the VPP all mocked up. Ill be video editing the next couple days for ep 06 and for the return of chaos daily. Next up on the to do list is the thrust mount, VPP servo mount, and the rest of the fake Turbine casing to enclose it all.
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GrizWiz
Elite member
Oh boy!!!!
chaos23
Senior Member
Forward turbine case thing is roughed out, went back through almost everything and adjusted dimensions here and there, over all the case is narrower. The gear reduction now has correct tolerances AND MANUALLY SKETCHED INVOLUTE TOOTH PROFILES, that took 3hrs all by its self
the batter tray thing is gone, will have re make it in the new confined space. And the carbon tube engine frame got all borked from the changes I made, but i was up all night working on the gears and making said changes so ill sort it out tomorrow
HAPPY NEW YEAR EVERYONE! see you all tomorrow.
the batter tray thing is gone, will have re make it in the new confined space. And the carbon tube engine frame got all borked from the changes I made, but i was up all night working on the gears and making said changes so ill sort it out tomorrow
HAPPY NEW YEAR EVERYONE! see you all tomorrow.
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GrizWiz
Elite member
Nice!
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