16 November, 2018 at 15:40 #60189
Thingiverse Link https://www.thingiverse.com/thing:3220102
For use with BlueBird BMS-385DMAX (13 mm wide) Servo but keep in mind that this should also work with Davids (12 mm wide) servo with a little modification. https://hobbyking.com/en_us/bms-385dmax-digital-servo-metal-gear-4-2kg-15sec-16-5g.html?___store=en_us
Impossible Tilt Motor Mount https://www.thingiverse.com/thing:3099720/files
Attachments:16 November, 2018 at 16:24 #60193
Keep in mind that updates as they’re made will be posted on Thingiverse.16 November, 2018 at 17:28 #60194
RCExplorer – DavidKeymaster
I’m following this with interest 🙂16 November, 2018 at 22:53 #60203
If all works to plan, i should have these printed from Carbon / Onyx (Nylon) and in hand by the middle of next week. Each set will be aprox 8 – 10 grams, not counting the motor-mount. (figure 13-15 grams total) This should be pretty close to the weight of the stock mounts (12 grams) but i plan on refining the design more after the Fit / Flight check.
Whole reason i designed these was that the sOat mounts are still an unknown. (Yes i have a set) Thus rebuilding the Copter to install something thats still evolving didn’t sound like much fun. Especially when i can just fly with mounts that install using only Zip-ties. Later if sOat becomes a reality i can take the leap.18 November, 2018 at 10:42 #60220
can you pls explain what is the advantage of your Diheadral Mounts against David’s stock mounts for the bicopter?
And btw jihlein and myself, we are flying with the OATs adapter….
So isn’t that a reality?
Servos on the OATs adapter are mounted, just like with the standard motor mounts, with Zip-zies. I am using BMS-21HV servos which are very fast which should be and advantage for a bi
18 November, 2018 at 15:19 #60225
- This reply was modified 9 months, 1 week ago by jstremmler.
Yes your flying but can you fly backwards without shakes, while still having a really responsive copter? Thus far I’ve not heard from Jihlein thats he’s at that point. Till then i thought I’d explore another angle.
Now as for the question: Dihedral mounts can offer stability at the cost of efficiency. This is in use by a large number of commercial Quads just for that reason. In a nutshell, the prop’s thrust is diverted away from the center-line of the copter. This helps the copter avoid it’s own wash.19 November, 2018 at 08:11 #60231
@kevin, sure I can fly backwards and my bicopter flies great backwards once I have done the transition from forward to backward flying smoothly with my sticks. But once the bicopteer is flying backwards its flying great.
Two more questions to your Dihedral mount:
1. What angle did you choose?
2. How can you mount the motors if the axis is going through the motor like in your picture above and are you using ball bearings for the axis?19 November, 2018 at 14:21 #60235
Pleases post video of the flight, especially the reverse flight.
1) I’ve chosen 10 Degrees offset as it’s enough to have a noticeable effect without getting crazy.
2) Both the Servo and the Support mounts are angled so that the Servo / Motor Mount can remain unchanged. See the attached “Better View” for details on the Servo in “Blue”. In the image shown, the Servo is a dummy object created to help provide a better reference when designing the mounts. This isn’t part of the design but was left in the image to be better highlight the angle.
Attachments:21 November, 2018 at 16:21 #60255
Installed and flown!
Will need some tuning work, yet it was stable and the oscillations were lessened.
Attachments:21 November, 2018 at 23:18 #60259
Been making some progress refining the design.
Attachments:26 November, 2018 at 21:06 #60305
Completed the design for the new motor mount. (shown in green)
Attachments:29 November, 2018 at 16:31 #60354
The latest 10 degree Dihedral prototypes have arrived printed from Nylon / Kevlar. (Servo Holder and Support Arm)
1st round prototypes: 7.8 Grams
2nd round prototypes: 5.1 Grams
Note: Was previously using the Impossible the impossible Tilt-Mech Support and David’s Servo holder. Together those are approx 5.8 Grams.
Attachments:17 December, 2018 at 11:19 #60586
Added the Turnigy S306G-HV Servo to the Custom Dihedral mounts. Completed the Auto-Tune with the Servos @ 7.2 V / 330 Hz! By far the smoothest and easiest Auto-Tune I’ve done.
Overall Tau of 20ms !!!
Log of Autotune 17-Dec-2018, with Dihedral Mounts, 7.2 Volt Turnigy Servo & DAL 6045 2-Bladed Props.
Log of Autotune 28-Nov-2018, with Dihedral Mounts, 6 Volt BMS-385 Servo & DAL 6045 2-Bladed Props.
Log of Autotune 16-Oct-2018, with Impossible Tilt-Mounts, 6 Volt BMS-385 Servo & DAL T5044 3-Bladed Props.
Attachments:2 January, 2019 at 16:17 #60742
RCExplorer – DavidKeymaster
I got the 3D printed parts Kevin! Looks great. You really can’t see the layers.
I’ll throw them on a copter when I get some time. Things are crazy as per usual. But at least I’m back in Sweden for a bit now.5 January, 2019 at 14:50 #60760
Please keep in mind that those mounts are very much a work in progress. Hence your feedback is critical to process improvement. Beyond that, the blade clearance on top of the Servo will be tight due to where the Servo cable pokes out from the case.
Side Note: Any chance you can share the design specs for the bicopter frame? I’m wanting to rework the canopy to add FPV. While i have flown FPV, my current design IS based off what i can measure. (using Runcam Mcro with intergrated transmitter) Thus it would take a lot of time consuming trial and error to get it 100% right without the original files.
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