With the Turnigy V-Spec getting scarce, it is time to option more motors. I also had some requests for longer barrels and more rail estate on the T19 platform.
Bird 1 and bird 2, let me introduce you both to this stone. Hy-Con model Delta:
All STEP and mesh files
This is equipped with a new motor option, Emax RS2205S. This, like most drone-market motors, is a threaded shaft motor.
It is widely available, torquey, not too expensive, and very axially short, which removes most of the bulges/stuff sticking out annoyingly that tend to be problems for thin-packaged horizontal cage rigs when transitioning over to threaded shaft motors from bolt-pattern motors. There are just some ~2mm tall hole plug heads on the bottom of the cover. These plugs result from keeping the old school cover dimensions, no real reason or rhyme to why I did it that way.
I do have plans to multiplex things a bit more between cage variants and motor options as I test and add more, but the Gamma Major short barrel cage really just needs a clean sheet redraw and some more polishing anyway. So for now, it's Gamma/Turnigy or Delta/Emax.
The wheel, being that this is a threaded shaft motor, has some new features.
Locating keys specific to the Emax are provided to fit into the rotor notches and allow the shaft to be held with the wheel for initial torquing of the nut.
This is a rotor OD piloted wheel and the shaft hole is a large clearance on the shaft to avoid overconstraint as usual.
A slight counterbore is provided to match a raised boss around the shaft on the rotor of the Emax motor and give full surface contact.
The ring of tiny holes is a toolpath control/selective infill feature to force the slicer to generate solid plastic in the web where the clamping load is applied.
A printable washer is used under the shaft nut to account for surplus unthreaded length. The web thickness is not increased unnecessarily (Ultracage) to this end as this has no structural purpose and adds a lot of inertia that might best be made optional. (Still, with how these run, I might slice wheels for them to add some more inertia anyway in the future.)
There are no left-hand threaded versions of this motor and they come with nylon insert locknuts, so don't go looking for a "CW and CCW pair" of them.
As per my usual design approach, this is a nonventilated wheel design. Excessive motor temperatures have not been a concern whatsoever.
I am not putting up anything except 9.5mm gap wheels with this and going forward. Closed-loop speed control completely removes the entire issue of "subcritical speed = bad" - subcritical with stiff speed regulation is actually a route to world class velocity consistency. The 9.5mm wheels turned down are easy on darts and very consistent.
Rails: Self explanatory.
Overall I am satisfied with the Emax RS2205S. It delivers a slight improvement in flywheel drive response versus the old Turnigies (which on the new control gear is automatically translated into a reduced feed delay without changing any settings! So much nicer than manual tuning) and is another, and more solid/trustworthy than the Turnigy, option but I don't quite like their "personality". They are modern, and aggressive, with N52 arc magnets, and tight airgaps. With so much field flux, the cogging torque is pretty gnarly, and they feel and sound more harsh. (They don't coast as well either - adjust your driveCoastTime down a bit if you have old world controls.) It's much like 3240s vs. XP180s in the old dark DC days. Sure, the latter has more torque and is objectively better, but the former feels... Happier. Same here, which is why for further motor options I am going to include some other motors with more Turnigy-like magnetics. The Racerstar BR2207S is one I already have on hand which is a sweet amazing sounding runner, and I will also be testing their BR2406S and perhaps BR2306S as all of these are cheap and plentiful.
No comments:
Post a Comment