[HN Gopher] Active Ball Joint Mechanism with Three-DoF Based on ...
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Active Ball Joint Mechanism with Three-DoF Based on Spherical Gear
Meshings (2021)
Author : gnabgib
Score : 44 points
Date : 2024-09-24 02:07 UTC (20 hours ago)
(HTM) web link (ieeexplore.ieee.org)
(TXT) w3m dump (ieeexplore.ieee.org)
| mikewarot wrote:
| Holy cow... Hobbing gears like these looks like a nightmare.
| There's going to have to be some backlash, or some precision
| grinding.
| DannyBee wrote:
| Agreed. This design is going to be very very hard to machine
| precisely and very expensive to prototype
|
| They don't even say exactly what they did or how long it took
| or how well the tolerances turned out. They only give the
| classic understated view:
|
| "Many parts of the prototype were built from high-performance
| plastics with high machinability and stable properties because
| the components of ABENICS have complex shapes, which makes
| estimating problems during prototyping difficult. Construction
| from strong materials such as metals will also improve the
| capability of the device."
| dist-epoch wrote:
| If they could make this work in plastic, it will be even
| easier to get the tolerances with metal. You can also mold
| the parts.
| 1970-01-01 wrote:
| Casting and metal printing are the only options. And
| casting of gears is not a solution unless you're using
| exotic metals.
| alnwlsn wrote:
| Can it even be cast? It looks like this would be really
| difficult to get to come out of the mold. Unless you go
| investment casting over die casting.
| 1970-01-01 wrote:
| Anything can be cast if your budget allows for it.
| Ferrari engines are a good example.
| adrian_b wrote:
| It should be possible to make it by milling, even if that
| would waste a lot of material.
|
| For casting, the initial mold must be made by milling
| anyway (or 3D printing), even if some intermediate molds
| could be made by casting themselves.
| torpfactory wrote:
| Eh, they make precision stuff like this all the time. If they
| wanted to make a bunch they would first standardize the sizing
| then create production tooling for the grinding setups. Those
| gears would come out basically perfect every time.
|
| The bigger problem is the output link is supported by the gear
| meshes. This means whatever load you put on it is directly
| supported by the small mesh contact patches. A more traditional
| system can have roller or ball bearing or bushing support.
| 1970-01-01 wrote:
| Exactly my thought. They're hand waving all complex
| manufacturing to 3D printers. This will be a hard plastic gear
| for the foreseeable future.
| ur-whale wrote:
| What I find truly amazing here: an IEEE article where you can
| just click on the PDF button and actually read the article
| without hitting you head into a paywall.
| gh02t wrote:
| Thankfully the open access model is becoming more popular,
| though I still find it insane that a lot of publishers demand a
| huge fee to publish articles as OA. I know they have to pay the
| bills and I guess it's better than ads, but they hardly even do
| anything anymore with online publishing and volunteer
| editors/reviewers.
| lloeki wrote:
| Was wondering if it's ABENICS (2021), and it is.
|
| Video: https://youtube.com/watch?v=hhDdfiRCQS4
| voxadam wrote:
| (2021)
| hartmel wrote:
| Previous HN discussion:
| https://news.ycombinator.com/item?id=34160356
| carabiner wrote:
| Even more previous:
| https://news.ycombinator.com/item?id=28556208
| tiahura wrote:
| When can I get my hip and shoulder replacements?
| smusamashah wrote:
| Won't this have lots of wear and tear?
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(page generated 2024-09-24 23:01 UTC)