Cum să alegi un motor#

Cutiile de Viteze#

Există două tipuri de cutii de viteze: planetare (sau orbitale) și pe pinioane. Structura lor internă și diferențele sunt discutate în detaliu în secțiunea Gearbox Internals. Pentru echipele începătoare, este suficient să știi faptul că angrenajele planetare sunt puțin mai scumpe, dar mai fiabile. Angrenajele pe pinioane se pot rupe sub presiune (de exemplu, când robotul lovește un perete), fiind nevoie de o înlocuire. Din acest motiv, este recomandat să folosești un angrenaj planetar pentru situațiile de sarcini mari, precum șasiurile.

Cutii de viteze cu ax necentrat și motoare disponibile#

Pericol

Cutiile de viteze cu ax necentrat nu sunt recomandate din cauza unei durate de viață scurte și o rezistență mecanică redusă față de cutiile de viteze planetare. Dacă alegeți să cumpărați motoare noi, este recomandat să cumpărați unele cu o cutie de viteză planetară. Atenție este necesară pentru a nu pune sarcină pe axul unei cutii de viteze cu ax necentrat. În special, motoarele cu astfel de cutii de viteze nu ar trebui folosite in aplicații unde se exercită o sarcină mare asupra lor, cum ar fi un șasiu.

Motoarele cu ax necentrat includ: :term:` motoarele AndyMark NeveRest Classic <NeveRest Motor>` (cu rapoarte de 40:1 și 60:1), motoarele REV HD Hex 40:1 Spur și goBILDA 5201 Series Yellow Jacket Spur Gear Motors. Toate acestea oferă performanțe și fiabilitate similare, așa că alegerea lor este în principal dictată de ușurința de montare și conectare la celelalte elemente din design-ul tău. (de exemplu, dacă folosești un kit REV, ar fi bine să alegi motorul REV HD Hex, deoarece utilizează același ax hexagonal de 5mm ca restul elementelor din sistemul REV).

  • Cutiile de viteze cu ax necentrat de la motoarele goBILDA 5201 sunt mult mai ieftine decât cele de la REV sau Andymark; dacă asta este bine sau nu rămâne la latitudinea ta. Aceste motoare folosesc conectorul de tip bullet pentru curent, mai puțin întâlnit (cel puțin în lumea FTC). Aceste motoare nu se mai fabrică. Axul de ieșire este unul in D de 6mm.

  • REV HD Hex Planetary 40:1 motor - This motor comes only in a 40:1 ratio, but does use the same connections (JST VH) as the REV Expansion and Control Hub for power which means no adapter cables. The output shaft is a 5mm hex shaft. REV UltraHex has a 5mm hex bore running through the middle of a 1/2” hex shaft, which makes adapting this motor to any length of UltraHex, and by extension, 1/2” hex shaft, very easy.

  • Andymark NeveRest Classic motors come in a few different ratios, which are 40:1 and 60:1. The output shaft is a 6mm D-shaft, and like all NeveRest motors use the Anderson PowerPole to connect to power. This connector is perhaps the most robust of the ones listed here.

Planetary Gearboxes#

Standard planetary gearboxes include Andymark NeveRest Orbital motors, REV 20:1 Planetary motor, and goBILDA’s 5202/5203/5204 Series Yellow Jacket Motors.

Any of these „standard” gearboxes are more robust than spur gearboxes. Like the spur gearboxes, the gearboxes from different vendors, while not interchangeable, are very comparable in terms of robustness. Once again, the main thing to consider here is your desired reduction, your desired motor connections, and your desired output shaft type.

  • goBILDA Yellow Jacket has the most varied selection of gearbox ratios with too many to list here, but utilize the rather uncommon bullet connection for power. The output shaft is a 6mm D-shaft or 8 REX (7 mm hex rounded to 8 mm).

  • REV HD Hex Planetary motor - This motor comes only in a 20:1 ratio, but uses the same connections (JST-VH) as the REV Expansion and Control hub for power which means no adapter cables. The output shaft is a 5mm hex shaft. REV UltraHex has a 5mm hex Bore running through the middle of a 1/2” hex shaft, which makes adapting this motor to any length of UltraHex, and by extension, 1/2” hex shaft very easy. The ratio of the HD Hex Motor is 20:1.

  • Andymark NeveRest Orbital motors come in two ratios, 3.7:1 and 20:1. The output shaft is a 6mm D-shaft, and like all NeveRest motors use the Anderson PowerPole to connect to power. This connector is perhaps the most robust of the ones listed here.

  • REV UltraPlanetary gearbox - The UltraPlanetary is a customizable planetary gearbox that is designed for FTC. The three gearbox options are 3:1, 4:1, and 5:1, and can be mix & matched to create a custom ratio. It is possible to use from one to three gearboxes for a minimum ratio of 3:1 and a maximum of 125:1.

    Notă

    While REV lists the UltraPlanetary stages as 3:1, 4:1, and 5:1, their actual gear ratios are slightly different. Consult the REV UltraPlanetary User’s Manual for the exact gear ratios.

    The UltraPlanetary was intended to give teams maximum customization without the typical limiting factor - high cost. The total cost for the three stage gearbox and motor is exceptionally good value for a customizable motor. In addition, the UltraPlanetary has a female 5mm hex output shaft which allows teams to customize the shaft length.

Choosing The Right Gearbox#

For regular use, any of the planetary gearboxes will fit your needs. Planetary gearboxes are just a tiny bit more expensive, but boast better backlash and efficiency, higher load capacity, and better capacity for shock loads than spur gearboxes. The tradeoffs, cost and mechanical noise, are almost never a factor.

Sfat

Because both gearbox types are so similar in price for similar ratios, we generally recommend the use of a planetary over a spur gearbox.

If you already own spur gearboxes, try to use them in lower-load situations and use planetary motors on your drivetrain.

For small reductions, it may be more economical to choose a motor you already own and build an external reduction using gears, chain, or belts. It should again come down to your desired output shaft, desired gear ratio, and for the UltraPlanetary, whether you want the ability to swap parts out on the fly.