Questions tagged [gears]

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Worm Drive Clutching Mechanism

Problem Description I have a project where I will need to be able to engage and disengage a worm drive (actually two of them). The worm drives are quite small. The worm gear is 49.2mm in diameter ...
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44 views

Efficiency of a planetary gearbox as a function of the lubricants viscosity

So I have a client that is asking about if they should switch from one lubricant to another in a planetary gearbox they have. The main advantage that this new lubricant has is that it has a much ...
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Volumetric oil pump efficiency goes up when viscosity goes down?? Strange behaviour

Riddle me this : we are driving an external gear pump (this kind) at a fixed RPM. At start, when the oil temperature is low (and viscosity high), the volumetric flow is much less than when the oil ...
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1answer
70 views

Gear profiles (involute and root) generated by power skiving

@Involutius contributed an article on the equations that describe the root profile of gears which are cut by a trapezoidal-profiled hobbing tool. From that article, I was able to do a slightly ...
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99 views

What is the deflection of planet-ring Gear Mesh along the pressure line and the position of the Plant gear?

For a Sun-Planet mesh in a planetary gear train, there will be a deflection $\delta_{sn}=\delta_{s}-\delta_{n}$ along the pressure line and the position of the planet will be determined by $\psi_{n}$, ...
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142 views

A round, plastic pinion in a lock?

I'm looking at a teardown of a Masterlock. The guts look like this What's strange to me is the black, plastic pinion that appears to be smooth and a strangely shaped cam: Here's the cam magnified: ...
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85 views

Does it matter what direction a herringbone gear turns?

Obviously, the forces and pressures should mostly be the same, but just in reverse. But when play, flex, and such are accounted for, are there any subtle differences to having a herringbone gear turn ...
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181 views

Advice on spring launcher project

I found an ingenious design of a spring ball launcher on grabcad and I'm interested in adapting it to accelerate a $43.7 \mathrm{~mm}$ diameter, $45 \mathrm{~g}$ golf ball enough to reach $65.5 \...
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1answer
94 views

Gears with tilting shafts

I am looking for the following mechanism: A pair of gears initially in side-by-side arrangement. The shaft of the first gear is fixed to a first plate. The shaft of the second gear is fixed to a ...
2
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1answer
70 views

Automatic compression of springs

I am trying to design something for a friend, but am struggling to come up with the mechanics. Can you help? So imagine a long extendable pole, like a bow staff. Imagine after pulling out a "peg&...
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58 views

Optimum spoke shape for wheels made of solid material

Currently I am designing a bicycle sprocket to be laser-cut out of 3mm steel. Steel is heavy, so I want to make some lightening cut-outs, and I want to optimize the shape of the cutouts. I will ...
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35 views

I'm looking for the simplest way to increase rotational speed from 120 to 5,000 rpm for a light duty device

I'm currently designing a device and want to increase speed from 120 to 5,000 rpm. Device is lightweight, hand operated, free spinning, low torque in/out. Picture a cheap fertilizer spreader from Home ...
2
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1answer
72 views

Determining the torque needed for a servo motor

I'm looking for a bit of clarity on a design I have in mind. Please bear with me as I have no background in physics, engineering and this is part of my first real DIY project, so the knowledge base ...
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35 views

Gearhead & 'teeth-track' to drive rotation of ringed encasement?

I am not an engineer, so apologies if this one is a bit of an ill-thought out... Can anyone show me an example of something like the following scenario: A small stepping motor driving rotation of a ...
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62 views

Performance of RC car under different gear ratio, measured data vs hypothesis

Assuming the driveshaft of the rear wheeled drive RC car follows the linear DC motor theory for stall torque and no-load RPM, also voltage supplied is constant and no inductance as well. Note: the ...
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56 views

Gearbox oil/grease leakage

Recently I encountered a problem of oil leakage from different driving systems SERVO gearboxes. The transmitted mechanical power ranges from 2 to 8 kW, while the motor speed (the gearbox input speed) ...
2
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1answer
346 views

Trouble with Base circle and meshing with spur gears

I am a novice who is trying to make some gears. I have followed the formula's but sadly something seems to go wrong and the gear's don't come out right. Below is some dimensions and pictures. Gear 1 ...
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62 views

Efficient Gearing to Climb a Rope Vertically

I am trying to design a gearbox of sorts that would climb a rope from turning a gear (motor, handcrank, etc). The largest issue is that, while both the top and the bottom of the rope will be attached ...
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64 views

Measuring Helix Angle

What is the best way to measure the helix angle of a helical cut gear? I have a sun gear from a planetary set that I would like to have custom made but I'm not sure the best way to get the helix angle,...
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197 views

Worm Drive Calculation

I have this setup: -Pully with a mass attached. -Worm gear drive to lower the mass with a constant speed. (Section A-A) Now if we look at the cross-section A-A, we can see the worm gear drive: ...
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29 views

Gear design for symmetrical opening of two parts

I'm trying to build a lamp which has about 20 identical layers stacked on top of each other. There is a central spine and, on each level, a pair of arcs attached to the spine that are hinged and which ...
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450 views

How to design CAD bevel gears from known outside diameter?

I'm working on a problem where I need to design and 3D print bevel gears to fit in the inside of a box and transmit a gear train around the inside corner, as roughly illustrated by the cross section ...
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4k views

Why is 14.5° a commonly used pressure angle in gears?

In gearing, according to Wikipedia and Dr. Rainer Hessmer's involute gear generator, the most popular pressure angles in the industry are 14.5°, 20° and 25°, with 20° being the most abundant. I can ...
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626 views

Straight sided serration dimensioning

I have invented something and I need to have some external broaches made but I'm being asked for some dimensions I simply do not understand. I need 4 external broaches. They all have the same major ...
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263 views

Helical - Worm Drive

Is it possible to have a helical gear and a worm gear with the teeth angled the same amount, so that the helical gear can drive the worm gear, unlike a spur gear. Can the helical gear also move the ...
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19 views

Sign convention for angular velocities in 3D gear train

Consider a Humpage gear train shown above. We are viewing the gear train from right and gear B is rotating in clockwise direction. If we consider clockwise direction as positive what will be the sign ...
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25 views

Gear Oil HP 85w-140 vs HP-140

I have a 4 Stroke scooter 150cc (SYM JET-14). Manufacturer recommends 85w-140 gear oil. The price difference between 85w-140 and single grade 140 is tremendous. Given that in my country and during ...
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50 views

What is a good approach on creating a custom robotics gearbox

I would like to put together a custom gearbox of the scale of around 50mmx30mmx30mm to fix a gadget that I am designing. My question is how should I approach producing this? Should I design components ...
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28 views

AutoDesk Inventor Export Dimensions from Design Accelerator Generated Spur Gear

I'm working on modeling a turret-like mechanism in AutoDesk Inventor. Part of my design involves a rotating table. In order to accomplish this, I used the spur gear tool to generate a set of spur ...
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20 views

How is the equivalent spur gear diameter of a helical gear equal to (d/cos^2α)?

The book I've got says that the equivalent spur gear radius(re) = (Semi-major axis)^2/(Semi-minor axis) of the ellipse made by the cut-section normal to the teeth of the helical gear. There is no ...
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206 views

How does this SpaceX Starlink ground station antenna's gear mechanism move it in both altitude and azimuth?

Ars Technica's Teardown of “Dishy McFlatface,” the SpaceX Starlink user terminal links to the YouTube video Starlink Teardown: DISHY DESTROYED! and a screenshot from there is shown below. There are ...
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35 views

What are the limits of small 3D printed gears?

How much tangential force should I expect a 10~20mm pitch diameter/1.5mm gear module 3D printed rack and pinion system to support without breaking nor sliding?
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27 views

Can we reduce pitch of a lead screw to reduce backlash of the lead screw?

In gear design, the backlash is introduced in the design itself (not by tolerances of manufacturing) to allow free meshing of the gears. The backlash in the design can be minimized by reducing the ...
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47 views

Building a custom indirect actuator, any thoughts?

I’m trying to create a custom indirect actuator, that is controlled by a microcontroller, for a custom robotics project. I have selected motor and gears (according to Fd = W = T2*pi) so that the ...
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44 views

Can we calculate the torque acting on the last gear determine teeth of the gears of the gear train in the below addressed manner?

The specifications of the generator is as follows: Efficiency- 70% Rated Torque- 0.56Nm Rated current- 14.3A Voltage- 24V Rotor shaft dimension- 1cm(diameter) The ...
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1answer
47 views

How to I determine the dimentions for a worm gear?

I have a worm gear set with no drawings. I need to model them. The only things I know are 1) The Gear ratio is 30, and the worm gear only has one thread. It is a single start as opposed to a multi ...
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99 views

Wobbling DC motor head

I have used 250 watt DC motor, for DIY electric potters wheel. Motor rated with RPM 3300 and geared reduction to 330 RPM. The issue I am facing is wobbling of the motor head. This issue is with the ...
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32 views

Bevel gear friction and inertia calculation

I want to calculate the friction and inertia between 2 bevel gears with straight teeth. I know how to calculate those parameters between regular gears with straight teeth. Is there any difference for ...
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37 views

Efficiency of harmonic gear drives

Does anyone have application experience with harmonic gear drive efficiencies as opposed to planetary or parallel axis reduction systems? I'm looking into drives with about a 25:1 reduction, and it ...
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82 views

I need a mechanism/method to control a shaft that can rotate at different speeds. (faster clockwise and slower anti-clockwise)

I need to develop a mechanism - Where in I have a shaft that needs to rotate at different speeds. Lets say at a higher RPM clockwise and a lower RPM anti-clockwise. This shaft is attached to my ...
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93 views

The optical encoder resolution

The optical encoder has a code wheel with a single track of slots and two photodetectors. The photodetectors are positioned so that they produce signals with a 90 degree phase difference. I want to ...
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30 views

gear design.improving gear strength

For improving the gear strength, which one is better based on manufacture and economy? Increasing module or increasing N? With the same surface strength.
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61 views

Need bevel gear for SG90 servo motor

I am looking for a away I can convert the horizontal rotation into vertical, typically we use bevel gear for such thing. But I am using a SG90 servo motor for which I am struggling to get the correct ...
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27 views

Steel Worm/Steel Wheel vs Steel Worm/Bronze Wheel

I have a question regarding worm drives, specifically double-enveloping types: Do steel worm/steel wheel combinations last longer than steel worm/bronze wheel or steel worm/brass wheel combinations? ...
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30 views

What are the some of the best (dis)engagement mechanism for small gears?

I’m planing to build a robot out of gears. I was wondering what kind of (dis) engagement mechanism would be suitable for gears that are about 2.5cm (1 inch) in diameter. PS: preferably, (dis)...
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2answers
116 views

Reacting Propeller Torque?

A motor is used to drive a shaft that is geared through 1:1 bevel gears to a propeller. The shafts are mounted on bearings in a hard casing that is attached to a 2nd ground. I want to know if the 2nd ...
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315 views

How to calculate bearing loads in a two stage helical gear box?

Here P, Q, R, S are the bearings and G1, G2, G3, G4 are four helical gears. The gear forces tangential(Kp), Axial(Ka), Radial(Kn) are known. All the distances are known. The forces acting on bearing ...
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289 views

Does the module of 2 meshing spur gears have to be the exact same value ?

Does the module of 2 meshing spur gears have to be the exact same value ? What is the allowable difference? So basically my module is off by 0 01 and my coworker made a model and it works. So I'm ...
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271 views

How to raise a pole with a handcrank and have it lock in place?

Background: I'm going to build a homemade wind turbine. It will be all fancy and rotational so that it's always pointing to the wind, so it will be mounted on a frame etc. This will be mounted on a ...
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49 views

What actuators do the me-shifter gear shifting system uses?

I have a shifter kart (125ccm kz2) with 6 gears. What I want to do is to change gears from the steering wheel. Like in the system mentioned in the question. I have the electrical and electronic ...