Questions tagged [gears]
The gears tag has no usage guidance.
269
questions
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Adding the effects of two rods to move a single rod
I have to deal with a situation where I have two parallel and completely independent rods whose motion is dependent only on external inputs, and I want to add up the lengths traveled by each rod.
My ...
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0answers
44 views
Continous Gear Shifter
Is there any gearing system that would allow one to make the torque ratio as precise as they wish? Bicycle gears have discrete ratios, and also have some annoying slippage when the chain falls onto ...
0
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1answer
19 views
Gear mechanism for automatic gate
I have a sliding gate installed on my compound wall. I want to control the gate opening/closing with a motor. I have the electronic circuitry to control motor start/stop. I m thinking about attaching ...
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0answers
19 views
How to fix a shaft in position, vertically [duplicate]
I am doing a project where I have to mount a gear shaft with two bearings on either end (deep groove ball bearings) but I am worried that they may fall through the bearings during operation as the ...
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2answers
34 views
Vertical gear shaft support
I have a question regarding how are the vertical forces on a spur gear shaft are supported. I am currently doing my undergraduate (in final year) and have only dealt with gearboxes where the shafts ...
1
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1answer
28 views
Geometric constraints on Planetary Gears
I would like to design a single stage planetary gearbox using standard gears.
There appears to be three primary conditions to ensure the geometry of the gears will fit - correct center distance, ...
1
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2answers
36 views
Engage and disengage DC motor from free-spinning reel
So i want to have a reel (~4cm diameter) that will pull a ~80cm string with a torque of ~8kg-cm (edit: thanks for the clarification). To pull I want to use a gear motor. E.g. 12V DC motor like this:
...
1
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3answers
30 views
Key fitting - Shafts and Gears
I am designing a gearbox and wanted to know whether the key on the shaft and gear must fit exactly with the bore in the gear and keyway in the shaft.
Ex. If there is a key that is 3x3 mm, and does the ...
1
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2answers
39 views
Optimal gear combination with the same ratio
Summary: In a gear train, with given target ratio and configuration (eg. number of gears and how many compound gear steps are involved), what are the considerations when trying to select the optimal ...
2
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2answers
26 views
How are planetary gearboxes held together?
I see that the housings of most planetary gearboxes consist of 3 parts: a front cap, a ring gear and a rear cap. Here's a common design:
In designs similar to this, the rear cap and the ring gear are ...
2
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1answer
46 views
Is there a way to convert a short throw in one direction into a long throw in two directions
I have a motor that I have created a simple adapter for; this lets us attach any parts we might design to solve the final problem:
I would like to convert the motors motion to oscillating motion in ...
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2answers
57 views
What is the easiest way to regulate the speed of a falling object?
I want to design a system that allows a 1kg metal brick to fall under gravity at variable speeds. The brick initial position is 20cm above a flat table. I want to have control on the duration (to ...
1
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1answer
23 views
Calculating force transferred from pinion gear to rack
I am really challenged as I need to fit a bunch of motors in a 6" box acting as linear actuators. I was looking for linear actuators (most I found were brushed DC) at first but the ones I found that ...
15
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3answers
6k views
How do bike wheels keep turning when the rider stops pedalling?
I am very confused with something regarding bikes...
How is it that a bike wheel continues to spin (either from momentum or from going downhill) when the rider is not pedalling, without also spinning ...
1
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1answer
27 views
Increasing rotation via simple gears
Complete amateur here with a product idea and a need to find out whether it can work in theory.
I need to push a lever vertically down through 90 degrees and have a lateral arm swing horizontally ...
1
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2answers
25 views
Calculating and Designing a Ring Gear for LEGO
I'm working on 3d printing a planetary gear for LEGO. I've got a constrained set of planetary + sun gears and was looking into designing a custom ring gear.
I've read a little bit into the design of ...
1
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1answer
26 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 ...
1
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2answers
35 views
Does the rack for a rack and pinion often have or need to have the involute profile?
I am looking at designing a rack and pinion system that will be laser cut out of some plastic. While the cad system that I am using has a spur gear generator, I was looking at the design of the rack ...
1
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2answers
38 views
Gear train using two inputs and one output. Understanding six link epicyclic gear topology - Interpreting displacement graphs
I'm interested in printing a working two degree of freedom planetary gear set. I searched around and found a paper from University of Maryland in 1988 (source). I am having difficulty translating the ...
2
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4answers
150 views
How can a clutch engage gradually without wearing away very quickly?
Here's an animation of a gearbox and clutch from Wikipedia.
I learned to drive recently, and was surprised at how the clutch worked, engaging gradually as I moved the pedal by fractions of a ...
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1answer
55 views
Determine if car is moving forward or backward
I would like to know if there is someway i can figure out if the car wheel is rotating in clockwise or anticlock wise direction.
Im working on a project which determines if car rolled back on a hill ...
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0answers
25 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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0answers
17 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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0answers
23 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 ...
1
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1answer
28 views
Inertia and friction between gears
I have a question regarding inertia and friction between gears.
I have a gear which is connected to the rod at one end and an electric motor which is connected to the other end. I know the torque of ...
3
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1answer
36 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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2answers
62 views
Calculating the torque required to move and hold an arm parallel to the floor
I'm a computer scientist doing a dissertation in robotics and I'm designing a mechanical arm that mirrors a humans, as such I am wanting to pivot the entire arm from a "shoulder" using a stepper motor ...
2
votes
1answer
48 views
Torque between concentric gears
First time asking question here.
I'm not a mechanical engineer!
I have a simple question that I can't explain the answer to it.
I have a double gear (2 concentric gears with different radius) and I ...
1
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0answers
26 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 ...
1
vote
1answer
68 views
Is there a way to auto-reverse cassette tape with gears only?
From what I read, tape decks auto-reverse by having a sensor keep track of an encoder. When the take up pulley stops turning, the logic board reverses the direction of the motor (and does some other ...
6
votes
3answers
735 views
How Much Efficiency is Lost in a Gear Train
I want to get a rough estimate for the transmission efficiency of two different gear trains. One is a one-stage gear train with 11.67:1 ratio (140/12 teeth) and the other is a compound two-stage gear ...
0
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0answers
19 views
Good resources (textbooks) with steel S-N curves?
Looking for S-N curves for common gear materials (steel, cast iron). Are there any sources with multiple materials compiled together?
Currently cobbling some charts but they're more inconsistent than ...
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3answers
49 views
Attaching Gear onto Motor
I want to attach a 12 toothed spur gear with a bore diameter of 6mm onto the shaft of this motor (6mm diameter). How would I go about doing this? From what I see, the shaft is smooth so is my only ...
1
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1answer
27 views
If a driver gear has larger radius than a driven gear, will a larger gear ratio result in more torque supplied to the driven gear?
Suppose a driver gear has larger radius than a driven gear. For example, we have a pinion with a main disk, where the main disk is larger than the pinion and the pinion is a follower. This is the case ...
2
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1answer
45 views
solidworks mating gear with shaft problem
I am trying to mate a gear with a shaft via a key.key coincident with gear and cocentericity of gear with shaft cannot both be made.
1
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1answer
88 views
Driving Gearbox in Reverse
https://www.maxongroup.com/maxon/view/product/251601
https://www.maxongroup.com/maxon/view/product/gear/spur/gs45/301171
Consider that this motor-gearbox combination is backdriven so that the motor ...
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0answers
52 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 ...
0
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1answer
27 views
small gearbox for experimental wind mill
The gear box will have little torque as I am only using a 12 by 18" wing which rotates. The two shafts I am using are 1/4 ", one form the wing and the other going the to pivot for the wing to circle, ...
0
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1answer
117 views
Motor, a gearbox and a drum with a cable lifting a mass
A lifting device consists of an electric motor, a gearbox and a drum with a cable for lifting a mass.
The speed after the initial acceleration is $v=0.5\,\text{m/s}$.
The gear efficiency $\eta=0.7$
...
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0answers
21 views
What is the top limit for torque per diameter ratio for electrical rotation mechanism working in a tube?
Use case: industrial stop valve placed in an another pipe welded perpendicularly making a T-shape.
To make the question more specific let's consider 50mm inner diameter pipe for the linear actuator ...
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0answers
23 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.
0
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1answer
124 views
How don't dog clutches collide?
I'm learning about how dog clutches work particularly in sequential transmissions.
I'm having a hard time understanding the principle which ensures dogs will always mesh correctly. I can easily ...
0
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1answer
39 views
Did Charles Babbage's Difference Engine use the sautoir carry mechanism from Pascal's calculator?
We know that Blaise Pascal built a mechanical calculator which had a carry mechanism called a sautoir.
You can see a video of it working here, and here.
We know that Charles Babbage wrote a book ...
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1answer
22 views
Gear train with fixed average speed but irregular instantaneous speed
Is it possible to create a gear train whose average speed is fixed, but whose speed constantly fluctuates? I'm imagining something that would ideally always complete a single revolution in fixed time, ...
2
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2answers
145 views
How to calculate the moment of inertia of a worm gear?
Should I consider them as a cylinder to find their inertia? Any tips will be helpful.
1
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1answer
59 views
Electric engine and transmission
What kind of automatic transmission would be the best to connect an electric engine with the rear axle of a RWD car?
Specifications:
200HP, 3000rpm electric motor
top speed 220km/h
The automatic ...
1
vote
2answers
52 views
A few questions about cars
When I start the car, why do I hear the engine working when I'm not pressing the gas pedal?
How exactly does the torque and power of the gears work?
Torque = Radius * Force
Power = Torque * Speed
...
0
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1answer
78 views
Calculating needed motor to spin a disk at low RPM
I'm designing a machine that I need to spin a horizontal disk at low RPM using a motor and gearbox. I'm not good at physics so I need help to find a motor/gearbox to fulfill my needs.
It's a ...
0
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1answer
59 views
Create Bezel-like ring mechanism
I'm designing a 3d print model of a ring that you can wear, but the outer surface of the ring can be dialed like a watch bezel.
Check this video to see how the bezel moves in grades so it stops on ...
2
votes
1answer
40 views
Gear switching for simple differential steering
I'm rather new to the field of gear systems, and to the field of RC models to which this case applies. I'm trying to design a system where a single variable speed engine would drive two different ...
