54
votes
Accepted
What is the purpose of these “partially filled in” locomotive wheels?
Those are counterweights. They work exactly the same as those lead counterbalance weights on the wheels of your automobile.
If they left those out, then those connecting rods and bearings would ...
- 775
30
votes
What is the purpose of these “partially filled in” locomotive wheels?
Those are balance weights against the joints used for the rods linking the wheels together.
- 15.5k
17
votes
Accepted
How can I calculate the power and torque required for the motor on a wheeled robot/vehicle?
I laid everything out so you should only need to read it from top to bottom and look backwards for variables, never forward. I also tried to lay it out so hopefully you know where everything is coming ...
- 5,237
15
votes
What is the purpose of these “partially filled in” locomotive wheels?
The oversized counterweights on the second set of wheels are to help balance the additional inertia of the pistons, piston rods and crossheads, which are directly connected to the wheels on this axle. ...
- 151
11
votes
Accepted
Is a chair with N+1 wheels ever less stable than a chair with N wheels?
Assuming all the wheels are evenly spaced on the same circle, then more wheels is always more stable than less wheels. However, there is diminishing return as the number of wheels gets large.
The ...
- 11.4k
8
votes
On a car with all-wheel drive, how does the engine provide the angled front wheels with power?
You could also include front-wheel drive in your question. It would be enlightening for you to look at what radio control rock crawlers do. It has much of the excess of a full-sized car stripped away.
...
- 5,237
6
votes
Accepted
Reason of Using exactly 5 Wheel Studs per Wheel
On reason is that die cast (alloy wheels) generally have an odd number of spokes. This is because having directly opposed spokes causes problems with residual stress distribution as the casting cools ...
- 15.2k
6
votes
RC car steering mechanism type
The key feature is that the steering has Ackerman geometry
This means that the steering arms coming off the back of the hubs are connected to the steering linkage at a point inboard and behind the ...
- 15.2k
6
votes
Accepted
What makes scooters unstable at high speeds?
As has been mentioned above the size of tires plays a major role.
Let's assume the manufacturer standards for a wheel after improving the shaft allows 1/100 mm of play. This much play would encourage ...
- 22.1k
6
votes
What is the purpose of these “partially filled in” locomotive wheels?
These counterweights are found on all piston-driven steam locomotives (not just Soviet designs), and even a few types of diesel locomotive using connecting-rod drive. As other answers note, their ...
- 161
5
votes
Why do cars have beveled tires?
To add to @ratchetfreak's answer, there 2 more reasons:
1. Manufacturing process
It's much easier and more reliable to make a continuous surface that us bevelled, that an angled surface from rubber ...
- 181
5
votes
Is a chair with N+1 wheels ever less stable than a chair with N wheels?
I think the "health and safety" regulation about 5 wheels is a compromise between stability and cost.
If your weight is on the edge of the chair seat and the chair has only 3 wheels, it is much less ...
- 12.5k
4
votes
Accepted
Why do baseball pitching machines have wheels stacked instead of side by side?
Quite a few of the machines allow to tilt the pair of wheels to arbitrary angle too. Some allow tuning speed of the two motors separately.
It's all about curveballs and Magnus Effect. One wheel going ...
- 6,125
4
votes
How to make wheel rotate slower in one direction than the other?
Sailboat 2-speed winches do exactly this. Winding the handle clockwise directly engages the drum via one ratchet, and when you wind it anti-clockwise a different ratchet engages an epicyclic gear. ...
- 171
4
votes
Why do cars have beveled tires?
If you press a cylinder on a flat surface the contact pressure concentrates on the edges and becomes very high. We call that edge stress condition. If the cylinder has a profile (curved instead of ...
- 723
4
votes
Accepted
Why is a cart with swiveling casters in front stable, but not if the swiveling casters are in back?
Consider what happens in front wheel steering, such as an automobile:
Turn the steering wheel slightly clockwise.
The front wheels each turn slightly clockwise.
Their rolling action causes the wheels ...
- 789
4
votes
Accepted
How to get a wheel pump to deposit water near the top of the wheel?
Consider an alternative to the current placement of the cans.
The image above from the Pinterest web site, UN Food and Agricultural Organization shows a wheel in which the cans (bamboo tubes) dump ...
- 6,940
4
votes
Why caster angle causes wheels to self-center?
There are two different concepts there:
caster angle
caster trail at wheel center
Figure Caster offset
Both the angle and the offset are important to determine the castor offset and the castor point ...
- 24.3k
3
votes
Accepted
Wheel rolling resistance
Before we dig into practical equations, I'll just say that tires are surprisingly complex in their behavior. There are a variety of equations that try to fit the experimental data reasonably well. ...
- 1,976
3
votes
How to add traction to a wheel?
Depends on a lot of factors, like what surfaces the car is going to go one, the size and weight of the car, if wheel-well dimensions are a constraint, etc...
In general however, if you're trying to ...
- 29
3
votes
Can a six-wheeled F1 car have a better acceleration profile than a typical F1 car?
The complication here is that the simple relationship between wight (or downforce assisted equivalent) coefficient of friction and traction is only true up to a point and in performance tyre that ...
- 15.2k
3
votes
Why caster angle causes wheels to self-center?
Figure 1. The castor point is the intersection of the pivot axis with the floor.
Figure 2. For travel to the right we have three situations: (a) No castor action. (b) Correct castor action as the ...
- 10.3k
3
votes
Why can’t we accelerate a rotating object after some point?
This gets back to the original answer by Tigerguy.
You have the maximum torque your legs can put out. You also have the maximum power your legs can put out (power = torque x rotational speed). But you ...
- 109
2
votes
Surprisingly Low Efficiency of Compound Machine [Project Help]
I have a few suggestions when it comes to managing forces:
Try putting the angle of the ramp and the angle of the cord in the same value. This will reduce the force required to pull it up as the ...
- 860
2
votes
Accepted
Compression and check valves
No, because the pump is designed to limits and if you exceed its working or maximum pressure then, for example, its seals fail and it just does not pump any more.
- 15.5k
2
votes
Accepted
Pacejka Formula - natural values
The actual parameters for real tyres tend to be heavily protected intellectual property, you won't find those anywhere. However, have a look at these various pages, they give indicative values of the ...
- 1,831
2
votes
What makes scooters unstable at high speeds?
There is less gyroscopic effect but this is not as much a factor. It is camber of two wheeled vehicle that is self correcting. If you push a bicycle backwards it will not stay up.
With the ...
- 489
2
votes
Dead mans brake on a hand-pushed wheelchair
You could have a spring loaded brake acting on the rear wheels, released only when the push handles are pushed, and bent down, like many airport carts. But in this case with light cables transferring ...
- 22.1k
2
votes
Help me build a mechanical gizmo involving a pulley (I think)
The simplest way to achieve this in my mind, is with two gears - one should have a drum attached with the rope wound around, and the other has the arm attached.
One benefit of this method, is that ...
- 7,726
2
votes
Meeting point of turning wheels with rear wheels
The meeting point of the angled front wheels will always intersect the line from the rear wheels.
All that happens as the vehicle changes dimension is that the turning circle becomes larger, or ...
- 15.5k
Only top scored, non community-wiki answers of a minimum length are eligible