DKNguyen
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Why exactly does a washer help distribute the stress around a bolt?
27 votes

It is for spreading out the stress. But it is also for giving the bolt a bearing surface to turn on. The washer always goes on the side (nut or bolt) that is being turned. It prevents it from marring ...

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Aluminum weight saving
20 votes

I believe it has less to do with strength and more to do with stiffness. A rod of aluminum of the same length and weight as a a steel rod will be just as strong (force required to break) but have ...

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How can I calculate the power and torque required for the motor on a wheeled robot/vehicle?
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12 votes

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 ...

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Why can't screws be used for locating parts?
5 votes

Screws and their holes have a few of problems: Screws are formed, so nowhere near as accurate as a hardened, ground pin. You probably could harden then grind a screw thread but obviously much more ...

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Why do blacksmiths use these 2 tools which seem to do the same thing
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5 votes

One is called a press, the other is called a hammer. At this point I am just regurgitating what I have read. You can see that the press is able to shape the metal more which is is good in that it is ...

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Meaning of quarter hole color fill in drawing
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5 votes

They are just identifiers for different types of holes. If the same symbol was used for every hole then every hole would need the size specified beside it if there was more than one type. With ...

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What is this "clamp" place on a piece of bar stock while turning it in a lathe for?
5 votes

It's a lathe dog. It grips the part and extends over so it can be pushed by the spindle so the lathe motor can turn it. Like the chuck, it grips the part so the part must follow it in the ...

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Electric go kart
5 votes

This cannot be answered as is because almost all the critical information is missing. Mechanical Power required to move to the go kart is determined by the force and speed required Motor Power can ...

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Working out Motor torque
5 votes

The biggest unknown you need to determine or guess is the coefficient of rolling friction. For reference, a coefficient for rolling friction of 0.3 is already very high and is for something like for ...

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Motor to rotate gear and hold place when powered down
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4 votes

Worm gears. The worm (screw) would lay horizontally and drive the spur gears in your photo. Worm gears inherently cannot be back driven so consume no power while holding position. However, they are ...

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is a positive acceleration indication that velocity must be positive?
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4 votes

No, positive acceleration, alone, does not need to imply positive velocity. Another term for "acceleration in the opposite direction of the velocity" is just "deceleration". The ...

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Why radio communication was limited to military use and did not become popular with general public like cell phones have become today?
4 votes

The radio spectrum is limited. There are is only a finite range of frequencies over which we can transmit so you if have two people communicate by directly transmitting to each other over two ...

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Why are hydraulic systems widely used to multiply force ? won't a couple of gears do the job?
3 votes

Hydraulics can be used more naturally with engines for servo-like motions (try reversing direction or holding position on a engine driven gear box). Piston must be of precise dimensions without any ...

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Highest point of stress in a multistage gear reducer
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3 votes

You are basically correct. The output gear since it is the one applying the most torque and will experience the most force on the gear teeth. That said, you asked about stress which means something ...

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Does more downforce affect the acceleration and top speed?
3 votes

You do not want to overcome the force of static friction when accelerating because that's when the dynamic friction takes over and your wheels slip. That means that the force applied on the edge of ...

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What's this tool?
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3 votes

It appears to be a base holding a scribe. Normally they are used to hold indicators (which are like touch sensors that measure how far the arm is deflected from their neutral position). You mount ...

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Chernobyl - why didn't they power their own circulation system?
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3 votes

Chernobyl does power its own cooling system during normal operation. It would be very strange if it did not. It uses the grid as backup and then uses diesel generators as a backup for the backup. This ...

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What does "rigid steel" mean in electrical construction plans and specs
3 votes

It is to distinguish it from flexible metal conduit.

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How to stop the leakage from the design?
3 votes

I think you might have tunnel vision after spending so much time designing the container. The solution is quite obvious, simple, and fast. When the cap is female, you have a soft, deformable pad at ...

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Welding Carbon fibre
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3 votes

You basically can't. The same way carbon fiber is made: Epoxy. Fiber-filled if need be...but won't be as strong as a weld though. The only other potential method I know of is to get carbon fiber ...

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How to calculate the moment of inertia of a propeller
2 votes

Assuming you already know basic moment of inertia calculations (and if you do not then you really should not be asking your question here prior to research): You can't develop an equation without ...

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How to I determine the dimentions for a worm gear?
Accepted answer
2 votes

You can use angle gages to find pitch angle. Looks like a feeler gage but for angles. You use thread measuring wires with a micrometer and equations to find thread diameters.

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How do I add resistance to a ball joint?
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2 votes

The ball joint can be seated in a split-spherical shell socket that is tightened by screw. The one below uses a hydraulic mechanism to tighten all the clamps present with a single knob, but other ...

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What is the name of this height-adjustment structure?
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2 votes

Maybe I'm not understanding what you have in mind but your drawing looks really complicated with sliding rollers in captive grooves and such. I also imagine the lateral movement when weighing ...

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Why does a jumping rope have no bending stiffness and compression stiffness?
2 votes

It won't just keep itself straight You know a steel beam held at one end won't just keep itself straight either right? It also bends under it's own weight when supported by one end. Just because you ...

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What causes the temperature to drop at the interface when two slabs are brought in contact?
2 votes

You're interpreting things that aren't there. I did not see anywhere in the source materials where it says the temperature at the interface is lower because of air gaps. The temperature is going to ...

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Implementing a locking mechanism for a rotating platform
2 votes

TLDR: I recommend either collets or shaft clamping pillow blocks, forces permitting. Collets is probably better, but shaft clamping pillow blocks are definitely easier and cheaper. You can also ...

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If every action has an equal but opposite reaction, then how is acceleration possible?
2 votes

When you push on a block, your hand applies a force on that block. An "opposite force" then comes into existence but exists elsewhere. It is not also applied onto the block. It is applied by ...

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Kollmorgen TBM frameless motor material
2 votes

Those are called flux rings. They're standard on pretty much all motors. They close the magnetic loops in the core so the flux doesn't need to escape into the air to find its way back to the other end ...

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Are mechanical pocket watches inherently water-proof and last "forever"?
2 votes

Pretty sure they are not all stainless steel. I would expect some brass and I don't think I would expect the springs to be stainless steel. Different metals with water result in galvanic corrosion. ...

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