17 votes
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How do I size metal plates to get the correct dimensions after folding?

Your assumption is right! A 300mm long plate with two foldings won't do! This is because you need to take into account the bend allowance and the bend compensation! But why is so? Here is a diagram ...
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  • 631
14 votes
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How to make factory machine hard disk drive more durable? How much its estimate life span?

Quite likely, the SSD killer is electrical. We can't entirely rule out mechanical vibration, but SSDs are pretty robust mechanically. A simple rubber mounting would increase the resiliency even ...
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  • 391
13 votes
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At what temperature do I risk altering the structure of steel?

In general, you want to stay below the recrystallization temperature. Steel is composed of grains, and different types of steel have different grain sizes. The size of these grains affects the steels ...
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11 votes
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How do I keep my bit from wandering on a drill press?

It's common to start with a shorter, stiffer tool such as a center drill or a spotting drill. In addition, using the shortest drill bit that drills the hole you need will increase stiffness. Because ...
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  • 4,501
11 votes

How to make factory machine hard disk drive more durable? How much its estimate life span?

First off, electrical and magnetic problems are not as bad as problems of vibrations and air contamination. Moisture in air plus dust or chemicals can corrode or short paths quite easily, and in our ...
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  • 6,133
10 votes

In aluminum machining, what are the most common factors that might cause a machined component to have warping issues?

The work history and temperature history of any metal can make a big difference in the final shape after machining. If the material was cold worked (e.g. rolled) there may be significant residual ...
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  • 1,976
9 votes
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Determining Drill Speed

You are correct that the cutting speed of the material is what determines the rpm for your drill-bit. This actually makes the calculation very simple. $$ \text{Spindle speed (RPM)} = \frac{\text{...
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  • 5,940
9 votes
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Is there an intuitive explanation for the Kinematic Viscosity unit of mm^2/s?

Dynamic viscosity represents the resistance of fluid to shear forces as you said. This is what lay people think of when they think viscosity. High dynamic viscosity = more resistance to flow. E.g. ...
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  • 2,511
8 votes

Are threads machined from high tensile steel more susceptible to damage?

First, I want to say that I'm suspect of that material actually being ASTM A311 (though I don't have a copy of that standard available to verify.) Looking on Matweb, this material is the closest I ...
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8 votes

Why are mass-produced metal parts machined by rotating the part against a stationary tool?

You can be sure the resulting surface is round. If you used a router and rotated the bit around the piece then you would get inaccuracies due to the movement being harder to control. Using a lathe-...
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8 votes

How can I cheaply drill a 0.1 mm hole in a small piece of tungsten?

99.5% pure tungsten? A lot depends on what the last 0.5% is. Ductile tungsten is made by adding a small amount of rhenium, for example. That makes it much more machinable, and improves your chances ...
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  • 466
7 votes
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How can I finish a round hole so it has 90 degree corners (flat bottom)?

You are likely referring to a counterbore hole, which may be drilled using a bit of the same name. Alternately, if you can't find a bit of the appropriate dimensions, it may be possible to remove the ...
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  • 3,981
6 votes
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Going distant in sourcing machining

I've dealt with this in many ways. Ultimately, here is what I look for when I have to go beyond local sourcing of custom parts: Responsiveness. You can have the best website in the world, but ...
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  • 5,313
6 votes
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How to drill larger bore in pipe?

What you are looking for is called a reamer. Some 10mm reamers: http://www.aliexpress.com/item/Free-shipping-cnc-nc-2015-Reamer-10-0-X30X75L-High-speed-reamer-high-degree-of-finish/32244988192.html ...
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  • 7,489
5 votes
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What is the difference between using separate lathe and mill or a combination machine?

The problem with a combo is that they are flimsy machines. Also, the quality is usually below that of a dedicated machine, sometimes way below. I would recommend getting a mini-lathe and a drill ...
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  • 1,605
5 votes

At what temperature do I risk altering the structure of steel?

The answer to your question depends a lot based on what kind of steel and what kind of heat treatment you're thinking of. For one point of reference, if you were working on a steel structure in the ...
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  • 4,501
5 votes
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What machinery should I invest in for tapping and threading?

For tapping threads, there are a few steps between free hand tapping and fully automatic machines. Which one is right for you will depend on the material you're tapping, the size of the threads you're ...
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  • 4,501
5 votes

How can I cheaply drill a 0.1 mm hole in a small piece of tungsten?

I am afraid that drilling tungsten will be very tough with any available drill bit. You could also consider laser machining (in my country, there is at least one company offering even small batches ...
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  • 273
5 votes
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How can I cheaply drill a 0.1 mm hole in a small piece of tungsten?

You really need to use a dial indicator to set up a 4 jaw chuck to the sort of accuracy required for this job. This is fiddly compared to a self centering chuck but has the potential to give you ...
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5 votes
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CNC milling of large cutouts

I'm assuming that you are cutting on a base sheet of some sort in my answer, if not, please do. In all my shop applications I have found that double sided taping the product to the base sheet is ...
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5 votes

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

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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  • 3,325
5 votes
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Does lead screw's thread have to be trapezoidal?

It's not exactly clear to me what you mean by trapezoidal thread rod. Like you noticed Metric threads are also trapezoidal (just like ACME with slightly difference face angels). Figure : Common types ...
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  • 22.7k
4 votes

How do I manufacture a fillet?

On a mass manufactured part, one solution is to cast the piece and shape the die (with an inside fillet) to form an outside fillet. Of course, if you want your casting to have an inside fillet, you'll ...
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  • 4,501
4 votes
Accepted

Difference between continuous wave laser and a pulsed laser

Pulsed lasers release their energy in very short pulses which can have incredibly high peak powers. A run-of-the-mill nanosecond laser will have a peak power in the multi-kilowatt range while a ...
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4 votes

Are there any materials that can not be drilled or sawed?

You may want to reword your question. What you are looking for is tamper evident materials or tamper evident technology. Searching for those may give you some better results. Be aware that anyone ...
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  • 7,489
4 votes
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How much larger must the ID of a cylinder be than the OD for a Slip Fit? Material: Delrin (Acetal)

0.01" is probably a decent place to start as a slip fit, though you can certainly go tighter. I might even question if you actually want a slip fit for this application. You say it's for an antenna, ...
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4 votes

How to define Knurl on drawing?

It looks to me like your guess was pretty good. The required information is only the type of knurl, the extents of the knurl, and the pitch. It is conventional to show the representative pattern, but ...
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  • 4,501
4 votes

How to define Knurl on drawing?

The (European) standard for knurls is DIN 82. The standard includes a proposed drawing representation as well. Its intention is to describe hand gripping aid knurls. As Ethan48 says, for fitting you ...
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4 votes

What are reasons to use cutting speeds different from recommended?

By necessity recommended speeds and feed rates are generalisations and, in practice the optimum for a given job can vary a lot. Recommended speeds are typically intended to be a reasonable compromise ...
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4 votes

Why are entry-level CNC mills cheaper than entry-level manual mini mills?

The two existing comments are correct IMO, it's mostly due to economics. The price to produce comparable CNC and manual machines might be close, but the demand for CNC's is much greater than manual ...
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