# Tag Info

17

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 of what's going on: When you bend a material, part of it will extend (the external part of the bend), while another part will retract (the internal part). The ...

14

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 further. Also make certain that both power and data cables have enough slack. Vibration might cause them to come loose, when under tension. So, to address the ...

13

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 behavior once it gets past the yield point. At the recrystallization temperature, new grains will nucleate and grow, which undoes any sort of hardening that the ...

11

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 of the flutes in a drill, the stiffness goes down geometrically as the length increases. The other variable you have control over is how you are holding the tool....

11

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 installations they are the primary reasons of failures if the devices aren't protected properly. The best option is just keeping all that's not necessary on the ...

9

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 stresses within the material. When you start selectively removing material, those stresses may cause the part to warp into a new shape. Cast metals and ones that ...

9

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. $$\text{Spindle speed (RPM)} = \frac{\text{Cutting speed}}{\text{Circumference}} = \frac{\text{Cutting speed}}{π \cdot \text{Diameter}}$$ The thing you need to be careful of is the units of cutting speed ...

9

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. honey has much higher dynamic viscosity than water, or cold motor oil has higher dynamic viscosity than warm motor oil. Kinematic viscosity is something ...

8

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-like setup the cutting tool is just a chisel that is cheaper to replace and refurbish when it's worn down than a router bit.

8

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 of drilling a hole. Even then - a 0.1 mm hole is extremely small, and I would not try to make a hole like that mechanically. You can try electrochemical ...

7

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 found in the 1050 steels. This search turns up quite a few results, but from what I can tell of A311, it's for cold-drawn and stress relieved bars, but doesn't ...

7

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 material using an end-mill tool in a CNC mill of smaller diameter than the hole (say 3 mm to the hole's 6 mm), and having the CNC machine mill a series of ...

6

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 http://www.aliexpress.com/item/Square-End-10mm-Cutting-Diameter-6-Flutes-HSS-Hand-Reamer-Milling-Cutter/32240625696.html http://www.aliexpress.com/item/Free-...

6

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 unless I know you are there for me when I need to change anything, I can't rely on you. Questioning. The best vendors I have for custom pieces ask questions and ...

5

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 United States, AWS D1.1 would limit the maximum heat in quenched and tempered steels to 1100 deg F. This temperature is compatible with preheating for welds or ...

5

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 tapping, and how large your production run is. The first step would be to buy a guided tap wrench, which is a regular hand tap wrench with a bushing you can ...

5

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 press and mastering them. You can do 95% of everything you would do on a mill with those two items. In general a lathe is a more versatile, more precise machine. To ...

5

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 with a very affordable price, comparable to the price of a single 0.1 mm drill bit - which you would almost certainly trash anyway). Or, you could build your ...

5

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 better accuracy for equivalent quality parts. Similarly you need to make sure that the part you are drilling is faced off as square as possible in the chuck and ...

5

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 sufficient when my machine doesn't have adequate suction.

5

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 circumferential direction but unlike the chuck it does not impose any radial positioning to the part. Why is this useful? Why not just use the chuck? Well, a chuck grips ...

4

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 need an outside fillet on your die. Assuming you're not casting, and working with a commonly machinable material, external corners would typically be rounded ...

4

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 with enough time and money can defeat tamper evident materials/designs. I am not sure what you are building, but you may want to consider a non-passive system ...

4

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 femtosecond laser can easily reach into the megawatt range. In contrast, CW lasers generally do not reach power levels in excess of a few hundred Watts. When these ...

4

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, and if you want it to extend and stay extended on its own like other collapsible antennae, a slip fit probably won't accomplish that. You'll need something that ...

4

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 not necessarily in true scale or projection. The following images are from a technical drawing textbook (Giesecke et al.): It goes on to specify that this is ...

4

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 need a more precise definition, at least for the outer surface (diameter, cylindricity, runout, etc.) One remark to your design: look for knurling tools on the ...

4

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 between material removal rate, quality of finish and tool life and it is entirely possible that in certain circumstances it is preferable to sacrifice one in ...

4

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 machines. Every shop I've ever been in, from mom & pop places to 1,000+ employees, has been 95% CNC with manual machines reserved for tool & die making or ...

4

Yes, it would be easier to drill the hole but there are other reasons. It's makes the shaft the same width as the red bearing also clamped by the green sides. The shaft will experience torque when the knob at the top is tightened. A hole though a round shaft would have high pressure on the curved edge at a point on each side some little distance away from ...

Only top voted, non community-wiki answers of a minimum length are eligible