# Tag Info

7

The minimum clearance occurs when the largest possible shaft meets the smallest possible hole. That would be in this case a shaft of $50.02 mm$ in a hole of $50.00 mm$. The difference between the two is the $-0.02 mm$ from the solution you found.

6

There are two different aspects in your measurement. On the one hand, you are dealing with tolerances. On the other hand, you cover probabilities in measurement systems. Just for a rough calculation: The probability of the real length to be within 9.8mm and 10mm is 95%. The certainty of this measurement depends on the distribution of your probability. For ...

5

Answering the question: What are possible types of low cost sensors I can use? There are several types of sensors that can provide millimeter level accuracy. "Low cost" is a very relative term, so you'll need to do some shopping around based on your specific budget. Optical sensors- Included here are those of the type you listed, though it's a very ...

5

To get that sort of accuracy over that scale is not trivial and probably won't be cheap. For smaller size up to a few meters a portable CMM would be an option (here's an example). These have accuracy on the order of 10 $\mu$m and are used for things like high end/F1 car manufacture. However, CMM type instruments wouldn't be useful for anything larger than ...

4

Even the best metal tape measure is susceptible to significant thermal expansion over large distances. Try a laser measurement device ('electronic tape measure') instead: http://www.engineersupply.com/Laser-Measurers.aspx The laser distance measure, flat plates clamped to the object, and some shims of known thickness, should be all you need to precisely ...

4

Measurement variations are very common and should be taken in to consideration when engineering systems. In most cases high precision equipment is available but might be cost prohibitive to justify purchasing for the project. Therefore, the goal of the engineer is to design the system to account for measurement variation. In this case the min and max limits ...

3

It says the flats shall be within 0.100 units of radial dimension positioned with reference to 'A'. i.e. if you were to make the rim which is a perfect circle, then mill the flats at the three positions, what you should see is that the flats are exactly the same sectional shape and size if the machinist was perfectly precise. Some minor deviation from ...

3

I believe this is a related mating envelope related to datum A for the three plates, per ASME Y14.5-2009.

3

Your clearance range is the minimum hole diameter minus max shaft diameter to max hole diameter minus minimum shaft diameter. Answer: Yes. Your math seems correct. This is a useful tool: http://www.amesweb.info/FitTolerance/FitTolerance.aspx

3

If you live in a country that uses ACI standards, you might consider specifying flatness using an FL or FF number. ACI 117, Commentary Table R4.8.4 has this information, with flatness ranging from "Conventional" to "Super Flat." For the dimensions you have listed, specifying anything beyond "Flat" is probably overkill since your forceplate will likely ...

3

Standard threads are classified for accuracy by a tolerance class (You can see a bit about the metric thread fit classes at http://www.amesweb.info/Screws/IsoMetricScrewThread.aspx .) The screws you find at your local hardware store will probably be a relatively rough tolerance class, meaning that the threads are designed to have some gap between them, and ...

3

For high accuracy over long distances it's typical to use general surveying techniques. You use a total station (like this) which will get you 1.5mm accuracy in a single shot. They're no laser tape measure. Repeated set ups /readings with some statistical corrections should get you easily below 1mm. Note too that these are immune to thermal expansion of ...

3

If it says +/- 1% then it means from -1% to +1%. in everyery standard i have ever seen. +/- is simply shorthand for writing a symmetric bound one can also make unsymmetric bounds like 0 to 1% or even positive positive bounds like +0.001 to + 0.025. Granted these are rare in electrical components but play a big role in mechanical engineering where its ...

2

The link provided by Ethan48 added a lot of informations. Tolerance classes: Note : * 6g is normally selected for commercial external (bolt) threads. Note : ** 6H is normally selected for commercial interrnal (nut) threads. The amount of movement allowed for external thread would be determined by axial counterpart to (radial) $T_{d2}/2 + es/2$. ...

2

Understanding "without any special procedures" as meaning simply dropping the cement in a pile, it would probably end up with an inclination approximately equal to its angle of repose. Unfortunately, this value is highly variable, and a quick search has resulted in many different values: 15 or 20 degrees if fine or coarse (1) 40-44 degrees (1) 39 degrees (2)...

2

Here is a link to a screw thread chart. http://www.engineersedge.com/screw_threads_chart.htm Note there are different tolerance classes, and also note the max is never over the nominal size. For the example 1/4-20 class 2: 0.2408 < d < 0.2489 class 3: 0.2419 < d < 0.25

2

The "incremental error" is the relative error in moving between two positions. (But only the USA would think of specifying a dimensionless quantity in "inches per foot" just to confuse people.) If the screw is commanded to move a distance $x$ (in any length unit!) the distance actually moved will be between 0.99995$x$ and 1.00005$x$ (because 0.0006/12 = 0....

2

As you have not placed constraints on the project implementation, consider that most welding requires a jig of some form to maintain alignment of parts. The use of the generality "most" also refers to simple clamping of two pieces prior to welding, which is common in non-critical alignment projects. Allowing for the specifications you've provided, consider ...

1

Just looked at my kitchen scissors; clearance approximately of +.001"/+.003".

1

In simplest terms, Functional Datums should have something to do with a part. E.g. a mating surface or a centerline of the bearing surface of a rotating shaft. A Manufacturing Datum is a feature used to locate and secure a part for a manufacturing operation. A Manufacturing Datum can use the Functional Datums or would be an entirely different feature. For ...

1

Broadly speaking opening a valve further reduces flow resistance, at least up to point but more travel means greater acceleration and thus greater forces on parts, which is magnified as RPM increases. Indeed with mechanical valves you get to a point where the return springs can't act fast enough and you starts to get harmonic effects where the valves ...

1

There are a couple of issues. Firstly laser cutting may well not provide good enough tolerances or surface finish to reliably produce the fit you need and you woudl probably be better off drilling the holes, possibly using the laser to create a reference mark or pilot hole. Secondly poly-carbonate and acrylic don't really like this sort of interference fit ...

1

Presuming laser cutter and not laser printer, the project you suggest would be most effectively approached by creating test pieces. With 5 mm thick acrylic, there are enough variables to make it difficult to provide certain answers. Cast acrylic behaves differently from extruded acrylic. High power lasers are able to use higher travel speeds than lower ...

1

One possible issue is galvanic corrosion. In certain conditions, if dissimilar metals are in contact with each other the more electronegative metal will corrode at a greatly accelerated rate, effectively the same situation a a metal/metal battery. This can be a particular issue if you have steel studs or other interests in a non-ferrous casting. Indeed ...

1

Precision and Accuracy are independent. As Andy has stated, accuracy refers to the ability of the device to measure as close to the absolute value as possible, whereas, precision refers to the closeness of the values in repeated measurements. Precision depends on repeatability and reproducibility of both the device and the measurers, assuming all other ...

1

0.01 of a mm is pretty tight by any standards, for example a typical jobing lathe might be graduated in divisions of 0.025mm. So 0.01mm is not impossible but certainly not trivial. This level of accuracy is also getting into the realms where thermal expansion and cleanliness of surfaces become significant factors. To put this into perspective a 200mm ...

1

Comments: Do not specify manufacturing methods; what method is used is best decided by the shop depending on what tools they have and what they want to do with the job; the number of parts ordered will have a big effect on their approach. In general, you should never try to tell a machine shop how to do their job, because they know MUCH more than you do ...

1

Effective sharpness depends on both the angle of the cone and the geometry of the very edge/point. In this case it sounds like you aren't aiming for very deep penetration into the surface so the tip of the point itself is likely to be the key factor. You also need to consider the ways that a sharp point wears. In general this can either be that material ...

1

Aluminium rubbing on aluminum generally will wear very rapidly. You generally want some sort of plastic bushing to reduce friction and wear. (Like with luggage handles there's just a little piece of plastic between the tubes) you should also have a bushing for the other end of the joint (the one inside that's not visible.) You should do a beam analysis to ...

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