# Tag Info

42

At the beginning of my career (1979) as a design engineer at HP, the mechanical engineer created the part design and then rendered it in pencil on paper, and then transferred it onto sheets of vellum paper held onto a huge flat tilting table called a drafting board which had a precision sliding arm on it with which parallel and right angle lines could be ...

17

In the offices I worked in, drafters were also expected to have a grasp of the trades required to build the thing they were drawing. They'd have some background in welding, fitting, and fabrication. They were expected to draw something that was a) faithful to the mechanical engineer's design, and b) practical to build. We'd often get comments from the ...

13

See the .gif below! EDIT: You may need to enable visibility of these handles if they're not on by default - it depends on your default profile/settings.

12

It's a massively important question. Short response: apply the concept of encapsulation. Divide into subsystems During development, assign design-ownership (distinct from project manager role, although may coincide in a small group) to subsystems, and to the higher level design Define interfaces (mounting, electrical, thermal, plumbing, material flow, etc) ...

7

Let's break it down: 5x - There are 5 of these holes, with the same dimension. You should be able to spot these fairly easily, as any similar holes with no dimensions on them. M4x0.7 - These holes have a Metric Thread, with 4mm outer diameter, and 0.7mm pitch. This is the "M4 Coarse" standard. ↧ 6.3 - The holes are 6.3mm deep. This is the 'full diameter' ...

6

Pitch diameter is the diameter of the pitch circle described by the mid point of the length of the teeth around the gear, as shown in this diagram: The pitch circle defines the point where the teeth of two gears meet: Let's say you have two gears, each with a respective pitch circle diameter of $d_1$ and $d_2$. The distance between the two gear centers, $C$...

6

It approximately means it is allowed or forbidden to have scratches at the place of round. When you are making cylinder surface you can to do it many different ways: milling, welding, soldering. In one case must be strong requriment for smoothness of surface (for example in bearings need to minimize friction). In other cases it is allowed to have scratches (...

5

As indeed answered by Greenonline, the centre distance is the average of the pitch diameters of the two meshing gears, but this is only strictly true when the gears are operating at standard centre distances, i.e. where the pitch circles are tangent to one another. There are indeed cases where two gears can be operating at non-standard centre distances, and ...

5

I think the duties that engineers have to perform are independent of the tools they use. Nowadays there seems to be a trend that everybody involved in a working process, regardless of if we are talking about research and development, design, manufacturing or service, relies too much on CAD (or any other software tools) itself. A good working process, and a ...

5

But I am left with a question I don't have the answer to, nor the resources to answer it. These days it seems most mechanical engineers (at least the ones I know) are really performing the role of both the draftsman and the engineer. IMHO Solidworks (and other similar products) for the engineer today are much like a scientific calculator back in the 1980 ...

4

The answer is that in order to survive and function, the rocket nozzles need to be cooled. How that's done varies with the application, but includes: Liquid Cooling Jacket: The liquid propergols and/or fuels ar circulated through a jacket around the nozzle before being directed to the combustion chamber. This is how the Saturn V F-1 engines and the Space ...

4

The way I would model the component shown on the LHS of your image is like this: Sketch the outer diameter of the circle on one of the home planes, say XZ, with the centre of the circle at the origin. Extrude the circle an equal distance in each direction, such that the XZ plane runs through it's centre Sketch half of a 'nub' on the same plane, with a ...

4

Imagine you were driving a car along the path shown in a cross section view of the radius - you need to make a 90 degree bend, and you need to stay inside the cones that denote the tolerance band. In the first image, you find yourself about to hit the cones, so steer sharply left, then almost hit the other cones, so steer right, left, right etc. In the ...

4

Measure 12.7 from both edges and the intersection gives the radius centre.

4

First, a big (100 or 1000 engineers) project is very unlikely to start from a blank piece of paper. A company like Boeing has designed many planes in the past, and therefore has a pretty good idea how to "guess" an initial design for a new one. One method that works is to start from an initial "guessed" design and refine it. Given the ...

3

It isn't open source, but for students Onshape is free. Onshape runs in the browser so it will work on pretty much any current computer regardless of operating system. It is real 3D solid modeling with good 2D drafting. I've played with it some and it works remarkably well and as CAD programs go is easy to learn. Because it is cloud based, it greatly fosters ...

3

One option is to import the jpeg directly into AutoCad and simply trace the lines you want over the top in a new layer. While this isn't automatic as such I suspect that it may end up being less trouble than going through multiple pieces of software and a your example shows there is a good chance that you will need to do a bit of manual tidying up in any ...

3

TL;DR; Possible but not nesseserily worth it. Introduction Its possible, but it is a bit questionable whether its actually practical or saves you any time. See when you photograph a section you get into measurement, and measurement is hard. Even just photographing that you get a easily traceable image needs some careful thinking about setup. In addition you ...

3

I'm not familiar with the Solidworks equal constraint but it sounds like this should be done parametrically in Fusion. Dimension the first line to a value. Then, dimension the second one, but instead of typing in a value, click on the dimension of the first line. It will set it to something like 'd1' and then if you change your first dimension, the second ...

3

Bottom or left based on what datum? It matters not, really. The end of the shaft visible in the photo is your mounting area. The drawing shows two sets of mounting bolt options. The inner circle formed by the holes in the first ring appear to be (surprisingly) SAE threads, 5/16" x 18 threads per inch, 10 mm deep. The second ring of bolt holes are showing as ...

3

Well I would suggest that you don’t thread one of the items - just have a clearance hole then a locking nut. Then, to get a precise position have a hole with a locating pin - this will ensure the positioning.

3

You need clearance at the bottom of the threaded hole or shorten the depth of the thread. This is to allow for the machining process and clearance for the cutting tool. Otherwise your thread will not be a long as you specified(because the machinist needed clearance, or the machinist will break a tool or drag the tool at the bottom of the hole if they are not ...

3

I think the hint comes from the tab that says SOLIDWORKS in the left column, near the top of the block of actions. It's not visible in this screen shot, but is clearly visible in the video linked in the post.

3

In highway design, this is called a superelevation and spiral transition: https://en.wikipedia.org/wiki/Track_transition_curve The length of the spiral is based upon the design speed. For USA highway design, guidance is provided in the AASHTO green book A Policy on Geometric Design of Highways and Streets. Considering that text is not available for free, ...

3

h11 is the tolerance range. There's a standard shaft/hole chart based on dimension/tolerance. (sorry about the images, I've searched on google but cannot find everything on the same image). h11 is applied to shafts, and H11 is for holes. With your example D4h11 is Ø48mm with tolerance of -0 to -160 microns. The referenced part can be (48-0,000) = 48mm (...

3

This question may be better suited for the software recommendation SE and perhaps could be migrated. Consider that Meshlab meets a couple of your requirements. It's open source and has a comparison capability: Measuring the geometric difference between two 3D models using Hausdorff Distance is a common approach in mesh processing. Many years ago (in 1997!), ...

3

Ok, looking at the "Filleted" file, it looks like you are trying to achieve the following: Yellow = 1mm Orange = 2.3mm Red = 5mm Your issue is primarily with order of operations. You need to do the yellow fillet first, in order to avoid the "sharp point where the two fillets meet" which you mentioned in your comment. The file that you ...

3

"... while minimizing the thickness of the end plate. I don't care about how much material I use." Those statements are in conflict with each other. If the end plate must be flat on the inside, you have constraints on the design. To reinforce the end plate without increasing thickness, consider a web of plates perpendicular to the end plate. If ...

3

Your question is a fundamental problem and does not have a single way to be handled. IMHO it boils down to the management of engineers and designers and is fundamental to the success of a company. IMHO (it might be very simplistic compared to what Jonathan R. Swift might have to offer, since I've only worked in a small company with less than 20 engineers ...

3

We didn't have to ask how to use our tools. This SE is filled with how do I... for Solidworks, Abaqus, Ansys APGL... I guess we spent more time drawing and calculating, versus figuring out how to make software do it. We probably also got a lot less done.

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