Category: Part

It’s All Over!

When “All Over” is applied to a Profile of a Surface, it pretty much defines the entire shape of a part in every direction.

ASME Y14.5M-2009 has been out for a little while now (after almost a year’s delay).  There are significant improvements and clarifications.  One addition in particular caught my attention, the ALL OVER symbol.  When applied to a Profile of a Surface, it pretty much defines the entire shape of a part in every direction (not just ALL AROUND which applies to the profile of a surface along a particular plane).

The symbol is either a double circle at the vertex of the associated bent leader, or the words ALL OVER placed immediately below the feature control frame.

ALL OVER symbols

The symbol indicates that a profile tolerance or other specification shall apply all over the three-dimensional profile of a part. It is applied as “unless otherwise specified” to allow for other existing dimensions and tolerances to take precedence.

ASME Example

The advantage of using this symbol is that it provides control of surfaces over an entire part without regard to part orientation, thus allowing us to directly reference the CAD model as basic and fully controlled, while still detailing critical dimensions and tolerances.  This may help companies better parts where they rely on the CAD model to provide complete specification.  In fact, where a CAD model is declared basic, companies may be able to effectively place the Profile of a Surface FCF with the ALL OVER symbol right into their drawing title blocks along side other tolerancing information.

Enhancement Request

So, I am teaching the students how to reuse pre-existing data in SolidWorks.  The project is using a Truarc – E-Clip retaining ring. Cool stuff – Toolbox has the Truarc catalog to just drag and drop.  Toolbox Pull-down has the groove generator with the intelligence to select the correct groove size/feature for the Truarc E-Clip by having the user just select the shaft surface. Awesome stuff right?  That is until you realize that the dimensions, relations and tolerances have to be applied manually.  All the information is there so why doesn’t SolidWorks just dump the info in.Here is the best part, up until that point the students think I am God handing out the solution that they could have used the semester previous.  “Oh man!  We could have used this on 4 project last semester”  Then we DEFINE the groove. “Why would I want to use this tool?” That is the outstanding question of the year!  Why have an incomplete tool.  It ends up being 3 times the work to define the groove than if you just did the revolved cut. No matter if your company is model centric or still uses drawings the size/location dimensions and tolerances still need to be there.  Please jump on this bandwagon and complete the enhancement request to finish this tool.  In theory it is a huge time saver and could potentially help designers and engineers from making mistakes about o-ring and retaining part numbers, sizes, dimensions and tolerances.  –Chris MacCormack

Methodology in making solid models (a discussion)

According to some of my sources (who shall remain nameless), there was a time when SolidWorks Corp thought about making a something like a best modelling practices guide for SolidWorks users.  The idea of best practices is something of which I’ve been critical.  The main reason is that every situation, environment, company and industry is different, with different needs.  Even the same tools in SolidWorks are be used in completely different ways to achieve desired results.

An example of this can be sheet metal functionality.  Sheet metal models may be created in one way for a company that makes cabinet chassis and be used completely differently at a company that makes furniture.  Heck, even within just one industry, different methods may be employed for different scenarios.

Each company should develop their own standard or set of standards.  Depending on the environment and type of modelling, these may be rigid, they may be very general, or somewhere in-between.  Set rules can apply to the models and assemblies.  Rules may even vary from project to project, depending on business needs.  Even non-design considerations come in to play when setting up standards.  Network setup, computing power, PDM/PLM/ERP programs, etc can impact methodology.

All of these variables make it impossible to establish best practices for all of SolidWorks users.  This is likely why SolidWorks Corp has seemingly dropped the idea of providing set best practices advice.

And the June SW Legion Contest winner is… (Part 2)

There are two winners for the June SW Legion Contest.  The official winner (Sandeep Pawar) and the unofficial winner (per the unstated and unofficial though originally intended rules) is Arash Erfanian.   Three individuals produced verifiable scalene ellipsoids with only three elements.  One individual used two sketches and one feature (3 elements total).  Two other individuals used one sketch and two features (also 3 elements total).  These made cleaver use of the scale feature.  After a suprizingly quick game of email roshambo, Arash came out on top, earning himself a CSWSP-FEA test.  Congrats to Arash.  He knows his scalene ellipsoids, and he knows how to play a mean game of roshambo.

As mentioned before, I received 11 submissions.  One submission was of a model that only had one 3D sketch and one feature (2 elements).  However, I was not able to confirm its scaleneness.  The solution was cleaver though; leave it to Matt Lombard to come up with such a simple approximation.  One of the other submissions was a surface model (not solid).  Unfortunately, it had more elements than the solid model submissions.

I don’t have access to the submissions at this moment.  When I do, I will go into further details about how everyone accomplished the goal.  I am not amazed by the variety of submissions.   I was surprizes at some of the methods employed.

And the June SW Legion Contest winner is… (Part 1)

The June SW Legion Contest asked the brave ones among us to provide the very simplest ellipsoid within Solidworks.  It turned out that the rules where a little too general.  In my excitement to announce this contest, I failed to specify that I was looking for scalene ellipsoids, not just any old sphere.  I also left off the detail that I wanted a fully defined solid model.

Due to this oversight, I will be awarding two CSWP tests this month.  One test will go to the person that technically fulfilled the initial requirements.  The second test will be awarded to the person that produced the simplest scalene ellipsoid.

June SW Legion Contest has received eleven entries from ten individuals.  A couple of entries were just for fun.  One was a PDF of a model created in AutoCAD, and the other was a simple sphere submitted by a fellow blogger (who himself is giving away CSWPs, so does not need another one from me).  Technically, his entry would’ve tied with the other entry that used the same method to create a Prolate spheroid.

The easiest way to make a sphere or similar object in SolidWorks is to have a single sketch of an arc that is then revolved.  We have one serious entry that used this method by Sandeep Pawar.  He has requested the CSWP test.  Best of luck, Sandeep, and congratulations!

I have further review to undertake in order to declare a victor for the search for the simplest scalene ellipsoid SolidWorks model among the entries.  I have four very compelling entries which I’m currently looking over.  More details to come.

Different ways to Mate with a SLOT -1

Now we have finished and learned the techniques of making a SLOT, the second question comes up in the mind is “How to Mate with a SLOT”. Again there can be several ways to achieve this and one may adopt the method which he/she finds easy and quick to use. In this chapter let’s discuss about various simple ways of mating with a SLOT.

To use these methods you need a simple plate with a Slot of any size, a cylindrical, rectangular or square part with diameter/width equal to or less than slot width. In this chapter I’m going to use the cylindrical part (pin). I will be covering another discussion on same topic with a square part too.

Start you assembly with the plate inserted as the base part and fixed. You can also use mating techniques to position your plate. Now insert you pin which you want to mate with the slot.

MS1

Method 1: With your assembly opened and both the part inserted, select the back face of the plate and bottom face of the pin. Add a coincident mate between them. You can select front and top faces too. This is to set the initial position. Now show on the temporary axis (View > Temporary axis) to display the temporary axis of the pin. Select the side face of the plate and the temporary axis of the pin and give a distance mate. Repeat this with the bottom face. Your pin is now in to the required position.

MS4

Method 2: Using the same technique as described in method 1, use the planes instead of the temporary axis of pin to give distance mates with the side and bottom faces of the plate. Your planes may vary from the one shown in the picture.

The difference in the above two methods is that in Method 1 the part is not fully define and its free to revolve on its axis whereas in Method 2, the part gets fully defined.

Method 3: This is a combination of above 2 methods. Add a distance mate using the side face of the plate with the corresponding plane of the pin. Now show up the temporary axis if they are not on. Select either of the temporary axes of the slot and corresponding plane of the pin. Add a coincident mate.

Method 4: If your slot width and diameter of the pin and equal then you can use this method. Add a tangent mate between the side face of the slot and the cylindrical face of the second part. Then add a distance mate with the bottom/side face depending upon the location of your slot with the corresponding plane/temporary axis of the pin.

or

Method 5: In this method, RMB on the edge of the plate and select “Midpoint”. Then select the corresponding plane of the pin and add a coincident mate. Then add a distance mate with the bottom/side face depending upon the location of your slot with the corresponding plane of the pin.

Method 6: This is tricky method and I prefer to use this method most of the time. Open the plate and edit the slot sketch. Add these two construction lines to your slot sketch. Now in assembly, select to show the slot sketch. Use the planes of the pin and mate them with the corresponding construction line

 

 

These are few of the methods which I use for mating with a slot. I would be interesting to hear if you more methods or any other method that you use for mating with the slot.