Wednesday, 1 October 2014

Design Checks for SOLIDWORKS Electrical

SOLIDWORKS Electrical Design Check #1 - Duct Filling Ratio (%)

SOLIDWORKS Electrical Schematic is a powerful 2D software to produce electrical wiring and cabinet designs. However, with just 2D there are limits on how you can visualise and verify your design. This is where 3D modelling comes in to play. With the additional Electrical 3D, you’ll be able to see a detailed finished product before it reaches the manufacturing stage. Also, within the 3D environment, there are tools which can help to aid in your design. For example, when it comes to choosing what size of ducts to use in your design, it usually involves manual calculations or guess work and sometimes it will be at the stage where the cabinet is built before knowing what size to use. With SOLIDWORKS Electrical 3D you can calculate the Duct Filling Ratio very easily.

After routing the wires, select Calculate Cable Duct Filling Ratio under SOLIDWORKS Electrical pull-down menu. Then click on the Calculation of cable duct filling ratio in the Command complete dialog.
To display the duct filling ratio, right-click the on the duct component and select Properties. Within the Part Properties dialog you’ll be able to see the duct filling ratio in the list.



SOLIDWORKS Electrical Design Check #2 – Voltage Drop Calculation for Cable/Harness
How do we calculate the voltage drop?
A simple answer to this question is to use Ohms Law. For most cables the resistance of the cable per meter will be defined by the manufacturer and we can multiply this by the length of the cable. Then apply ohms law Vdrop=IR to give us the voltage drop across the cable.
With SOLIDWORKS Electrical Schematic we can easily generate reports to display voltage drop and power loss across a length of cable or cables in a harness.

The information needed for the voltage drop and power lost calculation:
·         Voltage drop (V/A/km)
·         Length of cable (m)
·         Full Load current (A)
·         Applied voltage (V)
·         Inrush factor
This information will be added to the cable properties.
Important note: For SOLIDWORKS Electrical to generate a report the “Do calculation” box must be checked.
To generate the report go to Design rule check under Project tab. Within the Design rules manager you can add the voltage drop template that you wish to use, it would be a choice for cables or cables in harness. Once the appropriate template has been selected you will be to see the populated columns. To produce a report, select Generate Drawings and within your project documents you’ll be able to see a new report drawing is added.  

Thursday, 4 September 2014

Resetting the SOLIDWORKS registry

Over time within SOLIDWORKS it is possible to make a wide array of customisations to your user settings and also your user interface. It can be hard to keep track of these changes if you are editing them on a daily basis like I do. Also, we all know that system updates have been known to damage registry files that SOLIDWORKS needs to be able to function correctly.
So if you would like to fully reset all of your SOLIDWORKS preferences, or if you have noticed strange behaviour or missing icons since a recent Windows update. One option to resolve your issues it to reset the registry entry for SOLIDWORKS.
Firstly, be very careful when making modifications to the registry as this may cause serious instability on your system. As such, you will need full administrative permissions on your computer to be able to edit them.
The following guide illustrates how to create a fresh copy of the SOLIDWORKS registry for the current user of the machine in a Windows environment. This registry includes the system options and customisations that a particular user has set up. Examples of the types of elements that this controls are file locations, custom toolbars and system options. By creating a fresh copy of this registry, you will revert SOLIDWORKS for the current user back to default settings as if SOLIDWORKS is a new installation.
This process will not work correctly if SOLIDWORKS is currently running, so the first step is to save all relevant work and exit SOLIDWORKS.

The registry is controlled by your operating system and in Windows the process for   accessing the registry is as follows;

Click on the Start button in the bottom left of the desktop and in the search dialogue type ‘regedit’
This should find the regedit.exe program and if you click it from the list, the program will open.

In the Registry Editor window that is opened, expand the folder for HKEY_CURRENT_USER to find the subfolder for Software.

Within the Software folder, scroll down to find the folder called ‘SolidWorks’ and expand it. This folder contains multiple folders that control different aspects of SOLIDWORKS on your machine. There are separate folders listed here for each different version of SOLIDWORKS that is installed on the machine. In the imager to the right, you may see that I have multiple versions (2012,2013, and 2014).

It is always advisable not to make permanent changes to the registry without first checking that they will not damage your system. As such, at this point you can right-click the folder that represents the version of SOLIDWORKS that you want to reset (in this case 2012), and select to Rename the folder.

Rename the folder to something recognisable as shown in the image to the right by adding a suffix to the name. This ensures that the folder will not move when the folders are next sorted alphabetically.

Now that the Registry folder for that version of SOLIDWORKS has been renamed, when the software is next started and attempts to read the registry it will be unable to locate it. This forces SOLIDWORKS to create a new registry folder with a fresh set of the default registry keys in it, essentially resetting the software options to what they were when SOLIDWORKS was first installed. When launching SOLIDWORKS for the first time after renaming this registry folder, you will be asked to agree to the end user license agreement and treated like a new user.

If you would like to check the Registry Editor again at this point, either by opening a new session (as per step 1), or by selecting View – Refresh (f5) in the menus of the Registry Editor, you will see that a new folder has been created with the same name as the original folder that you renamed.

This is an important point to make because having the new copy and the original renamed folder allows you to revert back to the previous settings should the generation of a new registry folder fail to solve any issues, or if you would like to revert back to your previous settings. The process for reverting back is very simple. Ensure SOLIDWORKS is closed, delete the ‘new’ registry folder created in the above steps, and then rename the original folder back to its original name.

Wednesday, 6 August 2014

How effective is your insulation?

As an applications engineer, I’m often asked by customers to give advice on how to test designs using SOLIDWORKS. One of the most recent examples that demonstrates how quick and easy SOLIDWORKS makes this process related to testing how effective a layer of insulating material for an oven was.

The customer designs and manufactures insulation components to be used in industrial ovens and wanted to assess how effective those components were ate shielding the outer surfaces of the oven from the temperatures achieved within.

SOLIDWORKS Simulation Professional gives you the ability to run a Thermal analysis which can be carried out under a large range of conditions and on complex model geometry. But without the lengthy operation of setting up and running an analysis on a complex fully accurate model, here’s a tip on running that all important first test to see if the components and the material properties meet some basic criteria.
Firstly, simplify the study by only including what you have to for the moment.

I have done this by only including what I am interested in with regards to heat transferring from the inside of the oven to the outside face. This leaves me with as sandwich of materials representing the internal wall of the oven, the layer of insulating material and then the outside skin of the oven.

By reducing the information that you are including in any simulation study, you will in turn reduce the complexity of the study and therefore the time taken to mesh and run the study. Also, with less geometry to consider, the mesh used to describe your study can be made from smaller elements.

The next step after generating a suitable model for your study is to create the study (or mathematical model) itself.

If you haven’t already, make sure that your SOLIDWORKS Simulation add-in is turned on by going to Tools – Add-ins.

SOLIDWORKS Simulation is fully integrated into the user interface enabling you to dynamically move between modelling and simulation without skipping a beat.

On the Simulation tab on the command manager simply choose to create a new study and select the type of study that you would like to perform. Depending on the level of Simulation package that you have, only the study types available to you will be shown at this point. For this example, I would like to perform a Thermal study.

 A study tree is generated in the feature tree / property manager area of the user interface and this allows you to keep track of and modify your study. To speed things up even further, most functionality for controlling and running your study can now be accessed by right-clicking the relevant item in the study tree.

 All of my materials have been transferred over from my SOLIDWORKS model including the customer material properties that I have added for my insulation material. Also because my basic layers of material are all coincident, they will automatically have a bonded connection defined in the study.

For this particular study, I would like to test the oven when it is running at a temperature of 210 degrees Celsius over the period of an hour and it will probably take a few minutes to heat up. SOLIDWORKS Simulation Professional gives you the option to change the properties of the study to make it transient and to specify both the overall time and the increments to be tested by right clicking the study and choosing properties.

I've chosen to run the study for 3600 seconds at 60 second increments.
Now what I need to do is apply the variables to my study. By right-clicking the Thermal Loads section of the study tree, I get the options to add Temperature, Convection, Heat Flux & Power, or Radiation values.

To start, I would like to define what temperature the components are at the moment. To do this, I’ll create a temperature load as an initial value for all solid bodies of 25 degrees Celsius.

 I’ll then represent the heat on the inside of the oven by adding a Temperature load to the face that represents the inside of the oven and setting it at 210 degrees Celsius. But as I said, it will take time for the oven to achieve this, so I’ll click the edit button in the Variation with Time section of the properties.

Here I can set the time that the temperature source takes to reach particular values. I’ll set this to reach full temperature at 300 seconds (5 minutes).

One last thing before I run the study, I’ll specify that the outer face of the oven is subject to convection into the surrounding atmosphere. This is applied as a Thermal Load onto the outside face.

I’ll select the correct face and then add my Convection Coefficient and Bulk Ambient Temperature. A Coefficient of 5-25 W/m^2.K will represent natural convection into the surrounding atmosphere (i.e. no assistance). So a value of 20 should represent a well-ventilated area. You can also switch unit settings if it is easier for you, but 298.15 Kelvin works out at 25 degrees Celsius.
At this point you can specify any mesh size that you would like. But for this study I will simply use the default mesh size that SOLIDWORKS Simulation generates based upon the physical geometry. To save myself a couple of clicks, I can use the default mesh and run the study at the same time by right clicking the top of the study tree and selecting Run.

Due to the simplified model geometry and using lightning fast solvers, this study takes no time at all to solve.

I can analyse these results using a range of tools including Probe which is accessed through right-clicking the result plot. This enables me to analyse the results on just the face representing the outside of the oven and I can see that the temperature is reasonably low compared to the inside of the oven and I can check this information against my design requirements.

Friday, 25 July 2014

75 Years of Batman


If you’re not a comic book or super hero fan, today might have seemed just like any other day.  However, for those die hard fans of vigilantes, super heroes, protectors of the innocent; today marks a significant day in history; 75 years of Batman.
That’s right, Bruce Wayne’s alter ego, The Caped Crusader, The Dark Knight, The Batman, has been using his technician know-how and martial arts prowess since 1939.  And you may be wondering, why are you reading about this on a SOLIDWORKS Blog Post?

Let’s start with an easier question, one I think all engineers can relate to.  Often within circles of geeky friends, the question inevitably rises, ‘who is your favorite super hero’.  Personally, my immediate response is always, ‘either Batman or Ironman’.  This is usually followed by odd looks from the person asking the question.  Certainly, any other super hero has much greater powers than these two heroes?  But do they?  The interesting thing about Batman (and Ironman) is besides being extremely wealthy, they both are incredible engineers and industrialists.  Think about that for a moment.  Neither of these heroes have any supernatural abilities, just a desire to solve problems and use engineering as a solution.  Once I explain myself, I usually like to followup and mention that both Wayne Enterprises (and Stark Industries) most likely use SOLIDWORKS as a result!

With that, I thought today it would be fun to look at few of my favorite gadgets that Batman uses in his crime fighting efforts.  In doing so I spent some time looking over the last 75 years of tools, gadgets, and iconic vehicles used by Batman, and some of the complex engineering Wayne Enterprises incorporated into the designs.

Batarang: This device is one of the most iconic devices employed by the Caped Crusader.  The Batarang has had many different forms from a simple yet effective boomerang, to remote controlled and GPS guided versions.  Though the basics of the design are simple, the shape of the Batarang might make it less than ideal as a traditional boomerang.  If you look at traditional Australian boomerangs, they follow the design of an airfoil, ultimately allowing for flight.  However, the Batarang traditionally has a somewhat sharp leading edge for subduing foes.  Once you start to consider some of the more modern variations of this device, which incorporate electronics for remote and GPS controlled guidance, this story changes.  Today, aircraft such as the B2 Stealth Bomber and the F-117 Stealth Fighter would be unflyable by traditional human piloting skills. However, with the aid of fly-by-wire and computer controlled assistance, the computer makes 1,000′s of small adjustments a minute, constantly keeping the aircraft stable.  So, it might be safe to assume that the Batarang has found a way to package all of these electronics into a very small form factor.  I am going to assume that they used SOLIDWORKS Electrical and CircuitWorks to accomplish such a feat!

Grappling Gun: This practical device makes appearance throughout history as well, providing Batman with vertical ascension faster than any would be villain could catch him.  The Grappling Gun is one of my all time favorite devices.  In fact, an alternative design even makes an appearance in today’s Technical Blog post where I show how to use gear mates to build the gear-train in the device.
But as for the design of this device, it’s fairly straight forward, and many variants are actually employed today, albeit not in such a small form factor.  The biggest challenges with this device is incorporating a motor capable of lifting not just Batman himself, but quite often rescuing Vicki Vale from danger.  The torque requirements for this small motor would have to be pretty extreme, and in this case, I’m certain that they would have used SOLIDWORKS Simulation tools to calculate the loads and stresses to size and design this motor.

Utility BeltUtility Belt: The all purpose tool used by Batman over the years.  Not so much a single tool itself, but a very compact storage device for my of Batman’s other gadgets, most notably a fan favorite being the infamous Shark Repellent from the 1966 Batman Movie!  This device is actually quite a practical device used by nearly every law enforcement agency around the world, although, most don’t carry around Shark Repellent.  Utility belts come in a variety of sizes and purposes, such as mentioned, law enforcement, construction workers, hiking enthusiasts and many more.  Most today employ attachment mechanisms to allow for complete customization, and I would guess that the ‘hidden’ compartments within the Batman Utility belt are equally customizable.  The challenge faced with this gadget is obviously packaging everything into such a small space.  The perfect solution for this was most likely SOLIDWORKS design software, and heavy usage of Configurations for the many different varieties seen throughout the years.

TumblerTumbler: There are nearly as many vehicles parked in the Batcave as there are movies about Batman.  However, few get people as excited as the Tumbler which made it’s appearance in The Dark Knight.  This vehicle could perform maneuvers reminiscent of a fighter jet, while being a complete land vehicle.  The concept behind this has even had documentaries and behind the scenes series dedicated to it.  So when determining if this vehicle could exists, I think the answer is, it almost does.  SOLIDWORKS customer and Crowd Source Design project Local Motors developed the Rally Fighter years ago, which I would have to say comes pretty close.

RebreatherRe-breather:  This device featured in many of the older Batman films is actually quite a practice device employed today.  As an aid to scuba divers, a re-breather, or a scrubber as they’re sometimes referred to, absorb exhaled carbon dioxide and is ‘recycled’.  This gas then has any remaining oxygen extracted providing prolonged submersion over that of a typical SCUBA device.  A good example of this is the Seaquest Air Source from Aqua Lung another SOLIDWORKS Customer.

But again, Batman with his engineering know-how, as managed to minimized the overall design of this device to be completely portable.  To ensure he there is no lack of oxygen when pursuing villains underwater like in this iconic fight scene, you can be confident that he used SOLIDWORKS Flow Simulation to ensure proper airflow and circulation through the device.

Eyes and Ears: Batman has always had the need to communicate with others.  Whether this be with Boy Wonder Robin, his butler Alfred, Commissioner Gordon, or in recent years Lucius Fox at Wayne Enterprises.  The method of his communication is integrated discretely into the hood that Batman wears to conceal his identity.  Likewise, the hood also provides an array of optical enhancement capabilities that allow The Dark Knight to see in…well the dark of night. This incorporates an array of night vision, infrared and optical tracking.
Like many of the other gadgets discussed here, most of these capabilities can be found today, though in much larger and sometimes unwieldy variants.  What’s makes Batman’s versions so unique, is it’s ability to track information from his surroundings and provide feedback based on these results. Batman can then even relay this information on to the Batcave’s super computer tended by one of his crime fighting assistants where the information can be further processed.  This is ultimately a big buzz word today in the world of Engineering; The Internet of Things. Companies today are incorporating more ‘connected’ aspects into their designs.  Take Nest for example, a SOLIDWORKS customer.

They have developed a series of home devices that are are perpetually aware of their surroundings, constantly evaluating their environment and making efficient decisions.  What makes Internet of Things devices so unique is their ability to both collect data from their surroundings, take that information and make decisions and provide useful feedback to the end user.  In the case of Nest their thermostat monitors movement around the area, decisions the user makes about temperature, and ‘learns’ when people are home, when to turn the temperature down, and up, to save money on utility bills.

Batman’s device on the other hand has been used to gather audio and visual information and provide him with useful decision making feedback.  For a design such as this, you would expect a wide range of SOLIDWORKS products to be used in its design.  From SOLIDWORKS design tools to get the fit, form and function, tools like CircuitWorks and SOLIDWORKS Electrical to develop the complicated electronics and finally tools like SOLIDWORKS Simulation to ensure the design is rugged enough to take a ‘POW’ to the head.

We’ve only covered a handful of creative devices used by Batman and Boy Wonder over the years, and I’m sure many of you have your own favorites as well.  Unfortunately there’s not enough time to cover all of them, but each and everyone of Batman’s tools could be considered an engineering marvel in its own right. So my question to you is, what is your favorite Batman gadget?  Post your responses below!

If you happen to miss the link above, there’s another, more technical post I’ve created over here on the SOLIDWORKS Technical Blog. In this post I show how Batman, or rather ‘CADMAN’ in this case, might design the iconic Grapple Gun.

You can read more posts from  on the SOLIDWORKS Blog and SOLIDWORKS Tech Blog

Thursday, 19 June 2014

When an ‘off-the-shelf’ Spring just won’t do….. Part 2

It’s always great to get feedback and requests for content and following our last blog, we got a request for an example of detailing the end of a spring with some closed coils and hooks or tabs.
Here’s an example of one way that the tools in SOLIDWORKS can be used to create a more advanced spring end including some closed loops and a small tab. The tab can be made as simple or complex as you need it to be, the process would still be the same.


Firstly, I started with some circular sketch geometry centred at the origin of the part to create a Helix. But this time, in the options for the Helix instead of making it a constant pitch, I chose to make a variable pitch Helix. A table is displayed in the property manager and SOLIDWORKS will generate a Helix with a smooth transition between pitch values at the specified revolution counts. It is important to allow for this in the table by specifying a number of revolutions at the same pitch and then a smaller number of revolutions for any change in pitch.
In this example I have applied revolutions 0-3 with a 3mm pitch, then in the space of one revolution (3-4) the pitch changes to 12.5mm. The pitch stays at 12.5mm for 6 revolutions (4-10), and then it reduces to 3mm between revolutions 10 and 11. Finally, there are three more revolutions at 3mm (11-14) to keep the spring symmetrical. You may also notice that you can also control the diameter of the Helix. This allows you to create tapered Helices.

Because I centred my circular sketch at the origin, my Helix is also centred at the origin. This makes it easy to put in a centre line on one of the standard sketch planes as reference geometry.

From this centreline sketch, a reference plane can be added by selecting the line and the end point to fully define the reference plane. This reference plane is to be used for creating geometry that is flat to the end of the spring rather than angled like the Helix.
Next, a sketch can be drawn onto the newly created plane to define the tab at the end of the spring. In this example, I created a centre-point arc based at the origin with no dimensions. This is because I want to relate the arc to the Helix. You will need to rotate your view slightly to be able to select the arc and Helix end points and then add in a ‘Pierce’ relationship to connect the two pieces of geometry.
Next, I added in the detail for my tab at the end of the spring. I have created this all in the same 2D sketch, but it is possible to create a new 3D sketch to allow for any possible tab geometry.
This process can then be repeated at the opposite end of the Helix.

Once the opposite end of the Helix has been added to, the spring is nearly ready. However, at the connection between the Helix and the flat sketch for the tab, there is a change in angle which may cause a small ‘kink’ in the end of your spring.
SOLIDWORKS has a sketch tool that will automatically neaten this up for you with very little input.
Generate a new 3D sketch and go to Tools – Spline Tools – Fit Spline. This tool will generate a single spline curve that mimics the geometry that you select to a tolerance that you specify. By selecting the sketches at the top and bottom and also the Helix curve, and making the tolerance value sufficiently small, the spline that is generated will exactly match the desired spring. Increasing the value of the tolerance will ‘round off’ any sharp edges or corners such as the connection between the Helix and the 2D sketches. In the property manager, deselect the option for ‘Closed Spline’ as this will attempt to close the loop between the 2D sketches.

The resulting geometry is a single spline curve that is fully defined that we can use as a sweep path for the spring. A little tip at this point is to hide all of the unrequired sketch and reference geometry by selecting it in the Feature Manager Design Tree and selecting Hide. This not only keeps your graphics window nice and tidy, it also makes for easier selection when using the spline for feature use.

Next, a reference plane was easily created by selecting the spline and one of the end points of the spline. This generates the ideal reference for creating a sweep profile sketch as it is perpendicular to the spline that we will use for the sweep path without having to work out any angles or measurements.
For this example I sketched a circular profile of 2.5mm diameter.

Lastly, in the Command Manager, choose Swept Boss/Base. Because all of the preparation work has been carried out and only two sketches are visible in the graphics area, it is simply a case of selecting the circle as the Sweep profile and the 3D Spline as the Sweep path to create your spring.

Duncan Crofts CSWE is an Elite Applications Engineer at TMS CADCentre.