SC-Motion, a motion and dynamic simulation addin inside SpaceClaim has abilities to perform motion (kinematic) and dynamic simulation on SpaceClaim assemblies. The motion at the joint can be a rotation or a translation. These can be supplied as Equations as well, which is covered in the tutorial below (The embedded tutorial file can downloaded here )
A video with example motion equations is below. (The video can be downloaded here )
All the SpaceClaim assemblies and the corresponding motion equations can be downloaded here. The zip file further contains six zip files. Each of these contain SpaceClaim file and a .txt file with equation (for reference).
SC-Motion is capable of a lot of things (kinematics and dynamics) and we have been adding new features every now and then. Our latest update is to trace a point on a link as it moves in a simulation. One can also use a custom point to plot kinematic data (position, velocity and acceleration).
In this tutorial, we are going to see how to trace an ellipse (and circle) in an Elliptical Trammel assembly. Please follow the steps below:
Insert “Origin” (User Coordinate System or a Marker) on handle. By default, the origin is listed at assembly level. Rename it as “UCS1” and move it to “handle” by dragging and dropping it.
Start “SC-Motion”. UCS1 is listed as a marker under Components>Handle.
Right click on UCS1 and “Enable Trace”. Optionally trace color can be set.
Simulate (with defined joint rotation) and see the trace drawn during the animation (It actually draws an ellipse, hence the name)
To add more tracepoints, go back to SpaceClaim and insert another “Origin”. Rename it as UCS2 and move it under Handle component.
Come back to SC-Motion, UCS2 is automatically added under Components>Handle. Right click and enable trace.
Simulate and animate and now you can see an ellipse and circle drawn together !!!
More tracepoints (in the form of markers) can be added.
Plot of these custom markers’ origin can be seen in the form of their position, velocity and acceleration.
The assembly file with trace markers enabled can be downloaded here.
This tutorial shows how to assemble Worm Gears (that are imported) in SpaceClaim. These are typically used for very high reduction of speed in shafts (hence very high gain in torque) when the space is limited. The axes of shafts are skew and the angle between them is usually 90 degrees.
Update (July 20, 2012): Considered number of starts/threads in the worm in the equations.
When a worm gear assembly is imported inside SpaceClaim, we need to define Gear Condition/Constraint between them, which is done by selecting two cylindrical surfaces. The main task is to find out the radii of these mating cylinders (also known as Pitch Radius). The following diagram shows the equations of determining the radii Rg (Radius of gear) and Rw (Radius of worm) of the two cylinders, given the number of teeth in the gear(Ng), number of threads/starts in the worm (Nw) and the distance between the axes of the gears. We have two equations with Rg and Rw and solving for Rg and Rw is simple.
The revolute joints (consisting of a Align condition + Tangent condition) are defined so that worm and gear have a freedom to rotate (degree-of-freedom) about their axes.
The pitch cylinders are determined in the form of surfaces (which do not add up to the mass of the components)
Gear condition is defined between them.
Worm is rotated and the gear rotates due to meshing.
Go to SC-Motion. Gear conditions are made use of in the solver and simulation is done.
The SpaceClaim assembly file (with Gear condition defined) can be downloaded here.
This tutorial shows how to assemble gears (that are imported) in SpaceClaim. The type of gears considered is “External Gears”. These are typically used to increase or decrease the speed of shafts. Usually, one of the gears has lesser number of teeth (higher RPM/Speed) and the other has larger number of teeth (lower RPM).
When gears are imported inside SpaceClaim, we need to define Gear Condition/Constraint between them, which is done by selecting two cylindrical surfaces. The main task boils down to finding out the radii of these mating cylinders (also known as Pitch Radius). The following diagram shows the equations of determining the radii R1 and R2 of the two cylinders, given the number of teeth in the gears and the distance between the centers of the gears. We have two equations with R1 and R2 and solving for R1 and R2 is straight forward.
The revolute joints (consisting of a Align condition + Tangent condition) are defined so that gears have a freedom to rotation (degree-of-freedom) about their axes.
The pitch cylinders are determined in the form of surfaces (which do not add up to the mass of the components)
Gear condition is defined between them.
One of the gears is rotated and the other rotates due to meshing.
Go to SC-Motion. Gear conditions are made use of in the solver and simulation is done.
The SpaceClaim assembly file (with Gear condition defined) can be downloaded here.
Today, folks at SpaceClaim (Rich Moore, VP, Business Development and Bernard Beulow, VP, Corporate Marketing) informed us that AR-CAD has been listed as a solution partner of SpaceClaim. Solution partners are the companies whose software as addin/plugin extend the basic functionality of SpaceClaim Engineer.
As per SpaceClaim website,
SpaceClaim has formed strategic solution partnerships with the following companies to enhance the company’s 3D Direct Modeling software. These solution partners have bundled SpaceClaim Engineer with their software in order to to offer a specific solution to the market.
Do try out SC-Motion, our motion and dynamic simulation addin for SpaceClaim. For a brief overview of SC-Motion, go through our earlier blog post.
GrabCAD is a very good resource to share CAD models and is a bliss for engineers like us. Most of the CAD files we deal at AR-CAD are the assembly files which have some motion in them. Of late, we have been using a lot of their models in our work. In this tutorial we do the following:
SpaceClaim has a distinct advantage that it can import and export files of almost all CAD formats. This lets us import CAD assemblies already available at websites like GrabCAD and use it in SpaceClaim. In this tutorial, we have done the following:
Imported a Solidworks assembly of Backhoe mechanism in SpaceClaim, which we got from GrabCAD.com (By Babak)
Defined Assembly Conditions/Constraints between different parts
Start SC-Motion inside SpaceClaim, which is a completely integrated addin for motion and dynamic simulation.
Brief overview of SC-Motion user interface
Set Joint Translation (Simple Harmonic Motion) to three linear actuators
Set/View Mass and Inertia properties of parts (The tutorial was recorded for SpaceClaim2011, which did not expose mass and inertia properties through its API for us. The values were entered manually. Starting from SpaceClaim 2012 version, they have been exposed. So, in SC-Motion 2012 version, these values are populated automatically, which can be modified for a manual input.
Define Gravity for dynamic simulation
Perform Dynamic Simulation and see the animation.
View and analyse plots of the forces required at the actuators to achieve this motion (This is called inverse dynamics). By doing so, we can get an idea of the maximum force that is required at each actuator and accordingly suitable actuator from the market can be used in actual.
We hope the tutorial would be useful for people to get started with Dynamic Simulation inside SpaceClaim.
SpaceClaim is a very good software for modeling and is a pioneer in Direct Modeling. Since SpaceClaim 2010 version, it has assembly constraints/conditions using which parts can be modeled into an assembly. The best part about SpaceClaim assembly is the ease with which one can restructure the assembly tree. Once can literally drag and drop solids from one part to another and similarly parts can be dragged and dropped between different sub-assemblies.
Another plus point of SpaceClaim assembly is the way one can move around a particular part and see the effect of its movement on the whole assembly. This can be useful for basic kinematic analysis to determine if the assembly is working as expected or not.
Of all the tutorials(video!) we have watched, we hardly found a set of tutorials which cover creation of a simple SpaceClaim assembly from scratch. We have gone ahead and made the below three video tutorials for people to get started with Assembly modeling in SpaceClaim. The third tutorial in particular is on using SC-Motion, which is a motion and dynamic simulation addin for SpaceClaim.
1) How to model parts in SpaceClaim in an assembly, from scratch ? We have taken example of a Slider-crank mechanism.
2) How to define Assembly Conditions/Constraints between the parts ?
3) Motion and Dynamic Simulation of SpaceClaim assembly using SC-motion.
We hope that watching all the above tutorials would help people to understand the SpaceClaim assembly modeling.
It has been some time since we released SC-Motion2012 for SpaceClaim 2012 version. One can perform kinematic and dynamic simulation on SpaceClaim assemblies, without going out of SpaceClaim to any third party software/addin. It works completely inside and works seamlessly within SpaceClaim.
An overview of SC-Motion2012 can be viewed below.
SC-Motion2012 can be downloaded for free and used for 30 days for evaluation. One can purchase a full version by contacting us or their SpaceClaim reseller.
