Creating a model by using cutting action simulation
Creating a model by using cutting action simulation
(OP)
I am trying to create a model of a very complicated gear geometry. (Its a face gear) The geometry cannot be easily defined by standard geometric equations.
In the real world, to create this face gear, a spur gear shaped cutter is mounted at right angles to the face gear blank. The cutter is then revolved at a controlled speed relative to the workpiece.
So there is a combination involved of moving the workpiece (roatationally) at some indexing relationship to the rotation of the cutter.
Modeling the spur gear cutter is no problem. Modeling the face gear blank is no problem.
Can the final face gear profile be modeled in solidworks with some sort of technique that resemles the manufacturing process? I am not interested in visually simulating the machining operation. I am only interested in the final model of the face gear.
In the real world, to create this face gear, a spur gear shaped cutter is mounted at right angles to the face gear blank. The cutter is then revolved at a controlled speed relative to the workpiece.
So there is a combination involved of moving the workpiece (roatationally) at some indexing relationship to the rotation of the cutter.
Modeling the spur gear cutter is no problem. Modeling the face gear blank is no problem.
Can the final face gear profile be modeled in solidworks with some sort of technique that resemles the manufacturing process? I am not interested in visually simulating the machining operation. I am only interested in the final model of the face gear.






RE: Creating a model by using cutting action simulation
Use your mold tools to create a cavity in the base part which is the cut you want. Step and repeat as neccesary.
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Crashj
RE: Creating a model by using cutting action simulation
I don't think there is a good way to accomplish this. It is an enhancement request that I have turned in though. To be able to create a sweep cut using a 3d sketch for the toolpath and a solid as the cutting tool. I'm not sure about how Snowcrash is saying to do it, seems like you would need alot of copies of the cutting tool to make it work right and even then it wouldn't be exactly right.
mncad
RE: Creating a model by using cutting action simulation
if you know the number of teeth on the gear start with the mold cavity as SnowCrash stated above but use a pattern of the cavity instead of repeating the process this will save a little time.
RE: Creating a model by using cutting action simulation
Why not take a look at the SW Services and Support site? Login and guide to Support/Downloads/Model Library/Parts/Gears, Sprockets and Power Trans and scroll down to "Bevel2.zip".
This may help conceptualize what you are trying to achieve.
Christopher Zona
Litens Automotive Partnership
Concord, Ontario, Canada
RE: Creating a model by using cutting action simulation
I take you are trying to model an involute. My copy of Dudley's Gear Handbook Second Edition, Dennis P. Townsend, McGraw Hill, has instructions on how to approximate an involute. Check out their section on Gear Drawings. I used their procedure to test 3D CAD packages. It turned out to be an effective piece of software abuse.
Also, I have a copy of Engineering Drawings, by Thomas E. French, McGraw Hill. My copy is dated 1941, so I doubt this is in print anymore. I paid ten dollars Canadian for it in a second hand book store. It has a section entitled "How to Draw a Spur Gear". I have not tried out their technique, so I cannot vouch for it.
I suggest that you look around for some old drafting books. I knew about my Dudley's Gear Handbook. The other book took me five minutes to search.
JHG
RE: Creating a model by using cutting action simulation
RE: Creating a model by using cutting action simulation
I am not trying to produce an involute - thats no problem
EdDanzer
I tried the GearTrax software - it makes a picture but is totally inaccuate to actually machine anything with it - the main problem with GearTrax is that it treats helical gears like spur gears from a calculation point of view which is totally wrong - it looks to me like it was developed by software guys who dont know gearing
To draw and design gears, I use Web Gear Services software http://members.rogers.com/webgear/software.htm but for this problem, I am trying to create an accurate model of a face gear which has some similarities to bevels
krywarick6
I am familiar with the bevel gear example. It is not quiet the same thing that I am looking for. In that example, a loft cut is done using a sketched profile. The sketched profile lookis like it was developed by some other software.
What I am trying to do, is take several of these profiles in small increments of rotation (on the cutter axis) and then do multiple loft cuts just to define 1 tooth of the face gear. It seams to me that some sort of macro can do this but I am not familiar how to do that.
RE: Creating a model by using cutting action simulation
The tough part is figuring out exactly where your guide curves need to be to properly define your edges/surfaces. However, if you've got that behind you, the cut itself shouldn't be a problem.
Jeff Mowry
Industrial Designhaus, LLC
http://www.industrialdesignhaus.com
RE: Creating a model by using cutting action simulation
re: "...the main problem with GearTrax is that it treats helical gears like spur gears from a calculation point of view which is totally wrong..."
I haven't seen GearTrax. Still, I'm curious what you mean by this. Could you elaborate?
http://www.EsoxRepublic.com
RE: Creating a model by using cutting action simulation
Very simple
The standard pitch diameter of a spur gear (in metric units) is # of teeth x module
Therefore if the gear is module 1 with 20 teeth, the standard pitch diameter is 20 mm
In a helical gear, the standard pitch diameter is
# of teeth x module / cos(Helix Angle)
Therefore a module 1 - 20 tooth helical gear with a 10 degree helix angle would have a standard pitch diameter of 20.309 mm
Gear trax would draw the helical gear with a 20.0 mm pitch diamter - which means that the tooth thickness in the model would be wrong because it is taken at the wrong diameter,
RE: Creating a model by using cutting action simulation
Thanks, Spurs.
RE: Creating a model by using cutting action simulation
Regards,
Scott Baugh, CSWP

http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
RE: Creating a model by using cutting action simulation
I learned this through their demo on their web site. Maybe they would send me a full package to look at.
RE: Creating a model by using cutting action simulation
Regards,
Scott Baugh, CSWP

http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
RE: Creating a model by using cutting action simulation
And now for what we call "The Vulcan Conundrum":
If a Vulcan were to conclude that science fiction was illogical, would he cease to exist?
(Just starting the new year off with some fun!)
- - -Dennyd