I was thinking about creating a model of a Wankel engine mostly because the geometry is so intriguing. So far, all I have is this animation which was produced mainly so that I could understand the motion: wankel.skp (161.5 KB)
Very interesting. I’d love to see the final modeled version.
Wonderful demo, Jim.
It would make a great teaching aid for showing how SU animations work.
Animation by hiding top a level component instead of using layers.
Be aware of how nested groups and components might show up per scene though.
I would like to see the W.I.P.
Yeah, I already kicked myself for taking that approach … what a pain in the tush. Now that I have an idea of what I want to do, I’ve put component copies in each of 24 layers (12 didn’t seem to be enough). Turning on and off layers in each scene is a heck of a lot easier … especially since I want to add more details as additional components (such as the moving seals at the tips of the rotor).
Here’s my replacement version … I think this would make a better demo than the previous effort. The sad part is that I have to put this aside for a while and attend to my day job
wankel2.skp (2.1 MB)
I wasn’t particularly disturbed by your use of Hide instead of layers in the first model. Your new one is pretty nifty, but I’d like the scene definition to allow my choice of camera angle. (I’m aware, of course, that this is just a first cut.)
I don’t do a lot of animations, but I discovered that the Scene Manager has a Camera checkbox that I unchecked. That’s a really cool feature … I’ve always just stored each view definition with the scenes. I appreciate the tip
Here’s where I am currently: wankel2.skp (2.6 MB)
Making extendable legs animate
One of the questions posed in the forums related to an exhaust manifold and how to blend the manifold pipes. This got me thinking about car engines which led me to modeling a Wankel engine which led me to (belatedly) concluding that I should have stuck to something I’ve actually worked on before. Back in BC (Before Computers), I worked on cars a lot. Total rebuilds were limited to a 1969 Datsun 2000, a 1962 Porche 356B, and a 1969 Ford Bronco 170 straight six. My cousin bought a 1978 Mazda RX-7 when they first came out and it was constantly in the shop. That was about all I remember about it other than not quite understanding the rotary engine which had this wildly improbable epitrochoid movement. So why model a Wankel and not something with which I’m more familiar? This picture explains it:
It looks so much simpler …
While trying to model something I know little about, I’ve discovered that there are many many variations on a theme out there. Some of them are mislabeled, some are not clear with photographic details, some use custom parts. I finally narrowed things down to a Mazda 13B engine which has two rotors and a fairly substantial (if muchly erroneous) amount of information. As a result, I am on the fourth iteration of the annular gear and its recess as well as the second iteration of the stationary gear (which I originally thought rotated). So far, I’ve found very few hard dimensions and, when I do, most of these are conflicting in nature. Most of what I’ve created has been visually interpreted from numerous photographs and a handful of real numbers. In the meantime, I cleaned up the animation and uploaded it to the warehouse:
Fourth generation annular gear insert: Annular Gear 4.skp (402.1 KB)
I’m trying to learn KerkyThea … so far, I’m really impressed with all of the options, materials, lights, camera, even action. Based on a suggestion by my daughter, I imported some downtown L.A. buildings and wrapped a beer mug around them. Adding a tabletop and background gave me this:
A while back, I created a 4" diameter hollow sphere and projected a photo of my wife and myself on the inside. I had it 3D printed in “Full Color Sandstone” which allows the photo to be viewed through a 3/4" diameter hole in the side. I also created a three-legged stand to hold it so it wouldn’t roll around on my wife’s desk:
While working to import GIS shapefile data, I came across the Open Street Map project that supplies map data in XML format. At the time, I put the idea of an OSM importer on the back burner until I had the time and inclination to pursue it. Since I used downtown Los Angeles as the test case for the shapefile importer, I used it once again … here’s the area I exported from the OSM website:
The OSM importer creates edges for everything it finds in the XML file without worrying about whether or not it’s a closed polygon. This allows it to create roadways and parks and other non-polygonal information:
The importer can be downloaded from: https://sites.google.com/site/spirixcode/code/jimhami42_osm_importer.rbz
and the model for the above is here:
I thought I would create a jar with a screw-on lid that could be 3D printed … something simple that wouldn’t take too long, but would still be useful. The jar is 4" in diameter and 4" tall:
What did you call it in the list of items there I like it could I get the drawing to look it over ?
And can it be made with either ABS or PLA . . My last item with ABS was terrible but I had broken Extruder base and did not know it . . Since then I have replaced it with metal frame so it wlil not crack like the plastic one did
If you are asking about the model name in the 3D Warehouse, it’s 4" Jar With Screw Lid (3D-Printable) … you can also click on the link in the image above.[quote=“lynne, post:55, topic:9902”]
can it be made with either ABS or PLA
Since I haven’t actually printed this, I don’t know for sure, but I deliberately designed it with dimensions that should print okay with a MakerBot or similar extruder-based printer. If you’re up for giving it a try, I would be curious to know how it turns out.
[edited] @lynne - I added a second version in millimeters that is 2" (50.8mm) in diameter and height if you want to print something smaller that will consume less material and print time:
Thanks . . I will tell you after my new .4 mm extruder nozzles arrive and I get them installed and the bed leveled to the new Extruder nozzles . . I took the .35 mm off while waiting for the .4 mm to arrive . . So some time this next week I will be able to try them out and see how the jars come out . . Will even make one from ABS or try to . . My last ABS came out badly . . due to broken Extruder holder was like a spagetti holding the extruders in place hahaha
Bit of feedback for you. This is the small one printed in Black ABS. Prints easily. Very accurate fit. Somewhat agricultural for it’s size. Meaning it’s more tractor than sports car. I suspect you could keep nuclear waste in it.
But it’s very strong and durable and very watertight.
I printed this on a fast setting and have given it a once over with some sandpaper. A finer setting and care with finishing and you can have a nice polished finish.
Add a loop to attach a key, print it in bright orange and you have a hideaway boat keyring. Keep money or whatever inside and if you drop it overboard it will float. Even full of water this one floats as the walls are full of air.
I wasn’t sure how thin of a wall could be accurately printed … “err on the side of overkill” is my motto.
Thanks for printing this … I have printer envy
You could lose a couple of mm in wall thickness, but you’d need to test to see what is appropriate for whatever usage.
They are getting cheaper all the time.
I got mine slightly used for 400 Australian.
The same one new for you on amazon 600 bucks.
It has a pretty small build area but is very simple to use with very good results. It’s big enough for my quick work and I have access to a variety of much larger ones when I need them.