Linkage: Spline and Cam Tutorial
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- Опубликовано: 19 окт 2021
- Splines and cams are mostly working in the Linkage software (www.linkagesimulator.com) and this is a tutorial for creating a few cams. I decided to publish this first try with no rehearsal to get this out as quickly as possible. People are starting to install the beta software (www.rectorsquid.com/beta/link...) and I think this video will be very helpful.
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I am a mechanical educator, found this software unexpectedly by YT algorithm. This really an amazing software. Really handy and easy to draw.
Thanks. I'm glad you like the software. I hope to keep improving it in the future.
Slider options seems to be more realistic. This comes handy during design phase to trace movement of the follower tip. Thanks for adding this feature to linkage program.
thanks a lot ,already download the beta version,excellent work!
Thank you David, excellent feature!
I got the beta, thanks again! Cams are going to be super handy!
That's great. Please make sure to send email if you have any troubles with this beta software. Also feel free to give me feedback about how this feature works. I'm still working on it and there are some choices I made in the test app that I might change.
@@rectorsquid Will do. So far it works great once I sorted out that it is the arm link you need to join the cam to.
Amazing David.
Thanks.
Awesome!David.
Thank you for this addition and any further development of it. The program keeps getting better. I've used previous versions in the initial design of some of my 3D printed toys. Do you do any 3D printing? Cheap 3D printers and software like Fusion 360 are incredible tools for people who like to tinker.
I don't yet have a 3D printer but I have a lathe and a milling machine, along with some welding tools, if those count at all, lol. I guess I'm a bit old-school. Maybe I'll move into the 21st century one of these days but so far, I haven't had anything I wanted to 3D print. I'm glad you like the software.
I love the addition! I do seem to have an issue with the slider jumping to the opposite side of the cam and back in a twitchy way. Am I doing something wrong?
That could be a bug in the software. The algorithm to find the slider position on the cam is a bit weird and complicated and might be getting something wrong. Can you find my email address in the "about" box or in the documentation and send me a copy of your linkage file?
I will do that. Thanks!
I swear I looked for this answer... But I can't find any setting that allows me to add spline to the right click menu you are selecting from... Is there a setting for this?
There are no settings to change the right-click menu. The spline should be there as the last item in the menu. I assume that you are talking about the menu with images of elements that pops up when you right click in the mechanism. Find my email address in the "about" box or in the PDF documentation and send me an email. I want to make sure you find what you need and that will help me diagnose the problem.
It'd be interesting to see a specific cam or tangent slider, where a line segment is used to calculate the slide position, rather than the point, in order to produce more realistic cam behavior. Errors would occur if the slide tries to jump 'up' the cam (such as when part of the cam might catch the tip of the slider), or if it loses contact (as sliders do naturally).
The Linkage program already had a lot of code for creating and manipulating sliding connectors so it was most efficient to write the code using the existing sliding connector features. For cams, having a single point as the follower is also very unrealistic for how people might build real cams so I'm already way off from how the cam design process should work. To go further, a person probably designs the cam shape using timing "marks" and a specific radius at each of those marks (or by doing that and then shaping the curve to match). There's a lot of room for improvement with this feature for sure. I think my next project will be to let users enter times and radius values into some sort of entry box and show those markings so the cam can be edited to match the shape the timing marks define. - Dave
What is the name of the software sir
What about adding Russian to the program?
And subtitles in the video.
I wish I could but it would be a huge development task to add localization to this old Win32 MFC application. There is no good support in the old Windows API for translations and localization. I'll see what I can do about subtitles - I'm don't make a lot of videos and I'm still confused by the subtitle system (I have no idea if my English subtitles would get translated automatically by RUclips).
Uh. I sometimes wonder what kind of math is behind this linkage analysis. I once tried to think about steam engine Hausinger linkage mechanism and how to solve it for sliding valve movement. I was able to do it except two links: radius bar and combination lever both having three joints (and three other moving parts that are used to constrict their movement, one of them being sliding valve).
Naive analysis is like take all points on expansion link and lifting link that have proper distance, 3rd point is free and it's somewhere on a curve. Draw that curve for valid solutions. Now take two points of combination lever: one on circle defined by union link, other on line defined by sliding valve stem. Again draw curve defined by 3rd joint. Point where these curves intersect is 3rd point of both levers. Go from there and find positions of everything else. But it's basically solving four unknown parameters (angles on 3 circles, one linear parameter; or one common point and angles of two rods) of equations which are hard to write down and which contain lot of trigonometric functions.
I would be happy to discuss how the Linkage program solves some simulation problems. I used an iterative approach to simulate three-connection link problems. If you can send me an email, I would be happy to discuss more. I also wrote a few blog posts about this: blog.rectorsquid.com/?s=triad
Thanks for adding this, importing a spline is not possible?Thanks a lot!!
There's no real import of any sort in this software. The best you could do would be to figure out the .linkage2 file format and then create a file that contained the spline. The files are XML and use a 92-per-inch coordinate system, not inches or mm, and the splines are sort of self-documented since it's XML elements. You could create a spline and then save the file to see what it looks like. Then somehow create your own .linkage2 file for the spline you want to import. If there was an import feature, what format would you want to import?
@@rectorsquid Hi thanks for that, had a decease in the family so excuses for the late answer. I think SVG import would be nice, since they are xml also. I can manage though. Want to create a spline for a VAWT whith a variabe pitching simulation on the rotating blades (the cam is stationary, but the blades rotate around the center axis, in a four bar mechanism, so the blades pitch following the cam)
sir,i like linkage,hope you make it more powerful
I hope I can make it more powerful. But I'm working on a Mac version right now so it's not going to change much for a long time.
@@rectorsquid i think a rotate joint need to attach on the motion part, this is important function
there is no spline in my version
You must have an older version of the software and need to install a newer version. You can get to the Linkage information page here: linkagesimulator.com. There is a link at the top to the download page. The latest version is 3.16.14, and it has splines working in it.
@@rectorsquid yes you are correct, thanks. I am currently trying to change a 180° hinge that i have and am kinda struggeling with it. Are there some examples for that kind of thing?
I mean the last version kinda worked but i don't know how to define the start and end position