This tutorial goes over using the great freeware software tool Linkage to design a 6 bar linkage concealed hinge for an access shaft cover. The Linkage software is available from David Rector's blog: blog.rectorsquid.com/
@@chrisspamtest You can contact me using my email address in the "about" box. Make sure to send a copy of your linkage file. It is likely that you built a mechanism that would not work in real life and therefore won't work in the simulator. An example is a connector element or link element sitting in the mechanism that is not connecting to any other links - that connector or link is processed in the simulator and gets a simulation error because it's a mechanical part but has no other elements that define where it should be during the simulator. There are no hints because the the simulator has no other knowledge of why you did this.
@@rectorsquid Hi Dave, found your tool recently at work and have been using it, its great. However one quick question: is it possible to make connection points into a motor, but still allow for that motor to move with the linkage the same way the connection point would? Or does it automatically force a motor to be an anchor. Thanks!
This is exactly what I wished I could find. Instead I went brute force to solve my goal. I was making a Murphy bed. I needed the bed to rest at 24” (the height most beds rest at), but simply pivoting the bed up would run it into the low ceiling. I also wanted the head of the bed to be right up against the inner wall (most Murphy beds leave a gap where your pillow or phone could slip down). Furthermore, I wanted the pivot movement to not force the bed to rub along the wall (so I needed everything to pull away from the wall during the pivot). 4-bar linkage was the solution, and I had to drill a hundred holes into scrap boards and planks, to mock up a full scale test. I’d try a configuration, and then change the pivot points. I could not intuit the solution, so I just tried new pivot configurations till I got what I wanted. It took two days. This would’ve been awesome.
I’m sorry that you had to go through all of that trouble to find your solution. I guess it’s true that experience is the knowledge you need just after you needed it. When I was planning this project I thought about using cardboard mockups or trigonometry and a spreadsheet, but it looked like that was going to be really overwhelming. Good luck with your future projects, hopefully one day this will be useful for you.
This was an extremely succinct and well-done video. I love how you explained the exact problem you were trying to solve and showed the complete design process. Please continue to make videos.
Thank you so much for the kind words of encouragement, I'm really happy to know that it was clear and helpful! :-) I do intend to post some more videos in the coming months on similar topics.
Yay! A neat video explaining how to use 'Linkage'! I downloaded it a while back but reverted back to using blocks/layout in solidworks because I couldn't quite suss out 'Linkage'. But thanks to this video, I'm going to give it another try 😊
I'm so glad you're bringing light to this great software! Ive always taken the trial and error approach but would love to learn a more rigorous way to get a ballpark accurate design. What I mean is that you had a general idea of where the points needed to be, maybe from understanding another design or some other avenue. I'd like to learn more about finding those points
Thank you for your comment. I find thang010146's RU-vid channel (ru-vid.comfeatured) a great source of inspiration, maybe not so much for finding initial values for the points, but for defining the basic geometry of how the pivot points are related to one another. In general, I find a helpful approach in designing anything is to first identify any constraints, and then design around them. If you can figure out the name of the type of mechanism you're trying to use you can often find ratio tables on Wikipedia or elsewhere. Happy designing!
Outstanding video! It would be great to have more of your videos showing simple mechanisms, just to get people going and quickly up to speed. For example you said the piston in a cylinder is simple, please can you model that both in the side view and in the front view (so seperate linkage files)?
Thanks for the comment, I had thought that people might find the preamble boring and lose interest. In the future I will be sure to include a more thorough introduction.
I have to say, Linkage solved a problem with a water level sensor that I was trying to figure out. I really suck at mechanics and angles, and math numbers.... sigh.... I thought that my design was simple as it was just a horizontal bar with a gear at one end (to turn a potentiometer) and at the other end, a vertical bar with a float on it that was supposed to move up and down as per the level of the water. Sounds simple, huh!? Well, the problem was that the vertical bar would move back or forward due to the pressure of the float. It would just pivot on the horizontal bar. I was sure that I could solve this with some sort of support bar that would connect to the wall and to the vertical piece to keep it vertical no matter the position of the horizontal bar. I could not figure this out. So I saw a vid on Linkage and figured that this might help out. Well, I couldn't find what I figured would work, but I saw the scissor jack in the samples. That made sense to me. So using the images as a guide and using CAD, I made a scissor thing. With some tweaking, this turned out to be the solution! I made a "T" track for it to operate in. The top part of the T has the top part of the scissors, with 2 bearings. The vertical part of the T is a channel where I have the center of each scissor pair riding, using a nut that rides inside the channel. This is to keep the scissors from also pushing away from the wall due to the float. THIS THING WORKED!!!! I have it in operation right now and it's working perfectly. To move the horizontal arm with the gear-to-potentiometer, I used an aluminum wire that goes to the end of the scissors to the end of the horizontal bar. It just worked without issue. So thanks so much for creating this very helpful program and these instructions/demos/tutorials.
Would be really nice if you could do constraints and dimensions instead of having to math out all the coordinates for the anchors. Big change to the software to do that of course.
Can we use metric dimensions? It's just brutal hearing the constant need to convert fractions into 3 significant digits... That aside, it's cool that you can use simply drawing to roughly place points of interest, and then parametrically do precise placement...
Yes you can use metric dimensions, it's a drop down selection on the home tab of the ribbon menu. Regarding imperial fractions, I would search for a machinist chart online and then at least you'll be able to look them up instead of having to calculate them every time. Hope that helps.
You can simulate more than 6 bars with the software, but as far as I know it's limited to 2D (single plane). To do 3D linkages you would need something like Blender or Fusion 360.
@@stanhartley5311 I want to ask again. so, this software can't simulate in x-y-z-coordinate?. such as make a linkage with spherical coordinate. Thank you.
