Shapr3D 4 Bar Linkages

[@JLake3D]

Thanks Gregg! This is a great example. I’ve had trouble with constraints because I never bothered to learn them since I always got by without them. As my models get more and more complex I keep running into issues because of it. Currently doing a deep dive into the subject and this video has been the most help by far. Much appreciated 👍

[@frodev728]

amazing, thank you for sharing this. I had no idea the constraints could be applied this way.

[@SMW1977]

Thanks Gregg! Could you please help shed some light on how you managed to make the linkage mechanism work from single lines to 3D shape? I tried very hard for days without any luck - as soon as I added extra dimension to the lines, the linkage got broken down :( However, you seemed to have done it perfectly, as you easily showed the "bone" structure with/without "meat" on at 14s of your video. Look forward to hearing from you! Great thanks in advance!

[@greggjohnson621]

Hi Sumi, I’m glad you found the video helpful. To be clear, the extruded 3D bodies don’t move with the linkage (I sure wish they did and I hope they add that functionality) but I think you understand that. If I understand correctly, you’re asking about the 2D lines that I used to extrude into 3d bodies. So not the bones (the central lines of the linkage) but the 2D lines surrounding them. So (assuming I understand your question) what I did was to draw the bones and lock their length. Then when I drew circles around the endpoints of the bones, I locked the circle diameters. Then I drew (let’s call them Side lines) from the tangent of one circle to the tangent of the circle at the other end of the bone, and I set the Tangent constraints to ensure that the Side lines stay tangent. Note that I didn’t lock the length of the Side lines because you don’t want to set anymore constraints than are necessary. That gave me an enclosed area of half the width of the leg, which could be extruded. It’s a similar method, to the way I made the hydraulic cylinder profile at 3:40. Also note that to make the left and right linkages move symmetrically, I had one of those stretchy Hydraulic Cylinder lines on the left and right. I used the Equal Constraint to ensure that when the stretchy line changed length on one side, the stretchy line on other side was equal to it, so that linkage moved by the same amount. I hope that helps. Let me know if you have any other questions. I’m so glad that people are finding this video helpful.

[@SMW1977]

@@greggjohnson621 Thank you so much for your prompt and clear explanation Gregg! It's a shame what we need the most can't be achieved on Shapr3D, at least not yet. Really hope they can add that function soon!

[@paralellosll3849]

Version 5.6 does not allow this with the line tool you have to draw rectangles.

[@K3S01L2]

Is there anyway to make linkages work when the parts are in 3D form? As far as my understanding is working there is not, but I can be wrong too hmm... It would help a lot to find out crashing points etc.. Otherwise you need to imagine the part being in size and shape and only extrude it in end points.

[@greggjohnson621]

Not that I know of currently, other than making a copy of the parts and manually snapping the parts to those new positions. But most things can be developed in this schematic approach in Shapr then modeled out. For more complex 3D interference analysis, I would tend to rig linkages in Fusion360, Modo (maybe Blender?) once I develop the basic linkage schematic here. Then in those apps, the moving parts can be copied as instances so you can show the linkage in both the extended and retracted positions. Then modify a part and see it’s shape update in both positions at the same time.

[@Designer-Makeeva]

👍🔥

[@ProtonFilms_Mark]

Why doesn't the company provide this method in an actual tutorial? I've been on the fence about buying a license because I couldn't find any sort of simulation in Shapr.

[@greggjohnson621]

Yeah this is such a great capability, I’d think they’d promote it. When I posted the link on their help page, the creators of Shapr said they didn’t realize it could do this. I only discovered it because of that guy’s video showing the technique being used in Fusion360. I would add that for me, Shapr3D is WELL worth the license fee. It’s so fast and easy to learn and use.