Cams are simple to design but oh so versatile - Guide with examples
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- เผยแพร่เมื่อ 14 พ.ค. 2024
- Building on my previous breakdown of over centre mechanisms, in this video we explore cams. They offer an efficient way to translate rotation into linear motion, but they can also be used in other valid ways. In this video, we look at real world examples, and then break down the characteristics across a varied series of designs.
Source CAD for this video: cad.onshape.com/documents/ad5...
Exported plates of parts if you want to print the examples: www.printables.com/model/4902...
0:00 Introduction
Previous video on over centre mechanisms: • Over centre mechanisms...
Maker’s Muse example advanced mechanism video: • This Expanding Mechani...
0:54 Where do we find cam mechanisms?
Camshaft wiki: en.wikipedia.org/wiki/Camshaft
2:24 What is a cam?
2:58 Example 1: Basic
3:47 Example 2: Locking latch
4:44 Example 3: Dial
5:46 Example 4: Dispenser
7:39 Example 5: Automata driven by complex cam profiles
Polar bear with seal (automata) by Amaochan: www.thingiverse.com/thing:405...
11:07 Key characteristics summary
12:05 Conclusion
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Let's not forget that cams are how mechanical sewing machines do all of their non-straight stitches. It can get quite complex with several cams engaging at the same time moving the foot laterally and the feeder forward and reverse. If you ever get a chance to look at the guts of a mechanical sewing machine with interchangeable cams, I recommend it. It is pretty slick.
This is an awesome series. I really wish I went to school to be a mechanical engineer since I getting into 3d printing. The more I create things the more I realize how much that background would have helped me now. I knew about cams but never really went this deep into them and wasn't aware of the possibilities. Thanks.
Don't be sad, be happy you found this (partly?) retired teacher's channel to get the knowledge now! And then, go buy a basic university book on mechanics and you'll be golden 😊
That's exactly the kind of basic mechanics stuff I need! Thank you!!
A trick, I would use, for a satisfying click (at 5:04) with PLA would be to make "high resistance spots" very thin. This way the plastic can act like a spring to provide resistance without restricting the rotating motion as much.
(I will provide a link to a proof-of-concept model when I get to designing it)
I was thinking a detent would work better than a solid cam would in that situation. The solution you described works very much like a detent while also spreading the spring wear to multiple spring sections instead of the one detent.
Unless you are using Pro PLA or some other plastic, I would expect this to accelerate cracking of the housing. I have flat items printed in virgin "first gen" PLA and they are cracking just from the loading force of screws. And this is even through fender washers. In my experience, first gen PLA really requires over engineering to make it stable for mechanical applications.
@@beckoningjinx1119 Thanks for mentioning this! I was looking for this kind of mechanism but didn't know that it was called detent.
Really interesting indeed! Thanks a bunch, Michael! 😃
Stay safe there with your family! 🖖😊
Yeah I love this series. Keep teaching about MOVING mechanisms you can easily fab!
I've only watched a handful of your videos but have loved each one so far. I am not a 3d printer but I have a love for the simplistic yet elegant mechanisms that you explain. I work on Brown and Sharpe Screw Machines from the 40's that are completely cam driven. If you haven't, check them out or if you want, I'll send you some links to wear to watch them work. What they are capable of building is often quite amazing. It is sad but inevitable that they are going extinct with cnc systems. Keep up the great work.
Love these types of videos man. I’m still a student in high school, so these simple, well explained videos are really helpful for my personal projects. I bet your students loved you as their teacher, you are just to good at explaining concepts.
I’ve had the polar bear in a collection forever, time to print it! I love this series, thank you for the clear explanations and demonstrations!
I’m so pleased with how you gave a shout out to Makers Muse at the start because you two guys are the reason that I got into 3d printing and cnc work over ten years ago and most of what I’ve learned I’ve learned from the both of you, oh and Stephan over at cnc kitchen and good old Thomas Sanladerer, again, two guys who really know their stuff and give great advice. It’s good to see two such clever young Aussie teachers sharing their knowledge and wisdom with us all, thank you, I’m so very grateful for all you have taught me and this and previous video about the over centre mechanisms are equally great chunks of wisdom and wise advice. May you be blessed and long continue to teach and guide those learning this amazing technology. I’m personally just having an absolute ball trying to figure it all out, especially now that my Carvera tool changing desktop cnc machine has arrived, toooo cool lol a brilliant machine and the pinnacle of my journey so far from watching the video about a sub $200 3d printer, buying one and then progressing to adding a gel printer and now this incredible beastie that simply does the lot by changing tools as it goes and so far the quality and accuracy are simply total.
Everything promised and hoped for? yup, delivered. So I just wanted to say thanks for inspiring me on this decade long journey that is still only just beginning, thank you
@TeachingTech Nice general intro to cam design. Not sure you are aware but there is an Onshape custom feature called "RectToPolar" that takes a "linear" graph and wraps it onto a circle so you could literally draw the travel profiles you show at 9:00 and have it automatically turned into a cam profile, which can be more intuitive!
The fact that you and Maker's Muse recommend each other frequently is always nice to see. The community is always so friendly, even between such popular makers such as you two.
Great series. Loved the polar bear example.
Excellent instructive video.
Greetings from the Galilee
Best 3D Printing channel on TH-cam, love your vids Michael
Every secondary school in America needs someone with 10% of your skill as a presenter and producer! Bravo, good sir -- you do good work (hobby-passion-expression?) for any audience that can find you ...
Wow. These videos are so good. Even when you’re covering material I’ve known for years, you do such a great job of distilling and explaining the most essential details in a format that is very thorough yet easy and fun to follow. You are a gifted teacher and your videos are such a pleasure to watch.
Absolutely loving this series. Really interesting and informative, and it’s making me think about how I can apply some of these concepts to projects. Thank you.
Great walk-through video as always
Good examples
Thanks for sharing your expirence with all of us 😀
That's an amazing series. Huge thanks for it! Also appreciate the tip to check this polar bear model, not only it gives an understanding of how cams work, but also showcase the possibilities of the printing in a fun an adorable way.
This video is exactly what a lot of people including me need. I know tons of people that have 3d printers, but not the knowledge of how to create functioning parts and relationships between them. I love this and hope more is to come.
As a mechanical engineer, I do like using cams in designs. They are so useful in generating complex motion
Thank you so much! This was such an awesome video. You made subject I've never really understood, something that I now at least understand well enough that I'm excited to experiment with in my own projects. It looks way less complicated than I always thought it was, and I think that is because of your great way of teaching. I've always loved automata, and now I'm thinking maybe I should try to make a simple one of my own.
terrific series, keep em coming
Thank you for this series. It is easy to understand and helpful.
Well explained and put together - great work!!
I loved this, definitely gives me more options during design.
I'm really loving this type of video. Keep it coming!
Another useful video Michael, Great job👍😊
Great video. I teach cam-follower mechanisms at a high school in California. I will have them watch this excellent video.
A series of videos that explain different mechanisms used in 3D printed parts would be very useful. I have looked for similar in the past and found very little.
The CAM profile is very important but so is the follower's profile. Depending if the Follower is flat or rounded or even not-symmetrical will affect the final output.
Very true.
Thank you. Very informative.
Thanks very much, loved the style and content! Im interested in kinetic artworks! Perfectly explained too.
Cam shafts are like works of art to me. There's so much data encoded into them, and it always blows my mind that it's essentially a collection of very precise and complicated functions rendered into a static device. I don't think its a coincidence that the "Algorithm" in Tenet bore a passing resemblance to a car cam shaft.
Any tips on converting the desired motion onto the cam? Probably just a cartesian to polar graph but I've never done it and it'd be interesting to see it done.
“It’s quite useless by itself” best qoute ever! Just about spit my coffee after hearing that lol😂
This new series is an excellent idea! I'm really hoping there will be an episode that would explain how to use a servo motor (max. 180 degrees rotation) to open and close a (very small) plastic door. I just can't figure it out and I also couldn't find anything relevant online. I guess my Google-fu is not strong enough!
One comment on the video: cams do indeed turn (no pun intended!) rotational movement into linear movement, however, while doing this, they also accomplish something else: timing. It's very briefly mentioned in this video at 1:49 and it is also implied throughout the parts explaining the ICE and the bear & seal toy, but I think it deserves a bit more attention :) Just look what else was done using camshafts: th-cam.com/video/lAFMl5bkP5Q/w-d-xo.html
LE: For my episode wish above ChatGPT suggests pulley systems, crank arm, rack & pinion, or lever mechanisms. I still can't picture how it would look and work though :(
Great stuff!
Alot of detent mechanisms use a ball bearing with a spring behind it that pops into a divot at each detent position. A cam detent alone is somewhat rudimentary and awkward. If the perimeter that the cam seated into at each detent position were more "springy", the action would probably be smoother!!!
I was going to say the same, those switches use some form of dedent mech. The cam could work but the tip would need to be made springy with some form of live(?) mechanism.
A lot of the examples shown aren't cams, like that rotating slot for the bin with the nuts is simply a rotating window
Another great example of cams is using three lobes like is used in a rotary engine that is used to turn a shaft.
good format video
For feeders use a screw. Build a cam set the rear they drives an agitator so the feed doesn't clog
Fantastic ideas!
Super video. :D
Cam show with Michael? count me in!
6:52 i'll just leave it here
I used cams to make a self balancing walking biped 3d printed robot . Since you might not like youtube links posted here I will just say search, robothut biped mechanical balance walker robot. As with most of my 3d printed mechanical design I share the files as well in the discription.
Awesome stuff, can I suggest you do a couple DOF examples. I remember there is a matrix system that looks like L*cos(sigma) = y to design a mechanical arrangement
We can think of a cam profile as a sort of instruction or set of instructions for movement. A cam is effectively a program.
Fantastic video!
Could you please review the Creality K1?
Very Intresting,
whats the best way to do square inside a square so they dont jam
Thanks for these great examples.
Thinking about the dial. Would a spring loaded cam lobe get us the desired results without having to fine tune the tolerances? If so, maybe this would be a good use of a print-in-place spring mechanism?
Also, could you instead change the cam to have a complex cam profile and them have a spring loaded follower (like in your later examples)?
Great vid, but was hoping to learn about designing cam tracks and followers as well
I would appreciate any help regarding cam design. In the first example shown in this video, how do we control the duration (in degrees) for which the follower is lifted? I'm assuming it has to do with the radius of the lobe but I would like to know the relation between lobe radius and lift duration. Also does the follower dwell at the lifted height or does it spend most of the duration ramping up and down?
These things can also be used to solve complex math problems, and were even used in military fire control systems! Here is a video that explains this in great detail, along with some other cool mechanical stuff.
Section about cams starts at 4:36.
th-cam.com/video/s1i-dnAH9Y4/w-d-xo.html
Please more of the mechanism and how to design them
I think the dial would work better you made a cut behind the "spring" part, so that it could flex a little more freely
5:27 you need to put a spring on the cam !! juste create a deformation lobe !
@ 6:52 What nuts? _"DEEEZ NUTS!"_ 🤪
i try again i postet in under video 1 but no reply
I love you videoes. but any chance you can show how to build a rowboat that is almost build like a viking ship. with both ends higher then the middel one. and have a thiknes of the rowboat like 1.4mm think . lenght of the rowboat shoul be like 90 mm. hight of the rowboat 16mm on both sides but middle 14mm and with of the rowboat should be 30mm. i tryed in tinkercad and that i cant do it in. so now i like to lea
Some old automatons used cams with complicated profiles so the automaton figure could hold a pen and write a message.
The only cams in this video is the polar bear and your cam with the screw popping up, most knows that pop into places use a detent and not a cam, that window example would be a cam but it's not due to the fact that lobe merely stands in the way and does not force window shut when rotating
your cam switch needs a compliant part at the end of the cam
💕👌👍
i thought *cam* as in *cam*era (this is since the word cam is the first 3 letters of the word camera, highlighted in bold)
6:52 you said the meme
When you make cams, every issue should be solved with a cam
i think the goats woould disagree about subtituting goat pelletes with m3 nuts but i see the principle.
He said "deez nuts" lol, sorry I'm a child. Great vid as always!
How's that basement workshop doing?
Good apart from random no workshop related stuff stacked in the way. No news is good news in terms of the humidity.
Its not the exhaust valve you're pushing. The bigger one is the intake valve.
You are correct, my bad.
The rotating switch was a horrible example to use for a cam because you were relying on the compressibility of the plastic for your snap action. If that was made of any more rigid material, it would not work at all. those switches using a spring action for snapping between the detents... NOT cams at all. Cams are used to facilitate a different or timed movement and occasionally it has uses as a latch to lock into a certain position. maybe if you had cut a slice out of the side of that lobe to give it someplace to flex into, then your switch mechanism might have worked.
did bro really get a 570s
And then the vtec kicked in yo
Cam design is a much more complicade process than this ahahahahahaha
popular demand more like popular beband
What do you mean?
I'm a bit disappointed with the contents. I signed up because I was interested in 3D printing. Mechanical knowledge is for other channels. Of course interesting info, just not what I expected. You don't do much of this kind of content these days. What you would be interested in: Presentation of printers, new motherboards, new solutions, klipper settings, slicing software practices and what's new etc.
Hello Teaching tech and community,
I recently have been trying to push the speed of my 3d printer (ratrig v-core 3.0) and I don't have input shaping. To try and reduce ringing, I thought I would attempt to stiffen the frame. The result was that I added paracord diagonally to the frame like cables to siffen everything, a link to a pdf picture is bellow.
file:///C:/Users/adsik/Documents/Picture%20of%20Ratrig%20V-Core%203.0.pdf
I was wondering if anyone else had tried this, and, if you have input shaping with an accelerometer, how much it reduced the vibrating.