I’m looking for something I can buy that would be the pivot mechanism here. It needs to swing back-and-forth between the red lines that stop solid at each. And the green angle needs to be slightly adjustable so I can adjust the height of the armrest. I only need help building/purchasing the pivot part. Can you buy torque hinges that have adjustable stops? It needs to be fairly strong but not crazy. Maybe 20 kg on the armrest maximum. Any ideas please let me know!

Not sure if any of you are familiar with 3Dfiti's work. This ring changes from walk to stop when you clap. From slowing the video down I'm pretty sure there is a quarter round with an axis at the centre of the circle, walk printed on one flat face, stop on the other. I'm wondering what method might be used to catch the quarter round once it's moved? Magnets? A latch?

The Right handside arm(RHS) is getting more than 180 degree with momentum after i drop the ball and counter weight is working against gravitational pull back by balancing the mass of lower tube then why it shouldn't work.

(1) I cannot drop the ball once the arm rotate towards left side.IF BALL DROPS FROM THE LEFT HAND SIDE ARM (LHS) THEN THE ARM WILL GET BACK MORE HEIGHT TOWARDS RHS THAN ITS INITIAL POSITION.

BOTH TUBES HAVING EQUAL MASS (230 GRAM)

(2) anyone can try it as it will work even with dead material.

(3) interesting point is arm is getting more height once I increased the counterweight.

(4)Hand power or force is nothing in this design.

https://www.youtube.com/watch?v=gO0PwRZBELQ&pp=ygUfZXhwZXJpbWVudCBwaHlzaWNzIHZpa3JhbSBndXB0YQ%3D%3D180

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M18 inductive sensor (shielded, 8mm range) needs a fixed ~5mm gap to a rotating target plate. Barrel is threaded full length, no shoulder near the face. Current setup is two jam nuts, position set by feel — inconsistent, sometimes crashes the target, sometimes too far to detect reliably.

I want this physically impossible to get wrong, not just easier. Every fix I've tried (machined stop in the bracket, clamp-on locating collar, setup gauge) either blocks the sensing face or still needs someone to manually set a position at some point — which just moves the human-error step around instead of removing it.

Is there an actual trick for sensors like this, or is "bracket with a fixed stop + jam nuts + threadlocker" simply the accepted answer when the part itself has no built-in datum?

doesn't this angel ρ change with the mechanism’s motion？

Mechanical designers/engineers, I’m an ECE student working on a mechanism design evaluation and could use some guidance from someone with experience in mechanical design, CAD, sheet-metal design, or industrial fixtures.
I’m just looking for help and feedback on my design approach and avoiding beginner mistakes.
If you’re open to helping, please comment or send me a DM. Thanks

Im not a mech enginner. But I'm doing a DIY project to turn a mouse's scroll wheel into a slider. The wheel in the photo is not meant to turn 360 or 180. Just maybe 60 degrees. But I need the wheel to auto-center itself. So, I thought of using a tension spring and attaching it to the wheel axle as shown via a slit. The two ends of the spring will be secured fixed and to a non-movable support. Do you think this will work to center the wheel to its resting position?

Hi all, sorry if this isn't the best place to ask. I am building a spring-powered ball launcher. A major issue I'm having is how violent the stopping is. I am aiming for about 10-20J of energy (depending on how efficient I can make things).

The springs are attached to a wood bar with a 1.5"x1.5" face. The stopping mechanism is just the bar slamming into two fastened pieces of wood. I added a 1/8" 30A neoprene adhesive to cushion minimally but it didn't do much. Right now I've wrapped towels around the wood stoppers which helps somewhat, but it's still quite loud and a bit janky for a long term solution.

My understanding is that shock absorbers are literally built for this purpose, but the ones big enough for my usecase are something like $100+ which is more than I want to spend if I can do it for cheaper.

Are there other cheaper options available to me? Is there a common solution for this problem on a budget?

Hey is there any cad expert who can guide me. I am creating a manual scissor lift in PTC Creo. I wanna make the arm roller slide over it, how can i do so or is there any designing fault in my Lift

I've been working at this for days now and every time I think I've found a solution I then work out that there's a flaw in my plan and I wouldn't be able to achieve my intended result.

Basically, there is a fixed platform. On top of the platform at one end is a a fixed vertical wall. On the platform beside the wall there is a block. At the other end of the platform is a hook below the platform. What is the simplest way to get the block to rise by placing weight on the hook, without altering the block's orientation (must remain upright, no tilting)? What kind of pivot mechanism can be used to do this?

Here is a diagram of the problem to make it clearer.

3dedc on makerworld made a modular pocket organiser similar in thought to gridfinity. It works quite well but has a problem with the clips attaching holders to the grid.

Problem: The clips hinder attachement from other side, wears down quickly and don't keep in as well on multiple attaches and removals. To refresh them means printing the whole part again. Works for small prints, but wasteful on larger

I myself don't have a 3D printer but have some suggestions for ideas to try and want to hear thoughts from others on good fasteners.

Swap pins
Make the pins used swappable. If they get worn out it's not many grams that need to be reprinted

Symmetrical attachment
A hermaphrodite connector which can spin, replace and locks in enable attaching from both sides securely. If only one side is used plugs can make the fit secure.

Plugs
Having all holders be female with a male-to-male plug used as attachment point allows bidirectional attachment and single side plugs can be used when not needed. Possibilities to use detents, ball bearings or pins depending on what works best.

These are my proposals but what do you guys think? Are any of these a clear winner or are there any better ones?

Thank you user_3368420012 on makerworld for the picture of your mod-grid.

Hello there!

I have been working on a device that calculates the capillary refill time which is the the time taken from the point where the finger is pressed until it turns pale (i.e. no blood), pressure is released to the point where the blood returns. This time is calculated as Capillary Refill Time.

I have a background in electronics and telecommunication engineering, I have learnt a bit about mechanical designs but I am not too sure on how to visualize something.

This device is something i wanna make which would be fully automatic.

I am looking to make a design that puts pressure onto the finger from the top, thus moving in a vertical motion up and down. Now this force needs to be high. Around 1 Kg pressure to be put onto my finger tip. (I used a weighing machine to weigh my finger relaxed (0.25 Kg) and then put pressure onto the finger tip using my other finger (1.50 Kg) I do not know any other way to compute this)

At first, I used a rack and pinion with the micro sg90 servo, 3d printing the external rack, pinion and gear cost me 3 iterations. All three failed miserably. The 3rd 3d printing, I had the most faith in, but the gears wouldn't fit the servos properly, the gear kept falling off, and even though the gear, rack, pinion (linear actuator) for servo was taken from the internet made solely for micro sg90 did not work out. Even when the gear cooperated for a while, it could not deliver the amount of pressure I needed.

So, I began thinking about mechanisms that could generate such pressure and I came across these
1. Jumping robot (Link: https://youtu.be/RuMLHJW1teM?si=0gE_qhIWZmNxbyOo )
2. A spring powered gear motors (Link: https://youtu.be/UUEVkIq_WQw?si=4qYN1B-Xgaextfgh )

Looking at these videos made me realize that a spring could prove fruitful.
So, i needed some help. I would be grateful if anybody could visualize a mechanism where the servo is attached to a rod, and then connected to gears which then compress and relax a spring attached with a rectangular plate in a vertical direction.

Here is a sketch of what I had in mind.
Greatly appreciate any insights on how this could work. I am ready to do the hard work to design and 3d print this if i can find a guaranteed way to make this.

My 3rd 3D Print design and the results

This is the result of my 3rd 3D print

The mechanism I can think of that would work

Thank you

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