Control a gripping system with Arduino

Using Arduino Project Guidance
1

My question is very unusual because of my unorthodox method to solve my problem, I hope you can help me by giving me clarity.

I am making a mechanism to tie my shoelaces. That is, small actuators that pull the laces and keep them untied.

My problem comes in the setting. In other words, if I don't want the laces to loosen, I'll have to have the actuators on, that will discharge the battery, so I need a mechanical method to keep it always tight.

I thought of entering the cords through NO solenoid valves and controlling them with the Arduino MOSFET to turn them on and off. But honestly I don't know if the laces will stay snug against the solenoid valve.

Can you think of another simple solution?

2

Take shoes with Velcro fastening :nerd_face:

1 Like
3

Sounds like a good project. I couldn't find a better suggestion than yours.
Industry must use something similar.
Are you able to pull the laces taut? If so, maybe a small mechanical clamp?
Cable tie clamp tool?
[Cable Tie Clamping And Cutting Tool for Cable Tie for Plastic Nylon | eBay](Cable Tie Clamping And Cutting Tool for Cable Tie for Plastic Nylon | eBay?
Good luck, please keep us posted........

1 Like
4

Try double wrapping. You can look up a doctor's surgical knot.

1 Like
5

It's called a screw. Look for a motor with a screw gearing system.

1 Like
6

You could use springs to hold the idle/quiescent position with no power.
Actuators only used to create the ‘knot’, then relax.

1 Like
7

I am looking for an automatic process.

I plan to tighten it with the motors, but the problem is that with the motors I cannot tighten it infinitely because it consumes energy all the time, and you only have to block the cord to avoid having the motor always on.

Interesting, I didn't know something like that existed. (Look from minute 2:17 of the video, I guess that's what you mean), but, it can't be with knots because it's very inconvenient to remove and put on a small scale in an automatic process, it's easier to just grab the knot somehow and not allow it to move.

It can work since the screw stays static (unless you exert a lot of force, it has happened to me before), but remember that it is for a shoe, the screw is very long/big, and at the same time it makes the shoe not can be flexible.

Very good idea, they even sell this type of spring lock for laces, but, obviously, it is manual. Do you know if there is one that is automatic? Like NC solenoid valves, but instead of turning to open and close, turn up and down.

image
image1001×995 125 KB

The problem is that these valves have a very small orifice, I don't know if they exist with a greater space, so that the cord moves smoothly.

Solenoid Valve Specifications and Dimensions

What I'm thinking is:

That the cable is always blocked (normally closed), if I am going to move it that it be energized so that it opens.

But my problem is the orifice of the valve. Do you know about that or another alternative?

8

This problem was solved generations ago with the use of elastic laces.

1 Like
9

If you're going to use linear actuators then the screw itself should be able to just hold the laces in place. If you are worrying about it being to big though you can just have a motor on each lace just wrapping the lace around itself pulling it tighter and if they have a high stall torque without electricity that probably would hold it in place. Unless I'm not reading this question correctly.

1 Like
10

The problem is that would imply friction which would make the motor very inefficient indeed.

A gear train or screw however, magnifies the friction while not greatly becoming inefficient.

A stepper motor however exhibits a holding force - not actually friction - even when not powered. But this in itself provides little holding force except when magnified by gears or a screw as I described.

1 Like
11

No I'm talking about a metal gearbox motor that could even be really tiny like this one https://www.amazon.com/Greartisan-100RPM-Torque-Reduction-Gearbox/dp/B07FVNQZY6/ref=sr_1_2?crid=2FFOJEJCTPM50&keywords=high+gear+ratio+motor&qid=1650248559&sprefix=high+gear+ratio+motor%2Caps%2C81&sr=8-2
and then you could connect a 3d printed connector or something like that to the shaft with a hole in the middle that you tie the lace through so there wouldn't be any slipping from the lace.

1 Like
12

Link corrected: https://www.amazon.com/Greartisan-100RPM-Torque-Reduction-Gearbox/dp/B07FVNQZY6/

Certainly no danger of back-winding that gearbox. :grin:

1 Like
13

Well you don't have to use that motor I'm just saying something like that would be a really simple/basic way to tighten the shoelaces without them loosening. The only problem might be installment of the motor since a shoe would be a pretty awkward place to attach it and if you wrap it from a weird angle there's a risk of the lace unwinding or just it being pulled weirdly.

1 Like
14

Describes the whole project so far. :rofl:

1 Like
15

lol

1 Like
16

I was looking at a similar engine, this one.. But my problem is not the motor, but the grip/lock up of the motor. I can't use a screw because as I already said, it's too big and makes it uncomfortable.

As I mentioned before... I'm envisioning something like a valve that allows the shoe lace to move when it's open, and when it's closed it locks the lace. Although, it's unorthodox, that's why I'm looking for something better. Maybe something like a door jammer, I don't know. I want it to be small and easy to get to.

17

What I am saying is that if you do have a gear box attached to the motor like that because of the high to low ratio, it could provide resistance to the lace without any electricity because mechanically you have to put a lot of force to move the gears. So it turns the shoe lace and unties it and then the pulling force on the shoe lace isn't strong enough to overcome the mechanical resistance the gear set has and so it stays untied. In case you don't get what I'm saying imagine that it takes .02 Pound-force to spin the shaft just by your hand, then it has a gear box that makes it so 500 turns of the shaft is equal to one turn on the output of the gear box so the force it would take to turn that one would be 11.24 Pound-force, with no electricity involved.

1 Like
18

You're right. I was drowning in a glass of water.

The question is: what is the torque of that type of motor that you indicated? Let's say the 30 RPM. Can you help me with that?

Because, if it's not that type of motor, I can also use a small stepper motor.

19

DC 6v motor Something like this should work it has a 1000:1 gear ratio so that's pretty good. I don't know how high the stall torque would be with no electricity but I think it should be strong enough and I've gotten both of those motors before and I'm pretty sure that the 6v motor has a lot more stall torque than the stepper motors, at least when powered off. So overall I can't imagine the shoelaces pulling enough force to pull the DC 6v motors by themselves.

20

I have another question.

Let's say I use a transistor to turn my DC device on and off, can I reduce or increase the power that transistor sends? For example, with a digital potentiometer like this: https://www.amazon.com/-/es/Comimark-X9C103S-Potenciómetro-digital-Arduino/dp/B07Y24CNDL/

And this transistor: https://www.amazon.com/-/es/Bridgold-Transistor-amplificador-aplicaciones-conmutación/dp/B07RZTKTTT/

That's possible? I've never used it, I'll have to look for a tutorial.