A small question of agricultural mechanics ...

[Flytox]

[Grelinette]

If I dared I would also put a small electric motor, like on the cart!

[Christophe]

Thank you Christophe for your sketches and simulations. Your pliers are nice even if it looks like they are plasticine!

For the history of the friction forces, the problem does not arise because the end of the pliers is pointed and sinks well into the wood. By cons I am curious to see what will emerge from a simulation with the other system in parallelogram. I tried to understand where the forces are exerted but it exceeds my skills of virtual brain projection!

You're welcome, for plasticine it's just that it's faster to draw freehand than to assemble bars. To try and get your hands on it is enough

For the parallelogram system and the other, give me the dimensions of the arms of the 2 systems and I will see what we can do with Phun.

The modeling will not pose any problem but it will be necessary to find a tip to find the resulting forces in the results because apparently they do not appear in a quantified way ... or I have not yet found how ...

[Grelinette]

Here is a maximum of measures for those who want to make one because it is very practical, especially the blue and orange to catch the logs and carry them by hand.

The other with the clamps is to use with a "tractor" (horse, car). With this one which is doubled (4 clamps) I moved trunks of several hundred kg.

If measurements are missing, ask me and I will give them to you.

By cons Christophe, I do not know how you will be able to compare the 2 systems because the 2 clamps correspond to different uses (logs / trunks) and the dimensions are adapted.

[Christophe]

Great for odds. This is what was needed.

Well what is needed are the respective proportions.
Then we put the 2 at the same grip diameter and we look at which of the 2 needs the smallest tensile force for the same clamping force.

That was your original question, right?

In fact Phun is nice but I think that a calculation by hand with projection of force triangles will be faster to see the simplicity of the 2 systems.

Problem it's been more than 10 years that I have done more. Well it will make me a good exercise

[Grelinette]

By chance, I asked the store where I usually go for agricultural equipment if they had log clamps like the one in the photo with the orange handle ...

The seller looked at the photo with a surprised air, he went to see in his stock and brought me this model at a price of 50 €.

It is curious cr it is the same principle as that which I have at the moment but if we look at the system well, there are 2 parts which have are interchanged !!!
(I wonder if there is a difference in the clamping force)

I have indicated the dimensions for those who want to make one because it looks very simple to make.

and symmetry:
I assure you that when you have tried a tool like this (for those who often carry wood or logs) you can not do without it.
However, the seller barely knew and told me that he never sold any (which is a bit normal if he keeps them hidden at the bottom of their stock!)

[Grelinette]

uh ... after looking carefully, I think it's the same system! ...

Edit: holalala, apparently not, there is still a little difference ...

Well, I really can't see! (I will look better after the nap ...)

[Christophe]

Good Grelinette, I tried the modeling under Phun, I think there is no way to have quotes so it's fucked up. Unless kk1 knows how to do it?

Too bad because it limits the software a lot ... yet it is a feature that would be simple to implement!

Solution: go through a triangle of freehand forces.

[Grelinette]

Good Grelinette, I tried the modeling under Phun, I think there is no way to have quotes so it's fucked up. Unless kk1 knows how to do it?

Too bad because it limits the software a lot ... yet it is a feature that would be simple to implement!

Solution: go through a triangle of freehand forces.

It does not matter because in any case the "log clamp", whatever the system, is a tool which brings real advantages. (Besides, I will also try it to collect large stones).

I will still try to reproduce the parallelogram system which must have been well thought out by specialists.

Out of curiosity, I measure to see if the dimensions are proportional between the small and the large clamp!

[Obamot]

uh ... after looking carefully, I think it's the same system! ...

Edit: holalala, apparently not, there is still a little difference ...

Well, I really can't see! (I will look better after the nap ...)

In both cases, this is supposed to multiply the force exerted by a double lever design. The best is to take a log and try on the spot to see which is the most effective for clamping. But diwouar, yours has traces of oxidation: not good, that you should ... treat and oil ...

Note for a citrus fruit clip it is normal that it is orange