lifting arm

[Scooperman]

We are building a lifting arm for our featherweight

http://www.youtube.com/watch?v=uMU7kG7yFY8

We need to build it out of metal, thinking steel, but how thick should it be (can get it angle ground at work if not too thick). We will also need some for the front and bottom to help lift things, how thick should that be and what is the best way of joining it to the arm?

I have tried to search the forum but didn't find anything. All comments welcome, as long as they are nice.

Thanks

[Ellis]

Re: lifting arm

For the main arm bit you may want pretty sturdy steel, most likely box section (as it is cheap). You can get flat steel in quite good thicknesses, but that is only strong in one direction. Angle steel (known as angle iron I think) may be a compromise, as again it can be found cheaply in good thicknesses, and it is rigid in all directions. In truth, anything will do, if thick enough or enough of it. Worst comes to worst, build it as you think fit and bash it about a bit. If it bends, it's not strong enough!

As for the actual scoop bit, depending on how it is supported, you could have anything from very thin steel to solid plate. Again, it's a matter of just thinking about it a little.

On Tormenta's lifter, we used 2cmx2cm box steel, I believe about 1mm wall (maybe a little more) and that got absolutely crumpled by a single hit from NST. Take from that what you will.

The strength of the lifter isn't only in the material, but also in the mounting. With the design in that video, a hit right on the front of the arm would put huge stress on the rear of the lifter.

You also need to consider weight. Thick = heavy! And the more weight the actuator has to lift, the less potential lifting power you have. Touching on that, the actuator seems to be quite a fast one. Faster generally means lower power, and on that lift angle, I am not sure if it would have the grunt to lift a featherweight. Easy enough to test, using either math or something heavy! Then again, I have no idea of the power output of the Gimsons.

As for joining, nuts and bolts and/or welding.

[ewan]

Re: lifting arm

That actuator will have no problem at all lifting a feather :wink: