"Hooked" on this thread

Technical Technical Discussion
1

Hello from Team 4490!

We are using a ladder-like mechanism to pull ourselves up the tower and we have steel hooks atop this ladder.

If anyone has any hooks which they have used or hook ideas for us to use, it would be greatly appreciated as we are looking for a new design that will not bend as these do. The robot appears too heavy for the hooks.

When I say hook ideas, I am referring to designs or references to websites/forums where there are examples of different hooks to use.

Thank you again for your help!

2

I managed to find a set of hooks that would go perfect honestly. So… I suppose that this thread can now just be used for general discussion of hooks and things of the like?
Just do whatever it is that you do.

3

What is the weight capacity for those? If your robot is 140lb (120 + battery and bumpers) you might bend them.

4

We’re planning on using either one or two of these:

http://www.homedepot.com/p/Tornado-40-lb-Large-Steel-J-Hook-48034/202639947

I think the 40 lb. limit is for the wall anchor not the hook itself. So far we’ve tested a single hook to 100 lb. without issue.

5

We have no real way of properly testing it, so we used a teammate. That teammate being me, who weighs in at ~152. So… There is that. It could hold me up with no bending or any movement at all actually.

I guess that is a start.

6

This is the hook we used to lift our robot up the steel pipe tower in Rebound Rumble:
https://grabcad.com/library/first-robotics-rebound-rumble-hook-1

The model doesn’t show the screws used to hold the plates together.

It was made from 6061 aluminum using a bandsaw, grinder and hand tools. The hook worked fine. A similar hook should work this year.

7

We made excellent hooks on our 2010 robot by cutting them out of 1/4" aluminum plate. A bit of a pain, but with adequate stock you can do a lot of playing around to make sure they’re exactly how you want them.

8

We made a single hook out of 1/8 aluminum and it holds my weight with minor deformation (175 pounds)

9

We found that .125" has too much deformation on a twist, and twisting when you don’t want to twist is far too common in FRC. (Stupid dance music…)

We were also concerned about whether or not .125" would bite into the bar and cause damage that would Red Card a robot.

10

The RUNG is made out of steel. I don’t think an aluminum hook could cause any visible, let along serious dammage

11

If fifteen years of FIRST has taught me anything, it’s that if it looks like it might be a problem, you at least need to consider it.

12

I cannot argue with that!

13

We’re not planning to scale this year, but it seems that the hooks designed for an extension ladder or safety/fire escape ladder are worth checking out.