# Climber in a box help

Hey! We are currently trying to assemble our climber in a box for this year, and as our first year using a climber in a box we are almost clueless. We are trying to figure out how to measure how high we should make the climber and where on the robot to put it. Thanks!

It would probably help to include images of your robot.

1 Like

First, hereâ€™s a convenient CAD model of the climber to reference. Alter the pictured configuration variables to play around with the size of the climber and what it looks like extended vs retracted.

All of the tubes used by the Andymark climber are cut to the same length, so the â€śTube Lengthâ€ť variable in the model applies to all three tubes. There are four main variables that affect how long you should make your tubes:

1. How tall do you need the hook to go to reach your objective. This needs to be measured from the tip (bottom) of the hook, not the top curve of the hook, because that tip needs to go over the chain.
2. How short do you want it to be while retracted? This year, the main restriction is whether or not you want to fit under the stage.
3. Based on the rest of your robot design, how close to the ground can you mount your climber? The closer to the ground you can mount it, the more height you can get while extended.
4. The retracted height of the hook must be low enough for your robot to leave the ground completely when hooked onto the chain. Feels really silly when you design a climber that doesnâ€™t actually climb.

One big thing to be aware of if youâ€™re using the 2-stage climber is that increasing your tube lengths by 1" will increase the minimum height of your retracted climber by that same 1", but it will increase the maximum extended height of the climber by 2". This is because the extension distance is added to by the lengths of both the 1.5" and 1" tubes.

Now, the process for choosing your tube length: Because the tube length is only a single variable, you need to set some boundary conditions. The first one I usually do is identify the lowest down that you can mount the base of your climber. This will give you the most flexibility in length. Then, if you care about fitting under the stage, adjust the tube length so that (retracted height of the climber as a whole)+(height above the ground) is at least 1" t o 2" less than the stage. However, you may need to adjust the tube length shorter than this to fully leave the ground when your hooks are retracted. The other thing to decide this year is whether you want to single-climb only or try for harmony. Harmony requires climbing off center, which means the chain is higher and the hooks need to go up more to reach it.

Finally, the location on the robot is pretty flexible. However, if the hooks are too far away from the center of gravity of the robot, then you may just tip onto one edge of the robot instead of leaving the ground. Thus, putting your climbers close to the center of the robot is usually preferable.

To get more detailed than this, Aaronâ€™s recommendations to post your CAD will be needed.

1 Like

Thank you!!! we will check this out!

Our team is trying to assemble a climber in a box and it seems that we were shipped a disconnected spool? As in we have either end of said spool, but the cylinder in the center that joins both sides was not included. Does anyone know if this is part of a new design or any suggestions to connect the end pieces? Thanks!

Ideally the climber should be as close to robotâ€™s the center of gravity as possible. This is so the robot remains parallel to the ground and does not rotate around the hook and possibly fall off the chain or remain touching the ground.
If you have 1 climber in a box, put it at the center of gravity, if you have two, put them on opposite sides of the robot colinear with the center of gravity. It doesnâ€™t need to be right at the center of gravity, but the closer the better.

1 Like

Thank you!!!

1 Like

Ours also came with the winch spool as two separate aluminum pieces. I believe there is supposed to be a standard plastic 1/2" hex spacer between them when using the 2-stage kit, but I donâ€™t see any resources to find the actual part number they intend. Maybe look for a hex spacer that was overlooked in the packaging?

Side note, Iâ€™m glad it looks like AndyMark is transitioning to 1-piece spools, as we have had problems with the current solution allowing the rope to slip in between the spool pieces and either chew up the rope or cause inconsistency between the two climbers on the robot.