This year my team decided to use a tape measure climber. While doing the prototype for it we discovered that the tape measure moves from the center of the wheels and drifts to the edge. This ends up with the tape measure coming off the wheels and jamming the mechanism. I have a guide above the wheels to keep it in the same position yet it still drifts and the tape measure ends up jammed against the guide. This will ruin the tape measure over time. If anyone has any ideas on how to improve on this design that would be greatly appreciated. Thank you.
Do you have a picture of your mechanism? It’s hard to suggest improvements without seeing it.
Knowing nothing about your mechanism, I suggest that you check out this video:
great video and one of my favorite youtube channels
If I had 3 words to offer teams trying the measuring tape, they would be “don’t do it”. Those things are way unstable and we worked with the “Fat Max Extreme” which is one of the widest tapes you can buy. If you must proceed, you need a super positive drive mechanism, to engage the tape. Use a very light weight hook and put it on the back. Having a hook on the number side makes the tape even more unstable.
We didn’t try lifting with the tape. We had a 900lb-rated kevlar line we took up with the hook. The tape was the deployment mechanism only.
Trust me, these tapes are so sensitive to movement of any kind. Try other things first!
I have learned from experience that tape measures are not the most stable and strongest thing to use as a climbing mechanic. If you wish on using it check out some of the video in the other replies. Best of Luck!!
One of my favorite channels as well.
Another video to add for reference on this. I am amazed how consistently 1986 was able to get those tapes to deploy with out falling, especially with so much extension upwards and forwards. You can see at 2:18 that there are actually two tape measures per side, so that likely made a significant help in the stiffness of the tapes. As was mentioned though, the tape measures are only for deploying the hooks.
I will reiterate the word of caution though, this kind of mechanism is quite difficult to build. Pre-rookie year our team worked with another team in our area to learn about FRC and rebuild their practice robot for us to use at an off-season event. Additionally, some team members worked on a tape measure can grabber to no avail.
2016 boasts a lot of different climb designs that might guide you to a better solution. Remember to think about your robot height as you look for designs. Height has a lot to do with what designs makes the most sense. Good luck!
The reason I want to utilize the tape measure climber is because my team determined it would not be a priority for us. As a result I needed to make it not take up much room so they would be convinced to put it on the robot. As of now I have a working design that deploys the tape measure and can latch onto a bar. I still need to test how much weight the tape would be able to pull up. My next challenge is making sure the tape is perfectly in the center of the robot because I foresee if the robot tilts in one direction it will put a lot of strain on the tape if it bends.
All the teams with tape measure climbers that I’ve seen have used the tape to deploy a hook with a rope and they winch off of the rope, not the tape itself.
Is it necessary for your robot to not be tilted in order to score? What is required to ensure your robot stays horizontal while it levitates? What is required to ensure your robot stays horizontal while it levitates as your robot evolves? Is it easier or harder to design and build a mechanism that levitates your robot in some other orientation?
Most teams with successful tape measure climbers use this method, but we were able to use the tape itself in 2016 to lift our robot.
We did have the tape measures snap early in our season due entirely to driver error (significantly overdrove the mechanism), which was fixed by double-layering the tape measures on top of each other. I’ve attached a small document I threw together that year describing how the mechanism was set up.
I beg to differ to this: in 2016 we used a tape measure climber that worked phenomenal, and we were extremely proud of it. I can post videos and pictures upon request.
Hey Drew! I believe you were in contact with our old Head Mentor to make our climber in 2016 work! Nice to see you again!
If you don’t mind posting a picture/ video that would be great. For the climber did you keep the tape in the casing it came in? Thanks
Here is a clip of the measure tape climber system my team used in 2016:
It is very similar to what 1986 used as well. The measure tape is doubled for integrity and we used custom hooks on the end. A winch system driven by a window motor drives the measure tape and we have kevlar string attached to the a spool to tow the backside up.
Mechanical issues with the climber varied from the measuring tape kinking to the hooks bending out of place. We never used it in competition because of time it takes to climb, obvious mechanical issues, inability to align in time, difficulty for driver to use, etc.
Verdict: Don’t do it (especially if your bot is heavy).
We have attempted tape measure climbers before. Do not recommend. Very difficult to get right and like to snap and lose stiffness because robots are very jerky.