This is a video from Ri3D team O-Ryon:
https://www.youtube.com/watch?v=5PRBOK4l5xE
They’re using Competition Robot Part’s elevator roller kit:
http://www.competitionrobotparts.com/
I hope to see more great elevators like this one!
Love the simplicity of the lift. I’s assuming your just using weight of mechanism to keep tension on the rope?
Just to clarify, I’m not on the build team.
That being said, I believe they are just letting the weight of carriage tension the rope.
This is almost exactly what we were thinking of doing. Does one kit cover all you need, aside from pullies and arms and such. Or would I need multiple?
Also, did they use wide or square frame?
We were thinking Long would help more with counterbalance.
I’m not on ORyon either, but one of the members was at our design session last night.
Yes, ORyon is just using gravity to drop the elevator and tension the cable because c’mon man, it’s a 3-day old elevator system! :ahh:
The pulley and spool were separate parts from different companies.
I would not recommend pulley-spool approach because the cable will slip or come off the spool.
If you have the time, use a chain or timing belt system to avoid slipping on your elevator.
As for the linear slide itself, there are lots of options that are COTS but most are quite expensive.
We also prototyped with Rev Robotics Rail system and that will offers even more customization for elevator tower geometry than the robot compeition parts system.
How would you set up one of these chain or timing belt systems for use with an elevator? I haven’t been able to think of a way this would work.
Pardon my noobness.
You would make one complete chain run from bottom of robot to a tad higher than the highest point you want to lift to. You then would fasten your carriage to a certain section of that chain permanently. You would then rotate chain up or down and carriage will move with it.
(I am assuming you will be utilizing a single stage or “zero stage” where you just have a frame and then a carriage inside of the frame…the carriage being the only moving level.
-Ronnie
Thanks Ronnie!
I modified Craig Boezwinkle’s drawing of 254’s 2013 climber because it’s essentially the same thing. I also attached an example (25 in 2011).
How did you guys brace the REV structure? I was trying to CAD it up yesterday but i realized that the brace got in the way of the bearing
This is a great example…but if you can stay away from multiple stages…please do.
I second this. As a part of the build team of 103 during 2011 (25 and us build twin bots that year with a few modifications for each of us), I highly suggest staying away from this many stages. The less stages the better. Although this lift did work very well, we had some significant problems with the belt stretching (Because it was so long), as well as some other problems.
Another thing to take not of in this design: The top lift (middle section in the picture of 25’s bot) Had the grabber attached to the bottom of it, so the robot height was significantly taller than it needed to be when fully extended.
Other than that this lift worked extremely well for us, and we even made it to the finals on curie with that bot!
And since there’s one height limit for the whole match, and nowhere to do “the limbo”, a vertical multi-stage elevator for this game is unnecessary. On the other hand, maybe a horizontal one could be useful:
http://www.chiefdelphi.com/forums/showpost.php?p=1424330&postcount=4
While I wouldn’t recommend a cable for use in a string and pulley set up I would highly recommend a paracord and pulley set up.
If your “string” can come off of the pulley then you haven’t selected the right pulley/string combo or haven’t put a shield on it to prevent the string from coming out of the pulley. It is all in the proper selection and/or design of the pulley to “string” interface.
Power down is also easy to do with the string and pulley set up. I recommend a divided drum and a captive spring tensioner to account for the possibility or variability in wrapping on the drum.
I don’t understand why you would think that it would slip on the drum. The “string” should be anchored to the drum so no possibility of it slipping. You should not just wrap the string around the drum and tie it.
Millions of cars on the road today use a string and pulley set up for their window regulator and they last for many years. This method has been used for over 25 years.
Having used a chain driven lift on a number of competition robots over the years and using paracord and pulleys for the Team [REDACTED] Ri3D machine I would never choose a chain driven set up again. It is heavy, a pain to attach to and a pain to properly tension and problematic to repair quickly.
I think he may be talking about a continuous lift in which case you would want the “string” wrapped around the drum a few times (to prevent slipping) instead of anchored.
Does anyone know a source for the delrin wheels from this lift kit? We are interested in fabricating our own roller kit from the CAD files, and we’re trying to avoid lathing our own.
Do you or a team near you have access to a 3d printer? These seem like neat parts to make on them if you don’t have a lathe. Most universities and many highs schools will have 3D printers too if you can’t find one.
Thanks for the feedback.
There are definitely tradeoffs between a chain-lift and cable-lift. Let me see if we can summarize the differences.
Chain-lift:
handles more torque but heavier
needs more structure and pieces to implement
Cable-lift:
lighter but has the potential to slip or snap the cable with too much torque
easy to implement but more prone to failures
Teams can see some of the differences between the robots in Ri3D.
Team Indiana is a Chain Lift
Most of the other Ri3D teams are cord-lift
Competition Robot Parts has found another supplier that should allow us to get more parts out the door beginning Jan 16. Spread the word!