Our teams goal this year is to create simple and lightweight robot because it has been a concern in the past with overextending our abilities. Because of this, we are looking for a fast and effective (sub 10 second) climber because we see the climb ranking point as important.
In discussion today about choosing a climber, a team member brought up the idea of a scissor lift as it can quickly reach tall heights compared to an elevator of the same length and would be lighter. The team quickly decided that they liked it and decided to make this our climber of choice. The scissor lift would shoot up, put a hook on the bar, and then lift the bot up using a winch.
After this some students started researching scissor lifts used in prior competitions as we have never made a scissor lift before. We quickly found many of them to ineffective but couldn’t find much info as to why they were ineffective. Some students are still wanting the scissor lift but the team is somewhat divided. We were wondering if a scissor lift would be viable as a climber and hope to bring info back to the team as to if it is a good idea or not next meeting.
Scissor lifts are generally a bad idea in FRC. If you’re not extremely precise in your construction, all the slop in the many, many joints compound and you get a very floppy system.
Take a look at 3604 in 2016 and 2018 if you’re really interested in effective scissor lift climbers.
Look at 3175 (my team) 2018 if you want an example of many of ineffective ones. It’s not lightweight, and its not really simple. I’d highly reccomend just building an elevator.
Threads about scissor lifts used for scoring were brought up to the team but were mostly dismissed because they used the scissor lift in a different way. We are looking for info on climbing specifically and had issues finding information and asked here.
That’s a red flag. If you’re doing the research now, it means not a lot of research was done to make the decision. The above posts should be shared with the team, along with videos of highly effective, and much more prevalent, non-scissor climbers. THEN you should make a decision.
I will also mention that everyone who was on the team in 2018 and was part of building the scissor lift doesn’t like talking about scissor lifts and we agree as a team that was probably one of the worst decisions, if not THE worst decision we’ve ever made as a team.
That’s not entirely true. Many of the issues brought up are inherent to scissor lifts. Things like machining precision and the engineering/math involved are always involved. I wouldn’t dismiss it that fast.
Scissor lift worked great in Stronghold for us in the First event we climbed early and often, got tweaked and ineffective in the second event. So if you do it beware they can work and are compact and may give you that edge for low bot . BUT they are finicky , wobbly and typically easily bent… we used a slot instead of a hole so once our hook set the scissor would recede from the slot <—free hook release idea
This year low bot is taller than stronghold so evaluate other mechanisms as well. I thing the old adage is mostly true, teams do scissor lift once.
Maybe don’t be demeaning to people who look at ideas that work in the real world and try to make that work on a robot. Consistently successful teams have made scissor lifts work. Do I like it? No, I’m not a fan of scissor lifts, but people might read your post in a way that makes them feel crappy, and that’s not great.
