Should a scissor lift be slow and extremely sturdy or fast and slightly unstable?
Ah, the age old debate of speed vs effectiveness. I think this one would be more up to your driver’s style. Does your driver want something that will be consistent but slow or fast but occasionally like hitting something with a 10 foot pole? Personally, I would go for slower and more consistent but I’m also assuming it wouldn’t be unbearably slow to the point where it wouldn’t be competitive.
Ultimately, I would prefer sturdy over fast, but not to the point where it really, really slow and you can’t get much done. So I would say make it sturdy first, then work to make it faster.
Personally, I think that the whole point of having a scissor lift is to have a stable linear lift. If you wanted speed,there are other options that are faster than a scissor lift.
Something to keep in mind, because of the one skyrise section capacity limit, if you’re going to build the skyrise and cap it with cubes in 2 minutes(one match), then you may want a fast lift because thats lifting the lift up and down 7 times just to build the skyrise.
+1 to this.
However, when carrying 3-4 cubes, the added lift capacity can score you an entire large post. You may have a trade off for lift capacity versus speed.
I do agree with this as well
I think that the debate of effectiveness vs. speed largely depends on what you want your robot to be able to perform. After some game analysis, my team decided that the best approach for the skyrise is to have a fast lift because if your skyrise capacity is strictly one section, then the limiting factor becomes lift speed. On the other hand, for cubes, since the poles are so high up, having a large capacity and lifting slowly/reliably will be effective for optimizing cube points.
Reliability would also be a big factor. As a rule of thumb, lifts that are more sturdy tend to be more reliable. However, if you could construct a fast scissor that had the same reliability as the sturdy, slow version I would go with that. I agree that instability can be very problematic, but as long as the instability isn’t detrimental to the robots performance, I would go for speed and efficiency.
In my opinion it would behoove you to make the lift as sturdy as you can. However, you’re probably going to want to gear the lift for high torque and make it so that you can hold multiple cubes at once and score them without accidentally capping.
Well, you can be a bit of both. Have a super-sturdy base, and a low gear ratio. It’s sturdy and kinda fast.
NOTE: The lower the gear ratio, the more motors you may need to make the lift go up.
Good thought but question is what is the difference between fast and slow–an eight bar might be able to do it in 2 seconds whereas a scissors may take 3 for a full extension but you are only going to full extension once or twice in those seven lifts. There are no ideals or perfect lifts. I think regardless of the lift the important thing is reliability and then practice as a well driven reliable slow lift will almost always beat an erratic quick lift being driven for the first time the day of the competition. Quick though is a good goal but build it stable and reliable first and work on making it quick.
I would definitely go for slow and sturdy, unless you can make it fast and sturdy. Making your c-channels vertical instead of horizontal. That DEFINITELY helps it stop from swaying. The only problem is that one side may go up or down faster/slower than the other side.
When you say C-channel vertical versus horizontal…can you post a pic of vertical c-channel on a scissor lift?
This is it from a birds eye view
The top and bottom c-channels is the way most people make a scissor lift (Horizontal). The middle c-channel is a good way to make the scissor lift stronger (Vertical). Sorry if it caused any confusion.