How do I scissor lift?

You may need one of these too… If at first you don’t succeed…

http://ecx.images-amazon.com/images/I/41nhG-WDZ4L.SS500.jpg

Any reason for staying at the 24:36 ratio then? If your lift can lift 20+ Ibs (40 sacks), couldn’t you have lowered the ratio even more to increase speed?

A closer look at a scissor lift lifting:
https://docs.google.com/file/d/0B4gphpJJhHwiLTJPR3dQdmVmYXM/edit?usp=sharing

[https://docs.google.com/file/d/0B4gphpJJhHwib1M4WmJzM3VvYzg/edit?usp=sharing

Sorry for the quality, those were some intake tests, probably around late December-January.](https://docs.google.com/file/d/0B4gphpJJhHwib1M4WmJzM3VvYzg/edit?usp=sharing)

[https://docs.google.com/file/d/0B4gphpJJhHwib1M4WmJzM3VvYzg/edit?usp=sharing

Sorry for the quality, those were some intake tests, probably around late December-January.](https://docs.google.com/file/d/0B4gphpJJhHwib1M4WmJzM3VvYzg/edit?usp=sharing)

Nice! I noticed it went up and settled down a bit, were you using a PID loop for positioning?

It isn’t near that sophisticated. That is actually caused by our elastics. The latex tubing was adjusted so it held the lift near trough height. If the motors were detached, you could gently push the lift up an inch and the elastics would lift it up the remaining distance to trough height.

Hello, i have built a scissor lift for toss up, i have used 6 bars of c-channel (25holes) by 2 for each side, and it folds below 12" (to about 11") and extends to 39", we have a hook system that rotates around towards end of game to get us to grapple onto the bar.

but we use a 1:7 gear ratio using 393 high strength motors and all aluminium robot and it can lift itself up atm … without any intake weight, we are considering a brake of some sort to hold it in position at end of game

Could some one post a close up of the actuation mechanism and the bottom where the bars attach to the chassis or slide. I think that would be the most helpful.

I am away from our robot right now, but Tiger might be able to provide some pictures if their robot has not been torn down yet.

Was this achieved with 12 tooth metal gears walking around an 84 tooth fixed gear? This was a number leonardo and I were looking to confirm.

Also, I have a fairly developed concept for a scissor lift locking mechanism that I’ve spent a good deal of time thinking about - it wouldn’t require any motors, just one-way “gates”. I might be able to post some pictures once I get to the actual construction building…we’re focusing mostly on proramming classes right now.

Sounds like your bot’s pretty far along! Keep up the great work!

I need some help here… Today our team built a scissors using C-Channels and aluminium bars at a 1:5 ratio with 1 393 and 1 269 on each side. However, it wouldn’t even lift when there’s no load! We didn’t have much time to troubleshoot it but what are some possible causes for this? We tried to connect the wire to a motor on the drivetrain and the wheel spun perfectly fine.

Pictures may help in diagnosing your problem.

I’ll try to get some tomorrow is the problem still persists after troubleshooting.