Scissor Lift please help!

We have a scissor lift and were thinking of a new way to power it. we had it like this: but it didn’t really work out too well the shaft keeps twisting any ideas?
https://vexforum.com/gallery/files/4/4/1/8/5/9/_409449.jpg
Thanks
If the image doesn’t appear it’s in the robot gallery and my page of images.

It’s a little hard to tell from the picture but do you have the gear bolted to the bar you are trying to rotate, or are you using a lock bar to transfer? It may be helpful to put the bar you are rotating between the two bars that make up the section with the motor on it and bolt the rotating bar to the gear.
Here is a diagram that better explains this … https://www.dropbox.com/s/qpv0o1xdpii0zug/chinese%20scissor%20lift%20%231.png

On the 25hl bar the gear is free spinning (84th) and that same shaft it runs through the c channel which has lock bars on it. The shaft has broken at least 33 times

Yep, it sounds like you have the problem I thought you were having. VEX axles are not very good for transferring torque/holding any kind of weight. I would try to put the C-channel in between the two 1x25 bars and bolt the 84-tooth gear directly to the C-Channel. You can keep the lock bars on there if you want to but the best way is to directly mount the gear.

Follow above - great advice.

An additional thing to think about is to reduce the weight of the lift plus intake. Hard to tell, but it looks like the c-channel is steel? If so, change out to aluminium if you can. Are the 1 x 25 bars steel? If so, it may not be a good idea to change these to aluminium as the aluminium ones are not very rigid.

Cheers, Paul

Thank you so much! If your in our division at nationals or worlds
We won’t forget your help. Thanks

Were in a tight budget so this competition we have to use all Steel but well switch to aluminum after. Thanks great input

No problem, glad to help. You won’t see my team at nationals but maybe worlds:).

Aloha,

How about using liner slides to run the lift. I saw a great example on youtube.
http://www.youtube.com/watch?v=TYG7ZBaT5xU

And do not forget to use elastics…

Give that type of an idea a go.

Good Luck!

We tried this earlier in the season but it failed due to the stability factor. But thanks any way!

Have you tried linear slides horizontally instead of vertically like

http://www.google.com/imgres?imgurl=https://vexforum.com/gallery/files/1/6/8/2/HPIM0121.JPG&imgrefurl=https://vexforum.com/gallery/misc.php?do%3Dprintimage%26i%3D792&h=763&w=1024&sz=626&tbnid=tKxPsmy6aRf_sM:&tbnh=98&tbnw=131&zoom=1&usg=__tlHaQKEMp2UxmWeT5TgoXqdqRCM=&docid=4b0uFAhKZ2yhjM&sa=X&ei=esngUJXwNYK02gXa4IDoCg&ved=0CD0Q9QEwAA&dur=4029

No, but we did get our robot working very, very, smoothly. We don’t even have to build anymore just tighten.
But thanks for your help and everyone else’s. couldn’t of done it without you

Who motorizes scissor lifts:confused:… rubber band the **** out of it and then only lift once and have a pneumatic release:p… duh:eek:… and only Asians can build god like scissor lifts… :D:D

To have a lift that only raises once would be extremely inefficient, as the robot could only score once. And robots that only score once can easily be blocked or descored against, and all of that robot’s points would be gone.

who said that it would be for scoring…:D:D:D:D:D

In the case of some sort of expanding, ultra-defensive design, an elastic scissor lift could be an effective means of expansion.

but scissor lift are kinda good, but hard to build… they need to be built by Asians…

Hmm I wonder what it could be… and you worried about me giving hints lol