Need some help with forklifts
 

Hello Cd,

I was wondering what material did you use to pull your forklift mast up and down. Last year we used fishing line and that did not work very well. Can you please put a link to your material and we were thinking of using cable? Also could you include pics of your system.

Thanks,

Rc

Re: Need some help with forklifts
 

We didn't use a forklift but our feather was driven by steel cable which might be an option for you. Word of warning if it has plastic coating on it that will peel off LONG before the cable fails so you may want to strip it off in the part you use to secure it down. We were useless an entire match due to striping that plastic off and not being able to raise our elevator which covered our shooter.

Re: Need some help with forklifts
 

We used 3/32" diameter uncoated steel cable for all stages of our lift. We initially worked with 150 lbs. test fishing line, but it stretched far too much to be useful.

Re: Need some help with forklifts
 

228 has used 25 pitch roller chain on our 2007 elevator and Spectra cable on our 2005 elevator.

I'd also like to work on a design that uses timing belts sometime.

Re: Need some help with forklifts
 

Do you have links of where I can buy these products, thanks guys for your help.

Re: Need some help with forklifts
 

Two #25 roller chains for first segment.

Two 1/16" steel cables from ACE Hardware for the carriage segment. We never broke or stretched these cheap cables. They had springs attached to one end that allowed them to stretch when the carriage reached the top.

Can't beat ACE! :D

Picture.

Re: Need some help with forklifts
 

Look through "the usual sources": McMaster-Carr, MSC Direct, Grainger, or Small Parts.

25 pitch roller chain is easy to purchase, although Spectra (sometimes called Dyneema) cable is a bit harder to find. I prefer Spectra cable to steel cable; 7/64" Spectra cord has an ultimate breaking strength of above 1,000 pounds, it doesn't stretch any appreciable amount, and it's a lot lighter than steel cable at only 0.3 lbs per 100 feet. The only real downside is that it costs $1 per foot.

Re: Need some help with forklifts
 

I like spectra for a lot of things because it's so light, flexible, and relatively cheap, but we've discovered that it's pretty annoying for telescoping lifts and such. Spectra has pretty severe creep, which means that it slowly, permanently stretches when it's under load, especially a high load. So any lines that you pretension are inevitably going to get loose as the season progresses. I've since come to appreciate Vectran. It has a lower modulus than spectra, so it will stretch more under load, but it's approximately a heck of a lot more flexible and lighter than steel cable of similar breaking strength, and it has zero creep. Spectra is best purchased from kite shops:
A Wind of Change
Windstar Kites
Vectran lines are available at sailing shops:
Mauri Pro Sailing

EDIT:
Art, you're being taken advantage of if you're paying $1 a foot for spectra if you like it that much. See my links above. Buying in bulk should get you spectra for half that much.

Re: Need some help with forklifts
 

1251 had a lift system this year we used 1/16in thick steel cable and UHMW plastic pulleys with an 1/8th in grove to life our elevator up. The motors were the small and big banebot if my memory serves me corretly and don't quote me on this rs 440 and 550 combined in a custom gearbox. The material for the actual elevator was 2*1 1/8in wall box alumnium. 254/968 has a spool thats really cool its like spring tensioned. I'm sure Cory, Sanddrag or Travis can tell you more about it and where to get them. Some other notes about elevators don't put all the pneumatic lines thru igus on one side if you have more then 4 lines it doesn't work well and run as much line as you can inside then out of the elevator to keep everything out of the way. This will save you alot of dispair and grief during the competiton season.

http://www.chiefdelphi.com/forums/sh...=1251+robot+08

Hope that helps,

-Drew

Re: Need some help with forklifts
 

Where did you get the cable from??? I'll have to ask Cory or if he could explain it here with some pics, that would be greatly appreciated.

Re: Need some help with forklifts
 

Thanks for those links.

I was never the person directly in charge of purchasing spectra cable when we've worked with it, and that's the price I was told. Maybe because we only bought enough for our elevator and a spare, or maybe because we should have shopped around some more. Whatever the case was, I'll be sure to keep my eyes open in the future when 190/228 purchase some.

Re: Need some help with forklifts
 

I'd advise against spectra cable. Yes it is strong, but it doesn't take shock very well at all.

Re: Need some help with forklifts
 

This past year we used 1/8" nylon rope on ours. I was skeptical about how well it would work out, but thankfully it held up and only began to fray recently. In 2005 we used steel cable to drive our parallel arm.

Re: Need some help with forklifts
 

team 675 used #25 chain and # 15 chain to lift our two stage lift

Re: Need some help with forklifts
 

I don't remember the exact name of what we used, but I know it's some sailboat rope. I think like 1/8". We never had any problems with it. It didn't stretch much either. If you have a local West Marine, that's where we bought ours from. I tried finding it on their website, but I didn't find it.

This is probably pretty close: http://www.westmarine.com/webapp/wcs...$@#$@#$@# Num=11452

Our's is blue though, so it may be a different brand. Look at the breaking strength... 530lbs. That's a lot of trackballs.