Cable Pulley and power transfer

I believe a vex cable system would work well. For instance in some advanced robotic arms cables are used to transfer power to the joints or grippers of the arm when the motors are actually in the body. Ideally the cable could be cut and cinched to a drum that it would be coiled around. That drum, the cable, maybe some Teflon guides, and a few pulleys for in the arm would allow anyone to build an robotic arm with joints and grippers and keep the motors out of the arm where they look protruding and hurt the center of gravity. The cables linking the motors in the body of the robot with the joints in the arm would help streamline the arm making them look and work better. It could also be used as a winch or crane system. Just an idea wanted some thoughts on it.

I know i could use the chain and sprocket kit but you cant weave multiple chains inside of a c channel and they would rub against things and each other not making a smooth ride. I know i could probably make this kit for myself but i like the more professional look to the kits. This takes it a step beyond the chain and sprocket kit in transferring power. Thoughts on this idea are appreciated.

Antique Gilbert and Meccano Erector Sets sometimes include small brass and plastic pulleys such as those that I used to assemble my Vex based DIY Electric Train Set shown in the Vex gallery. Another source of professional looking pulleys are the 2" ir 3" garage door pulleys that are attached to 3/8" diameter axels, which are found at you local hardware store. These pulleys include ball bearings for smooth motion and could easily be adapted to Vex robotic applications as you suggested.

I have also used small to medium sized Lazy Susans also found at a local hardware store for my Vex and Vexplorer based robots. These could be made into a sturdy drum or wire spindle assembly by attaching two of them together using Vex standoffs and then used to coil thin wire or nylon cables.

Yeah those are all great ideas that i could build with from local stores but i was looking for the “vex look” which makes the set look more professional.

Does anyone else have a need for a kit like this?

Here is an idea for building the spool out of standard VEX parts.

The 40-tooth chain sprocket has four holes in it and there are tubes that extend those holes out to the same height as the center square-bar hole in the middle.

Four screws and nuts in each of those holes and you have a spool. You can make it wider with the small black spacers. Just use the screws from the tank tread kit if you need longer screws.

You do have to use care when to guiding the cable towards the spool. The teeth on the sprockets are very effective at catching the cable and making a mess of things :).


I should experiment with this some time! It’s a good idea!

Our team uses a winch system to lift our cube manipulator up for the Elevation competition.

I’ve done that before. You have to keep the string tight, or it gets tangled up, but it does work.

I just built an arm robot this week with the pulleys to transmit power. I didn’t build it just so i could try this concept out, but i really don’t have any extension cables except for the 6" one you get in the kit, and i had to use that somewhere else. I’ll post pictures soon!

hate to bring up dead posts. but saw this and recently built something using pulley’s it’s the close up video of all of the gears and pulleys but something has happened to my WMM seems to not want to use my camcorder video yet. So a video of it actually on a “misison” will be shortly in the next few weeks when i get it figured out. I don’t like having to add extra steps to do what i used to do. but thats something non vex related. Anyway some background on what it is.

My nephew has recently started to take a serious interest in robotics and i thought hey i got all this stuff collecting dust lets play. He’s 11 and autistic so it’s a challange sometimes to get his ideas out in a working model but i think we accomplished a great deal with this though it’s large and bulky and and not as clean as i would have liked but we worked through some things as a learning curve like screw sizes the difference between the 1/4 inch and the 1 inch and how to tell them apart but he brough up more advanced things like center of balance before it was even an issue. It uses 7 motors and 2 micro controllers and transmitters. He was facinated on the pulleys i had and he asked if we could make the entire thing work with the pulleys and so we did. I get to spend about 3 hours a day with him durring the week so this took a while to build with stoping to explain how things worked and all. He was very happy with the way it worked out and what not. We spent many hours playing and doing various “jobs” around the house with it. I’m really posting this for the main reason that i still think that pulleys of various sizes would be a great idea for vex to work with. This video shows how much they can change the way you move things like an arm or even as a winch to make a moveable platform. Anyway i hope you all enjoy and as i said i’ll make haste with the other video footage.

We are currently working on another project so more to come. If you have any questions or comments please feel free to send a pm.