Help - Can't figure out way to connect spool to webbing

[Mike Marandola]

Do you have access to files, a drill, and taps? If so, this is a possibility which I have seen done this year. Here is a very rough sketch not to scale:



If you have a file, you could file a flat on one side of the pulley, drill and tap holes, make a little washer plate (regular washers would also work), then fasten with two button heads. It might be a good idea to melt the edges the the hole with a lighter, or even make the holes with a soldering iron to prevent any fraying. Also, you might want to find a way to increase the size of the flanges to prevent the webbing from tracking off.

[Sperkowsky]

Originally Posted by Mike Marandola

Do you have access to files, a drill, and taps? If so, this is a possibility which I have seen done this year. Here is a very rough sketch not to scale:

Snip

Also, you might want to find a way to increase the size of the flanges to prevent the webbing from tracking off.

This seems like the most robust option. We have taps but I don't think anyone has ever used them should be an interesting learning experience if we choose this route.

Also yea we have these little PVC Plates I am going to drill the middle out of and use as flanges.

Thanks btw this is a big help!

[Mr V]

In the past my team has bolted the webbing onto a spool. You do want to melt the hole through the webbing I've used the chuck end of the appropriate sized drill bit heated up with a propane torch. You will want to use a button head bolt and a big thick washer or plate just make sure that there are no sharp edges that will cut the webbing or wear through over time. I'd also recommend a single bolt and a larger washer/plate than two bolts side by side. You also want at least 1 1/2 wraps on the spool before the webbing is loaded. That way a lot of the force is carried by the webbing cinching on itself and not on the bolt and hole.

[DaveL]

There are many ways of lifting an elevator.
If you look at some of the robot release videos you will see teams that lifted the elevator with a belt and with chain. Some lifted from the center and some teams lifted from both sides of the elevator.

We chose to use chain from both sides in a loop, to balance the lifting force side to side and to pull the elevator down, to reduce the chance of the elevator jamming. We also located our motor in the frame to lower the robot's center of gravity.

I understand that you are trying to keep things simple and quick to build.
So my suggestion follows a tow rope design. We used 2 AndyMark flanges with a small spacer and bought some thin high tensile rope and tied a loop. Inside the loop we tied our tow rope. I think it was a 1/4" Dacron (sailboat) rope. The sides of the flanges were enough to keep the rope from slipping off.
If you want to go with the belting, you can fold the belt over and sew it closed, then pass the thin rope thru and tie it to the flange. If the flanges are too small to contain the wraps, rivet a disk with a hole cutout to the inside of the flanges.

To keep things really simple, just use spectra line. Its real thin and super strong or just use the Dacron rope (line).

AndyMark sells hex and round bored flanges.
http://www.andymark.com/Hubs-s/215.htm

Rope
https://goodwinds.com/line-winders/b...ctra-line.html
http://www.westmarine.com/buy/new-en...ne--P012357679
http://www.westmarine.com/buy/fse-ro...e-49--12946836