We have been using Kevlar reinforced rubber belts, but are struggling with them slipping and stretching no matter how much we tension them. We have also snapped one belt so far, and fear it may happen again. So what are you guys using? Sorry I do not have the specific part number.
Sprocket and chain. You can put a bolt through a couple links in the chain and bolt it directly onto what you want to move.
We’re using BRECOflex AT5 belts, which are made with polyurethane, reinforced with steel cables. We also are using clamp plates with the tooth profiles cut into them to hold the belts in place and also apply tension. (full disclosure I work for BRECOflex and we do offer a discount for all FIRST teams!)
+1 for the sprocket and chain. 4 4-40 screws through 25 chain with nylocks holding it on. Stayed together when we practiced and it fairly easy to adjust.
25 chain. We’re linking the chain to a glide by cutting the head off of 1/4" bolts, making flats on the shank (whack it with a hammer, careful not to mash threads), drilling a 3/32" hole in the middle, and forming a link of the chain into that hole using a Dark Soul tool(Vex sells a similar chain tool). The threaded bolt end allows a tensionable connection to the glide.
Edit:
I’ll try to remember to get one this evening.
Loving that idea. Thanks.
Any pictures of this handy?
25 chain, but we just riveted through the chain onto a piece of 1x1 L bracket on the top of our lift
We TRIED 25 chain but the chain would wear in an elongate so we went over too 35 chain which is greased better and has less elongation!
we opted for #35 chain, the tension-er is a turn buckle mounted to our lower brace of the climbers linear slide. also we have a hanging sprocket that is spring loaded to keep our chain taught to the drive sprocket (chain is contacting close to 270 degrees on the drive sprocket) to minimize any slippage
#35 chain with 8-32 bolts sandwiching a pair of gusset plates on either side of the chain. Same idea as the VEXpro linear gusset kits, but we made one set of the gussets ourselves to interface with our design properly.
Since the gussets ride along the front side of the chain, we remove all tension from the backside. We accomplish this by using a sprocket with a mount that clamps around the mechanical supports for our elevator. Because the mount is clamping rather than attached to the supports, we can adjust its location to adjust tension.
I like mrcools idea of riveting in the chain. Didn’t think about that and when we used the 25 chain we used the 4/40 bolts but bent the ^%$# out of those.
Luke and Lil
Do you have pictures of your tensioning solutions. My rookie team is looking at adding one and are stumped at this point.
Hopefully this should link externally without you needing an account. If not I’ll upload to imgur later.
so ours is very similar to Lil’s but our tensioning sprocket is free hanging down from the top with 2 pieces of angle aluminum and then springs to pulling it towards the interior of the robot keeping it tight
Our setup is in the middle of our lifter and not on the side. Trying to figure out a tensioner in between the two sides of the lifter.
My team is currently just using #25 chain with 4-40 bolts. We have 2 chains for our lowest stage of our elevator (just redundancy) and a total of six bolts.
We have the same setup but with 8x 4-40 bolts. I’m worried about them breaking. Any teams that used rivets in #25, did you use 1/8"?
climbing rope
1/4in low-stretch rope.