Plastic Clamping Blocks

This year VEXpro introduced plastic clamping gearboxes & bearing blocks.

We used the plastic clamping blocks extensively with our 2015 DiscoBots’ robot.

We experienced a couple failures but for the most part we have been very happy with the results.

I will post a picture of a few of the failures on our website in the near future.
Any other interesting experiences from teams using plastic clamping blocks ?

We used plastic clamping blocks in conjunction with the single reduction clamping gearboxes for our elevator gearboxes. We experienced a problem where if ALL the thru-bolts, not just the clamping ones were not installed, the gearbox cracked under high tension loads. This is partially because we cantilevered the chains that drive our elevator, but once we drilled and installed all the thru-bolts, this problem was alleviated and our elevator ran much more smoothly.

The clamping gearboxes worked like a charm for this purpose and they were super easy to install. Overall I would highly recommend both these products, but make sure to mind the types of loads you are placing on them. They are plastic at the end of the day, and will fracture if loaded too heavily. I’ll try to dig up a picture from our cad of how we implemented them.

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We used them in our drivetrain this year, but not in our elevator. For a game with more severe shock load requirements (read: defense) I would have been more concerned about their plastic construction, and that might have kept me from trying them. I am glad we did.

Through two events and 34 matches so far this season, they are holding up fine. I would use them again, possibly even when we need to play defense in some future game.

Excellent, and inexpensive as well. I look forward to hearing more about these.

Be sure not to over-tighten the fasteners. Someone over-tightened the two screws holding the motor on one of the clamping gearboxes. The screws have a fairly small head and they completely “crushed” their way through the plastic. The motor popped off with very little effort.

This. We ruined two by overtightening. It is very easy to not realize when they are tight.

We also did that to one of ours. Also watch out for over tightening the bolts that clamp them to or go through the 2x1; although doing so didn’t seem to stop the bolts from holding the gearbox in place, if you start spinning the nut it will strip out the hexagonal shape that holds it in place, making it nearly impossible to remove the bolt without destroying half of it to be able to get a wrench around the nut.

We also found that one of the clamping bearing blocks had the inside half crack into two pieces during Palmetto. I didn’t notice any problems as a result of it though; we replaced it as soon as we noticed it had happened. I believe that this was one of the ones supporting a wheel (6" VEXpro mecanum, cantilevered out with about .75" of space between it and the bearing IIRC). I wouldn’t be surprised if this was the result of something dumb we did though, these sorts of things always seem to end up being that way.

Other than those two issues though they’ve worked great for us. We used four three stage gearboxes (one plastic clamping gearbox, two plastic clamping bearing blocks each) on our drive-train. My only major complaint is that putting the holes in for the bolts going through the 2x1 tube is a real pain to do without putting the piece on the mill or drill press since the plastic pieces can’t be used as a reference to drill through; this makes putting them onto an already assembled structure a pain, although this can be easily avoided with a bit of forethought and planning.

We’re using both on drive and it’s working fine for us. 4 pairs (gearbox + bearing block) x 4 wheels.

We are running Versa Planetary into the input of the clamping gearboxes with much success. At our first regional we had one failure on the clamping gearbox which we have decided came from a combo of being over-tightened and strafing into the scoring platform causing an abnormally large side load. They are cheap and super easy to install, just keeps spares on hand.

Team 4618 has used both the clamping gearbox and bearing blocks on our drive train. We run 6 inch vex mecanum and they have lasted about 2 hours of driver practise and a regional without fault

We used the clamping gearbox on both our practice bot and our competition bot without any issues. We also used the plastic WCD bearing block on the practice bot, but the metal version for competition. We have so far logged around 50 hours on the practice machine, and maybe 20 on the competition version, and have zero incidents. We have twice rebuilt our 10:1 versaplanetary box used for the elevator though; considering what we put it through that’s hardly a hassle.

We have worn out three sets of orange Banebots intake wheels, and have beefed up our 3D printed parts a few times. I can’t say enough how refreshing it is to not have defensive damage to deal with after each round!

I love the plastic bearing blocks. Cheap. Simple to use. Don’t need precision holes. And work in just about every place if used correctly. The only thing plastic we have had a problem with so far is the plastic hubs. Plastic versa hubs do not like thunderhex in a high torque load and they especially do not like hard stops with thunderhex. Other than that, I would purchase all of these again

I’m sure there is constructive criticism to be had for vex this year, as in any year, but really. I am nothing but impressed. Two years ago I started searching everywhere (like, worldwide) for a product exactly like what they produced with VersaFrame. What a company.

We’re running four of the gearboxes and one of the bearing blocks–happy with the results.

I’ll echo everyone else’s comments about tightening on the gearboxes–we have to make sure everyone has proper training before they attach/detach any bolts from the gearbox due to risk of deforming the plastic.

Running 4 aluminum clamping bearing blocks on the drive train, 1 plastic clamping gearbox as the first stage of the lift.

For the drive train blocks, we had to shave away some powder coat in order to get these on after powder coating. No big deal - they are tight-toleranced for a reason.

There wasn’t much finagling to get the plastic clamping gearbox onto the powder-coated rail it lives on. It still slides for tensioning, but takes a lot more force (expected).

Do any teams have experience with these plastic bearing blocks on powder coating?

I don’t believe the plastic versa hubs are intended to transfer torque loads at all; vex reccommends them as a support item to be used in conjunction with an aluminum hub.

They are also usable for torque transfer, but obviously can handle less torque than their aluminum counterparts. This makes them good for lighter duty applications.

I’ve used them how you described, but also for some rollers this year.