Originally Posted by GeeTwo
I've bought plenty of servos and some accessories at ServoCity, but the prices of their structural elements have sent me elsewhere. I have also used actobotics for light duty FRC manipulators, such as the shaft hardware and hubs for 3946's scoosh (gear manipulator) in 2017
; good stuff. I was happier with it than the REV motor mounts and such.
The Actobotics system is superior quality to the Tetrix system.
- The 0.25" D-shafts are much better than the Tetrix shafts, come in a wider variety of lengths and have higher torque carrying capability (but it is still not good practice to use the shafts to transmit high torque)
- The D hubs that Actobotics uses do not have the issues of the set screw coming loose and spinning on the shaft
- Using bearings instead of bushings makes everything run smoother with less friction and more power going to the wheels or mechanisms
- The structural components have a larger number of holes which allow for a greater flexibility in attaching components
- The Actobotics system has a wide variety of special components like splice plates, gussets angles and so on that make it far easier to attach the structural elements together in very rigid assemblies
I will admit that you pay a little more for the quality that you get, but some of that is expected (a bearing does cost more than a bushing, for example). Last time that I priced out the structural elements, the prices were very similar for comparable lengths.
They do have adapter pieces that can be used to match the hole pattern of the Tetrix system (they have adapters for the structural components, motor mount holes that fit the andymark motor end mounting holes, D-hubs that fit the tetrix wheel hub pattern and couplers to join different diameter shafts), so if you want to mix and match, you can. But our teams tend to pick one system and use it pretty much exclusively.
One of our 4 FTC teams has been using the Actobotics system for the past 3 years and produced amazingly robust robots. The robots never seem to need the regular set screw re-tightening that the tetrix based bots do. A second team decided to switch over to Actobotics this year and seem to really be liking it. A 3rd team is experimenting with the T-slot (80-20) approach with some success, but that system is not as easy to build with and it is not as easy to mount things to the frame using that system. The 4th team is still using the Tetrix system.
I would say that, other than the price, one of the biggest challenges is the sheer variety of parts that are available. Once you take them out of the bag, it is often hard to tell whether the coupler is for a 6mm shaft or a 0.25" shaft, for example. We have ended up with a lot of parts and it is hard to keep them all sorted so that they can be easily located. So we end up ordering new parts rather than finding and using the parts that we already have. Part of the problem is we still have shelves full of Tetrix parts as well, so our storage space need has tripled and we have not been diligent at adding the extra storage and sorting bins, so the parts tend to end up collecting in totes without any real organization.
Bottom line - Actobotics gets 2 thumbs up from our club!