The REV kit is an infinite-pitch, extrusion based building system which uses 15x15mm aluminum extrusion and is complemented by channels. With extrusion, there are no fixed mounting holes, increasing adjustability and flexibility. For example, tensioning chain is simple when sliding the mount or bracket increases tension. Extrusion systems are one step towards a custom bot, as it needs to be cut to length using a saw or bandsaw. In addition, REV also offers both 45x45mm U-channel and 15x45mm C-channel, which is stronger than extrusion and provides stiffness and support when needed. The REV system uses metric dimensions (15 mm extrusion, M3 hardware), with the exception of #25 roller chain. REV also uses 5 mm hex steel shafts for motion, which some vendors have added compatibility for in recent months. REV also has pattern adapters for other systems built into many parts such as the aluminum brackets. Another advantage to REV is the delrin (a kind of low-friction plastic) components reduce the kit cost, but many products have stronger aluminum options as well. While plastic typically is suitable for a new team, the aluminum parts are recommended if your budget allows for it. Furthermore, REV has released new products such as channel mentioned above, the UltraPlanetary gearbox which has customizable planetary ring gear ratios, as well as UltraSlide, a low-profile aluminum slide. In general, REV has a steeper learning curve than other build systems, owing to the fact that mounting points in mechanisms need to be accounted for. However, this is not necessarily a disadvantage. The REV kit is good for teams willing to invest the time into an extrusion building system. It has the ability to integrate channel along with extrusion, as well as the option to upgrade parts for those wanting a further investment into the REV building system.
Another advantage to the REV kit is the compatibility of 15x15mm Misumi extrusion. REV extrusion isn’t as structurally strong as Misumi for two reasons. REV extrusion is 6063 aluminum, while MiSUMI extrusion is made out of A6N01SS-T5 aluminum, a stronger and stiffer alloy. Additionally, the MiSUMI extrusion has a larger surface area, so there is more area of contact. Misumi offers greater strength at a lower bulk cost. Additionally, Misumi will cut to the half millimeter for free, making it a great option for teams needing an exact cut. The drawback to Misumi is that it is quite a bit heavier than the REV extrusion. It is encouraged that teams use Misumi for drivetrain and structural support, and REV for mechanisms that will be under low to medium load. REV also sells punch tubing, which is 15 mm aluminum square tubing that is compatible with ⅛” rivets. This will prevent bolts from loosening or sliding around, as punch tubing requires teams to drill through the tubing in order to fasten parts to it.
Kit of Parts¶
2 40:1 HD Hex Motors
2 Core Hex Motors
4 Smart Robot Servos with other attachments
Smart Robot Servo Programmer
15 mm aluminum extrusion, various lengths
Omni and traction wheels
32 gears in 7 different sizes
10 sprockets in 3 different sizes
Delrin bearings and pillow blocks
Motor and servo power/data cables
Slim Robot Battery and charger
5.5 mm nut driver and 5.5 mm hex wrench
Extrusion systems don’t need to worry about tensioning as mounts are adjustable to your needs.
Extrusion allows teams to save space as opposed to channel, and is lighter than aluminum channel.
Extrusion allows infinite positioning options instead of being locked in to a specific distance - useful for fine-tuning a mechanism.
Delrin products are inexpensive yet durable for most use cases.
REV has the option to upgrade to aluminum parts if need be - something that no other build system offers. (not for all parts)
5 mm hex is a robust shaft and motion system and is easily adaptable to Ultrahex ½” hex shaft. Other companies have adapting options with 5 mm hex.
Punch tubing is a great final iteration option if you are sure about placement.
Channel complements extrusion extremely well - having the adjustability of extrusion and the rigidity of channel makes it a very solid build system
Steeper learning curve, more time consuming to prepare extrusion.
Requires tools such as a saw and bandsaw
Requires forethought and planning of extrusion length and placement
Parts loosen over time (to remediate: use punch tubing)
M3 bolts, especially those sold directly by REV, are prone to bending under higher load (such as when used as an axle for a pulley)
5 mm hex shaft is also prone to bending, especially if the shaft is long.