Over the past week I have had the chance to play with the Actobotics runt rover Sprout. I posted an unboxing of this bot last week. The chassis has proven to perform well overall with little to no problems, though there where a few.
I'll start first with what I see as the issues because as I said there are not many.
First the clip-on board mount; it does make it easy to put on and take a controller board off the bot but there are issues with the board slipping (left and right) and can cause wire connection problems if hit. This is lessened with a smaller board such as an Arduino Uno but as the board length goes up so do the bump risk.
The second issue was with the area that the battery holder would go. It was a tight fit and if you used a four cell AA flatpack you have to unsnap the decks at least part the way to get access to the batteries. If you use LI-ion, Li-po or a 2x4 AA holder then this should not be an issue at all. I think the Spout would be the only one in the series that would have this issue. ** See below **
The third and final issue deals with the ABS caster on the bottom of the bot, and this will be a problem with any of the chassis in this series that uses same type caster. The caster itself is made from 3 mm ABS just as the rest of the chassis is. When it's mounted on the bot it points from front to rear. On hard surfaces such as tile, wood or other hard smooth floors the robot moves and turns easily. On rough surfaces though such as carpet and very uneven floors the problem comes in to play. What happens is the caster gives a lot of resistance on turns and sometimes even going forward or backwards. For for my bot, I ended up just replacing it with the small ball caster that was roughly the same size as the supplied ABS one. After this change it turned on rough surfaces a lot better.
Now for all the good points!
The quality of the materials that the chassis was made of was very good and saw no issues with mine at all. The chassis went together easily and stayed together and had no issues with falling apart during use (always good!). This was a concern of mine after seeing it was snap together.
This chassis, though small has many mounting options and enough room for a controller, H-bridge and sensors as well as batteries and even to possibility of things like small grippers. It's very light and moves easily in it's intended environment. You can mount IR sensors for line following or proximity detection, ultrasonic sensors for obstacle avoidance. There are holes to mount servos with standoffs on the top deck. This bot as well as others in the series comes with the Actobotics mounting holes, so it will easily interface with that line of components, but is not limited to only those.
The robots motors and wheels were good quality and performed well. The wheels are made of rubber and not nylon and had very good traction. They are easy to put on and taken off the motor shaft but stayed in place with no issues. The gear motors themselves come with two encoder mounting options. One is from the double D axle shaft and other is from the longer motor shaft on the rear. So this allows for adding an IR wheel encoder to the axle or a Hall effect sensor encoder wheel to the motor shaft.
The pros:
- Very inexpensive and a good value
- Easy to assemble
- Great quality
- Lots of sensor mounting options
- Snapping holder for controller board with lots of board options (standard size Arduino, Raspberry Pi, etc…)
The cons:
- The controller can slip in holder
- The snap in ABS caster is problematic on uneven surfaces
- Battery access may be an issue
Conclusion
Overall I believe this is a great chassis for the money, it's inexpensive, easy to work with and is a good designed and well made. It would be great for a beginner or anyone that wants a bot to experiment or play with. It's easily set up as a follower, obstacle avoider or any other thing you can think of!
** Amendment: The Flat pack 4 cell AA setup I was using is an old one I had from Radio shack. It has a cover and a switch on it. I dug up one with no cover and it just did fit in the rear side openings. **
Pictures:
