Introduction: Time Lapse Rover V2.0 for EMotimo TB3
One of my favorite DIY projects was building a time lapse rover for the eMotimo TB3. At the time, it was unique in the fact that no one else had one, at least from what I could find on the internet. Instead of being limited to a fixed length of slider, my rover could travel big distances for time lapse sequences. Since then, eMotimo has released their own version called the cart. It's very elegant and simplistic, but also $359. The retail number on the parts I used is around $210 but I was able to get that down used discounts and coupons. I thought that I would be able to come up with a new version of my rover, and have some of the same qualities as the eMotimo cart at a lower cost. This build will showcase what I came up with. In a sense, it is very similar to the original rover, but now has skate wheels for smooth surfaces, and the motor is mounted vertically to reduce tension on the drive shaft. The motor is different on both rovers, and each have a method for mounting additional cameras such as a GoPro.
Maybe we'll call this Hyperlapse Rover Mark II.
Step 1: What Is a Time Lapse Rover and Why Do I Need One?
Motion time lapse sequences bring additional depth and interest to a time lapse sequence. However, most people use a slider that is limited in how far the camera can move. The rover solves that problem as you could have it move 2 feet, or 200 feet. It's unlimited in how far it can go. The nice thing about the TB3 is that you can do move-shoot-move sequences as the TB3 controlls the 3rd Axis stepper motor. The example video above is using the first generation rover I took at the Millennium Bean in Chicago. The new V2 Rover will work well on smooth surfaces, and will work much the same way.
Step 2: Parts List:
Most of the parts were allocated from ServoCity.com using Actobotics parts. Think of these as the grown up version of the erector set. The eMotimo cart is a trike with a single drive wheel, but I decided to go with a tried and true design with 4 wheels on a rover that has 2 wheel drive. Here's the list:
1 x eMotimo TB3 and external battery(I would assume that the eMotimo Spectrum will work just fine. I'll let you know when they send me one to test on my rover)
- 1 x 15" Actobotics Aluminum Channel
- 1 x 9" Actobotics Aluminum Channel
- 1 x 4.5" Actobotics Aluminum Channel
- 4 x 4.90" Wheels
- 2 x Drive Wheel Adapters
- 2 x 8mm Flanged Standoff A
- 2 x 8mm Non-Flanged Ball Bearings
- 1 x 1/4" Spacers
- 3 x 1/4" Hub Pillow Block
- 2 x 1/4" Flanged Ball Bearing
- 4 x 90 degree quad hub mount C
- 1 x 90 degree Quad Mount E
- 1 x Flat Channel Single Bracket
- 2 x 32 Pitch, 24 Tooth Bevel Gear
- 1 x 10" 1/4" Precision D-Shafting
- 1 x .770 x .770 hub Adapter
- 1 x 1/4" Aluminum Set Screw Collars
- 2 x 1/4" 6-32 Socket Head Machine Screw
- 1 x 1.5" D-Shaft
- 1 x Planetary Gearmotor Mount B
- 1 x 1/4"-20 Knob
- 1 x 6.35mm to 8mm Aluminum Coupler
Secondary Camera Mount (Optional)
*** I'm using a much slower stepper motor in this build compared to the original rover. Each project I test different gear ratios. There should be more torque with this motor, but otherwise, it is probably slower when moving. For time lapse, that isn't an issue except for the original set up.
Step 3: Put It All Together
I'm not going to go into too many details on how I assembled the rover as the pictures should help showcase the design. Basically, the stepper motor, mounted with a planetary gear motor mount, connects to a d-shaft using the 8mm to 6.35mm coupler, which connects to the bevel gear. This gear is what turns the rear D-Shaft and back wheels. The biggest difference in this rover versus the original design is the way that the stepper motor is mounted. On the version 1 rover, the motor is installed underneath the main channel perpendicular to the back axle. On this version, I just mounted it vertically on the back axle, reducing stress on the shaft. Since it's not in the way of anything, it probably makes more sense to have the motor mounted this way.
The front axle can be turned to different angles to make the rover arc as it travels, and adjusted using the tension knob. The eMotimo Tb3 is connected to the rover with the Arca swiss plate and adapter. You could attach the TB3 using a direct connection, but being able to take it on and off without tools is convenient.. The battery is mounted using simple velcro.
Let me also state that you probably don't have to have the larger skate wheels. The 2.975" wheels would probably work just fine, and lower the rover to the ground a bit. I just liked the look of the larger wheels, so there isn't any advantage to it from what I can assume.
If you buy your stepper motors directly from eMotimo, you do not have to wire the motor using the molex connector. Since I wanted different gear motors from what they sell at eMotimo, I needed to solder and wire the motor myself. Here is the wiring diagram necessary to complete this:
- Black Motor –> Black jumper
- Green Motor –> Red jumper
- Blue Motor –> Orange jumper
- Red Motor –> Yellow jumper
Step 4: Final Product Next to Big Brother
As you can see from the pics, both rovers are about the same size. The wheels are really the biggest difference with version 1 rover having RC off road wheels, and version 2 having skate wheels. The drive train is pretty similar, though mounted differently. I'm trying to find time now to go out and test version 2. I'll try and post the time lapse video when I get some decent results!