A rugged and simple gearbox with 2 useful ratios and slots for easy mounting. Powered by 1 or 2 common FIRST robotics 500 series motors
What is the Switchbox?
Switchbox is a new gearbox for FIRST robotics that has face and edge slots for easy mounting, can be quickly repaired in the field, and has two useful gear ratios: 1:20 and 1:90.
We are a group of students from the 7 year FIRST Robotics Team, the ausTIN CANs. We've built many robots for competitions, and used almost every available gearbox. We believe that all current gearboxes have shortcomings. With Switchbox, we've tried to build our ideal gearbox for rigorous world of robotics competitions.
What makes Switchbox so cool?
- Easy to mount. The Switchbox can be mounted on the face or edges. We use slots instead of holes for mounting to allow sliding. This helps in aligning gears or tensioning chains or belts.
- Multiple motors. The Switchbox can be powered by one or two 500 series motors, which are very common in FIRST robotics.
- Easy to expand and maintain. The Switchbox is easily assembled and customized to different gear ratios. If a gear becomes stripped, maintenance is simple, and only one of the mounting plates need to be removed, the motors do not need to be detached from the mounting position.
- Durable. We chose large, durable spur gears that can stand up to the abuse of competition.
What shortcomings did we see in existing gearboxes?Existing planetary gearboxes' ratios aren't always optimized for what teams use them for, because of their max torque load. When these planetary gearboxes strip and break, the internal gears are hard to replace, often times requiring the replacement of the whole gearbox and motor, to save time during the heat of competition. Mounting certain gearboxes prove to be sometimes difficult because of the precision required to drill the mounting holes.
What rewards are available?
- A single dollar buys our our gratitude, and helps us along!
- There are two t-shirt rewards
- Stress test: we will run our gearbox under stress and publish the data online
- Switchbox gearbox with one gear reduction (20:1). This is the exact same frame and first gear stage as the other Switchbox. The only difference is that the final gear stage, axle and bearings are omitted to save money.
- Switchbox gearbox with two gear reductions (20:1 and 90:1)
- The original orange plastic prototype gearbox! There is only one of these in the world!
If you choose one of our t-shirt rewards, please go to the link below to sign up for your shirt size: http://www.customink.com/signup/1o23vdl2
There is also an unlockable reward: the Stress Test. We are committed to creating a durable gearbox that stands up to real-world robot competitions. To help further this goal, if this reward is completely reached, we will conduct a stress test and publish the results online. We will examine the effects of real-world torque and speed over time. At a minimum, we will run the gearbox for one week or until failure. Note that our exact experimental set up is yet to be determined.
What's the money for?
The $15,000 will be for an initial production of 50-90:1 Kits, 50-20:1 Kits. The money will be spent on purchasing all of the parts to make each gearbox. 60% of the money will be going towards the purchase of the gears. 15% is going to the precision machining of the plates and shafts. 15% is going to the purchase of the purchase of bearings and mounting supplies. The last 10% is going to reliability and material testing to make the SwitchBox smaller, lighter and more reliable. Any money left over will go to the furthering of our product or the furthering of our robotics program.
What are the specifications?
- Dimensions: L: 7.5" W: 1.5" H: 4.2"
- Motor types: 500 series- Banebots, Andymark, Fisher Price
- Motor pinions: 12 tooth 32dp
- Mounting options: slots on either end of the top/bottom
- Mounting hole diameter: 1"x1/4" slot
- Gear reductions: 20:1, 90:1. Note: these gear reductions have been updated since our original prototype. See FAQ below for details.
- Shaft types: 3/8" hex shaft with machine rounded ends
- Shaft diameters: Idler shaft 1 1/2", Output shaft 3"
- Max output torque: 11.25 N*m, 56 N*m
Please note that these specs may change slightly as we modify the prototype to be more manufacturable. We will post news about any specification updates.
We will ship the Switchboxes to our backers starting December 15, 2012, just before the 2013 FRC Robotics season. The ship date is based on when we receive the gears, shafts, machined sheet metal, bearings, and the other parts necessary parts for the gearbox. Then once we've gathered all the necessary materials we will assemble and ship the gearboxes.
We will make the CAD files of the finished product publicly available. This will help teams to include them in future designs, and will make it easier to modify and repair the gearbox.
How its made:
We will be purchasing most of the gears and bearings from West Coast Products. We plan to get the plates of the gear box cut from a water jet cutter at a local business then have them bent using a break. Our plan is to make the shafts in house in our shop. Then once we have all the individual pieces we will assemble the gearbox in house
Risks and challenges Learn about accountability on Kickstarter
We believe the major challenge we face is physically making a large quantity of gear boxes. We've tried to do a lot to mitigate this risk, but its something we've never done before. Our mitigation are listed below:
1) Our team has been working together for seven years making robots for FIRST competitions. We have lots of experience in designing, machining and building complex machines.
2) We have full access to a machine shop, and we have years of experience building cool stuff. Oh yeah, we have some awesome mentors who will be supervising us.
3) We have already established relationships with our suppliers. West Coast Products, who supplied the bearings and gears for some of our prototypes. We are working with Custom Sheet Metal Inc. to have our mounting plates cut on their CNC water jet. They've already done a test run in Lexan and another in aluminum.
The orange prototype has gear ratios of 5, 25 and 125. It looks like your final product will have ratios of 20 and 90. Why the change?
We made this change for two reasons:
1) After interacting with potential customers, we believe that 20 and 90 are more useful gear ratios.
2) This also lets us build the gear boxes faster and at lower prices. This is because these ratios allow us to take advantage of commonly available, off the shelf gearing from our suppliers.
The cheaper Switchbox only has one reduction, 20:1 instead of both 20:1 and 90:1. This is accomplished by not including the final gear reduction stage. This means one shaft, one set of bearings and two gears are omitted. This saves $35! The frame and first gear reduction stage are the same in both gearboxes.