Welcome back to another update in the (re-)build process of the featherweight Schnauzer. In the previous blog post I've described the mounting of the wheel boxes to the base plate as well how I did manufacture new side armour plates out of Hardox. In this blog post I am going to talk about the assembly of the complete drive train. As a first step I did disassemble the whole motor and the gearbox in order to check all parts for damages sustained during the last fight(s). After the gearbox and the grease have been removed the Robot Power Magnum 775 motor with its gear pinion remains, as you can see on the following picture.
On the next picture you can see the shaft of the planetary gearbox. If you take a closer clook you will notice that the diameter at the front of the shaft is smaller than the diameter at its back. It was necessary to reduce the diameter because the bevel gear which needs to be attached to the shaft only has a 10 mm wide bore. The reduction was done by my uncle with a lathe (Thank you 🙂 ).
After this step I could start with reassembling the gearbox. The first step was to put back the four small gears on the four rear shafts of the gearbox shaft. Together they form the second stage of the planetary gearbox.
Then this unit is inserted into the front ball-bearing which is press-fitted in the front motor base plate.
Afterwards the first stage of the planetary gearbox with three bigger wheels on its three rear shafts are inserted into the previously assembled second gearbox stage.
Now the outer ring of the planetary gearbox which has gears inside can be imposed over the gears of the first and the second gearbox stage.
Finally the motor can be attached to the assembled gearbox.
After mounting the back plate the assembly process of the RobotPower Magnum 775 motor is complete.
Since the front part of the gearbox shaft was cut down to a diameter of 10 mm the bevel gear can now be easily attached at the shaft.
In the next step three M4 set screws are inserted in the threads evenly spaced around the bevel gear.
On the next picture you can see a close-up of the set screws.
After the set screws have been screwed completely in (by using an allen key) they are on one level with the surface of the bevel gear. In order to prevent them from vibrating loose Loctite bolt adhesive was applied.
In order to mount the motor to the base plate of the robot an polycarbonat adapter plate was manufactured.
On the next picture you can see a bottom view of the polycarbonat adapter plate.
Finally both motors were mounted on the base plate utilizing aforementioned adapter plate.
In the next picture you can see how the bevel gears of the motors are interlocking with the bevel gears of both rear wheel boxes. This solution consumes little space while still allowing for powerful motors.
Next you'll see a glimpse of the bottom side of the base plate. Notice how all screws are embedded in the base plate by means of counter sunk drilling:
With the drive train being (mainly) completed it was time to start to work on the wiring. As a first step two polycarbonat panels were manufactured and mounted between the front and the back wheel boxes. The upper panel contains one red LED for signalizing that the robot is powered. Furthermore two red connectors (for the removable link) and one black connector (for charging the battery) are mounted on the upper panel. The lower panel consists of a green and and yellow signal LED - they do not have yet a functionality assigned and are kept in reserve for future upgrades.
A more detailed picture of the upper panel:
A more detailed picture of the lower panel:
Stay tuned for further news about Schnauzers progress 🙂