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Improved qdd100 packaging

There are a lot of steps necessary to get a product to market, not just a fancy render. I admit to being far from covering all the bases yet, but we’re getting there. In that spirit, I recently upped the packaging game of the qdd100 with some custom boxes and foam inserts. Pick one up at mjbots.com!

mjbots power_dist r4.3b

I’d like to introduce the newest mjbots product, an updated revision of the power_dist, 4.3b available at mjbots.com today!

This version has a number of improvements over the previously released r3.1:

r4.3b r3.1
Voltage Range 10-44V 8-34V
Maximum load capacitance 4,000 uF 400 uF
Quiescent Current 300uA 5mA
Current (Continuous / Peak) 45A / 80A unrated / 100A
Energy Monitoring YES NO
Switch Mode High Side Low Side
Dimensions 50x80mm 45x70mm
Price $139 $79

The only real downsides are that is more expensive and slightly larger.

pi3hat r4.4

It seems like all the posts I’m writing these days are for new products! Here’s the pi3hat r4.4:

There are two changes from the previous r4.2. First, it now supports voltage inputs up to 44V. Second, in support of future upgrades, the 5th CAN-FD port has been upgraded to support 8Mbps, but downgraded to no longer have a wide common mode voltage range.

THUS, IT IS NOT SAFE TO CONNECT THE CAN-FD PORT ON THE pi3hat r4.4 TO A power_dist r3.X BOARD.

qdd100 beta 2

I’d like to introduce the qdd100 beta 2!

This is the newest version of a quasi-direct-drive servo from mjbots. It has a sleek new look, and improved performance all around:

Beta 1 Beta 2
Peak Torque 12.5 Nm 16 Nm
Backlash +- 0.2 degrees +- 0.1 degrees
Voltage Range 10-34V 10-44V
Mass 470g 475g

Comparison from beta 1 to the new beta 2

Additionally, the M3 mounting holes are now 3mm deep instead of the previous 2mm, which gives more flexibility when designing mounts.

new product day: mj5208 brushless motor

Welcome to the newest mjbots.com product, the mj5208:

This is a high quality 5208 sized 330Kv wound brushless motor with short pigtails intended to connect to moteus controllers. All the moteus devkits as of last week are shipping using this motor instead of the previous “semi-random” motor.

Specifications:

  • Peak torque: 1.7 Nm
  • Mass (with wires): 193g
  • Peak power: 600W
  • Kv: 330
  • Dimensions: 63x25mm

There are two bolt patterns on the output, a 3x M3 17mm diameter one, and a 2x M3 pattern spaced at 12mm. The stator side has a 4x M3 pattern spaced at 25mm radially and a 3x M2.5 spaced at 32mm. The axle protrudes a few mm from the stator, making it easy to adhere the diametric magnets needed for moteus.

New product day: moteus heat spreader

The moteus controller is capable of a lot of instantaneous power. However, to fully make use of that power, you’ll need to keep the mosfets cool on the board. moteus has two mechanisms for that:

  1. A heatsink can be mounted to the bottom side of the PCB between the board and the motor. This is most useful when integrated into a servo motor, and the servo housing can be used as a heatsink.
  2. Mounted to the top of the board, attaching to the MOSFETS directly.

In addition to the MOSFETs, the gate driver chip, the DRV8323 can produce large amounts of heat, especially when the controller is run at a higher voltage, like the 44V that the moteus r4.5 supports.

moteus r4.5

Meet the newest revision of the moteus controller!

Yes, it does look mostly the same as the r4.3 that has been getting a lot of use lately. This revision exists mostly to improve manufacturability, but I snuck in a minor design improvement while at it. Now, the maximum voltage input is rated up to 44V from the 34V of the r4.3! (Note though, that the pi3hat and power_dist still are limited to 34V). Otherwise the new controller is fully electrically, mechanically, and software compatible with the r4.3.

Playmates

Just a video update… I’m not generally offering the quad A1 for sale *yet*, but if you’re interested in an alpha version, you can write info@mjbots.com

You can of course already get nearly all the non-3d printed parts at https://mjbots.com