Wait, the BOM has 4 x Qdd100. And each Qdd100 is listed for like $500 USD. So these robots are $2000+ is that normal? I was hoping for a cheap DIY haha
In the field of robotics there are a lot of things that are expensive to do well, but you can do them badly at a much lower cost.
For example, for many industrial robot arm applications you need an arm that doesn't wobble - so you need stiff links and low-backlash actuators. You need to be able to precisely follow straight lines, so your position control feedback loops need to run fast. Six-axis control of the end effector is standard, gotta be able to move and rotate in X, Y and Z to accomplish arbitrary assembly tasks. And of course it can't be slow - on a production line, throughput is money! Don't forget the need for reliability, a design for 24/7 operation, and availability of maintenance and spare parts for 15 years. $20,000 please.
On the other hand, a robot arm for educating kids? Doesn't matter if it wobbles, or if it's slow, or if the position control isn't great, or if there are some rotations it can't accomplish, and it easily breaks. It'll still be cool and teach the kids plenty of stuff. $200.
$2000 is a typical price for a university group project that'll land somewhere between the two.
Hmm yeah one could probably replace those with regular serial servos for a tenth the price, but this sort of actuator does require both a lot of torque and an extremely fast response rate, which tends to equal expensive oversized FOC controlled BLDC motors with a low gear reduction.
In the field of robotics there are a lot of things that are expensive to do well, but you can do them badly at a much lower cost.
For example, for many industrial robot arm applications you need an arm that doesn't wobble - so you need stiff links and low-backlash actuators. You need to be able to precisely follow straight lines, so your position control feedback loops need to run fast. Six-axis control of the end effector is standard, gotta be able to move and rotate in X, Y and Z to accomplish arbitrary assembly tasks. And of course it can't be slow - on a production line, throughput is money! Don't forget the need for reliability, a design for 24/7 operation, and availability of maintenance and spare parts for 15 years. $20,000 please.
On the other hand, a robot arm for educating kids? Doesn't matter if it wobbles, or if it's slow, or if the position control isn't great, or if there are some rotations it can't accomplish, and it easily breaks. It'll still be cool and teach the kids plenty of stuff. $200.
$2000 is a typical price for a university group project that'll land somewhere between the two.