Just to be clear, I don't want to claim expertise I don't have: I'm only just a bit past that stage in my career and have had a lot to learn in the past few years.
Just a stream of consciousness set of notes from my reading of the article though:
* The design of the interior machined parts looks like a classic case of why machinists make fun of / mildly dislike engineers. "As long as I can make it in a 3D model we can make it out of metal, right?" They're beautiful, but if a part is going to be hidden from your end user, maybe think about how much manufacturing time those artistic rounded fillets are going to take up and design something that can be run on a 3 axis machine instead of a five axis machine.
* That injection molding. Wow. I'm kind of in two minds about that, because I can at least get behind the idea of spending time and money on the part of a machine your customers will be touching and seeing every day but good lord is it expensive, especially for low volume boutique products.
* The gear system. I'm surprised to see a set of spur gears in there vs a planetary gear set. Planetary gears are quiet and space efficient while also being able to transmit large loads. I'm surprised there actually wasn't a gearbox manufacturer from the cordless drill industry (another high input speed -> high output torque device) that they could tap to get a already designed and mass produced gear-train for much less money.
That's about what I thought. That recessed fillet makes me think someone clicked "fillet" in Autodesk Inventor, not realizing what it does to the machining time. The machined parts seem to have machined features on all sides. I wonder how many setups that takes. If they'd designed it out of thick flat plates, the plates could be cut on a water jet or plasma cutter, or machined with one setup on a 3-axis mill.
I haven't done injection molding, but I know that making the molds is the expensive part. Once you've made the molds, making parts is cheap. If there was an overoptimistic market projection, the mold cost per part would seem low.
There's a fairly common arrangement for presses where a motor drives a worm gear which drives a ring gear with a threaded or ball screw hole. Here's a consumer-appliance grade version from China, used in an oil press, pasta extruder, or juicer.[1][2] $2 in quantity 500. The first thing to do in mechanical design is to find out what you can buy.
Fancy molds with high tolerances require multiple iterations of making molds then destroying them. You can also find that parts are not able to be shot, usually before, but sometimes after making the mold. The texturing and cuts are expensive and difficult as well.
If they were going for Apple-level tolerances, they're walking into a minefield.
Just a stream of consciousness set of notes from my reading of the article though:
* The design of the interior machined parts looks like a classic case of why machinists make fun of / mildly dislike engineers. "As long as I can make it in a 3D model we can make it out of metal, right?" They're beautiful, but if a part is going to be hidden from your end user, maybe think about how much manufacturing time those artistic rounded fillets are going to take up and design something that can be run on a 3 axis machine instead of a five axis machine.
* That injection molding. Wow. I'm kind of in two minds about that, because I can at least get behind the idea of spending time and money on the part of a machine your customers will be touching and seeing every day but good lord is it expensive, especially for low volume boutique products.
* The gear system. I'm surprised to see a set of spur gears in there vs a planetary gear set. Planetary gears are quiet and space efficient while also being able to transmit large loads. I'm surprised there actually wasn't a gearbox manufacturer from the cordless drill industry (another high input speed -> high output torque device) that they could tap to get a already designed and mass produced gear-train for much less money.