I'm skipping J1 Turret housing and spindle for now because they are mostly lathe part and Lael is already proficient in lathe work and this will be a great gateway for the first CNC operations.

Moving down the list, I machined the turret platform.

OP1 is very similar to the previous parts where we face up, machine the contours, drill holes and chamfer the edges:

OP2 is done is 2 steps: decking the hat with a facing operation, probing one of the hole to run the chamfering:

Then OP3 is drilling but we take advantage of holding the part in this orientation to clean the corner, in OP1 that corner was limited to the radius of the contouring tool (in my case a 1/4in end mill)

In this orientation, we clear the corner, limited now by the corner radius of the endmill:

And finally the 2 holes in the last operation:

With that J1 Turret platform is down and I have enough parts to let Benjamin and Lael start the machining and the build. Future updates will be around end of July with them, stay tuned, J2 Turret housing, J2 Arm and J5 housing are very interesting form a machining stand point.

As always, thanks Chris for your amazing design, your support and your help inspiring the next generation of machinists, robotic engineers and all-in-all makers !

Moving on to the J1 and J3 motor mount. Simple parts really with the same overall process:

OP1, main features:

OP2, removing the hat and de-burring

OP3, drilling the set screw holes on the last face:

Since this is my 2-1/2th AR4 I'm building (IAR3 then converted to AR4 back in 2020, see post here: https://www.anninrobotics.com/forum/robot-builds/ar3-in-florida), I am acutely aware of the difficulties to wire everything in the tight controller box.

So I took the liberty to modify the box, since it is now detached from the machined base and enlarged it by 30mm in both length and width. Of course that meant enlarging as well the tray and the lid. I took some hum creative liberties with the lid design:

Here is the box printed and connected to the base with 2 M4 bolts:

Next is J1 Base Plate, very similar machining than J0 Base:

J1 Base Plate OP1, we machine the key features

J1 Base Plate OP2, re-using the jig from J0 Base, we hold the part upside down and machine the hat:

This is a bit more tricky because the 4 M8 bolts are in the way

First we machine 3 areas clear of the bolts:

then remove 2 bots and machine that area:

then swap the bolts and machine the last area:

After some taping, J1 Base Plate is done

As per last time, I have opted to make the base a solid piece of 6061 aluminum (and close the bottom, to prevent dust/dirt into the J1 belt). I have modified the electronic enclosure to attach to the base with 2 M4 machine bolts.

J0 Base OP1, machining of key faces and features:

J0 Base OP2 (removing the "hat"):