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J1 Turret Platform Shape on AR3

After a major family tragedy I'm finally getting back into the box of AR3 parts and continuing on my CNC machining education. Much like the Gingery Lathe project taught me casting and simple machining the AR3 is all about learning how to better use my LinuxCNC converted milling machine. Eventually the AR3 will become a tool changer and part swapper.

I'm modelling a lot of the parts as 3D printed first to get a feel for how they fit together and how to machine them.

The question is why the J1 Turret Platform that is 3D printed doesn't have the notch that the drawing and metal part does?

4 comments

Comments (4)

Chris Annin

Sep 22

I did make a correction to the J1 platform to offset the position of the J1 spindle. I would recommend using the latest models from the AR4-MK3 for the J1 turret platform and J2 housing. Please email me and I can send you any updated step files you need.

johnd

Sep 22

Replying to

Thank you Chris. From what I can see for the AR4-MK3 the only difference is that recess. The Hub recess is in the same place relative to the sides and bottom.

I've already recreated the AR3 part in AlibreCAD and MecSoftCAM. I'm already into all the other CAM generation for the AR3 version. Yes more holes. Shouldn't make a difference though?

I'll print the STL version of my drawing today just to verify the fit. The forum won't let me attach the STL.

Chris Annin

Sep 22

Replying to

I believe that will work fine. You are correct there will be some additional holes that were omitted when the part was updated.

johnd

Sep 22

Replying to

There is also an error in the J2 Drive Spindle PDF Drawings for both the AR3 and AR4. I haven't yet checked the AR4-MK3. My J2 Motor+Planetary drive has a 14mm shaft and 5mm keyway. The pdf drawing shows on the left hand side the bore is 14.014mm. However on the right hand drawing it shows that same hole as a radius of 6mm. The larger relief hole behind the motor shaft is correct at 20.625mm.

My 14mm reamer was, with a bit of work, able to enlarge the 3D printed model to be a tight sliding fit onto the planetary drive shaft.

Oh and the key on the drawing is marked as 4mm although the sketch doesn't look aligned with the slot so really should be 5mm.

The screw circle radius or diameter is not documented although it can be found from J2 Tension Ring drawing as 23mm.

Although the spindle drawing says tap with 3mm bottom tap I couldn't find the depth of the hole. I mention this because the 10mm flat head screws for attaching the J2 Tension Ring only protrude out about 2.9mm and that's with a generous countersink hole.

From the photos in the assembly manual the tension ring looks more like it's 6.35mm rather than almost 8mm thick. Is that an error?

Edited

ANNIN ROBOTICS

J1 Turret Platform Shape on AR3