[Skyfire]

No personal offense, but:
I fear you are going to early from drawing to a cast:
I mostly see straight wooden plates and too few taper angles as you mentioned.
Apparently, you tilted the plates, but the internal ribs look like straight plates.
It will be quite difficult to implement all the internal radii with filler.
In some areas the material is much thicker than in others, which will likely cause distortion in the cast. Consider beefing up the ribs to make them as thick as the walls.
The weight of the head doesn’t appear to be a match for the z-motor size. Have you done calculations or tests? Keep in mind, most data you get is the holding torque of a stepper, not the dynamic load. Do you have the efficiency data of Z lead screw?
I can’t detect any wiring of motors and limit switches in the drawing. If not implemented in the design, than you may need a hole here and there where there isn’t.
You mentioned coolant later to be added. So you’ll need skirts and covers for your linear bearings and ball screws. If not already implemented in the design, I fear, it will either not look pretty or skirts will leak against the iron cast.
There are no fasteners in your design, so I do assume you'll drill and tap holes later. I find this quite risky as you may oversee one or the other screw head can't be reached or needed to be counter sunk.

Hi Stewi. Thank you for further comments.

a. I do have place tappers for every side wall of the molds. and the tapers are not of the same angle. for some walls not too deep or apperant surface, using smaller angles, and for larger and machining surface, and especially inner ribs, use bigger angle. within the range of 1-5 degree. I think maybe the photos don't show the angles clearly. I will try to show the angles in photo after painting works.

b. I made the inner ribs seperatelly with tapper and glued them inside the frame. so It's easy work to make the ribs with angle. so no fllers will be needed.

c. Yes. The molds are not of the same thickness many places. It’s just the part need machining in future. After machining the slots and grooves etc, the thickness will have nearly same size so cause no dissortion. And, in formal manufacture, all castings need ageing treatment to eleminate inner stress to prevent it.

d. The head weight & Z motor torque issue is a important item. I agree with your opinions on motor torque issue and ballscrew efficiency issue. Both of them need to consider the dynamic spec. but not of the static ones. The motor size shown in the drawings are just use the same motor model with X, Y axis in PTC. The Z motor should be bigger than X,Y ones. And, there are also other way to solve this iss in industrial machines like balance weight method or N2 strut. I will test this during assembling and testing progress. All of the motor and ballscrew data are avaliable from supplier side and of course need to refer to the data sheet.

e. Yes I didn’t draw the wires and holes etc in the design and the fasteners also. I just have no much time to do so many detailed works. But they will be shown in CAD sketches that I also have finished now.

f. About the covers etc. You are correct that they must be added on the machine. I didn’t show them in the design because I have had many experience on similar machines and not a big problem for me. I promise you will see on finished machine.

And thank you for your detailed comments again. I think your comments are very helpful for building a machine. I’m sure you have many experiences in building machines. I’m very happy to discuss with you on further details.

Regards