So previously, I built a CNC router that was, frankly, a waste of money. JazzCNC kindly referred to it as 'made from spaghetti'.

Since that time, I have bought and retrofitted my Denford VMC which I still have but will sell once Thor, or Zeus is created. I want to have a machine that can move quick, cut Alu with ease and potential a bit more too. I dont generally work with steel but Id like the option to cut some at times.

Ive been itching to do a new build for a while and pulled the trigger recently on some parts. I kinda started a thread looking at some design ideas a few months ago however I wasnt sure that the design I was showing would work. I found some bits online and am now designing around some parts that I have.

If there is one thing to achieve, is a machine a bit more rigid than spaghetti. I am hoping that when you look at the selected parts, this may be achievable.

Let's discuss design first.

Thor, fixed gantry design, the base and gantry designs are not complete, there is a lot of optimisation that can be done. I wanted to get an idea of machine size, weight and design options with the specific rails and ballscrews I have. I have also spent a lot of time reading different whitepapers on machine design and whilst I certainly dont know a lot, I understand a lot more about some of the design criteria, materials and rigidity.

Thor is a fixed gantry system. I originally wanted to do moving gantry (like the Datron machines) however I was dissuaded on this on the basis of getting good rigidity is difficult and I dont want to run two ballscrews / motors for Y. The availability of the bits I bought have also contributed to this.



Subsequent to this design, a number of concerns came up. Some of them are around how to make the structure and get the surfaces flat. I intend using either UHPC or some variant or some form of Epoxy Granite or similar.

I then spent some time over the weekend going back to a fixed head design. I watched many videos where a lot of modern machines use this tried and tested method and the design below, suitably called Zeus, was born.



Whilst I was coming up with the design, I really struggled with getting the Y table size larger than 65% of what the fixed gantry offers. The 'overhang' of the Z Axis is also concerning however I kept at it.

I then spoke to the person that has sold me all the mechanical bits (my pimp) and his advice is to go with the fixed gantry design. We discussed this at length and currently, my plan is to build Thor (top design).

So, parts.

X Rails - Bosch Rexroth 45mm rails, 1180mm long using high preload roller bearing carts.
Y Rails - as above.
Z Rails - INA 25mm rails, 346mm long (I'm trying to source 500mm rails) with roller bearing carts.

Ballscrews, well, I have a selection. For X and Y I have 6 leadscrews, all 40mm with dual preloaded ballnuts and different pitch options from 10 to 20 mm.

For Z, I have some Eisenmann screws, 32mm, 5mm Lead, dual preload ballnut.

Motorwise, I may have jumped the gun a bit but I am hoping that with all the different options of screws (all use 3080 mounting bearing) that Ill find something that works well in terms of pulley ratios.

I have gone for Panasonic Servos, A4 range. 1.5KW for Y, 750W for X and Z. All of this will be controlled with the CS Labs IP-A unit.

All in all, I am looking forward to this build. I'd love to be testing already but still very far from that.

No more spaghetti and aiming to get speeds of around 20m/min with acc rates of 5m^2.