First cnc build from surplus liquid dispensing machine

[ryzen]

Hello,

I`m preparing to build my first CNC that could cut wood, aluminium and steel. I started this thread to gather some preliminary feedback about my idea in general (I have not started designing the machine yet). Build log will follow.

At the moment I have opportunity to get old (but functional) Speedline Camalot 5000 liquid dispensing machine for free. This machine has solid steel frame, full metal side plates, large metal tube construction. Total weight of the machine is ~900 kg so frame itself must be around 800 kg or more. I know that this nothing compared to commercial machines that weigh 3-8 tonnes but should be usable right?

To me it seems like this machine has quite strange design - Y axis rails are mounted to block of metal that is bolted to the ceiling of the cabinet. X and Y axis rails are mounted to gantry running on Y-axis. I can imagine that this design is probably not the best for cnc machine unless gantry and frame are super heavy and rigid.
Very coarse pitch lead screws are used for translating rotational motion to linear motion - not surprised that both resolution and repeatability are 25 microns only.
I`m actually even thinking about building smaller cnc router first. I think that current Y and Z axis on this machine would be suitable for smaller machine.

some photos:





















Why I`m thinking about building cnc is that I also have 2 super bulky precision machined linear rail support bars (1.6 m long and around 75 kg each) from old Siemens pick&place machine and brand new Bosch Rexroth linear rails (25 mm) with 4 new guide carriages. I`m thinking that this would be quite good setup for Y-axis.
Unfortunately I do not have any long ball crew for Y axis so I have to purchase one. What size/brand manufacturer do you recommend?
I do have two 1605 ball screws (~50 cm long) that I salvaged from old Siemens pcb lifting units which probably can be used on X-axis. They look super nice like most parts on Siemens machines.
I also have many servo motors and drives.

I would really appreciate some input regarding how suitable this machine is for cnc conversion.
Is it too weak because its center of gravity too high (all the commercial machines have most of their weight very close to the ground)?
Should I just build my own frame from scratch?
If suitable then would you recommend going for fixed gantry design or not?

Thanks.