Ever since dabbling with a used CNC shark(and immediately selling it) 10-12 months ago, ive been on the lookout for a 'real' machine at the right price. Even going so far as to sell my restored Powermatic 72 to free up shop space and shop money for such a machine. The saw is out and im living just fine the last two weeks with the Felder saw/shaper as my only table saw. My local CL had a shopbot pop up that is pretty old. A 2004-2006 machine that is a PRT model. I think its listed at $4,500, which isnt exactly a smokin deal, but it made me wonder at what point is this machine worthwhile? $2,000? Less? What are pitfalls with older machines where they become almost value-less? I know controllers are expensive components to keep an eye out for. This specific machine has the updated controller that is a couple years old at this point, and not much of a worry. Is it possible to wear out rails or ball screws/lead screws enough to matter? Im not necessarily pursuing this machine, but it had me wondering and wanting to start this thread about older 4x8 machines. Ive seen a couple over the last year and they appear like 'OK' deals close to my budget, but i dont know enough about CNC routers to appreciate their used value. For example, its hard to wear out a table saw, or for a table saw to become obsolete compared to newer models. Quite the opposite, actually. In the case of this Shopbot, i feel like a new $7,000 Avid CNC kit would smoke the PRT.
Even though this isnt the greatly improved PRS model, im guessing this steel frame provides enough rigidity for most of the cuts i would want to do. The CNC shark had the structure of a wet noodle. What is disappointing is this PRT has a PC router as a spindle, maybe NEMA 17 or less steppers, and an outdated software package. These are most likely critiques leveled against most mid-level machines that are 10+ years old. With that in mind, is there a specific point where CNC routers became more affordable/better designed etc? Knowing the very little i know, it seems like frame/gantry designs from 2008-2010 are still relevant and potentially still in production today. This is me looking at companies like Shopbot, Camaster, Shopsabre etc.