Wobblycogs CNC Mk1

[JAZZCNC]

The highest it seems reliable at with 3Nm motors is 12m/min (so about the same as Jazz's but with substantially smaller motors),

Not much difference really because I have single motor turning 2 screws and you have 2 motors, plus 34's are stronger and will hold more torque higher up the curve.!!

Don't see the point of going to all the expense and trouble of implementing a rotating nut design and all it's complexity's when the standard setup will still allow everything he needs anyway.? The extra expense of components and having someone (Namely You) machine the rotating nut assembly cancels out extra cost of 34's etc for what is affectively wasted speed has he'll never cut at those speeds and Rapids are only usefull in quite limited circumstances.!

If speed is required then yes I'd take the rotating nut assembly route has it clearly will allow higher feeds but if cutting below 7mtr/min which most materials are then why go to all the trouble.??

[Jonathan]

If speed is required then yes I'd take the rotating nut assembly route has it clearly will allow higher feeds but if cutting below 7mtr/min which most materials are then why go to all the trouble.??

I agree - clearly the only reason to do it is if it works out cheaper or if you especially need the higher speed and (perhaps more importantly) acceleration. Personally I would do it even if the cost is slightly greater since the factor of safety will be much greater, so you will have a more stable system. Perhaps ask Chai for the price separately for two RM1610-1800mm and RM2510-1800mm so we can compare the relative cost more precisely?