Hello all


I m Nathan, a CNC machinist (fitter and machinist) based in Sydney Australia. I have 16 years trade experience and about 10 years programming setting and running CNC machines. I have experience with Mazak, Cincinnati, Heidenhain, Okuma, Fanuc, Gibbs and mastercam. I m retro fitting for the first time and my knowledge on the software and hardware of what makes a CNC tick is fairly superficial. I m keen to love onto the next phase of setting up and maintaining my own CNC machines. I ve started with an Optimum optiturn tu 3008g

My plans are as follows.
Z and X axis CNC control

CNC control tail stock with load sensor

set up tool post for automatic tool change (using an additional stepper motor for indexing tool post with a location pin)

convert spindle from a gear box to a VFD VSD

I m planning on doing this progressively and trying to let the work pay for the improvements so staging and upgrading is the plan.


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Welcome Nathan, I hope you get a lot of enjoyment from your Machine conversion

I am using a CNC Router and make wooden products so from the other side of the planet when it comes to your type of equipment, I am based in Melbourne. I did do metal work back in the day when they taught wood working and metal working in schools so have a basic knowledge of operting a lathe ect

But Ive got a dumb question CNC control of the tail stock would move it into position? and load sensor would allow for it to exert the correct amount of holding force onto what is being machined? But is the CNC controller supposed to basically move the tail stock until it reaches a preset force received by the load sensor?

Are there load sensors that you can dial in a force preset that send a digital or switched output when that target is reached?

I am pretty sure you would have to use a digital or switched input on the Masso to bring the tail stop to a stop (Maybe it is a feature in the CNC lathe controller)

Cheers and Welcome



Hi Steve,
for the tailstock to operate at a set pressure against the work piece, you have set the motor to stop at a particular current draw to set the torque. I won t be able to set a particular torque setting as such but you can calculate how much torque the stepper is putting out for its current draw. You make a cheat sheet that gives the torque value with different levels of current draw. If that makes sense. Generally 0.8kn is enough force to hold most medium sized jobs. Once you know much current the motor draws to exert 0.8kn you then then manually set it. Then limit the draw on the motor​


Hi Steve.

to answer your previous question a little better. I ve done a bit more in depth research and it seems the best solution is to use one of the inputs such as the chuck clamp/unclamped signal. Considering that normally this is done by a switching voltage, load cells convert pressure or load into a voltage output to communicate. Connecting the load cell output to the Masso via an input such as the clamp/unclamped would mean that once the voltage output is high enough from the load cell then the Masso should register that a certain state is obtained. Using a command from the controller to clamp the chuck that triggers the motor driving the tailstock would achieve what you want. It s essentially hijacking the controller into thinking it s doing one thing but making it do another. As a by product it adds a safety feature that the program won t run unless the tailstock is in position.