Preview Taig CNC Lathe
Update! Article Published!
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Here is another one of my “Sneak Previews”. You can read the previous posts that hinted at this concept. The post before this showed where I was going.
You can see assembly is not complete but this reveals the complete design. The only part I had to make was the conversion mounting plate between the Taig lathe and the Taig mill table. The base plate of the mill is 3/8 thick and so is the adapter plate. A 3/4 inch 10-30 bolt works perfectly with the existing holes and doesn’t extend through the adapter plate. I am thinking of epoxy (and bolts) in the final assembly of the mill base to the adapter to prevent any possible shifting.
The adapter still has the Dykem from the very careful layout of the holes. The base plate was also squared very accurately (on my X3) and this precision is used for squaring the lathe on the mill table. I am aware the lathe bed must be accurately aligned with the mill table.
The pulleys and a chuck will be installed next. One cannot help but notice that honking motor hanging out there. That is the standard 1/5 hp PSC mill motor. 1750 rpm (only $30!) The power is a simple plug in to the existing switch.
In this view it can be seen that even with the full lathe mounted there is plenty of travel in the Z axis to handle any width of material that will fit the chuck and bed clearance. I will experiment to determine if the stock Taig tool holder needs to be mounted farther to the right. I think it does for wide facing cuts. A quick change or turret tool post could certainly be used. The base of the tool holder is a 1″ extender originally for raising the spindle for turning larger parts.
This setup is begging for motor variation and experimentation. I made the base plate adapter wider than the mill table so there would be space for future mounting points that clear the mill bed. Lots of ideas here including motor slow speed control for CNC thread cutting. My controller is already designed for speed feedback and control. (with proper motor and rotation feedback)
This design allows for use of the Taig tail post. Some CNC lathes are shown with the chuck or collet only. So using the full lathe bed the options go up.
Why did I put the lathe head on the right? There are many reasons for this design. Others may like the archaic head to the left and this design can be assembled that way, but consider these reasons:
1. The tool feeds from the top, a given with this layout.
2. The Taig spindle and accessories are all right hand thread on. All cutting should be done with CCW rotation facing the spindle so all working torque will tighten the thread on and not loosen it. No reversing of the motor.
3. The cutting bit is now visible from the top of the bit facing the operator. Clear vision of what is going on in chip clearing.
4. Simple change in X direction either in controller or programming software.
5. The motor is in the back, out of the way of the action (in this initial design). Sharing right side space needed for the stepper motor.
This design is extremely quick change. Slide off the lathe and tool holder and slide on the complete mill motor/spindle and the machine is back to mill work. No permanent mods to the mill are required.
I consider this a great starting point. The “modders” out there can carry this to any extreme. I am already thinking ahead to more motor options. All the rest is about as good as it gets… or I can make it.