Centroid Community CNC Support Forum

Hello,

I am revisiting starting a new project of converting a Lodge and Shipley Powerturn manual lathe model 2013 to CNC, but am looking for a little guidance. We do not use the lathe for turning applications but rather strictly for drilling along the Z axis, so this should hopefully simplify it a bit. I am thinking using a Ø32 or 40mm ballscrew with a 2:1 HTD belt reduction to a 1kW AC servo.

I am looking at using the Acorn and Lathe Pro software.

Here is the servo motor and driver that I am thinking of using.
https://www.omc-stepperonline.com/t6-se ... 0h2a3-m17s

I feel I have a firm grasp on the mechanical side of the project as I am thinking I will remove lead screw, feed rod, apron gearing, Z axis motor and related. Then install the ballscrew, bearing blocks/housings, servo motor and pulleys.

Where I am mainly struggling, is determining what electrical components to remove from the machine currently and what to reconnect. There is a lot going on currently in the enclosure that I am not 100% sure of. Unfortunately I do not have any documentation or schematics for the machine and have been unable to find any.

I know for the new controls I will need the following to be incorporated;
- Servo motor and driver
- VFD for spindle motor
- Current Coolant pump (or another if not compatible)
- Z axis limit and home switches
- Acorn and power supply
- E-stop
- Circuit protection
- Mini PC

Is the best approach to remove all unnecessary items in the current enclosure and put the new items in there or to add a new additional enclosure?

I am just not fully sure what wiring and components/circuitry from the original configuration will stay and which will get removed. It has a Reliance Rectified Power Module which from my understanding was because the lathe used to have a DC spindle motor. It is not connected anymore and the spindle motor was swapped out to AC with a VFD.

VFD
https://www.motion.com/products/sku/028 ... MIVNURJVjo

Any help or suggestions would be greatly appreciated. This is my first time attempting to retrofit a machine as I have only made a 3 axis mill from scratch with the Acorn.

Suggest you do the following...

First - take a big piece of cardboard and draw a rectangle on it that represents the existing enclosure. Make a note of any non-moveable interference inside or outside the enclosure.

Second - using the appropriate Acorn schematic as a guide, lay out all the components you need inside the enclosure. Cut out cardboard pieces of approximately the real size and start playing the 'No enclosure is ever big enough' game. Don't forget to add an extra relay or contactor (or 2), because someone is going to say "We really need a XXX installed if we want to do YYY job. How hard would that be?" about 3 seconds after you're done.

Third - make a list of all components that are outside the enclosure (motor, switches, pump, indicators, etc.) and make some cardboard pieces for those. They need not be to scale, but this will help you remember everything that needs to exist on the machine while thinking about where cables are going in/out and what size they are.

Imagine you're mounting & wiring everything inside the box. Does it all fit? Can you keep the Acorn away from the VFD and noisy motor cables?

Is there room to separate the low voltage signal conductors & components from the high voltage stuff? Where are all the cables going to enter/exit the enclosure?

Can you keep the heat-producing components at the top and cold stuff down low? Does the enclosure have a (working) ventilation system in it, or do you need to plan on cutting some holes for fan(s) and vent(s)?

Do you plan to have an operator panel with integrated keyboard & monitor, or just a rickety shop cart/table with a keyboard & mouse on it? An operator console is a great place to put the mini PC - keeps it away from drive heat and noise.

You appear to have a couple of line reactors at the bottom left of the enclosure - one of those would be nice to re-use for the VFD if it's an appropriate kva. Everything else looks kinda suspect. Even the disconnect looks ratty and could be replaced with a fused disconnect to cut down on component count & wiring.

My guess is that you'll wind up gutting the existing enclosure. It'll be easier to work on, and you won't have any leftover components/wiring that can trick the next person troubleshooting the thing (i.e. you, after you've forgotten what you did the first time).

And another thing...

Buy a label maker that can print directly on shrink tube; it's a game-changer for wiring.

I'm partial to Epson as they have the cheapest per-foot refills, as well as the smallest diameter tube available of all the 'big' label maker brands.

Hi spumco,

Thank you for the response and ideas. I like the idea of cutting all of the components out of cardboard and creating the layout that way. I have done some more digging on the machine and I think I have a firmer grasp of what is going on. It sounds like from the factory it had a DC spindle motor, hence the Reliance power module and someone swapped the motor out and connected it with a VFD.

Building from scratch in a sense was easier for me because I had a blank canvas and was really bound on time. However, with this project we currently use the machine for production, so the amount of down time will have to be minimized as much as possible. I feel if I can have everything laid out, then stripping the current cabinet and installing all of the new components should not be too bad. I learned the hard way on my first build that I wish I would have gotten a bigger enclosure.

For the operator panel we are going to use a touchscreen and keep the pc in the cabinet. This will at least be the solution for now. The console would be great but looking to keep costs down where we can right now.

If you want minimal down time:

Partly disassemble to get measurements for fitting the ball screws, servos and limit switches

Make drawings or CAD models and mill these parts

Benchtest the Acorn board and second step the servos and spindle drive

Build the cabinet, test with servos and limit switches connected.

If everything is ok and your mounting parts are designed and made ok,
bolt on the stuff can be done in 1-2 days.

Uwe