Taking the CNC Plunge

[chuckorlando]

Looks good. If you dont mind me asking... How much money do you guys have in one of these conversions? You would need something like the kit linked and then ball screws? Anything else besides a PC?

 

[TomS]

Does yours have the power down feed and 3PH motor?

Was looking at the pics... the X drive unit is obvious... what is that black drive unit in the wood box at the back of the column?
THX

I didn't get the PDF option because I'm converting to CNC. The motor is single phase 120/220 volt AC. A three phase motor and VFD is something that I may do after I'm up and running.

I did a trial run in each of the speed ranges after changing out the headstock oil. I was pleasantly surprised at how quiet it was. The three axis' were smooth through their full travel. I checked the spindle taper run out with a .0005" DTI and the needle barely moved. Overall the machine appears to be good quality.

Tom S

 

[TomS]

Looks good. If you dont mind me asking... How much money do you guys have in one of these conversions? You would need something like the kit linked and then ball screws? Anything else besides a PC?

I've done a lot of reading on other CNC builds to get a feel for what it takes in the way of materials and effort. For me the mechanical part of the conversion is not that difficult, it's the electrical/electronic areas where I'm weak. So I could get my arms around the material requirements I put together a BOM. The big dollar items are the mill, motors and electronics, ballscrews and nuts. A PC is required but not that expensive. It's the CAD and CAM software that can run into some dollars. You still need to gather the miscellaneous electronics (relays, breakers, switches, wire, etc.), a box to put it in, and motor mount materials, plus other miscellaneous items. By my estimation I'm going to have about $5,500 in it by the time I'm through. Some have spent less and some more.

I hope I've answered your question. If not let me know and I'll share the details.

Tom S

 

[zmotorsports]

Looks great. Congrats on the mill and sounds like you have a solid plan for the CNC conversion.

Mike.

 

[chuckorlando]

Thanks for your time. How much of that is just in the conversion? It would cost an arm and leg to cnc my bridgeport so if I went that route it would be on a smaller newer machine or an older already cnc factory job. Just wondering what one might expect to pay minus the mill and cad/cam.

 

[TomS]

Thanks for your time. How much of that is just in the conversion? It would cost an arm and leg to cnc my bridgeport so if I went that route it would be on a smaller newer machine or an older already cnc factory job. Just wondering what one might expect to pay minus the mill and cad/cam.

Minus the mill and CAD/CAM expect to spend $2,000-$2,500 for a ZX45 conversion.

Tom S

 

[GA Gyro]

Just curious here...

When folks CNC a '45'... is it still possible to use it manually... or is it either/or?

Seems there would be times where hands on was easier than setting up a program to do something simple.

Obviously a noob question... however one has to learn...

 

[JimDawson]

Just curious here...

When folks CNC a '45'... is it still possible to use it manually... or is it either/or?

Seems there would be times where hands on was easier than setting up a program to do something simple.

Obviously a noob question... however one has to learn...

Apologies to TomS. We are kind of hijacking this thread, but I think this a very pertinent question.

The most common and least cost conversion uses stepper motors that are either direct or timing belt coupled to the lead screws. With the stepper motor powered down, it is possible to overpower the inherent mechanical (magnetic) resistance of the stepper motor manually. It takes a fair amount of force to do so and the stepper motors cog due to their design. Assuming that you are using a standard 200 step/rev motor and have a 5 pitch lead screw that is direct coupled, then the motor will cog at 0.001 inch increments. Irritating at best on the X and Y axis. On the Z axis, without decoupling the quill from the lead screw, it is impossible to use the quill manually. Without providing a very convenient way of decoupling the stepper motors from the lead screws, manual operation is not very practical. If I couldn't switch over in under a minute, I would find it very irritating.

Another and more costly option is to use DC servo motors. These have almost no mechanical resistance when powered down. The Z axis lead screw still must be decoupled from the quill to manually operate the quill. The down side of this is the cost and the more complex control system.

 

[TomS]

Apologies to TomS. We are kind of hijacking this thread, but I think this a very pertinent question.

The most common and least cost conversion uses stepper motors that are either direct or timing belt coupled to the lead screws. With the stepper motor powered down, it is possible to overpower the inherent mechanical (magnetic) resistance of the stepper motor manually. It takes a fair amount of force to do so and the stepper motors cog due to their design. Assuming that you are using a standard 200 step/rev motor and have a 5 pitch lead screw that is direct coupled, then the motor will cog at 0.001 inch increments. Irritating at best on the X and Y axis. On the Z axis, without decoupling the quill from the lead screw, it is impossible to use the quill manually. Without providing a very convenient way of decoupling the stepper motors from the lead screws, manual operation is not very practical. If I couldn't switch over in under a minute, I would find it very irritating.

Another and more costly option is to use DC servo motors. These have almost no mechanical resistance when powered down. The Z axis lead screw still must be decoupled from the quill to manually operate the quill. The down side of this is the cost and the more complex control system.

Jim - no need to apologize. I'm a CNC newbie too and looking for as much information as others will offer up. My build will be a learning experience as I don't have any prior CNC exposure and I'm real weak when it comes to the electrical/electronics side of the conversion. Anyway should be a fun project.

Tom S

 

[jbolt]

Just to add, on a 45 clone the Z can be driven by the head or quill. Driving the head allows for more useful cnc head travel and leaves the quill free to use manually. On that note I did a power down feed on my smithy quill using a stepper driving the fine feed worm. I can use the fine feed manually when not powered but if it is turned too fast the stepper will lock which would be extremely annoying in the X Y of a mill table.

I did not bother trying to make my PM932 cnc conversion usable manually. The few manual operations I have needed to do are easy enough using the MDI interface or pendant.

Jay