CNC Mill Turn Project

[LotsaChips]

Recently I saw several YouTube videos of guys who figured out how to use their CNC mill as
a lathe with gang tooling. I have an IH CNC mill (now Charter Oak) so I quickly got very interested in this, since the price of a CNC Lathe was totally out of the question. It was fascinating to watch, but they did not provide enough information on just how they did it. One guy said he did this using Mach3 and had to write macros to make it work. Some of them wrote the Gcode by hand. There was never enough information in these videos. Sounded way to complicated.

I spent a lot of time on Google searching for information. I quickly learned that the CAM software starts
and $1000. Then there was the problem of figuring out just how these guys got Mach3 Turn to work since it
does not have a Y axis. I found two posts with critical clues. Fusion360 by Autodesk appears to be the best bet for the CADCam software for my needs. The second software is MSM Mill Turn by Calypsoventures. This becomes the interface with Mach3 with the ability to set Y axis offsets very easily. The only other mill turn software I found was MasterCam Mill Turn. Prices start at $4000. I will be testing both MSM Mill Turn and Fusion360 software within the next week or two.

Having selected the potential software for this project, I just completed the preliminary design for the tooling
to make this all work. Attached is CNC Lathe.pdf that will show the setup. This is version 1.0. I hope to get some feedback to make this even better in version 1.1.

With the impressive 22" Z travel axis on the IH mill, I will have the capability to have a usable 9" of material length to work with. I will be using an 1" ER collet for the material holding. The gang tooling is set up to be able to turn up to 3" in diameter. With a 3" 3 jaw chuck with an r8 spindle, I will also be able to turn up to 3" pipe as well.

Here are the cost estimates for this project.

Fusion360 $0.00
MSM Mill Turn $0.00
(both software packages allow free use to hobbyists)
7 piece lathe turning tools $100.00
3" 3 jaw Chuck with R8 $100.00
3 1/2" Jacobs Chucks $30.00
Materials $50.00
Total $280.00

Not a bad price for a CNC Lathe!
Feedback?

 

[Jonathans]

I have also been interested in doing this but haven't thought I could figure out the G code adjustment yet.
Your gang tooling looks good. Naturally the riser will need to be more rigid than the drawing shows.
Also. IMO, 9" of 1" material without a tailsock supporting it might be too much. I would start with something shorter.
Good luck with this. I can't wait to hear how it goes.

 

[LotsaChips]

I also have the same concerns regarding the riser. Like I said, this is V1.0. I am thinking of adding welded internal stiffeners or changing the design to a rectangle built out of 3/4" steel.
Thanks for the input.

 

[RJSakowski]

I will be interested in following your progress. I have done some CNC lathe work with my Tormach 770. I used the 4 way tool post that I had replaced with a QCTP on my Grizzly lathe for mounting the cutting tools. Since then, I have designed but not yet built a more universal tool post mount for the mill. My goal was to make a sturdy design that could make optimal use of the Z axis travel of the mill. Other issues were, rigidity, mounting method, ability of the tooling to get into recesses of the work, clearance for the mill head, and ease of installation I designed the and removal.

The designed mount works with the 4 way tool post but could just as easily be used with a QCTP and associated tool holders. It has mounting positions every inch from 2.2" to 7.2" plus another 2.5" by using different tool positions on the 4 way. The base mounting matches the table T slots, providing two mounting locations in the Y direction.

The machining that I have done was fairly simple and I wrote my own G code. The only issue I had was not realizing that arcs were actually the reverse of what would be programmed for milling. I haven't explored using Fusion to generate code yet.

 

[LotsaChips]

I just got MSM Mill Turn loaded. Basically, it is just a screen set for Mach3. But it is also a little bit more. Mach3 Turn has no Y axis, so all it can do is control X and Z. MSM Mill Turn controls the Y axis, independent of Mach3. Attached is a screen shot of this. This is loaded on my drafting system for testing. I will be shortly loading this on my CNC system and run some simple tests with a single cutter, just straight cutting. I hope to get Fusion360 loaded this week so I can do more complex lathe work.

 

[Wreck™Wreck]

Can you not rename an axis at the software level? Different machine manufacturers use different axis definitions.

 

[LotsaChips]

Can you not rename an axis at the software level? Different machine manufacturers use different axis definitions.

I have heard of some doing that, but in this case it is not necessary. I use Mach3 so the Z and X axis are controlled by this software. MSM Mill Turn handles the tool offsets on the Y axis, independent of Mach3.

 

[Robert LaLonde]

Can you not rename an axis at the software level? Different machine manufacturers use different axis definitions.

I have heard of some doing that, but in this case it is not necessary. I use Mach3 so the Z and X axis are controlled by this software. MSM Mill Turn handles the tool offsets on the Y axis, independent of Mach3.

Wait. What? So does that mean you program 3 axis of offset for all your tools, and don't actually worry about setting up tools on the same height?

 

[Wreck™Wreck]

Wait. What? So does that mean you program 3 axis of offset for all your tools, and don't actually worry about setting up tools on the same height?

No, every machine has a designation for each axis, if your software calls a particular axis "A" and the machine calls it "B" a program will not be able to execute commands on a nonexistent A axis, changing the name to B will solve this at the software level.

Using a mill control for lathe operations may simply cause a name problem between axes, 3 axis lathes have X, Z and C, C being the spindle, most 3 axis mills have X, Y and Z.

 

[Robert LaLonde]

I'm familiar with CNC setup actually. Typically on a lathe its assumed all tools are setup on spindle center for tool height and unless you have a C-Axis spindle control you only use Z and X for basic control. Z is along the bed and X is across the bed. Oddly enough the DRO on my 1440 uses X & Y, but I could put a sticker on it if it really bothered me. LOL.