[Joe-at-CNC]

I'm 90% of the way through a CNC conversion of a little 7x10 lathe. Z-axis is done, I need two little gears and a bracket for the X. For electronics I've got all the hardware except a parallel cable (on order) and have started wiring it. For software I'm using Mach3 for the CAM. For CAD I'm stuck, dead in the water, beating my head against a brick wall. I've been looking and evaluating the 10 million CAD programs out there to find one that is
1. easy enough for my old brain to learn
2. CHEAP!
3. able to export files to something MACH3 recognizes as belonging to a lathe.

So far everything seems to be geared towards mills, or lasers, or routers. I found openSCAD that looks so promising - it does 2D and 3D and seems easy enough to learn. But I haven't been able to figure out if I need to design in 2D, 3D, or what I need to do after I've designed the part to get Mach3 to recognize it. That seems like the program I'd like to use, if I can get it to work.

I've also tried sketchup, freeCAD, HeeksCAD, DraftSight, LibreCAD, BobCAD, and a bunch more that went nowhere. Some I could design in but not export, others were too complicated to even plot a simple circle. I haven't counted, but I'm sure I've got over a dozen different programs installed on this computer that took longer to download and install than they did to try and quit on.

The internet is littered with mini-lathe conversions but nobody seems to be talking about what CAD they're using to design parts. Can someone who has done it and is actually using their LATHE to make stuff PLEASE point me in the right direction?

Thanks,
Joe

[Joe-at-CNC]

Hmm, 10 days and not a single response? I'm beginning to suspect that all those people bragging about their great CNC lathe might have been stretching the truth a bit. Or maybe they did actually build the lathe, but are unable to get software to make it work? Well I've continued to work on the problem and let me tell you how I solved it myself.

So I finished my CNC lathe conversion and it's a real beauty. I went off on my own tangent for the design. I threw out the stepper motors and the entire box of electronics - no breakout board, power supply, limit switches etc. I went for the clean look. Then what I did was I went out to the backyard and trapped me a woodchuck. I had my local vet replace his front teeth with some nice carbide inserts and then I zip-tied the little sucker to the front of the cross-slide. His butt was hanging out the front a bit, but that's OK because I needed someplace to shove the end of the USB cable. The other end went in the computer. Now all I do to make stuff on the lathe is to search Google images for the item I want and hit the print key. He squeals a bit at first, but then he gets to chewing and before you know it, the object is completed. Problem solved, no need for CAD!

[carlowens]

did you ever think that the place to ask what people are using for cad for their lathe conversions is the forum discussing lathe conversions? you're asking about cad for a specific purpose not just general cad info. the cad doesn't need to be anything special anyway, just about any cad program can draw a round part, what is more often asked is what cam people use for turning.

[Joe-at-CNC]

Yea! That was a helpful reply.
Yes, I did think before posting here. I went through the FAQ, and the wiki, and looked at all 317 (I counted, twice, might be off by one or two but I'm pretty close.) forum titles and went into each one that looked helpful.
I also tried the search tab with terms like lathe software, lathe CAD, turning CAD. 2D etc.

In the end, I figured that this was a general CAD question I had, and since the title of this forum is "General CAD Discussion" then this is the best place to start.

OTOH, maybe the software question is super double-probation top secret information that you're scared to post on the internet. I can understand that too. If anyone reading this is actually using a CAD program to write files for their lathe, and have successfully written the design, converted to g-code, and dumped into mach3 or any other controller please feel free to let me know via private message how/what to do and I promise to keep the secret safe.

thanks!
Joe-at-CNC.

[LeeWay]

For a lathe, all that is needed is a simple profile of the part. Half of a flat drawing is sufficient. The other half being identical is redundant.
Some of my parts really are as simple as three straight lines. Any cad out there can do those.
I mainly use TurboCad and have been using it for about 10 years. The 2D side is easy to learn. 3D a little more difficult. I am just starting to learn SolidWorks. It is quite different.

I don't think I would recommend either to a beginner.
Any CAD will take some time and effort to learn even the basics. Plenty have video tutorials and that is how I answered a lot of my initial questions. Watched the videos.
I am sure there has to be some Free Cad somewhere. At least no complaints on the price. Get your feet wet with it and then get something better. You will eventually want to expand your abilities and a free program probably won't let you do that much.

Do you have any video tutorials of the Woodchuck interface? I think that might be worth a look. Welcome aboard and don't forget pictures of the lathe.

[carlowens]

Yea! That was a helpful reply.
Yes, I did think before posting here. I went through the FAQ, and the wiki, and looked at all 317 (I counted, twice, might be off by one or two but I'm pretty close.) forum titles and went into each one that looked helpful.
I also tried the search tab with terms like lathe software, lathe CAD, turning CAD. 2D etc.

In the end, I figured that this was a general CAD question I had, and since the title of this forum is "General CAD Discussion" then this is the best place to start.

OTOH, maybe the software question is super double-probation top secret information that you're scared to post on the internet. I can understand that too. If anyone reading this is actually using a CAD program to write files for their lathe, and have successfully written the design, converted to g-code, and dumped into mach3 or any other controller please feel free to let me know via private message how/what to do and I promise to keep the secret safe.

thanks!
Joe-at-CNC.

see that's your problem, there isn't lathe CAD, like i said any CAD can be used to draw the part or profile you want. CAM is the software that takes the drawing and creates the gcode and there are some CAM programs that are lathe specific. learn about software in general first so you can make an educated request.

[Joe-at-CNC]

Carl, thanks but those generics aren't helping me. I know any CAD can draw a circle. I also know what CAM does. And while there might not be "lathe CAD" there are big differences between 2D and 3D and full view and half profile. I did quite a bit of reading/viewing and hands-on research before here. Have you ever drawn a circle in CAD and converted it to g-code for a lathe? (I guess that could be used to turn a fat rod into a skinny rod). I've tried, couldn't get it to work consistently. It turns out that mach3 doesn't want to be fed a circle, it wants to be fed a half-profile 2D view, and a half-profile 2D view of a circle is a line. If you have a specific CAD that you have used to draw for a lathe then please let me know, and let me know if you've drawn it in 3D/2D, full or half profile, and had it work on a lathe, please let me know what 2 programs you used that worked. Those are the specifics that I'm looking for and I appreciate any specific information that you or anybody who has done it can give me.

Lee - thanks! That is the sort of information I was looking for. I had almost figured out the partial profile part the hard way - I tried drawing in 3D and then exporting, but mach3 consistently said it wasn't a valid lathe file. Then I tried a full 2D shot, and had the same problem. When I would slice the full 2D profile into half I'd get a few of them to work. But a lot of them would have errors because the axis weren't aligned correctly or I had some line extending too far into the negative. That told me half 2D profile might be the way to go, but that positioning properly on the axis when drawing seems to have something to do with it too.

I can get turbocad 18 fairly cheaply. If 2D is fairly easy to learn then I could give it a try. When you have drawn in turbocad for your lathe, do you do full 2D and slice in half, or just the half profile? And do you have to do anything special with the alignment/axis before exporting?

thank again
Joe-at-CNC.


For anybody else out there who has done it - what CAD did you use, did you start in 3D or 2D and compress/slice it first, or 2D full profile and then slice, or just 2D half profile? Did you find it easy enough with your program that you'd recommend it?

And a follow-up on openSCAD - I found that easy to learn. But because of the way it does curves (It doesn't really do arcs) there is no easy way to do a 2D half-profile, and all my attempts at converting/slicing a 3D view have failed, so it looks like that one's off my list for now.

[carlowens]

no you don't know what CAM is because you still think you can go straight from CAD to a gcode file that mach 3 can use. CAD won't output a file that will run on mach 3, there has to be cam program to generate the gcode. here's something specific. CNC Lathe Software | 2 Axis Lathe CAD-CAM Software | BobCAD-CAM | BobCAD-CAM it has cad and cam together in one program. have you tried using the turn wizards in mach 3 turn for simple operations?

[ger21]

When you say you're using Mach3 as CAM, are you using a really old version of Mach3, or are you using LazyCAM and LazyTurn?
There's a LazyTurn manual on the Machsupport forum that goes into detail on how to bring a 2D .dxf into Lazyturn.

[LeeWay]

I have drawn them in every way imaginable, but the simplest is always the easiest to import into CAM. When I am drawing something complicated like a chess piece, I want to see what the full profile looks like. Sometimes it can look a lot different in half view. Then when satisfied, I draw a center line and delete half. Then delete the center line. You are left with a profile of your turned part. CAM can import either full or half drawings. You tell it to show what you want to see and how it should interpret the CAD drawing.

The key is placement on the grid initially in your CAD. Show the grid and there are points or coordinates that you can see. I place my parts at 0 X, 0 Y. This part is the center of my half drawing at the point where my lathe tool would first touching the part. This is where you might do a facing operation.

Most CAM will let you choose a Datum point or origin point in an imported drawing. I just always set it up correctly in CAD and tell the CAM to use the original origin.

I recently needed an upgrade for my CAM for turning and got a lot of quotes.
I had been using an old version of Dolphin Turn.
I wound up just getting a new copy of it. They do have a hobby version and free fully functional trial downloads good for 30 days.

You might be able to use Lazy Turn in Mach 3, but it is no longer supported and it is pretty buggy. A lathe crash is far more costly and dangerous than one on a mill. Both, however are to be avoided.

Dolphin also comes with an easy to learn simple CAD program that makes it very simple. It simply opens up the drawing in CAM when you are ready. They also have video tutorials on Youtube.
That is where I would begin if I had it all to do over again.

CAD-CAM Software | CNC Software by Dolphin CAD-CAM USA

[Joe-at-CNC]

Carl, I'm trying to be nice here but I don't think you've read my original question up in post 1. If you've designed a profile in CAD, and turned that profile on a lathe, then you would have been able to answer that question by now. Since you haven't, and since you doubled-down by linking to a $1200 software program, I'm going to assume you don't have any answer for me. So please don't keep responding. It just fills up the post count, and people who might actually have an answer might assume with so many posts that my question has been answered.

Gerry - Thank you. I'm using the current demo download of Mach3 (Version R3.043.066) with LazyTurn and LazyCam included to do the conversion. I've got a manual from the mach3 website and have been going slowly through it. Mach4 is out and when it comes time to buy I will probably buy that. I'll look at the machsupport forum for the manual you referenced to see if it is different.

[ger21]

Here's the Lazyturn manual:

LAZYTURN MANUAL

[Joe-at-CNC]

Lee! Thanks! I think you just solved a good portion of my problems. I've been setting the axis correctly it seems, but I haven't been deleting the centerline. That's been throwing up most of the errors.
I was on the dolphin site again this morning, didn't see a price. I'll go back and look for the hobby version.

When I am drawing something complicated like a chess piece, I want to see what the full profile looks like. Sometimes it can look a lot different in half view. Then when satisfied, I draw a center line and delete half. Then delete the center line. You are left with a profile of your turned part.


That is where I would begin if I had it all to do over again.

CAD-CAM Software | CNC Software by Dolphin CAD-CAM USA

EDIT: And Gerry, thanks for the link to the manual.

[G59]

What about all the Wizards included with mach3. Or even the NewFangled software that simplifies a lot of the cam operations? Would that not help?

Never mind, it's all for milling I think.

[LeeWay]

I was having some problems with the wizards several years ago when I tried them. Some would work as expected. Others not. They would rarely show the part on screen correctly even though it would turn right. I just wasn't satisfied with the inconsistencies of it.

I will say that different versions of Mach 3 probably handle the wizards differently too and there is probably a better version then I was using back then.
I haven't tried them recently.

[Joe-at-CNC]

G59, there are a few wizards for the lathe portion of mach3 - threading and some simple 1-step operations. Not nearly as many as there are for the mill side. I'll be using the threading wizard once I get the spindle encoder hooked up.
LeeWay - I don't know which ones are buggy or not, but it's my understanding that all the wizards are written by users, not by ArtSoft, and aren't supported, so I guess it's just like any of those apps you can buy for your phone - some will be great, some will suck. I guess it will be a trial and error for each one, and hopefully if I end up needing a particular wizard it will be the one that works.

[G59]

Joe, you have any pictures of your machine?
I have one of those toy lathe thats been sitting on floor at the shop, will be interesting to see what you can do with one.

[carlowens]

Carl, I'm trying to be nice here but I don't think you've read my original question up in post 1. If you've designed a profile in CAD, and turned that profile on a lathe, then you would have been able to answer that question by now. Since you haven't, and since you doubled-down by linking to a $1200 software program, I'm going to assume you don't have any answer for me. So please don't keep responding. It just fills up the post count, and people who might actually have an answer might assume with so many posts that my question has been answered.

Gerry - Thank you. I'm using the current demo download of Mach3 (Version R3.043.066) with LazyTurn and LazyCam included to do the conversion. I've got a manual from the mach3 website and have been going slowly through it. Mach4 is out and when it comes time to buy I will probably buy that. I'll look at the machsupport forum for the manual you referenced to see if it is different.

i've tried to help but you seem dead set against taking advice. i use bobcad/cam for drawing the part and generating the gcode mach 3 turn can use. fyi, if you call bobcad don't accept the face value price, they'll make you a sweet deal like they do a lot of people and you could get it for a few hundred like i did. for simple operations i use the wizards as i suggested.there are 14 different turning operations in the wizards if you bother to look. you test your code in the air before you run a part so you know it works correctly. bobcad has tons of tutorials on turning like this, https://www.youtube.com/watch?v=ypgL7pdnPj0 i got your thread jump started by being the first to respond but good luck, i won't be responding anymore.
carl

[Joe-at-CNC]

G59 - I'll post pics in a separate thread once I'm 100% on the hardware build. I'm waiting on two gears and a belt at the moment (for the X-axis) and should be ready in another week. I'm curious as to how much it can do myself. Worst case scenario is I get frustrated with it, chuck it up in the 4-jaw of my Leblond and turn it into a candlestick.

[G59]

Worst case scenario is I get frustrated with it, chuck it up in the 4-jaw of my Leblond and turn it into a candlestick.

Ha, Ha, Ha,.......... too funny.