what to look for when searching for cnc mill kit?

[thriller007]

I do like having a manual mill and I love the idea of cnc but I am a total newb at cnc. I currently am running the craftex cx 601. If I was to convert it to cnc could I just run it manually with power off the steppers with handles as well? Is it best to buy a kit with all the adaptor plates and electronic goodies or say start by converting to ball screws and still use as is and build up eventually? Or is it best to just find a different small mill to do a separate project all together? Space is at a premium for me. What small machines or cnc parts do you have sitting in your shop that you have collecting dust that need some loving? thanks in advance.

 

[kevin.decelles]

My opinion: two machines if you have room

I have a 6x26 knee mill (manual) and another knee mill that is a cnc project in progress (running on lead screws with open loop steppers). I have had to use the manual mill often to assist in the conversion

There are many projects that I’d rule out the cnc for, having a manual mill is essential imho

I may convert to ball screws but need to do get some use of the cnc in its current form First


Sent from my iPhone using Tapatalk

 

[jcdammeyer]

CNC has a pretty steep learning curve. You might even find that you don't end up liking it.

For example have you run your system with a DRO? Most things can be done, often faster, with a DRO and a drawing with the offsets from a home position compared to writing your own G-Code.

How do you do your drawings? CNC is really mostly about creating G-Code either from drawings or writing your own. Although with MACH they have wizards that automate many of the mundane operations like facing etc. Less of that in LinuxCNC.

Having said all that if you have a lot of backlash in your system you've probably already seen that you really can't take deep cuts and climb mill and accuracy even with backlash compensation (which comes with it's own issues) isn't really as good as ball screws without backlash.

I've taken the approach that I want to learn how to use CNC and work with it before going through a massive retrofit that might not be easily reversible. Therefore I have stayed with the ACME screws for now until I have a stable and well working system. And I have had my problems with some of my choices but I've also been really slow at converting because I had a Shumatech DRO and scales and those were installed within 6 months of getting the mill so I've never really looked at the handle scales. They're gone now anyway.

I've found that unless the stepper motors or servos are physically disconnected from the drivers turning them is difficult. They act as generators and the circuits tend to then short that signal causing quite a load. Once you have a pendant on your CNC system along with the displayed position the handles are a little bit redundant anyway and the handles unbalance the shaft when it's turned quickly.

So before you change to CNC think about how you will use it. How you will create the G-Code. What level of precision do you want. Ultimately if you continue with CNC you will probably end up installing ball screws.

Another question and I don't know the answer with respect to MACH4 but with LinuxCNC you can do power tapping where the CNC synchronizes the spindle with the Z axis and taps holes automatically. Pretty cool actually. If you want that feature then you definitely don't want backlash in your Z axis.

Just some comments and ideas. I'm still an amateur thrashing about in the swamp often fighting alligators and forgetting that I'm there to drain the swamp to get rid of the alligators.

 

[thriller007]

CNC has a pretty steep learning curve. You might even find that you don't end up liking it.

For example have you run your system with a DRO? Most things can be done, often faster, with a DRO and a drawing with the offsets from a home position compared to writing your own G-Code.

How do you do your drawings? CNC is really mostly about creating G-Code either from drawings or writing your own. Although with MACH they have wizards that automate many of the mundane operations like facing etc. Less of that in LinuxCNC.

Having said all that if you have a lot of backlash in your system you've probably already seen that you really can't take deep cuts and climb mill and accuracy even with backlash compensation (which comes with it's own issues) isn't really as good as ball screws without backlash.

I've taken the approach that I want to learn how to use CNC and work with it before going through a massive retrofit that might not be easily reversible. Therefore I have stayed with the ACME screws for now until I have a stable and well working system. And I have had my problems with some of my choices but I've also been really slow at converting because I had a Shumatech DRO and scales and those were installed within 6 months of getting the mill so I've never really looked at the handle scales. They're gone now anyway.

I've found that unless the stepper motors or servos are physically disconnected from the drivers turning them is difficult. They act as generators and the circuits tend to then short that signal causing quite a load. Once you have a pendant on your CNC system along with the displayed position the handles are a little bit redundant anyway and the handles unbalance the shaft when it's turned quickly.

So before you change to CNC think about how you will use it. How you will create the G-Code. What level of precision do you want. Ultimately if you continue with CNC you will probably end up installing ball screws.

Another question and I don't know the answer with respect to MACH4 but with LinuxCNC you can do power tapping where the CNC synchronizes the spindle with the Z axis and taps holes automatically. Pretty cool actually. If you want that feature then you definitely don't want backlash in your Z axis.

Just some comments and ideas. I'm still an amateur thrashing about in the swamp often fighting alligators and forgetting that I'm there to drain the swamp to get rid of the alligators.

Thanks so much for your honest input. I do want to dabble with gcode and the inexpensive way to learn this for me was buying a CNC router. It is a small 3018 pro but I am just starting on it. I am currently using Candle but have played with UGS as well. I am a beginner with fusion 360 as well and have not done machine operations with it but just basic design and 3d printer stuff.
I do like the idea of not changing to ball screws right away. Also I do use a dro on my machine. Could I leave the dro on? What size of a mill are you doing and what size stepper motors are you using?

 

[Janger]

What’s a small 3018 pro cnc router?

 

[YYCHM]

What’s a small 3018 pro cnc router?

https://canadianhobbymetalworkers.com/threads/new-to-cnc.3934/

 

[jcdammeyer]

Thanks so much for your honest input. I do want to dabble with gcode and the inexpensive way to learn this for me was buying a CNC router. It is a small 3018 pro but I am just starting on it. I am currently using Candle but have played with UGS as well. I am a beginner with fusion 360 as well and have not done machine operations with it but just basic design and 3d printer stuff.
I do like the idea of not changing to ball screws right away. Also I do use a dro on my machine. Could I leave the dro on? What size of a mill are you doing and what size stepper motors are you using?

Mine is like the Grizzly G3616 but from House of Tools. I tried a 1200 oz-in stepper with a Gecko on the knee and DC Brushed servos on the other two axis but have now converted totally to AC servos from Bergerda.
My Mill Conversion

I use AlibreCAD and now changing to MecSoft CAM (Was AlibreCAM). The CNC control system is LinuxCNC although the PC is still dual boot for MACH3 on Windows but haven't booted and run MACH3 since 2020. I've also been experimenting with a Raspberry Pi4 and MESA 7i92H for CNC.

The advantage of MACH is the wizards. They simplify a lot of operations without ever doing CAD/CAM. Linux has some command line programs (afer all it's linux which is still in the dark ages) that generate G-Code from parameters. I have started creating graphical user interface programs that create G-Code from parameters. But it's on the back burner at the moment.

 

[thriller007]

Mine is like the Grizzly G3616 but from House of Tools. I tried a 1200 oz-in stepper with a Gecko on the knee and DC Brushed servos on the other two axis but have now converted totally to AC servos from Bergerda.
My Mill Conversion

I use AlibreCAD and now changing to MecSoft CAM (Was AlibreCAM). The CNC control system is LinuxCNC although the PC is still dual boot for MACH3 on Windows but haven't booted and run MACH3 since 2020. I've also been experimenting with a Raspberry Pi4 and MESA 7i92H for CNC.

The advantage of MACH is the wizards. They simplify a lot of operations without ever doing CAD/CAM. Linux has some command line programs (afer all it's linux which is still in the dark ages) that generate G-Code from parameters. I have started creating graphical user interface programs that create G-Code from parameters. But it's on the back burner at the moment.

I looked at yours and it is much larger than mine for sure.

 

[jcdammeyer]

I looked at yours and it is much larger than mine for sure.

A friend of mine here on the Island got the equivalent to the G3617 which was, at the time about $500 more, and had a much longer X axis table along with a longer horizontal yoke since it has the Horizontal Mill Spindle.

In hindsight I wish I'd made room for it in my wallet since my table can pivot. But I'm not sure, for helical gearing if that will matter with full CNC including an A axis. It's on my do list to try and make helical gears. For what I don't know. But it's something I'd like to try and do.