CnC build help

Nick, Congratulations. I knew you'd figure it out.
 
Glad you got it working. Homing actually looks for a home switch on each axis to set the machine to zero (or your offset). You can zero each axis manually and the set limits for each axis in the software though without switches.
 
NJS, congratulations on getting it working. While I have homing switches on my mill I almost never use them. I feel they would be critical if you had an automatic tool changer or you did fixture based production. But for one-off parts, I just zero each axis to the part that I am working on.
 
Like boswell said they are rarely used , but limit switches or setting the machine zero to the same point with every use and having the soft limits set in Mach may save a crash. If you don't have any limits or home switches, and you are working on a piece that may require a cut near the limits of an axis just make sure you jog to the extents of your cut envelope to make sure you won't exceed the limits of any axis during a cut process. If you do this you should never have a problem... get in a rush and forget to do so and ... well you can guess. A crash can be pretty hard on the end mill, steppers, couplings etc.
 
Home switches I don't use but LIMIT Switches are Critical. Many times I have been working on the edge and tripped a limit switch or even had a bug in my G-Code and triggered a limit switch. If you exceed a limit while moving slow it is possible that the steppers will just skip when it hits a hard stop but if it were to happen when you were in Rapid movement the mass of the table could cause some serious damage. Much more than the cost of some limit switches. I would NOT recommend using a CNC machine without a limit switch to protect your investment.
 
Hey guys,
Thanks for the info. I will look into getting some limit switches. Just in case.
Now I need to learn how to use cad.
Thanks again for all the help.
Nick
 
Regarding CAD there are some great ones that cost $$ like Autocad and Solidworks some less $ that various people have recommended over time. The best CAD system is the one you can afford and that you get lots of practice/experience with. I am using a 2012 version of Autocad. I have heard lots of good things about Fusion 360. It is apparently free for hobby users and has the advantage that there is a CAM module that is built in or available also for free.
 
Hey guys,
here goes I build custom pool cues and normally do all my inlays by hand or with an pantagraph. So I was wondering if you guys know of any good tutorials for mach3 that go in detail on how to do inlays? Also any tutorials that would go into how to make a cylinder that tapers . I figured out how to make multiple faces on a cylinder, just trying to make it a bit easier on my self.
Thanks
Nick
 
While there are a lot of tutorials on youtube for Mach 3, what you are asking about seams more in the CAD and CAM area. Working on a cylinder is typically done using a "4th Axis". Forgive me if you already understand this. A 4th axis is a rotary chuck that is controlled via Mach3. To make use of it, and pretty much any CNC you need to design the work in CAD then use a CAM package to translate that to G-Code then Mach3 takes the G-Code to tell the motion controllers what to do. You can skip the CAD and CAM steps if you want to hand-code the G-Code but that can be quite a job for complex parts.
 
NJS Custom said:
Hey guys,
Thanks for the info. I will look into getting some limit switches. Just in case.
Now I need to learn how to use cad.
Thanks again for all the help.
Nick
Click to expand...

You can use your limit switches as "home" switches in Mach - there's a setting for that somewhere. The point of having a home switch, even if it's not super-repeatable, is that once there is a home position stored in the controller as G53 (machine) coordinate, you can then use macros to drive automated stuff. Like having parking positions that aren't dependent on the various G54-G5x work offsets.

For example, I've set a "Park 1" to have the table be all the way forward and centered for loading/unloading. "Park 2" is centered and most of the way back for washing chips off the table & parts. "Park 3" is centered in Y, and mostly left as I have my 4th axis on the right side. I use this as a way to get over quickly to indicate a gauge pin in the 4th. "Park 4" is similar, but for a fixture plate reference hole on my trunnion table.

There are also macros and functions which use a Z-home, such as auto tool-length plates. Also useful for setting the top of the Z-travel during 'safe' retract moves.

As far as the pool cues go, I think your best bet is to taper them on a lathe and then do the inlays on a 4th axis. If you raise your tailstock (offset the small end by half the total taper amount) you'll wind up with a surface which is parallel to the table. The patterns will then all be a the same Z-height.

If you're doing work near the handle end then the patterns won't be too far off. But this will work only for 'indexed' stuff - i.e. not wrapped around the handle circumference.

However, if you think you're going to do something complicated that wraps around the thing, then the decreasing diameter will require CAM and a cue held straight along the rotational axis. The CAM will figure out the decreasing diameter and adjust Z-height appropriately.
 
You must log in or register to reply here.
Back
Top