Rounding stock - first hurdle

[studio-n]

First, thank you for opening up this sub forum. I have my first question. Please forgive me if it's been answered while in beta, and I will read thru all the forum messages but here is my problem.
I'm uploading as much info as I can.

I have been playing and trying to get use to the details for the 4th axis attachment. My main question is how and where is the Z-Zero determined?
I was trying to do a simple rounding of the stock down to 0.22”. what I got was stock rounded to 0.52” in diameter.
This first attachment is the screen showing both the head/tail positioning after it was set up. Also is a portion of the gcode showing the Z position should be at 0.11 which should have given me my 0.22 diameter.

Second shot is the material set up in Aspire using the wrapped set-up Gadget. So basically I’m telling it it is 5.5” long and 0.34” to start off with. I’ve selected my Cylinder Axis at the bottom (so in the center line of the head and tailstock.
I got there by lowering my Z axis until the bit just touches the dead center of the tail stock. It is an accurate 0.5”, so I then dropped it an additional 0.25” and set my Z0. The bit is right in line with the tip of the dead center and I then click on Z0 to set my Z axis.

This third shot is the Create rounding Toolpath in aspire. So my starting stock is 0.34” and I set my final Cylinder diameter is 0.22” I’m in the X axis wrapping the Y.

And finally you can see the appropriate post processor is chosen and again the diameter is 0.22 from center.
(darn it, could only add 3 pictures. But you get the idea.)


Ok, so with that and the fact the G-CODE says Z=0.11”, how did I end up with a rounded stock that is 0.52 in diameter??? What is the supposed starting point for my Z0??
Incendentally, as the program ran, the Z stayed at 0.11” but was clearly not 0.11 from the centerline.
Please let me know what I’m missing. I’m sure others may have this same question.

Regards and Thanks,
Nick Silva
Studio-N, Dallas

[Ronwoodson2]

Nick,
I zeroed the headstock off
the highest point of the chuck housing (not the jaws).I then measured the housing diameter (3.5 inches, I think)
and entered the radius (1.875) in the 4-Axis section of preferences. This tells the machine that the z zero is
1.875 inches below the tap off point(top of chuck housing). Click 'set motor end' and it is done.
I tapped of the tailstock on top of the housing {behind the knob). I think I used .625 for the radius of the
tailstock chuck--my machine is running another job now, and I can't check for sure). Click set for the tailstock
end and that tells the program your z zero is .625 below the tailstock tap off point. I could not reach the
actual tailstock rod to tap off.

I also shut down the program after changing settings in the preferences. Not sure it was necessary, but it
worked for me.

I tried tech support, but whoever answered knew software but not much about hardware and 4th axis, so I
tried several approaches, and made every mistake known to mankind, and invented a few new ones, but
my machine is working fine now.

Good luck, and let me know if I can share any other misfortunes with you.
Ron

Edit: I'm not to be trusted with my math--if the diameter was 3.5, the radius would definitely be 1.75..
Sorry

[studio-n]

thank you Ron,
I'll try those tomorrow when I get a chance. It is definitely a little trial and error figuring out the preference #'s.
I sent in a support ticket to NWA and it will be interesting to see what their response is (if any).

Cheers!
-Nick

[Ronwoodson2]

Also, I think the morse taper will fir in the threaded headstock without a chuck. If so, this would give more length
available on the spindle.

[studio-n]

nope, neither a #1 or a #2 morse taper fit into the headstock.
-Nick

[jeb2cav]

Hi Nick,

A couple of comments.

First of all, someone at Rockler just decided to expose the 4th axis beta testing forum and renamed it instead of creating a new one - like that would be useful. I can tell you that there is nothing useful in this forum other than posts made since it was exposed. In fact, it can be confusing at best, and contradictory and mis-leading at worst.

The Z0 is actually the centerline of the spindle/material. You've noticed by now a change of terminology in the buttons on the SCP when you Enable AAxis, and the button and term you'll see is Move to Offset. This offset is calculated based on your tap off of either end, and settings in the A|4th Axis preferences. There is not touching the zero plate or bit against the material. When the SCP is in AAxis mode, it is moving to an offset point that establishes where the tool starts when running a 4th axis job (in the same manner that it does when running a 3 axis job, but Move to 0,0,0).

If the material is larger in diameter than the diameter of the Lathe Front/Left (Motor End) Chuck Radius - you will want to ensure that you compensate for tool clearance in your A Axis Safe Height preference.

I think if you look at the Z value after you tap off, you'll find that it makes sense, without going through the additional steps you performed - which I think may have thrown it off. I frankly would need to try this out - not something I'm able to do right now - to see if it would screw anything up. Thinking about what you did makes me think that it may be a good idea to disable the ability to 'Set' any of the axis values as you might in 3 axis mode.

You should not have to exit the SCP after making changes to any of the Preferences in the SCP. The latest build I see from using the check for updates from the SCP while connected to the internet is [14]. If by chance you have a version earlier than [12], you may in fact run into a problem with A|4th Axis preferences, and exiting SCP and restarting won't solve them.

If you have specific questions with the A|4th Axis preferences that the manual (not the quick start guide, but the manual) is not helping your resolve, please post them and I'll see if I can clarify.

I also found this evening that Aspire 8 did not come with the create rounding toolpath gadget. I've sent in a question to Vectric support. I may not have recognized the 'new' way to do this using Aspire 8 or VCarve Pro 8.

[studio-n]

I think if you look at the Z value after you tap off, you'll find that it makes sense, without going through the additional steps you performed - which I think may have thrown it off.

Actually, after I tap off, the Z value is like 2.75". so no, it doesn't make sense.

I also found this evening that Aspire 8 did not come with the create rounding toolpath gadget. I've sent in a question to Vectric support. I may not have recognized the 'new' way to do this using Aspire 8 or VCarve Pro 8.

The create rounding tool path gadget doesn't seem to work in 8. I'm starting using it in 4.5 then saving an opening it again in 8 to save the tool path with the new post processors. Cheers!

[BrianM]

I also found this evening that Aspire 8 did not come with the create rounding toolpath gadget. I've sent in a question to Vectric support. I may not have recognized the 'new' way to do this using Aspire 8 or VCarve Pro 8.

Hi,

The 'Create Rounding Toolpath' was missed off the initial release of V8. If you do 'Help - Check for Updates' in the program you should be informed that there is an update available which after installing should re-instate the gadget. If your computer with V8 is not connected to the internet you can download the patch from this page ...

http://www.vectric.com/support/program-updates.html

Sorry for the confusion.

Brian