G-code Helix Problem

[Burkhardt]

I am trying out my new maze software g-code output on the Shopbot demo but apparently the G2 command recognizes only arcs/circles but not a helix. I know there is a limitation that the center axis for the circle has to be vertical but I have not seen the helix issue mentioned. Or is there something special that needs to be done?

I could convert helixes to a sequence of a circle and a step-down but that would not be so elegant (mainly used for drilling holes larger than the bit).

Thanks, GB

[Ger21]

Have you looked at the Spiral option in the CG command?

[srwtlc]

G, knowing that you aren't using SB controls, If you use Mach3, isn't there a wizard that does a helix (I can't remember)? What software do you generally use for toolpaths? If you use VCP/Aspire, you can use a spiral ramp.

[Burkhardt]

Sorry about the confusion...this is for my special homebrew maze generator software, so no other CAD/CAM is involved. It does create direct gcode output and when using the G2 gcode command to make a helix it works well on my native gcode reading controller (Planet-CNC, not Mach3) but I am quite sure it will work on Mach3 as well.

Not sure if Shopbot control can do this at all but I found a workaround. I insert a G1 command after every G2 line. For g-code controllers it does not matter because the bit will be already there and the Shopbot will just ignore the helix, make a circle and the step down to the next level. Well, that is the theory, I hope somebody will try it out.

[scottp55]

G., Like normal,don't understand G-code.
Are you talking like the helicoid?(not sure of terminology) that the spiral ramp option in Vectric uses?

[scottp55]

Oop, heres code for that one.

[Burkhardt]

Thanks Scott,

I guess that is it. I did not know that Vectric dissolves such a Helix (or spiral) into hundreds of linear segments for Shopbot. Not to be critical but that is done somewhat more elegant in regular g-code. If you specify a new z-level for an arc command that is different from the start z level it makes such a spiral with a single command and lets the machine controller deal with the rest.

But it is not a big deal. This function is only used for drilling alignment dowel holes, entry and exit as well as side transition holes which can be done in individual circles just as well.

[scottp55]

Be interested in the comparison Gert, although in real life, the spiral ramp option is so quick it's going to be hard to compare. Spiral ramped holes I DO know about:)
Hope Steve's problem wasn't Windows related-Have to install and read instructions over coffee and then try on windows 7 laptop:)
Hope Scott W. is trying this one:)
scott

[ssflyer]

Gert,

I hope your workaround works! :)
As far as I know ShopBot still doesn't support helical interpolation, or for that matter, directly support arcs in any plane other than the X,Y plane.

I agree, it would be nice to be able to use a single line of code vs. a thousand or two for a spiral ramp...

[Ger21]

I hope your workaround works! :)
As far as I know ShopBot still doesn't support helical interpolation,

As I mentioned in my earlier post, according to the Command Reference, the CG command does a helical circle if you use the Spiral option.

[ssflyer]

Ahh - thanks Gerry! one I had overlooked!