contour ramp from bottom to top

[cherokeechief79]

I have a round tube with holes and counterbores for screws .the counterbores are on the inside and the screws will point outward.

I have a keycutter with a reduced shank that fits thru the hole and would like to contour ramp upwards.i can do it fine going down but cant get it to work properly going upwards.any ideas?

it will ramp upwards but will not do the small fine pitch I want.

[crazy^millman]

Draw your helix using the create helix and drive it that way. That method has been asked for, but not done. Helix Mill will allow for this for finishing, but you have to hand edit the roughing out of the toolpath. I will normally do a 6" Helix to get an almost straight line then use the toolpath editor to remove, but have found using a helix does exactly what I want no muss no fuss.

[cherokeechief79]

thank you.

im currently running it from top to bottom.its aluminum so it takes the first cut no problem.

in steel I will need to rethink it the way you described.

[gcode]

On ‎3‎/‎15‎/‎2018 at 10:10 AM, cherokeechief79 said:

I have a round tube with holes and counterbores for screws .the counterbores are on the inside and the screws will point outward.

I have a keycutter with a reduced shank that fits thru the hole and would like to contour ramp upwards.i can do it fine going down but cant get it to work properly going upwards.any ideas?

it will ramp upwards but will not do the small fine pitch I want.

cheat

use a thread mill tool path and set the pitch of your fake thread mill to the pitch of the helix you wIsh to cut

a right hand ID thread mill tool path set to climb mill will do exactly what you want

 

[cherokeechief79]

that's great gcode!

that would definitely work!

[Brian Pallas]

I will make a toolpath with what I want, except top down. Then backplot and save the geometry. Then clean up as needed and make a new toolpath using that geometry.

 

The other day I used circle mill for depth cuts on a back counterbore that I wanted to machine from the bottom up. I put a point at each depth I wanted and set all my linking parameters in "Incremental" and "0", except for the clearance. Is there a way to get depth cuts from the bottom up with one chain or point?

[gcode]

9 hours ago, Brian Pallas said:

Is there a way to get depth cuts from the bottom up with one chain or point?

MC2019 Circle Mill supports "Step Up" and undercut tools.

A quck and dirty toolpath looks like it performs as advertised

[huskermcdoogle]

Another method I have used is to mirror a 2D contour ramp toolpath.  Program it above and mirror it below.