Having a go with F360....

[Davek0974]

Top and bottom plates drawn, just the spacer block left.

The smaller hole in the bottom will take a 20mm spigot that will lock into an R8 collet in the spindle.




Metal arrived today and the mill is almost ready to go.

[Davek0974]

Ok, first job :)

Something i used to make manually in small batches, would use a 5C collet block horizontally in vise, cut one side, rotate 90deg cut next and so-on. The diameter of the tool created a radius at the root of the square part.



Gonna have a go with CAM, modified the vise jaws so i can clamp a blank vertically and work round tip using a ball-nosed cutter.

Blanks are 1/2"dia and tip is 5.5mm sq. It also 605m36 steel so slightly harder than plain mild.

I have it drawn up in F360 and worked out the feeds/speeds in HSMAdvisor which gave me 420rpm, 84mm/min on a 12mm HSS tool. DOC is 11mm - 6mm radius and 5mm straight.

F360 wants to take the whole cut in one pass - would you feel happy with that, seems heavy. Although i selected 2d Adaptive, i think its too simple to work any magic on and it seems to have created a standard path.

[Davek0974]

Ok, back to this task, nearly ready to get cutting now :)



My thoughts are to fix the waste strips down to table,
set plate square to axes,
clamp plate on top,
mill the slot
drill the three holes tapping size through
drill the part holes to clearance size
tap the holes in the scrap and bolt part down
remove clamps
mill the two large holes
chamfer
mill the outer profile
flip over and bolt down
mill slots
clamp part again
remove bolts and counterbore three holes.

I think that maintains accuracy between the slot/holes and the two big holes??

I could maybe add two extra holes between the three bolts for 6mm dowels if needed?

The bottom plate will be easier as i only have to drill the three bolt holes and maybe dowel holes and then clamp down using the same offsets for the part.

[magicniner]

I think you're over-thinking it ;-)
Square your stock and drill & tap the clamp holes manually.
Stick it in a vice on parallels with thin sheet sacrificial spacers on top and machine all the internal features, including slot.
Hang it out of the vice to profile and slot one end outer curve, flip and repeat.

[Davek0974]

It won't fit in my vise though :)

[Davek0974]

Ok, work holding issues aside, say i have machined the inside features etc and want to create the outer contour...



F360 knows the exact size of the raw stock but I'm buggered if i can figure out how to create a path to machine the junk away??

Do you need to draw a box/path around the stock - if so whats the point of putting the stock size in?

You cant select the stock in a process so i cant see its point?

[Davek0974]

F360 is doing my head in ;)

I have my front face set up with my chosen work coordinates system (WCS) as front left corner, Z is of course up/down.

Now, i presumed that if i wanted to machine a feature on the bottom or underside face of that part i could rotate it round, do a new setup and set my WCS as top left corner with Z again now being upwards???

I have spent an hour messing and given up for now - it will not let me position the WCS how i want it and persists in putting either the x or y axis in the wrong direction, i post processed a trial and it does not work as it is off the table in Mach3.

Any ideas how to machine stuff on the underside of a part???