[awemawson]

Not actually used rounding end mills before, but set one up in the machine today and put it in my FeatureCAM tool crib and did a trial rounding of a square boss. Tool showed up on the FeatureCAM virtual screen as cutting a nice rounded edge as I wanted, but the tool path took my physical tool, whipped it round the boss at a height with the end at Z=0 so no cutting.

Setting tool height I'd done exactly what I do for all the tools - use a Z height touch off sensor on the end of the tool.

Now the Round feature dialogue box lets you set an X,Y,Z offset, and by setting Z = -5.00 mm (it's a 5 mm radius rounding end mill), Now the virtual screen shows the rounding 5 mm lower, so wrong, but the physical tool cuts in the right place.

I can overcome this by fiddling my tool length by reducing it by the radius (5 mm) of the rounding cutter, but what should I be doing, here - what do you do to touch off a rounding end mill ?

[hjl4]

Touch off Zero at tip of cutter, and then minus Z half of your radius in Z and same for X or Y. If I remember correctly that is. Been a long time.

[hjl4]

Wait a minute, that made no sense.

[awemawson]

70 plus FeatureCAM fans and NONE of you knew this :violin:

Well eventually I found an obscure reference to this in the FeatureCAM help file. When setting Edge Rounding cutter the touch off point is the upper part of the curve. This obviously is pretty impossible practically, so I will continue to touch off as normal on the lowest part, then add the cutter radius to the tool length offset in my control. If you think about it this achieves the same thing, as from bottom to top of the radius of the cutter IS one radius :banana:

[hjl4]

Well it's kind of what I suggested. I'm sure their could be a million users on this forum, and if no one has a need for a rounding endmill, and the help file being pretty vague as is, then you are forced to come up with your own solution. Personally, I do what you do. It works. Lately I've been doing most of the rounds on sides with ball mill. Yes It certainly isn't as efficient as a rounding endmill, but it also works and very well I might ad. It just takes a lot longer.
Glad you came up with a solution that works for you.

[Perfect Circle]

Here ya go.
You can choose to touch off at shoulder or not.
It is more easy for the operator to not touch off at the shoulder

:cheers:

[awemawson]

Loverly jubbly

However my V13 doesn't have that tick box !!!!

[Perfect Circle]

DOH!
I'm sorry :wee:

[awemawson]

Delcam obviously saw the error of their ways and added the box. I was surprised that the earlier version I have didn't use the end of the tool and calculate the cutting position, as not only is it a very simple calculation, it brings the rounding cutter into line with all the other tools we use and touch off on the end !