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Mastercam 2018 question

M. Roberts

Aluminum
Joined
May 11, 2021
Hello all,
In MC 2018, I am trying to do a simple task; center drill and drill a hole...I want to CD the hole and leave a chamfer at the top after I drill it. I used the depth calculator, entered the desired diameter of the chamfer, and hit the overwrite button; the numbers it inputs into the depth is not correct...I cant figure it out. I do not have the "tip comp on". I am using a standard #7, 60 degree CD, and I would like the top of the hole to be 0.525" diameter....any thoughts...constructively speaking

Mark
 

Mtndew

Diamond
Joined
Jun 7, 2012
Location
Michigan
Check the model of the center drill. I'm pretty sure the default sizes for center drills in Mastercam are FUBAR.
The pilot size and length are not accurate. You will just have to redo them as you go and save the tool model.
Once it's correct you never have to worry about it again.
 

M. Roberts

Aluminum
Joined
May 11, 2021
I did review the tool geometry that MC gave for the 5/8 CD, and it was in fact off. For some reason, it wants to use a #17 versus the #7 that I change it to , even after I click on the prompt to "overwrite". Again, the CD is 5/8" and I want the top to be 0.525"; it says that I only need to go 0.1577" deep....the drill section is 0.350"...
 

Mtndew

Diamond
Joined
Jun 7, 2012
Location
Michigan
I did review the tool geometry that MC gave for the 5/8 CD, and it was in fact off. For some reason, it wants to use a #17 versus the #7 that I change it to , even after I click on the prompt to "overwrite". Again, the CD is 5/8" and I want the top to be 0.525"; it says that I only need to go 0.1577" deep....the drill section is 0.350"...

If I remember correctly, the incorrect value that the default center drills have is the "Drill Length" value. It comes from the end, but is dimensioned as if it's coming from the full diameter of the pilot. So you would need to add in the length of the drill point to the Drill Length so you get a correct toolpath.
This was brought up by me way back when, but I don't think it's ever been fixed.
 

LockNut

Stainless
Joined
Jan 6, 2007
Location
Bergen County
Not to start an argument here, BUT, why are you using a center drill to drill a hole? Center drills are old school for drilling and should only be used for the original intended purpose, to drill for a live or dead center, period. Use a spotting drill.

Paul
 

Mtndew

Diamond
Joined
Jun 7, 2012
Location
Michigan
Not to start an argument here, BUT, why are you using a center drill to drill a hole? Center drills are old school for drilling and should only be used for the original intended purpose, to drill for a live or dead center, period. Use a spotting drill.

Paul

You can't say that as an absolute.
There are plenty of times when you would use a c/drill then drill a hole. Maybe he's limited on the # of tools he can have in the machine?
 

Rstewart

Stainless
Joined
Jun 14, 2006
Location
Huntsville Alabama
When I get a new tool in, I draw it and save it into my mastercam tool library.
You should not trust any "standard" tooling that is in the default library.

Also, center drills Suck!
 

colton_m

Plastic
Joined
Apr 16, 2015
Hello all,
In MC 2018, I am trying to do a simple task; center drill and drill a hole...I want to CD the hole and leave a chamfer at the top after I drill it. I used the depth calculator, entered the desired diameter of the chamfer, and hit the overwrite button; the numbers it inputs into the depth is not correct...I cant figure it out. I do not have the "tip comp on". I am using a standard #7, 60 degree CD, and I would like the top of the hole to be 0.525" diameter....any thoughts...constructively speaking

Mark

It appears that the depth calculator does not account for the stepped geometry of a center drill. For the purposes of depth calculation it assumes a #7 center drill is the same shape as a 5/8" 118deg drill. I get the same Z value for a .525" finish diameter with both of these tools. You'll have to hop into a side view, draw the tool at a suitable depth and just use that Z depth.
 








 
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