topic Re: Drill, chamfer, tap in Inventor Forum

Drill, chamfer, tap

Anonymous — Thu, 19 Jan 2017 13:42:51 GMT

I want to create a threaded hole in a plate, which is to be machined as follows

1. Drill hole

2. Chamfer hole (lead in chamfer)

3. Tap

I can't figure out how to get this correct in Inventor. After creating a chamfer, it is impossible to tell the thread tool to start the thread from the surface of the plate. When creating the 2D drawing, I have to manually create a sketch to extend the thread to the surface.

I've tried to reorder the Inventor model history, but this doesn't change anything.

How to proceed to get the correct design?

Re: Drill, chamfer, tap

Anonymous — Thu, 19 Jan 2017 13:48:13 GMT

How about a note on your print: (DEBURR ALL TAPPED HOLES 0.5)

Re: Drill, chamfer, tap

swalton — Thu, 19 Jan 2017 14:06:09 GMT

Why not use a threaded hole with a chamfer as one feature?

Edit your thread.xls file if you need a custom tap drill size.

EDITED TO ADD: I noticed that Inventor will trim the thread lines in the drawing if the chamfer OD is larger than the thread major diameter. That makes sense to me because the chamfer operation has removed the material in the part that would be cut to make the thread.

Screenshot from Inventor 2014.

Re: Drill, chamfer, tap

Anonymous — Thu, 19 Jan 2017 14:07:30 GMT

Thanks. Didn't think of this possibility, as this was an imported component where I used feature recognition.

Re: Drill, chamfer, tap

TheCADWhisperer — Thu, 19 Jan 2017 14:10:50 GMT

@Anonymous wrote:

1. Drill hole

3. Tap

1. Just out of curiosity, when you did not use the Threaded Hole feature - what size hole did you use in you image? (Did you use correct tap drill size? Was the imported part correct size tap drill hole?)

3. What size tap specification did you use?

3a. Bottom tapped holes are expensive (broken taps) and will anger the machinists on the shop floor. It appears to me in your image that you have specified a bottom tapped hole. (full depth of drill)

Re: Drill, chamfer, tap

Anonymous — Thu, 19 Jan 2017 14:16:53 GMT

machinist's love +/-.005" on pilot and tap depth too 😉