topic Re: M4 thread preperation for CNC in Fusion Design, Validate & Document Forum

M4 thread preperation for CNC

an18211821 — Mon, 22 Jun 2020 12:06:51 GMT

I added 4mm Holes in my design so that after sending the part for cnc milling, i will use a thread drill to create the threads.

I want to use M4 screws, so the question is , is 4mm diameter for the hole correct or should i use less that 4?

On the design i added the m4 thread without the modeled optio

Thank you

Re: M4 thread preperation for CNC

TheCADWhisperer — Mon, 22 Jun 2020 12:52:50 GMT

@an18211821 wrote:
I want to use M4 screws, so the question is , is 4mm diameter for the hole correct or should i use less that 4?
On the design i added the m4 thread without the modeled option.

No Ø4 is not the correct hole size - there would not be any material to cut the thread???

But if you use the Hole-Tapped command then Fusion will automatically enter the tap drill size (smaller than 4mm). If you use the Thread feature command then Fusion will automatically change the hole to the tap drill size (smaller than 4mm).

Did you measure the hole diameter? Your picture doesn't show the critical information.

Re: M4 thread preperation for CNC

g-andresen — Mon, 22 Jun 2020 12:49:48 GMT

Hi,

take a look at such elementary tables

günther

Re: M4 thread preperation for CNC

an18211821 — Mon, 22 Jun 2020 12:51:22 GMT

you are correct, the dimension did change automatically. Thank you!

Re: M4 thread preperation for CNC

an18211821 — Mon, 22 Jun 2020 12:55:27 GMT

Should i provide to the machine shop the step file with the thread included or is it better to send the design with 3.3mm holes and do it manually? Because i think most likely they will not be able to create threads with their machine. What would you suggest me?

Thank you again

Re: M4 thread preperation for CNC

TheCADWhisperer — Mon, 22 Jun 2020 13:40:51 GMT

Send detail drawing with the STEP.

@an18211821 wrote:
Because i think most likely they will not be able to create threads with their machine.

I do not know what this means?

Any machine shop can create threads.

Re: M4 thread preperation for CNC

an18211821 — Mon, 22 Jun 2020 13:51:53 GMT

i didnt know that.

Its the first time that i will use CNC service.

So , in this case i should select the "modeled" option, correct?

Re: M4 thread preperation for CNC

TheCADWhisperer — Mon, 22 Jun 2020 14:34:58 GMT

@an18211821 wrote:
So , in this case i should select the "modeled" option, correct?

Typically - no.

You would normally leave it on cosmetic, but create 2D detail drawing with the thread specification given on the 2D drawing.

I recommend that you File>Export and then Attach the *.f3d file here and also pdf of the drawing before you send it to the machine shop.

Re: M4 thread preperation for CNC

an18211821 — Mon, 22 Jun 2020 14:54:20 GMT

Thank you Sir