Custom tapped holes?

brian_brady

I am trying to make a tapped hole with a non-standard countersink. I select an ANSI standard, tapped hole and turn on countersink. If I edit the countersink diameter or angle to meet my needs, the hole changes to custom and cannot be tapped. Why? Before I started teaching, the company I worked for had its own standards for adding countersinks on the entry side of tapped holes to act as assembly aids, not for the head of a screw. That is what I want but cannot achieve with the hole tool. I can kludge something by using the chamfer tool, but I want the dimensions to be the diameter and the included angle, not the depth and half angle of the countersink.

Can this be done and I am just missing something? Or is this another yet reason to not switch my class over to OS from Creo?

lemon1324

The way the hole feature is written, the whole set of drop downs is simply a user-readable way to set the numerical fields below.  If any of the numerical fields are changed, the drop downs get replaced by "Custom." However, the other numerical fields aren't changed, so if you choose the drop downs to set up a countersunk tapped hole and then change the countersink diameter and angle, the tap drill diameter and depth are unchanged.

This is of course a loss of some design intent, but the resulting geometry is identical.  And since the Onshape hole tool currently doesn't do cosmetic/modeled threads, and drawings don't do automatic hole callouts, it doesn't lose too much, since you'd manually call out the holes in a drawing anyway.

I'm sure hole callouts are on the improvement list, and that should result in a better way to handle nonstandard holes as well.

lemon1324

The way the hole feature is written, the whole set of drop downs is simply a user-readable way to set the numerical fields below.  If any of the numerical fields are changed, the drop downs get replaced by "Custom." However, the other numerical fields aren't changed, so if you choose the drop downs to set up a countersunk tapped hole and then change the countersink diameter and angle, the tap drill diameter and depth are unchanged.

This is of course a loss of some design intent, but the resulting geometry is identical.  And since the Onshape hole tool currently doesn't do cosmetic/modeled threads, and drawings don't do automatic hole callouts, it doesn't lose too much, since you'd manually call out the holes in a drawing anyway.

I'm sure hole callouts are on the improvement list, and that should result in a better way to handle nonstandard holes as well.

Narayan_K

@ brian_brady  ,Onshape itself decides the drill/tap diameter, counter sink diameter, counter angle as per the standard you selected and according to the size you given.So for Standards holes you need to give information from the drop down menu,according to this input onshape decides the numerical value as per the standard.
When you change the numerical value it will not obey the standard which you selected hence it is turning to custom.For your need you need custom size so you can enter the tap diameter,counter diameter, counter angle and hole depth manually.Since there is no cosmetic/model in thread and no hole callouts for drawing,taped hole and drilled hole doesn't make any change.

brian_brady

I guess since you cannot use dimensions and conditions applied during the design process to define drawing dimensions, then having correct thread callouts does not matter. You have to manually create thread and hole notes in drawings and update them manually if the design changes. This whole drawing to model design intent disconnect really bothers me. Models and drawings should have 2-way associativity, but they don't in OS.

Narayan_K

@ brian_brady , Thank you for your feed back.Definitely in future Onshape will have this.You can raise a ticket for improvement request.