Threading Shafts and Holes with Supressable Modeled Threads

john_hauck

I would cherish a bit of advice on threads again.

My goal is for a Part Studio to use the Configuration Panel to turn threads on and off.

• When off, the dimensions should be as-machined (before cutting the threads) - and supported by Drawing hole/thread callouts.
• When on, the correct threads should be modeled.

For external threads, I think I am OK:

1. "External Thread" tool
2. "Thread Creator" FeatureScript by Dave Cowden
3. Configure suppression with the Configuration Panel

For internal threads, this gives me the wrong sized thread:

1. "Hole" tool
2. "Thread Creator" FeatureScript by Dave Cowden

See this document for an example - the goal is a set of matching M10x1.25 threads on the shaft and hole.

     
     

The only work-arounds I have are:

• Use a move-face option with some magic distance when enabling internal threads.
• Use "Threads" FeatureScript by Julia Schatz - which is less configurable.

How can I improve my designs?

eric_pesty

Configuring the size of the "blank" hole should be an easy enough thing to do...
Have you tried the "threadlabs" featurescript?
I like that it offers options for different thread representations so all you should have to do is configure the one feature.
https://cad.onshape.com/documents/5c0528b62c1fbb13a2a0e739/v/f86229e7f586f8517a2068a9/e/7cbb452d4d5e963a034ce616?jumpToIndex=2851&showReturnToWorkspaceLink=true

EvanReese

check out the Thread Lab feature by @antlu65. It's got a lot of functionality that, for me, makes it a replacement for the thread creator tool.

john_hauck

@eric_pesty & @Evan_Reese,
Thank you your replies.
I did indeed try Thread Lab and found that for internal holes created by the Tap feature, it too makes the threads too small.
Here is an updated version of the document that allows switching between Thread Creator and Thread Labs.
https://cad.onshape.com/documents/8709f9d60bec3de1edf2665d/w/d5b45dd621951389b8276062/e/8d9e6e8fe5b7d91b4755b349?configuration=List_r0zfKFIEfl5JGj=Thread_Lab&renderMode=0&rightPanel=configPanel&uiState=645298dd3d600e5acab3915a

eric_pesty

Right, I guess that makes sense as the thread "features" just use the hole "as-is" to create the thread.
I think the simple solution is to just configure the "tap" hole diameter to 10mm for the threaded configurations (and leave it at the standard tap diameter in the unthreaded configuration):



https://cad.onshape.com/documents/cc32ccff9e99836af3879e82/w/4e553a8c737282cb1e3ac5cf/e/9b51577bc9d1a293c1f38cd0

As a side note, if the part is going to be drilled and tapped using "conventional" machining then there might not be much value in having the actual thread modeled and this should be used sparingly due to the performance impacts... The main application is for 3D printing (or I guess sometimes for producing "illustrations" like rendering of customer documentation).

john_hauck

eric_pesty said:

Right, I guess that makes sense as the thread "features" just use the hole "as-is" to create the thread.
I think the simple solution is to just configure the "tap" hole diameter to 10mm for the threaded configurations (and leave it at the standard tap diameter in the unthreaded configuration):

As a side note, if the part is going to be drilled and tapped using "conventional" machining then there might not be much value in having the actual thread modeled and this should be used sparingly due to the performance impacts... The main application is for 3D printing (or I guess sometimes for producing "illustrations" like rendering of customer documentation).

Thanks, I get it ... and yet ... I would like more.

When modeling without threads, I just use the Hole feature, and set it to "tapped" and specifying the thread. It creates a hole that is useful for the tapping operation. A drawing of the part correctly calls out the thread. That means the Hole feature "marked" the hole in the geometry with the appropriate thread size and pitch (somehow). This is good... very good. Kudos OnShape.

So my wish would be that to model the threads, the FeatureScripts should just read this information from the geometry (like the drawing do) and then do their thing. They should not even ask what thread or pitch to use, since that is already there.

I really don't want to write this myself as it seems like an obvious thing that someone already tackled.

Finally, why do I care about modeling threads? Well, it helps not just with 3D printing, but also with checking the fit between threaded holes and shafts. If there is a mis-match, it is easy to spot. And like you mentioned, it also helps make renders much more realistic... and who would dare stand in the way of more realism in their renders?!

Cheers and thanks for chiming in and reading this far in my rant.

eric_pesty

Threads set using threadlabs are able to be recognized by the thread callout feature in drawings, however I am not sure if the data can be "read" by a Featurescript.

I'm also not sure what it would take for a feature like Threadlabs to set the size of the hole!

Hopefully @antlu65 see this and chime in!

john_hauck

I’m going to start over and explain how I deal with threads in the hopes that this will explain my feature requests.
Here is an OnShape documument that helps explain the situation.

Non-modeled external threads

The built-in feature tool “External Thread” is what I want to use for the simple fact that is being supported by OnShape.

It requires that the cylinder diameter matches the thread’s outer diameter. So, for an M10 thread, the cylinder’s diameter should be 10mm. The External Thread sets up the model so that it appears on drawings, showing both the outer and inner diameters of the threaded area. The drawing’s Hole/Thread callout automatically displays the thread information on the drawing as well. This really is all that is needed to send a part to be manufactured by a machine shop.

Modeled external threads

Since all the thread information is already in the model, it would make sense if the thread geometry would be driven by that information.

If I change the thread pitch in “External thread” then the threads modeled would change as well.

I could then use the “Configuration panel” to define whether I wanted modeled threads or not (by suppressing ThreadLab). Using two configurations of the part in the same drawing, I could make something like this:

However, you will notice the callout created by ThreadLab 0.3 is inconsistent.

Requests for External threads in ThreadLab 0.3:

• Add an option to be driven by the External thread data of the part.
• Remove the drilling symbol from the threaded callout for external thread.

Non-modeled internal threads

The built-in feature tool “Hole” is what I want to use for the simple fact that is being supported by OnShape.

Select tapped and specify the thread, pitch, thread depth, hole bottom, and tap clearance. The Hole sets up the model so that it appears on drawings, showing both the outer and inner diameters of the threaded area. The drawing’s Hole/Thread callout automatically displays the thread information on the drawing as well. Specifically, drill an 8.8mm diameter hole, 5mm deep, and then thread it as M10x1.25. This really is all that is needed to send a part to be manufactured by a machine shop.

Modeled internal threads

Since all the thread information is already in the model, it would make sense if the thread geometry would be driven by that information.

If I change the thread pitch in “Hole” then the threads modeled would change as well.

I could then use the “Configuration panel” to define whether I wanted modeled threads or not (by suppressing ThreadLab). Using two configurations of the part in the same drawing, I could make something like this:

However, you will notice the callout created by ThreadLab 0.3 is incorrect, because it is driven by the diameter of the hole, and not the information added by the “Hole” feature.

Request for internal threads in ThreadLab 0.3:

• Add an option to be driven by the Hole data of the part. This means the threading operation will remove material, not add it. It also means performing partial threading based upon the configuration used to make the Hole.

I hope I have been clear and maybe even compelling.

bobby_hodges

newbie here, thanks for explaining this, I have no idea what I am doing and this helps.