Creo Screw

[Victorino Eagle]

The CREO ONE Robotic Screw enhances our advanced modular platform by simplifying pedicle preparation while maintaining navigational accuracy and increasing pullout strength compared to pedicle screws tapped to size. CREO ONE is part of the CREO AMP family. CREO ONE is compatible with CREO MIS and CREO AMP implants, and uses CREO navigation instruments.

Now in Creo Parametric, an expanded library of fasteners and parts now comes standard with the software. Just click Tools > Intelligent Fastener > Screw and then click a datum point, an axis, or a hole on your model where you want to add the connector.

The Intelligent Fastener tool library includes screws, washers (flat and lock), and nuts. Plus it can automatically create holes and counterbores. But if you want even more connector magic as you work, explore the Creo Intelligent Fastener Extension (IFX). With the extension you can customize fasteners and the system will automatically check the integrity of your connections if the model ever changes.

Aaron Shaw joined PTC in 2013, currently he is the Senior Manager, CAD Demand Generation. He is responsible for the CAD marketing strategy and execution worldwide. He enjoys playing golf, eating spicy foods, reading, traveling, and rooting for all Boston teams. Aaron is a graduate of Penn State, you can follow him on Twitter @AaronEShaw.

I downloaded an iges file of a vented screw. I would like to modify it to make it longer. It is currently 8mm long, and I want it to be 50 mm long. I have tried to mirror it as a way of elongating it, but the ends don't mirror correctly.

Here is a copied and moved thread geometry to "lengthen" it. If you index the translation value, you can align the threads, so they pass a cursory view. This is a total hack for a cartoon only. If you need the actual geometry, build a model from scratch.

What none of this addresses, though, is the question of *why* have threads modeled in the first place. Screws with threads look cool and all that when you're making a small assembly, sure. But, I've encountered large assemblies where the person building it had 100s (or even 1000s) of these, and the questions are always "Why is my assembly so slow to load?" and "How come my hidden line removed views on the drawing are all messed up?". Doing this kind of thing adds 1000s more surfaces for the hidden line algorithm to deal with, results in pretty much solid filled blobs when the view scale is sufficiently small, etc.

Okay, so I've created two holes coincident which have axis A4 and A8 as shown below. I want to add a flat end screw which will stop at the bottom, with the bottom of the screw being flush with the bottom of the hole A8, however when I go to 'Tools' > 'Screw' and add the constraints, it places a screw which goes past my hole A8 until it reaches the other side of my surface. How do I constraint it so the screw stops when it reaches the bottom of the hole?

Can it still spin in the hole? In Wildfire (I haven't yet upgraded), if you check 'allow assumptions' it should show as fully constrained. Alternatively, you could also orient a datum through the axis to one of your assembly datums...

Allow assumptions does not appear until I have added the third (counter productive) constraint of flat surface on top of screw to flat surface of panel. The assumption I assume is to do with the rotation about the axis which I don't care about.

I can't say for sure in Creo since I'm not using it but Wilfire 5 what I've noticed is when you select the conical surfaces it creates an insert constraint. However, it appears that what it does is aligns the axes and because of this you can flip the direction of the constraint and the part will flip its direction which is the reason it is only partially constrained. You have essentially created the same constraint. You will need to select the mate constraint from the list first and then select the conical surfaces. I believe it's possible to constrain a countersunk screw with a single mate constraint with the allow assumptions checked.

1.Whether you select cylindrical part to cylindrical part or conical part to conical part ;CREO will consider it to be a co-axial constrain. Even after these 2 constrains you will see one degree of freedom(because it will not consider conical surfaces as mate or aline constrain)

2. you must give another constrain to limit the remaining degree of freedom(a distance constrain(mate and aline constrain in wf) between the top flat surface of the conical part and the flat surface of the counter part will do)

I think I understand what you are saying but my problem still is that I can't dimensionally constrain the top surface of the screw to the top surface of the sheet metal part containing the countersunk hole because that is the dimension I am trying to establish.

When the head of the screw sits in the countersunk hole I need the geometry to establish if it is proud, flush or sub-flush to the surface of the sheet metal part when the conical part of the screw head is sitting tight against the connical part of the hole. If the size of the counter sunk hole in the sheet metal part is changed then the screw head needs to automatically move up and down relative the the top surface.

The insert contraint has dissapeared in Creo which is why as stated in my original post I was doing coincident on the axis of the screw and hole incase there was no cylindrical part of the hole due to the panel being too thin.

I think this will allow what you are looking for because if the hole changes, the screw will not and it will stay fixed at the bottom of the "V". If the CS hole changes, the depth of the CS usually does, too.

I've used Point On Surface to constrain awkward, conical geometry before. It's usually more reliable to specify the type of constraint before selecting references; then find a vertex at the minor diameter of the hole countersink, and use the conical surface of the fastener head.

Does the "centered" constraint give you what you are looking for. I tested it quickly and it seems to regenerate as you are wanting, and it only took the one constraint to place it with the references being the conical surface of the screw, and the conical surface of the countersink.

I'm working in CREO 2.0 where mate is no longer an option, and coincident doesn't fully constrain the assembly. In WF 5, one could constrain a countersunk screw to a countersunk hole by aligning the cylinder with hole then mate the two countersink surfaces. CREO 2.0 doesn't work the same...no mate.

1) How does Windchill handle the standard hardware library? For example, if I create a screw using the library, what happens when I check it in to Windchill? How does it work if another user creates the same screw and also tries to check it in?

3) I notice that the DIN912 option only creates one object in my workspace, but the ANSI-Metric will create a huge list of parts in my workspace even though I only used one screw in my assembly. Why does the ANSI-Metric screws create family tables in the workspace, but DIN912 does not?

As for Windchill. the first user to create a part and check it in wins. Everyone else will have to use that screw from Windchill and not create a new one. Windchill will NOT allow a second file of the same name to be checked in.

1) The goal should be to have all fasteners in Windchill. Then all user can use these fasteners. It does not make sense to create the fastener for each user (even if this is possible if you do not check it in). It is also possible to add your legacy fastener data to IFX (require the full version).

2) IFX only has sizes from M4 up to M36 at the moment. Of course you can add other sizes if needed. But this also require the full version. If you want you can add a enhancement request to PTC to add other size.

3) There are two kinds of library parts in IFX. One use a single part for each new fastener copied from a template part. The other kind use a family table with all instance for each size. In IFX you find the files with family table in the subfolder \parts\prolibrary. In these folder some fasteners from the ProLibrary are added.

I load the Lite version IFX library into Windchill. Any user then uses the screw creator within Creo 3.0 in their assembly to add screws to their model. The screws are then added to the workspace automatically. I would also like to add two parameters to the fasteners for an internal part number and description. This would be the same parameters for all users.

The movie was very helpful, thank you. I tried the instance creator and selected a folder on my desktop for the export location. After the export completed, the screws did appear in my workspace. The folder on my desktop was empty, however. Is the export folder just used as a temporary location as the workspace gets populated with the parts?

Also, I opened one of the screws inside of Creo. I am able to add parameters to the part. For example, I added a "part_no" parameter and Creo accepted the edit. I closed the file, emptied my memory, then re-opened the file. The "part_no" parameter was there. It seems that I can add parameters or am I missing something?

the export folder is needed if you work without Windchill. Then you can create all your file in an archive folder and add a search_path for this location. If working with windchill the files are stored in Workspace.

Family tables only add 1 extra part to your workspace, the generic, if done properly! I have family tables of hardware items with over 700 instances and pulling 1 instance into an assembly and then saving the assembly only adds the generic and the instance used to a workspace. There are preference settings that need set for it to work properly.

One thing we do is have the family tables in a library in Windchill and set the preference that library objects are read-only when pulled into a workspace. This reduces the ability of the end user changing a library part. Only 2 of us here have librarian rights to modify library files. You can set Creo with a config.pro setting to not regenerate read-only objects, too. This helps for both library and released parts.

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