How can i model/where can i find "male female connections"

[Anonymous]

Hi all,

I have modelled a 3D splint which will be produced in 2 parts however it needs to be able to fix together over the arm.

 I would ideally like to have the cast printed in 2 parts (ie bottom and top), which will be fastened together at certain lengths depending on the total length of  the cast. On both the bottom and top parts, i would like them to join like a male and female electrical component ( like a plug with a socket ), or another example would be like 2 pieces of lego. I have attached an image of a previous design which utilizes this concept. If you look closely, one of the parts will have 3 or 4 "plugs" which go into the other parts holes or "socket". I like these designs because they allow the cast to remain smooth and prevent the catching of the cast with other things and are essentialy manipulatiing existing material to make a "mate" or "joint". https://www.xkelet.com/ also has a great design where the 2 pieces of the cast join like a plug and a plastic ring holds them together.

I have been shown that there is default connectors in meshmix, miscellaneous. However I would much prefer ones like in the photograph i have attached or the link. Could anyone suggest a way of modelling these or whether someone knows where i could find parts such as these? i have searched some websites for free .stl files but cannot find what i am looking for.

Thanks,

Ray

[Anonymous · Accepted solution]

Sorry, I can't see the details of the connector in your image. Could you post a sketch?

The ring connector is a nice solution so i did this using booleans and attached a obj file (see below).

Load this file to MM. SelectAll (Ctrl+A) and do ConvertTo/ConvertToSolidPart. In the following flyout  set CreateNewObject in the dropdown and enable MaintainDimensions. Clicking Accept you added this part to MESHMIX/MyParts.

This part is a special one. It combines 5 different objects: Two halves of the connector, the rubber ring and two objects we need for cutting off material from the casts.

Let's say we have two shells to connect:

Go to MESHMIX/MyParts and drag and drop the part onto one of the shells.

Now dragging the little white sphere in the widget's centre you can move the part to the desired location. Dragging on the ring around the sphere you can rotate the part (Don't drag the arrow at the ring which would do scaling). Roughly align the groups to be in a line with the gap.

You'll notice that the part tilts as you come close to the gap. Try to get satisfying position. Accept.

Make the new object the active one and run EDIT/Transform to refine the position. The wider region (the either connector) should dig into the two shells :

Now run EDIT/SeparateShells to split the part into its 5 elements.

Activate one of the two shells and with Shift pressed on the cylinder in the middle. Run EDIT/BooleanDifference. You will not see the change as there's still another cylinder. 

Activate the second shell and with Shift pressed again on the cylinder in the middle.

Run EDIT/BooleanDifference again. Now the connector gets visible.

Click on one of the shells and with Shift pressed on the corresponding half of the connector. Run BooleanUnion.

Do the same with the other shell ant its connector half.

Done. The exploded result:

[Anonymous · Accepted solution]

[Anonymous]

Instead of creating a pattern for each scan you might try this attempt:

Create a single surface template base mesh where the halves of the cast are not connected but combined to a single object (red):

Set the scan to be a target in the scene browser (activate Magnet - I changed menu View/TransparentTarget so it's still rendered opaque here)

Optional: SelectAll of the template and run Edit/AlignToTarget to get a rough alignment - This might fail.

Here the template is oversized. Use Deform/Transform to make it fit as good as possible.

Still all selected run Edit/AttractToTarget.

In the tool settings disable all checkboxes

The preview might look not that good, but accepting should make it fit to the scan:

All of the template being selected run Edit/Extrude and set the desired Offset and the direction to Normal:

Again all selected run Deform/Smooth:

Finally run EDIT/Separate to split the two halves of the cast:

This projection of the template to the target is doable in MM but gives little options to control. There might be issues if it comes to a situation where the distance of a surface region is similar towards different regions of the target (e.g. between thumb and pointer the template might be projected towards thumb or pointer, maybe the result is a mix of both directions...).

There's a nice special app (free for students) out there doing such non rigid registration of surfaces to a scan: Wrap3.3 . Maybe you are using an Artec scanner? If so: Its Studio application allows non rigid registration too.

Think using a template could speed up your workflow. To do the extrusion stuff and adding connectors return to MM.  

[Anonymous]

Hi Magweb,

Thank you so much again! Is there anything you cannot do?! Could you recommend a software to create the connection? I have inventor on my PC, could I used inventor and make that connection using 5 different parts?

Many Thanks

Ray

[Anonymous]

Hi Magweb, 

Thank you for this additional information. This would be great for me to include in my project as it will aid the technician in the production of the cast.

I do not understand how you created a "single surface template base mesh". Did you create this by the not defining an "offset" to the cast and by going through the method you have showed me previously?

I will download the software and play around with it! it will help greatly with automating the cast design process.

How did you become so good with mesh mixer? Can you recommend any tutorials which I can practice with to improve my use of MM? 

Thanks

Ray

Many Thanks!

Ray

[Anonymous]

Unfortunately I can't make water to wine 😉

Ok, basically any CAD package able to export a mesh (preferred  .obj) can be used. Check the mesh after import in MM whether there's compatible tessellation. Many CADs export with less as possible tris which are pretty big or stretched. Consider to do a remesh before you convert it to a part. Remember: You need to do Booleans later on and this works best if there's a mesh with triangles of a (almost) equal edge length.

Basically you can do this based on meshes in MM as well (the connector posted as an attachment above was done in MM), but admit: Non-mesh attempts might be faster.

The fifth element of the part is the rubber ring. Basically you do not need that. A male and female element plus a two elements to subtract (if needed) from A and B halves are enough.

[Anonymous]

Good old question about tutorials:

Some time ago RMS found time to post some vids:

Some maybe not that up to date: YouTube Chanel MM

There's a Meshmixer playlist from 123D times: Meshmixer101

MakersMuse did some nice vids on MM:

MakersMuse at YouTube

or Nick's training (paid):

Honeypoint3d

I started to use MM in its very early days with only a hand full of features. As time went by there came new tools one by one so it was much easier to learn.

I think the most efficient way to learn MM is to work through its MMManual and check out the tools and their parameters at the same time. Think it's the best trying to understand the tool and its parameters using simple objects. MM isn't oriented on a fixed workflow so you need to get an overview about the tools. You need to be able to plan your further workflow, to decide which tool to use for this and that, how to solve issues aso. That's pretty hard to get via a tutorial as they do some example workflow in most cases.

MM's either power is the combination of the tools.

Some idea if you really want to learn MM:

What do you think about a dialog here? You work through the manual, topic by topic and give a report of what you've understood so far, where your problems are. I'll give you feedback, maybe correction, hints and challenges...

Think this way we could get a valuable resource here and you'll learn it from scratch.

----

Yes, the template above was done by  Extracting the two halves. I selected the pattern to keep using SELECT and discarded the rest. Think this pattern isn't related to the concrete scan (maybe different fractures might need different patterns). I didn't want that they fit perfectly to show the AttractToTarget. So I deformed the extracted surface. The point is, that this must not be a watertight object, but just surfaces with open boundaries.

[Anonymous]

Thank you for providiing me with all this information. I will check it all out!

"What do you think about a dialog here?"- I think this is a great idea! I would like to at some point be able to help those on this forum, and i think this would be an excellent way to familiarise myself with the software.

Thanks again!

Ray

[Anonymous]

Great, so let's do it.

I'm waiting for your reports and related questions. Do it when you find time to do.

[kskelil]

How are you able to create the cast with this design? I'm referring to both the holes and the curved cut that separates the pieces.

Thanks!

[Anonymous]

You mean the red base pattern above?

This was done on a Extraction of the dense source mesh (scan) by brush-SELECTion and SmoothBoundary:

Select the region to be supported by the cast:

Run Modify/SmoothBoundaries on this selection (Please note the tool settings in the following images):

Run Edit/Extract with Offset at zero:

Immediately after accepting the extraction hit Y to make the extraction a separate object. Hide the original scan object and SELECT one half of the cast using the selection brush:

Again run Modify/SmoothBoundary (Note: I enabled PreserveMeshBoundary to keep the outer seams of the cast).

Hit Y to separate the halves.

Enter SELECT again. Set a tiny brush size and double click at the blue boundary. This is a bit tricky. Maybe you want to zoom in. You should get only the boundary faces selected:

Hit Shift+. (dot key) to expand the selection until you've got a selection wide enough to be the outer frame of the cast's half.

Run Modify/SmoothBoundary on this:

Now use the selection brush at a proper size to paint the filling pattern (Remember: Holding down Shift while brushing subtracts selected faces):

Again run SmoothBoundaries. Here it may happen that the tool can't smooth some boundaries for the not selected islands own too few faces (such issues are shown in pale red) and you need to do some changes at your selection. If it works you should get orange regions with blue rings all over:

Accept the result, Hit I to invert the selection and X to discard the islands:

Do the same with the second half. Finally activate both halves (Hold down SHIFT to activate a second object) and run Combine:

[Anonymous]

Can you help walk me through creating an articulated action figure or a ball jointed doll?