Create male/female mold pieces for diy fingerboard

[Anonymous]

Hey,

I am currently working on printing my own Fingerboard using layers of filament, which I plan to press with a mold. I have read couple of posts regarding the generation of molds by creating the positive fingerboard first and use the mold tool afterwards. This way works fine, but the mold has a weird way of cutting the two parts, since Inventor assumes that I want to build a "pouring" mold, while instead I want to build a press mold. In the attached picture of the finished mold you can see, that the mold parts are not cutted "following" the shape of the fingerboard, but instead in a more horizontal way.

In the second picture (fbmold_extrusionproblem.png) I tried to place a working layer beneath the fingerboard and then do an extrusion from the working surface to the lower layer of the fingerboard. Sadly, the function I tried ("to the next" in english?) shows the error message that no volume could be created. Is there maybe a function in Inventor to get an extrusion off an arbitrary surface of a part? That would be really easy since I could just extrude each part of the mold off the top and bottom layer of the fingerboard.

I hope you can help me out on these problems.

Thanks

[JDMather]

Can you zip and Attach your fingerboard part here?

[Anonymous]

Hey thanks for the fast reply! I included two models in the zip, the old one from the question yesterday and the new "final" one id like to continue with.

[JDMather]

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@Anonymous wrote:

... the new "final" one id like to continue with.

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And which one is which?

Which file do you want to continue with?

[andrewdroth]

You want the parting line of the two mold halves to meet in the center of the board, is that right?

[JDMather]

Is your Design Intent to have a uniform thickness?

(Your design is not currently uniform thickness.)

I made some changes to your design (See Attached), but suspect I will be making additional changes based on your responses to questions - before I demonstrate two mold techniques.

[andrewdroth · Accepted solution]

I think you will need to manually define the parting line. A quick and dirty way to do this would be to offset the faces of your part before you added the fillets.

Once you have the parting line it's just a matter of making a solid that you can split into two halves using that parting surface. The issue is that the split surface need to extend to the edges of this new solid. So I would either add extra width to the new surface, or as I show model the bare minimum mold and then you would just do a direct edit on the outside surfaces or something to give it some more coverage around the part. But this gives you an idea of how to make it.

After that just do a Boolean cut of the original deck, and each of the mold halves.

it's kind of crude, but should work for this process.

[Anonymous]

@Anonymous Sorry I forgot to mention that of course. The one I want to continue with is the ...highshape_higherconcave. Thanks for pointing out the thickness issue, I am aware that this came from the lofting and rounding I used while doing the model. I would be happy to see your advices for the molding!

[Anonymous]

Hey Andrew, thanks for the reply! Yes I want the partine line to:

-follow the angles of nose and shape to the end of the mold extrusion
-follow the concave of the deck in direction of the boards width if you know what I mean. This point I dont really know how its done since I would need to define the parting line following the boards shape (nose to tail) and afterwards let the parting line follow the concave of the deck (left to right if you look from the top).

[Anonymous]

@andrewdroth Sorry forgot to mention that I will have a look into your solution once Im home! Thanks in advance.

[andrewdroth]

No problem,

As for the thickness issue, a good way to address that is to model your deck as a single surface, add all the fillets to the curvature, then do a thicken to get the final thickness. Then you can fillet the edges round.  If you do it this way you are guaranteed a uniform thickness. 

[JDMather]

...and this surface can be used to define your parting "line".

[johnsonshiue]

Hi! On top of what experts already mentioned, I found there was a better way to create the fillets on the rims. The problem with your approach is that there are vertical lateral faces all around. This is bad for mold. A good mold should not have vertical faces (parallel to pull direction).

I used All Round Fillet to remove the vertical faces. The draft analysis shows better result. Also, you can define parting lines (silhouette curves) much more easily. See attached files.

Many thanks!

[JDMather]

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@Anonymous wrote:

@Anonymous Sorry I forgot to mention that of course. The one I want to continue with is the ...highshape_higherconcave. Thanks for pointing out the thickness issue, ….

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Bump.

Just pushing this back to the top so that I don't forget.

[andrewdroth]

I took a crack and making the board from scratch.

The file is 2020 version so I'm not sure you can open that, but hopefully the screencast sheds some light on the process.

[Anonymous]

Hey @andrewdroth , this looks amazing! Thank you alot. One thing that bothers me is that I do not want to have a kind of "pouring mold", but I want to use it to press PLA filament or wood veneer together, so the imprints of the board into the upper and lower molding part are a problem. Is there a way to build the mold without the last step of including the origninal shapoe into the two mold pieces if you know what I mean. Kind of like a pressing mold.

[andrewdroth · Accepted solution]

@Anonymous Can you explain how you are using the mold?

I searched push molds but I just come up with pushing clay into voids.

Are you applying something to a 3D print?

[Anonymous]

Hey @andrewdroth,

I want to print both parts, then put some woodwn or pla veneer in between and press them into a fingerboard shape. The clay approach also works, but there i cannot define the shape and concave of the deck the way I want.

Your solutions worked fine btw! One thing Im currently not perfectly fine with is that I dont know how to slide the molds extrusions with my parting surface, if the molds extrusion is wider than the defined parting surface. But I will try the print the next days anyways.
Thanks again

[andrewdroth]

Oh OK.

So essential a mold like how snowboards are actually made! I'm assuming you either cut the blank to shape first? or do you trim the edges after forming?

It that case you just wouldn't subtract the deck solid from the mold solids like I did. You would just using the parting line surface to define the shape.

I used a 'ruled surface' with the 'tangent' option to extend the parting line surface past the extents of the mold extrusion.

EDIT: Usually this type of forming is achieved with pressure and heat, although you may be able to use layers and glue as well, how are you planning on keeping the final shape?

[Anonymous]

Yes exactly like real skatebords and snowboards. I will cut it afterwards or grind it into shape. Good advice, I will try to resize the mold these days. Thanks