Create a coin footprint with an indentation in mind

3D Design Volume Model
1

Hello

I have to make an impression for a client in a 20mm thick plate.

In this cavity, an operator will have to place a part with complex shapes, such as automotive air piping.

The problem is that the part will just come out of the injection molding machine and therefore it will not be retracted.

The customer provides me with the CFD of the part on the final side, so cold and after removal

The size of the footprint to be made will therefore be larger than the CFD piece!!

 

How can I make the impression of my part in the plate taking into account the removal not made?

The fingerprint function seems to be the most suitable, only the formula used to calculate the withdrawal is different from the one provided by my client.

Is it possible to change this formula or is there another solution?

2

Hello

 

For me the idea would be to apply to your piece (dfn) an "enlargement" defined by your removal and then subtract it from your 20 mm  plate or to use the impression function by unchecking the removal. 

 

It's a bit of a hack but hey you should get the desired result.

 

Kind regards

 

Bastien

3

Thank you for this quick response.

I just tried to make an enlargement of the part but the problem is that Solidworks asks me for a value.

Except in my case this value is defined by a formula that takes into account the DFN.

The offset value to be entered therefore depends directly on the size of the part "point by point".

If the room was a simple square it would be very simple but here it is curved in all directions!!

4

I have a little trouble understanding that the formula provided by your customer is different for me, it must in the end give you a percentage of withdrawal and it is this information that is requested by solidworks to create the imprint. See the link

 

 

http://help.solidworks.com/2012/French/SolidWorks/sldworks/HIDD_DVE_INSERT_CAVITY.htm?id=fe511f11597c42daaaab3db4770050bc#Pg0

 

I only see that for the moment someone else will surely have the solution if it doesn't work like that

 

Bastien

5

EUREKA

 

your parts will have already made part of their removal, it remains to be seen what percentage of the removal will already be made at the exit of the mold

6

In my opinion, your customer's part will have a uniform shrinkage since we are talking about a case of thermal expansion.

either we apply a scale function on the customer part to "expand" it, or we apply a shrinkage coefficient on the impression.

7

The formula given by the cleint is as follows: 

Mold Output Dimension = DFN Dimension + (DFN Dimension * 1/3 * 0.012) + 0.4

0.012 being the shrinkage of the mold 1.2%

8

Mold Output Dimension = DFN Dimension + (DFN Dimension * 1/3 * 0.012) + 0.4

 

So out of the mold there is 1/3 of the removal made and 0.4 must be the functional set of your imprint.

 

For me, you should take the maximum rating on your dfn, apply the formula to it and then compare this odds obtained with the dfn rating which will give you a gap and then you deduct the percentage you will have to apply to the withdrawal on your footprint.

 

Kind regards

 

 

Bastien

9

Yes, I see what you mean but adding 0.4mm in the formula gives me a value that is no longer proportional to the DFN rating and I can't add this parameter in the footprint function.

Unless you do it in 2 operations, do the impression function with 0.4% shrinkage (1/3 of 1.2%) and do another function (which one?) to add the 0.4mm clearance

10

So we come back to my first idea, first magnification of 0.4 and then imprint, taking into account only the withdrawal of the formula (1/3 of 0.012)

 

No???

 

Bastien

11

Yes that's right, I must not have understood the 1st answer.

What functions can I use to make the enlargement?

12

For me, it has to be done in two steps: first extract the surface of your dfn, sew them and then make a thickening of 0.4, see link.

 

http://help.solidworks.com/2011/french/SolidWorks/sldworks/LegacyHelp/Sldworks/Features/HIDD_DVE_FEAT_THICKEN.htm?id=2da117d152584c4a9c2b66721a6d96b2#Pg0

13

Thank you so much, I'll try this and see if it works.

14

If it's a volume piece you can use the offset surface function (on the entire surface) of your value of 0.4mm and sew them to reshape a volume, then use a scale function to affect the percentage

15

For the magnification in %: you do it with the imprint function.

 

And for the 0.4 set, you select your surfaces and you click Insert / Surface / Offset

16

Hello

the removal of the part is a homotethy of your part according to the 3 axes X, Y and Z

The coefficient to be applied depends on the plastic material used

For example, if the plastic has a shrinkage of 0.5%, the multiplier coefficient is 1.005 according to the 3 axes

 

Here

Have a nice day

Christopher

17

So in the end you succeeded or not?????

 

Kind regards