Introduction

Coldstream's generative design engine supports handling manufacturing constraints. In Standard Design mode, manufacturability is supported through out all resolution levels, while for for Custom design the manufacturability is only guaranteed for the detailed resolution. Your specific manufacturing settings and default profiles can be managed directly through the libraries page. This page explains what parameters are required for each manufacturing method.

CNC milling

Parameter	Unit	Explanation	Required (Standard Design)	Required (Custom Design)
$R_f$	$m$	Governs the solid structure width.	Yes	Yes¹
$R_c$	$m$	Represents the milling tool and thus governs the channel width. This parameter also puts a limit on the inner curvature radius of structures.	Yes	Yes²
$delta$	$m$	Limits the channel depth.	Yes	Yes³
$orientation$	[-]	Gives the user control in which direction the channels are generated: Planar CNC: parallel to the selected orientation axis. Radial CNC: the orientation axis is parallel to the center of the design region axis.	Yes	Yes
¹ In Custom Design, R_{f_max} is not respected. ² In Custom Design, R_{c_max} is not respected. ³ In Custom Design, $delta$ is by default equal to the full height of the design region.

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Note
For Standard Design, a baseplate is required to connect all the structures. The plate thickness is given by the minimum feature size: $\min(R_{fMin},R_{cMin})/2$ . The maximum plate thickness allowed is 66.7% of the delta.

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Important
The design region should be hollow in order to use radial CNC milling.

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Note
The same parameters apply when selecting Skiving manufacturing.

Die casting

Parameter	Unit	Explanation	Required (Standard Design)	Required (Custom Design)
$R_f$	$m$	Governs the solid structure width measured at the tip, excluding the fillets.	Yes	Yes¹
$C_f$	$m$	Governs the the minimal curvature radius of the solid structures. If no value was given, the default is set to the minimal structure width divided by 2.	No	No
$R_c$	$m$	Gives users control over the channel width between solid structures. If no lower or upper limits are provided, the default is set to the structure widths.	No	No²
$b_{r,i}$	$m$	Governs what fillet is added at the root of the structures.	Yes	Yes
$b_{r,o}$	$m$	This parameter governs what fillet is added at the tip of the structures.	Yes	Yes
$angle$	$°$	The draft angle of the fins.	Yes	Yes
$delta$	$m$	The maximum height of the cooling structures.	Yes	Yes³
$orientation$	[-]	Gives users control in which directions the cooling structures are generated	Yes	Yes
¹ In Custom Design, R_{f_max} is not respected. ² In Custom Design, R_{c_max} is not respected. ³ In Custom Design, $delta$ is by default equal to the full height of the design region.

📘
Note
For Standard Design, a baseplate is required to connect all the structures. The plate thickness is given by:

$\min(b_{ro,corrected}+R_{fMin}/2,b_{ri,corrected}+R_{cMin}/2)$ +RcMin/2)

Where:

$b_{ro,corrected}=b_{r,o}\tan(\pi/4-\alpha/2)$

$b_{ri,corrected}=\delta\tan(\alpha)+b_{r,i}\tan(\pi/4-\alpha/2)$

The maximum plate thickness allowed is 66.7% of the delta.

3D printing

Parameter	Unit	Explanation	Required (Standard Design)	Required (Custom Design)
$R_f$	$m$	Describes how thick the structures can be.	Yes	Yes¹
$R_c$	$m$	Describes the channel width between structures.	Yes	Yes²
$\alpha_{overhang}$	$°$	The maximum allowed overhang angle. This property is set by default to 45°.	No	No
$l_{unsupported\; cantilever}$	$m$	The maximum allowed unsupported cantilever length. This property is set by default to 2 millimeters.	No	No
$l_{unsupported, bridge}$	$m$	The maximum allowed unsupported bridgeable length. This property is set by default to 4 millimeters.	No	No
$orientation$	[-]	Dictates in what direction the structures are manufactured.	Yes	Yes
¹ In Custom Design, R_{f_max} is not respected. ² In Custom Design, R_{c_max} is not respected.

Sheet metal forming

Parameter	Unit	Explanation	Required (Standard Design)	Required (Custom Design)
$R_f$	$m$	Governs how wide the added structers can be. If no parameters are provided, the structure width will be identical to the channel width.	No	No¹
$C_f$	$m$	Lower limit of the structure's curvature radius. If no parameter is specified, the curvature radius is equal to the minimal structure width divided by 2.	No	No²
$R_c$	$m$	Governs how wide the channels can be.	Yes	Yes
$b_{r,i}$	$m$	Specifies what fillet radius should be added at the root of the structures. It is measured on the inside of the bend.	Yes	Yes
$b_{r,o}$	$m$	Specifies what fillet radius should be added at the tip of the structures. It is measured on the inside of the bend.	Yes	Yes
$t$	$m$	The thickness of the stamped plate.	Yes	Yes
$angle$	$°$	The chamfer angle of the channels.	Yes	Yes
$delta$	$m$	The height of the fluid region.	Yes	Yes
$orientation$	[-]	The normal of the stamped plate.	Yes	Yes
¹ In Custom Design, R_{f_max} is not respected. ² In Custom Design, R_{c_max} is not respected.

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Important
The design region for sheet metal formed cases should be tall enough for both the fluid channels as well as the plate thickness! The design region height should thus be equal to the sum of channel height (delta) and the plate thickness (t). The fluid domain should locally be increased in height with the plate thickness (t) wherever there is a design domain.

Slice view of the final sheet metal formed design on the left and what ColdStream expects as input on the right.

Electric wire generation

Parameter	Unit	Explanation	Required (Standard Design)	Required (Custom Design)
$R_f$	$m$	The diameter of the generated electric wire.	Yes	Yes¹
$C_f$	$m$	The minimal curvature radius of the generated electric wire. If no value is specified, the default is set to the wire diameter.	No	No
$R_c$	$m$	The minimal spacing between different sections of the generated electric wire. If no value is specified, the default is set to the wire diameter.	No	No²
¹ In Custom Design, R_{f_max} is not respected. ² In Custom Design, R_{c_max} is not respected.

When selecting the 'electric wire' manufacturing setting during the case setup, an additional field will appear asking you for a voltage. This is the voltage that will be put on the electric wire. Together with the material properties and the selected wire diameter, this puts a limit on the power outcome of the wire:

P= \frac{\pi r^2V^2}{\rho l}

Where:

$P$ represents the generated power in watts $[W]$ .

$V$ represents the voltage on the wire in volts $[V]$ .

$\rho$ represents the resistivity of the material used in ohm times meter $[\Omega\cdot m]$ .

$l$ is the length of the wire in meters $[m]$ , which has an upper limit based on the size of the design domain.

$r$ is the radius of the electric wire in meters $[m]$ .

This manufacturing technique is very different from the other ones. The design region that will come out of this optimization will have a heat source due to the Joule heating.

How to select the appropriate manufacturing setting for your design case setup?

The manufacturing type needs to be selected when setting up the design region. After selecting the manufacturing method, you need to select the manufacturing parameters. This can be a predefined set of parameters or you can add a new set of parameters to the libraries.

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Important
Note that an orientation should be specified. It is very important to look at the orientation of your model and make sure that the right orientation axis is selected!

Select manufacturing settings in the design subregion setting window

How to add a new set of manufacturing parameters?

To enter a new set of manufacturing parameters, you need to go to the libraries and enter the manufacturing section. Here you can add a new set of parameters by clicking the add settings button.