Dialog: 3D-Cam

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Dialog: 3D-Cam

3D-Cam

See Add 3D Cam

Note:

We do not calculate the surfaces of 3D-Cams when you open a model. To see the surfaces, you must edit and rebuild the 3D-Cam from the 3D-Cam dialog.

tog_minusHow to open the 3D-Cam dialog-box ...
MD-3D-CAM-DIALOG-SELECT

Frequently, you cannot see the 3D-Cam in the graphics-area.

STEP 1: Find the Cam-Part

The 3D-Cam is a child to the Cam-Part.

1.Click the Mechanism-name-tabRed-14-1 that has the Cam-PartRed-14-2 as a child.

In the graphics-area or the Assembly-Tree:

2.Click the Cam-PartRed-14-2 that has the 3D-Cam as a child.

 

In the Assembly-Tree, the Cam-Part (Cam-Shaft1

Red-14-3
) is selected.
MD-3D-CAM-DIALOG-EDIT

STEP 2: In the Assembly-Tree

The 3D-Cam is a child to the Cam-Part.

1.Explore the Cam-Part(Cam-Shaft1

Red-14-3
) in the Assembly-Tree to show its child elements

2.Right-click the 3D-Cam element

Red-14-4

In the shortcut menu:

3.Click Edit Element

Red-14-5

The 3D-Cam dialog is now open.

3D-Cam dialog

3D-Cam dialog

3D-Cam dialog

There are two buttons at the top of the 3D-Cam dialog:

Click the Rebuild-48 button to update the 3D-Cam when you edit any of the parameters in the 3D-Cam dialog.

See below for more details.

There are three tabs:

Cam

Display

Export

CAM tab

Rims in 3D Cams

Rims along the Cam-Flanks (Purple), the Top and Bottom (Orange), and Points along each Rim.

Preamble:

Four(4) Cam Surfaces

A 3D-Cam has four(4) surfaces. The four(4) surfaces are the:

•2 × Working Surfaces: these are the Cam-Flanks that are in contact with the Follower-Roller

•Root Surface: the floor is deeper in the cam to be clear of the end of the Follower-Roller

•Top: you do not need this surface in the actual cam. We add it to close the 3D-Cam.

Rims and Points

Rims: are along the length each surface. We distribute Rims equally across each surface so that are approximately parallel with each other.

Points: are along the length of each Rim. We distribute Points equally along each Rim.

You control the number of Rims and the number of Points in the Cam Mesh Density separator.
MD-DIALOG-3DCAM-CAM-MESHDESNISTY

# Points per Rims:

The number of Points along each Rim

# Rims per Flanks:

The number of Rims across each Cam-Flank (working surface) of the 3D-Cam.

# Rims per Top / Root:

The number of Rims across the Root and Top surfaces (non-working surface) of the 3D-Cam.

# Hoops (for CAD)

Hoops wrap around the 3D-Cam . They connect all of Rims at the same Point#. We use Hoops to help SolidWorks model the surfaces.
MD-Taper-Roller VelocityDiagram-464

Preamble:

These parameters are for Tapered Follower-Rollers.

[ Linear Velocity () = Radius( ) × Angular Velocity () ]

Cam Flank Velocity: different points on the cam-flank surface are at different radii from the cam's rotational axis.

Therefore, a point that is at a large radius from the Cam's rotational-axis has a greater velocity than a point that is at a small radius.

Cylindrical Follower-Roller Velocity: all points on the surface of a cylindrical follower bearing are at equal radii from its rotational-axis. Therefore, the tangential velocities of all points on the surface of a cylindrical roller are identical.

The velocity of the cam's surface and the follower's surface can only be equal to each other at one radius from the center of the Cam. The follower-roller must be skidding at all other points!

Tapered Follower Velocity: the surface velocity of a tapered-roller increases as its radius increases. If its apex is coincident with the rotational-axis of the cam, it can have a surface speed that is equal to the surface speed of the cam. Thus, it can roll on the cam surface as the cam rotates. This is possible during the dwell periods.

Nevertheless, cylindrical or barrel rollers are usually used as they are readily available, cheap, and they can withstand high loads.

Two Extrusions - different Extrusion-Offset

Two Extrusions - different Extrusion-Offset

The Roller Diameter of a Tapered Roller?

First, review the Extrusion-Offset and Extrusion-Depth parameters that define the Profile Extrusion of the Follower-Roller.

Use the Extrusion dialog to make the Extrusion-Depth parameter equal to the actual Width (or Length) of the Follower-Roller (frequently, the 'B' parameter in bearing catalogs).

Extrusion dialog: (Note: Part-Offset parameter = 0 mm).

Extrusion-Offset (mm): Position (Z-axis) to the Primary-ContourRed-14-1b from the Mechanism-Plane.

Extrusion-Depth (mm): = Dimension between the PrimaryRed-14-1b and SecondaryRed-14-2 -Contours. Positive value ONLY
MD-Taper-Angle-360
MD-DIALOG-3DCAM-CAM-ROLLER-PARAM

 

Taper-Angle of the Follower-Roller.

Taper-Angle (degrees) inclines the Flanks of the 3D-Cam. The taper angle pivots about the Secondary-ContourRed-14-3.

This is not as convenient as the Primary-ContourRed-14-2, for which we apologize.

With reference to the image to the left, you can see that a Negative Taper AngleRed-14-6 decreases the diameter of the Roller in the +Z-axis direction.

Whereas, a Positive Taper Angle, increases the diameter of the Roller in the +Z-axis direction.

 

Z Offset for Debug - ignore.

 
MD-Taper-Angle-360-2
C = Actual Roller Width

C = Actual Roller Width

Recommendation , if you want to use the Taper-Roller parameter:

Edit the parameters so that Secondary-Contour of the Profile for the Follower-Roller is on the Mechanism-Plane.

STEP 1

Edit the Follower-Profile (Extrusion) with the Extrusion dialog

The Extrusion-OffsetRed-14-4 should be the negative of the Extrusion-DepthRed-14-5.

Extrusion-Depth(mm) = Actual Roller Width(mm) (Equal to dimension C in SKF catalog

Extrusion-Offset (mm) = – Extrusion-Depth(mm) (Equal to negative of dimension – C in SKF catalog.

The Secondary ProfileRed-14-3 is now on the Mechanism-PlaneRed-14-1b. The Taper-AngleRed-14-6 parameter rotates and pivots on the Mechanism-Plane.
MD-Taper-Roller Parameters-Settings-General-3

STEP 2:

Use the Roller Clearances separator (see below ) to edit the Root-Clearance and Top-Clearance to extend the flanks as you need for the actual roller and 3D-Cam
MD-DIALOG-3DCAM-CAM-ROLLERCLEARANCES

Preamble:

There must be a small clearance for a Follower-Roller to roll between the Cam's flanks.

Also, you must make sure the Follower-Roller does not touch the Root/Floor of the Cam-Blank.

Thus, Clearances are practical considerations.

To calculate the basic 3D-Cam (without Roller Clearances), we use for you the:

•Radial dimension of the Circle that represents the Follower-Roller.

•Extrusion-Depth of the Extrusion you add to the Circle as the depth of the Cam-Flanks

•Part-Offset + Extrusion-Offset of the Extrusion from the Mechanism-Plane to locate the Cam-Flanks.

You should use the actual dimensions of the Follower-Roller, and use Roller Clearances to give the clearances you need.

Radial-Clearance (mm)

Important: Total Clearance = 2 × Radial Clearance.

A positive Radial Clearance moves the cam-flanks out, from the Follower-Roller.

A negative Radial Clearance moves the cam-flanks in, towards the Follower-Roller.
MD-3DCAM-Clearance-TopRoot-360

Root-Clearance

A positive value that moves the Root-Face towards the center of the Cam -see Note.

Add Root-Clearance to make sure the Follower-Roller does not touch the actual Root (the floor) of the cam-groove/track.

Top-Clearance

A positive value that moves the Top-Face away from the center of the Cam - see Note.

Add Top-Clearance to make sure the top-face of the model is outside the Cam-Blank

Note:

The Top-Face may be the Root-Face of the Cam - vice-versa!

To find which is which, Experiment! Enter a value for the Root-Clearance and click the Rebuild button. Observer in the model which face moves.
MD-DIALOG-3DCAM-CAM-FLANKLENGTH

Preamble:

Flank Length parameters apply to Indexing Cams.

When you add a 3D-Cam, we calculate for you the cam over a complete machine-cycle, 0 – 360. However, Follower-Rollers of indexing cams are not in contact with the cam for a complete machine-cycle, 0 – 360. The Follower-Rollers progressively engage, then disengage with the cam, in a similar way to gear teeth.

You use the parameters in the Flank-Length separator to calculate the cam for the period in which the Follower-Roller is engaged with the cam.

Flank-Length:

Start-Angle

End-Angle

These angles are with respect to the Master-Machine-Angle.

When you edit the Start-Angle and End Angle, we re-calculate for you the Cam from the Start-Angle to the End-Angle.

The number-of-points along the cam do not change. Thus, the points along each rim are nearer to each other.

DISPLAY tab

Click to expand/collapse Display in Graphic-Area 
MD-DIALOG-3DCAM-DISPLAY-DISPLAY

Preamble:

The Display tab controls how you show the 3D-Cam in the graphics-area.

Solids* | Hoops | Rims.

☑ Solids*: show or hide, 3D-Cam as an MD-Solid

☑ Hoops: show or hide a hoop at each Point - see # Points

☑ Rims: show or hide the Rims along the 3D-Cam

* You must enable the Solids check-box to see the 3D-Cam in other Mechanism-Editors and the Model-Editor

Color

•Use the Windows® color-picker to select a color of the 3D-Cam

Transparency

•Use the slider to change the Transparency of the 3D-Cam.

Display Cam Contour as...

•Pressure-Angle

•Cam-Profile

When you show the 3D-Cam as Pressure Angle, the faces have a color-code.

•Red identifies a high Pressure-Angle

•Blue identifies a low Pressure-Angle

Minimum / Maximum

By default, the color-code scales to the maximum and minimum values of the Pressure-Angle

If you want to change the scale, use the Maximum Value and Minimum Value boxes.

Auto-scale button

Click the auto-scale button to reset to the maximum and minimum values again.

Flank 1 visible, Root Visible, Flank 2 Visible, Top Visible

Show or hide each surface.

EXPORT tab

NOTE: From MD13.2, it is easier to save the 3D-Cam as a STEP file with the Save button.

MD-DIALOG-3DCAM-EXPORT-SWPATHS

Preamble:

After you export a 3D-Cam to SolidWorks, copy the path and file-name of the SolidWorks document into this dialog. Then, later, you can use this dialog to open the CAD model of the 3D-Cam again.

Get Cad Part Path button

Click the button to copy the path and file-name of the SOLIDWORKS document into the Path of SLDPRT (Cam) box.

Open Cam Part button

Click the button to open in SOLIDWORKS the SOLIDWORKS document that is in the Path of SLDPRT ( Cam ) box.
MD-3DCAM-EXPORT-SWTRANSFER

Preamble:

We recommend you save the 3D-Cam as a STEP file - See Rebuild and Save buttons

Alternatively, you can use these buttons to transfer the Cam-Blank, and the 3D-Cam to SOLIDWORKS.

Before you click these buttons:

1.Open SolidWorks

2.Start a new SOLIDWORKS Part document and make sure it is the active document.

Transfer Cam Blank button

•We export for you the sketch of the Cam-Blank and its Axis-of-Rotation to SolidWorks.

•We instruct SolidWorks to use the Cam-Blank and Axis-of-Rotation to add a revolved feature.

Transfer 3D-Cam button

•We export for you each Rim and Hoop

•We instruct SolidWorks to:

oCreate a surface from the Rims of the two Cam-Flanks, and the Top and Root faces

oIf the cam is an Indexing-Cam we add end-cap surfaces

oKnit the surfaces together with the Knit-surfaces feature

Cut 3D-Cam into Cam-Blank button

•We instruct SolidWorks to:

oCut the Knit-surfaces feature from the Cam Blank revolved feature.

oHide the Knit-surfaces feature.

You may need to edit the Surface Cut feature to reverse the direction of the cut

REBUILD and SAVE buttons

Click to expand/collapseRebuild and Save Cam buttons
Export tab

Export tab

Click the Rebuild-48 button:

•to recalculate the 3D-Cam with updated parameters

•before you transfer the 3D-Cam to SolidWorks

•before you save the 3D-Cam

Click the SaveCam-48 button:

•to save the cam as a STEP, TXT, or a SLDCRV file-type.

STEP file-type (recommended)

You can open a STEP file-type in most 3D-CAD programs.

See EXAMPLE 1 : Export the 3D-Cam as a STEP file, below.

TXT, SLDCRV file-types

We save for you the XYZ coordinates of each Rim as a separate file.

In the image, left, there 20 Rims. We save for you 20 files, one file for each Rim.
Rims in 3D Cams

Rims along the Cam-Flanks (Purple), the Top and Bottom (Orange), and Points along each Rim.

Export 3D-CAM

Click to expand/collapseMETHOD 1: Export the 3D-Cam as a STEP file (RECOMMENDED)
MD-DIALOG-3DCAM-REBUILD-SAVE-2

In MechDesigner:

In the 3D-Cam dialog:

1.Click the Rebuild-48 button

2.Click the SaveCam-48 button

3.Select STP as the file-type, and save the cam - for example, CAM.STP

Note: STP file-type is the same as the STEP file-type.

SOLIDWORKS

1.Open Cam.STP file in SolidWorks®

2.If you are prompted, do Import Diagnostics.

3.Close Import Diagnostics command

Depending on your SolidWorks® settings, you may need to:

1.Right-Click Cam.STP in the Feature Manager

2.In the shortcut menu: Click Dissolve Feature and Yes, break the link

3.Right-Click - again - the CAM.STP in the Feature-Manager

4.In the shortcut menu: Click Import Diagnostics

In the Import Diagnostics dialog

5.Disable Attempt to Heal All button, and then close the Import Diagnostics command.

6.Save Cam.STP as a SolidWorks® file-type. E.g. Cam.SLDPRT.

MD-Dialog-3DCam-SW-DissolveFeature
MD-Dialog-3DCam-SW-ImportDiagnostics
MD-Dialog-3DCam-SW-SaveAsSLDPRT
SOLIDWORKS: Cam-Blank

SOLIDWORKS: Cam-Blank

In SOLIDWORKS

Open the Cam-Blank:

1.Open the prepared SolidWorks® part Cam-Blank.SLDPRT.

 
SOLIDWORKS: Insert Part

SOLIDWORKS: Insert Part

SOLIDWORKS: Combine > Subtract

SOLIDWORKS: Combine > Subtract

Continued...

Insert the Cam.SLDPRT file (see Part 1)

2.Insert menu > Part... ; select “CAM.SLDPRT”

3.Click the Tick at the top of the SolidWorks feature manager.

Cam.SLDPRT is now a feature and a Solid Body (Cam<imported)

Ideally, the orientation of the CAM.SLDPRT is correct relative to the Cam-Blank.SLDPRT. If not, I find it easier to move the sketch (in SolidWorks) of the Cam-Blank to the correct Plane - experiment!

Continued...

4.Insert menu > Feature > Combine:

a.Select Subtract as the Operation Type and,

b.In the Bodies to Combine box, select

i.Cam-Blank as the Main-Body and

ii.Cam<imported> as the Body to Subtract.

 
SOLIDWORKS: Result

SOLIDWORKS: Result

Result:

You should see the Cam-Track in the Cam-Blank.

Note: It is possible that the Solid Body “Cam<imported>” is not in the correct place relative to the Cam-Blank. For example, Cam<imported> and Cam-Blank.SLDPRT are not defined on the correct Planes.

In this case, redefine the sketch-planes of “Cam.Blank” (easiest method) or move “Cam<imported>” (more difficult to do)

To move Cam<imported>, do:

1.Insert menu > Feature > Move/Copy... and select Cam.SLDPRT as the body to move.

Click to expand/collapseMETHOD 2: Transfer the data directly to SOLIDWORKS

MD-SolidWorks-NewPart

Not usually recommended - we recommend that you save the Cam as a STEP file - see METHOD 1 - above.

STEP 1:In SolidWorks®,

Make sure the active document is a Part document:

1.Open SolidWorks®

2.Add a new Part

3.Save the new Part
MD-3DCAM-EXPORT-SWTRANSFER

STEP 2:In MechDesigner

In Export tab > SOLIDWORKS Data Transfer

1.Click the Transfer Cam Blank button

We send for you the sketch-loop and rotational-axis in the Cam-Blank tab to SolidWorks.

In the image to the left, you can see in SOLIDWORKS:

•3DSketch1 which is the rotational-axis

•Revolve1 which is the feature that revolves the sketch-loop into the Solid.

See Getting Started Tutorials 6C for more information.

 

MD-Dialog-3DCam-Exporttab-CamBlank-inSW

MD-Dialog-3DCam-SW-KnittedFeature

MD-Dialog-3DCam-SW-KnittedFeatureA

STEP 3:Click the Transfer 3D-Cam button

To make the transfer quicker, show a drop-down menu in SolidWorks®.

For example, show the help menu drop-down.

We do not know why this makes the transfer faster, but it works.

1.Click the Transfer 3D-Cam button

We control SolidWorks to use the data to:

1.Add the Rims as Curve entities

2.Add four Surfaces features (or six if the Flank-Lengths are not from 0 – 360)

a.two Cam Flanks; one Floor, and one Top Surface

b.two 'End-Caps' if the Flank-Lengths are not from 0 – 360.

3.Add the Knit-feature to knit the Surfaces

MD-Dialog-3DCam-SW-Insert final

STEP 4: Click Remove Surfaces from Blank button

1.Click the remove Surfaces from Blank button

The 3D-Cam Surfaces Cut into the Cam-Blank.

Wait! - you should now see the image to the left

If you see ONLY the CAM TRACK and not the Finished Cam (see image below)

STEP 5: Save the Part In SolidWorks®

1.Insert > Cut > With Surface

2.Select the Knitted 3D-Cam Surface - the last feature in the Feature Manager.

3.Edit the Surface Cut feature in SolidWorks® and click the Change Direction button.

4.Hide the Knitted Surface feature of the 3D-Cam.

MD-Dialog-3DCam-SW-Negative