The following tutorial is an introduction into 3d solid modelling using NX5. Included is a step by step procedure on the

different ways to model the following component. This is one of the parts you will use in the assemblies tutorial so make

sure you save all the parts for use in later tutorials. You should begin with this one, then move onto the shaft, then the

pulley and finally the base plate.

Block Design

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Open up NX it should look like this, press the new part button in the top left corner

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The following menu should pop up, to use 3d modelling use the model template. Type in the name of the part which in this case should be Base Block

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Then select where you want to save the part using the button next to the folder text box. Make sure that you place your files in a folder on either your U drive or a USB

Stick for future reference. Once you have finished with the name and location of the file press enter

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This is the screen that should pop up once you have made a new part file

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In order to get the proper layout select the roles button on the left hand side of the page and select advanced with full menus

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Once the full menus have been selected we can begin modelling the base block. To model the block we must first draw a 2D sketch of the object. To do this you must

select the sketch button on the top left corner of the tool bar below the NX start button.

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The sketch plane menu will pop up prompting you to select which plane you want to sketch on, NX will default to the X-Y plane however you can select any of the 3

planes that are automatically created with the part file

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By clicking on which ever dotted line on the axis will make that plane the sketching plane. Once you have selected the datum plane select select ok to begin sketching.

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The toolbar on the top line will have changed, this toolbar has the 2d sketch functions, dimensions and constraint tools, curve offset and projection tools. Of interest to

us is the curve buttons and dimension buttons. To exit out of sketcher you must press the finish sketch button with the finish flag on it.

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The first way to make the part is to use the profile curve button, this allows you to have a number of curves that join from head to tail. To begin select on the (0,0) point

at the intersection of the two axis. Once selected you can move the line to any position.

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NX has Automatic constraints that allow you to achieve a certain orientation of the line. In this example you can auto constrain the line to be vertical as shown by the

little vertical arrow next to the line, however you can passively turn this off when sketching by pressing the Alt Key. The auto constraint will be turned off while the Alt

Key it is depressed and you are sketching.

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One you have clicked the line, you can then draw a horizontal line as shown above, as before you can auto constrain the line to be horizontal which is shown by the

horizontal arrow. NOTE: the different auto constraints will be shown next to the line while you are attempting to place a line, be careful that it doesn't auto

constrain to a position that you don't want.

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You can then make the basic shape without the correct dimensions. Note that NX also allows you to make non constrained line lengths similar to previous ones, this is

shown by the fine dotted line.

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However, the memory is not big, so in order to make that vertical line a similar non constrained length

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You must drag the cursor over the initial point you want to be in line and then drag the mouse across

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This allows you to make that part a similar length, however it not a fixed position, nothing is holding the pieces in this orientation apart from the vertical/horizontal auto

constraints and the original point you clicked

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Finish the sketch by joining the final line

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To stop using the profile sketcher either press the Esc Key until the button is deselected or press the profile button again to stop the profile sketcher. To show that the

line lengths are not fixed or constrained select any of the lines and hold the mouse button down and drag the curves around.

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Another way of doing the same sketch is to draw the correct number of line on the page and manually constraining them. However as before when drawing the lines

they can auto constrain themselves to the other lines. As shown below

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Auto constrained perpendicular lines

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Parallel, again be careful when drawing the lines as they can auto constrain to orientations you do not want, so to remove them hold the alt key while drawing the lines

to prevent these from coming up

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To begin making the geometry after you have drawn the lines select the constraints tool which is located above.

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By selecting the constraints tool you will notice that the cue line has asked you to select the curves to constrain and that this particular sketch needs 32 constraints to

be fully constrained. Also each end point has the x-y axis on the end. To begin we will select the first line and constrain it to the datum axis.

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Place the cursor over the end point of the line and the line should turn magenta and a two orange circles should appear at the ends of the line. Select the end point

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A new tool bar has come up and the line has turned orange, the constraints currently allowed only make the current point fixed in space. To put this line on the datum

point you must select either one of the axis or the point at the intersection of the two lines.

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First method, by two axis, select the vertical axis following the line end point and select the point on curve function.

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End point has moved to be in line with the axis, colour has changed to lime to show that it is partially constrained

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Select end point again

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Select the horizontal axis and select the point on curve button

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Line end point is now fixed to the intersection of the two axes.

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The other method is to do the same as before by selecting the end point of the line

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But instead of selecting the two axis you can select the point that exists at the intersection point, and then selecting the coincident constraint

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Same result as before, once constrained unselect the constrain button and drag the line around to see that the end point is fixed with respect to the datum

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To make the line vertical again select the constraints tool and then instead of selecting the end point select anywhere along the line and the tool bar above will come

up. This allows you to make the line, horizontal, vertical, a constant length or a constant angle. Only use the vertical or horizontal constraints.

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In this case we want to use the vertical constraint so select that from the toolbar

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The line should now look like this

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Now to join the lines together select the end point of another line

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And the endpoint of the other line and select coincident button

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This again places the line on the end of the first curve and again unselect the constraints tool and drag the endpoint of the line around to see that it isn't constrained

completely.

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Select the middle of the line again and constrain the direction of the line. If you accidently constrain the line vertically instead of horizontally you can undo the

constraint as shown

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To undo you can select the show/remove constraints button

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Once selected this menu pops up, the top radio buttons allow you to select single lines, multiple line or all the lines in the sketch and the bottom buttons allow you to

remove only the highlighted constraints or all the constraints in the list.

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Select the line that was wrongly constrained, you can see in the list there is a coincident constraint with the first line and a vertical constraint.

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Select the vertical constraint and select the remove highlighted button to remove the constraint.

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Once you have finished press the ok button

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Reselect the line and select the horizontal constraint.

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Once you have made the line horizontal repeat the process for each of the other line using the same procedure.

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Once it is complete it should look like this and you should also note that the sketch only needs another 6 constraints to make it fully constrained.

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The other way of making the geometry is to just use the auto constraints and the snap point tool bar above. Each of these buttons allows certain parts of the lines to be

quick selected. The first is to allow snap points to be selected,

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The first button is the end point which lets you select the end point of a line

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The second is the mid point snap tool which selects the middle of the line

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The Third is the control point which picks either end, mid or main points in the sketch or on the line

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The fourth is the intersection snap point the gives you the intersection points of two lines

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The next allows one of the 4 quadrant points to be selected, really handy for tangent tools

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The arc centre snap point allows the centre of an arc to be quickly found.

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The points snap tool allows the points to be selected points are a manually entered item which can be referenced

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The final snap point is the point on curve feature which allows you to select any where on the line without snapping to a predefined point

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To begin select the line tool and select the point snap tool and select the datum point.

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Draw a line vertically up

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Then select the end point snap tool and select the end point of the line and draw a horizontal line

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Once these are drawn draw the same geometry as before.

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Again the geometry should look like this

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The next step is to dimension the sketch to fix the lengths of each line. To do this you must select the Inferred dimensions button in the tool bar.

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Once selected you should see a tool bar come up and in the cue bar it asks you to select a line or lines to dimension. Also in the tool bar you there is a ref button, this

allows you to only put on reference dimensions to allow you to see what the length of a line is, this is not a constrained dimension(driven dimension) which actually sets

the length of the line.

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To dimension a line you can either select the line as shown where you place your cursor over the line and click

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Once you click you must move the dimension line across off the part and somewhere out of the way and then select again. What you see here is the length of the line

that was drawn. In the text box you can input the value you wish the length to be

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Input 25 and press enter.

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The other way to do the same dimension but slightly more stable is to select the two lines perpendicular to it. Begin by selecting the bottom line, as you can see the

length of the line comes up, however do not click anywhere on the page, we are not interested in that length just yet

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The select the top line as seen highlighted in orange, once this is done, click off the part to apply the dimension

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And as before you input 25mm and press enter

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You can now do this for all the sides.

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To modify the value just double click on the dimension you want to change.

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Which can be changed, also to exit from the dimension tool either press escape until the button is not selected or deselect the button with the mouse. Apply

Dimensions to all the sides

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Once all the dimensions have been applied the lines turn maroon to show that the sketch is fully constrained.

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If you sketch turns orange as seen here, it means you have over constrained the sketch by placing too many driving constraints, you can see that the top three

dimensions are the same as the bottom dimension. What you can do to fix this is either delete the bottom constraint or one of the top constraints or convert the

bottom dimension to a reference dimension.

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By deleting the conflicting constraint then selecting the ref button you can reapply the dimension, but note it will not drive the length of the part

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Select the ref button

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The new dimension is a different colour to the rest of the dimension and make sure you deselect the ref button before trying to create more driving dimensions

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Notice that there are a few of the same dimensions in the same part, what you can do is constrain the lengths of the line to just one dimensioned line.

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Go into the constraints tool and select one of the dimensioned lines.

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Select a second line anywhere in the middle of it (not at the end points), more options come up in the tool bar, (the first is collinear this allows two lines to be inline

with each other without actually touching, you know the next two, the third is the parallel constraint, next is the perpendicular constraint, the one after that is the equal

length constraint, ignore the last two) for this example use the equal length tool.

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Notice that the sketch is over constrained again, delete all the other dimension apart from that one we used before.

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Now select the first line and then all the other lines and select the equal length tool. Make sure the first line you select is the line with the correct constraints otherwise

it can sometimes cause the program to crash.

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As before the sketch is full constrained, but now instead of there being 6 dimensions, there is only one which allows easy manipulation of the whole body. Try changing

the value of the dimension to see what happens.

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Changing the value to 40 allows fast updates of the geometry. Although this is an idealised body if you drive you models like this you can save time when changing

dimensions

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Change the value back to 25 and we can now add a hole to the body as per the initial drawing. Select the circle tool in the top bar

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Select somewhere on the page and click and add a circle to the drawing. We can now position the hole with respect to the body and constrain it such that is always

stays in the middle of the block at the top.

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Select the constraints tool again and then move the cursor over the cross in the middle of the circle and click it

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The circle is now highlighted. To make the circle always sit in the middle we will use the midpoint constraints tool

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Select one of the vertical lines around the centre of the line and a new tool bar will come up, as per before you can place the centre of the circle on the line or else you

can place it on the mid point of the line, select the mid point button

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You can see that the circle is now on the mid point of the first line. Select the centre of the circle again

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And select the horizontal line at the top and use the midpoint tool

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The circle is now constrained to be in the middle of the two lines. We can now apply a dimension to the circle to make it fully dimensioned

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Select the dimension tool and the outer edge of the circle to apply a dimension

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Click on the work sheet to apply the dimension and allow modification. The size of the hole can be now input, which can be done one of two ways, to keep the model

dimensionally constrained with respect to the original dimension from the block we can type in the name of the dimension p9 or whatever yours becomes into the text

box as such

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When you type in p an auto complete option comes up is shows all the different options for what the dimension can be, the top line shows p9 vertical from this

particular sketch which we can select by highlighting and pressing the tab key and then dividing by two to make 12.5mm diameter.

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Press enter and the sketch becomes fully constrained. We can now modify the size of that initial dimension to scale the whole part. Change the dimension to 40

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As you can see the whole part has scaled appropriately, however if the size of the hole doesn't need to change we can manually add a dimension

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To change the dimension from a formula to a normal value you select the dimension while in the dimension tool and then

select the f(x) button and then click on the make constant button

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The dimension becomes a normal dimension again and we can input the 12.5mm size and change the original dimension back to 25mm

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Now that we have drawn the correct geometry we can make this sketch into a 3d object. To finish press the finish sketch button in the top left hand portion of the

screen

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We are now back in the main level of the modelling part of NX. If we want to go back into the sketch we were working on we can go to the part navigator on the left side

of the screen

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This is the parts navigator which allows you to see what operations you have performed to make the component, to get back into the sketch we can either double click

on the sketch item in the menu or double click on the sketch itself on the main part of the screen, don't click on the sketcher button again all this does is opens up a

new sketch which will confuse you.

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Double click on the sketch item or the sketch itself.

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And we can modify the sketch again. Go back to the main screen by pressing the finish sketch button

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To make the part solid we use the extrude function, because we are trying to give the 2D sketch a 3rd dimension into the page we extrude the part. Once we press the

extrude button a new drop down menu appears which allows us to make a solid feature. Always look at the cue line to see what steps are required. To begin look at the

curve rule drop down box on the top line, this allows us to select different lines within the sketch.

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Typically the connected curves rule is used in case you have multiple lines in the sketch that you do not want to extrude. Begin by selecting the outer line

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You can see that by selecting one of the lines all of the lines that are connected to it are selected at the same time, we also want to extrude the hole so we then select it

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Now that all the curves are selected we can then choose how far we want the extrusion to go. The menu allows us to go either way with the extruding,

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You can also use the green drag handles to change the size of the extrusion.

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Because the depth of the part is the same as the height of the sides we can either manually input the 25mm into the end distance or type in its relative name from the

sketcher which if you recall was p9. set the start point to 0 and the end distance to p9 or whatever your dimension happened to be.

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We can now apply the extrusion which is referenced to the original sketch

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We finally have the first part of the model, one of the base parts. To modify the extrusion either double click on the extrusion

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Or go to the part navigator and double click on the extrude feature in the tree. This is the first seed part of the assembly we will be making.

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To add chamfers to the edges of the part you select the chamfer tool on the toolbar.

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You are able to add chamfers to any convex edge you want, for concave edges such as the join in the top box you use the face blend tool. For starters to select which

edge you want to chamfer

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Start by selecting the first edge. You can specify the size of the chamfer to just the use the drag arrows on the part itself. In this case specify a 3mm chamfer

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The press apply if you want to add more or ok to finish using the tool

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Add chamfers to every edge on the part to clean up the edges and press ok

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The part should look like this. The next step is to add blends to concave sections, use the face blend tool on the toolbar

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In this feature you must select faces to blend, ignore the type of blend just use the rolling ball blend. Make sure the curve rule has the single face option selected

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Select the first face and press the centre mouse(scroll wheel) or select then face chain two button

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Again make sure that the single face curve rule is selected and then select the second face. Now specify the radius and press apply

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Specify a 3mm radius and apply

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Your part should look like this, you can now do the same thing to the other side

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The next step is to add holes for the bolts to go through. Select the hole tool from the menu above.

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Select the face you want to apply the hole to

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You are now back in a sketcher window however all we want to have is reference points to which we want to align the holes

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Start by drawing two circles then select the constraints tool

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Select the centre of the first hole

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Then the edge of the first side to want to place the hole and press the mid point button

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Select the centre of the hole again and then the other vertical side

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And then press the midpoint option

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The hole is now in the correct position, ignore the size of the circle you have drawn all we want is the centre point, repeat this process for the other hole

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You should now have two circles lined up in the centre of the part, finish the sketch to return to the hole tool menu

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We can now make the holes, firstly select the arc centre of the two circles

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Click on each centre point

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Now you can make a number of different holes depending on the type of bolt you are using the form drop down menu, you can either have a simple hole, countersunk

for countersunk bolts which gives a tapered seat or a counter bored hole for a cap head screw which gives two holes of different diameter to allow the shaft of the bolt

to go though and the head of the bolt to sit in to keep the head flush with the surface. In this case we are going to use simple but for the other two make sure you know

the size and angles of the heads of the bolt to make sure the are sized correctly to suit your bolt

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Input a diameter of 6mm and select the through body option in the depth limit drop down box. Then press apply to make the holes

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Your part now has two bolt holes for the part to be mounted. The model is now complete

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