Build one part.
Then connect the mechanism.

1. Exit the rectangle sketch. Choose Features → Extruded Boss/Base, set a blind depth of 30 mm, and accept.
2. Select the plate’s broad top face and start a new sketch. Draw four circles for the guide holes.
3. Locate their centres 30 mm from the nearest long and short plate edges. This produces a 190 × 90 mm centre pattern. Relative to the rectangle centre, the positions are horizontal ±95 mm and vertical ±45 mm within this sketch.
4. Give one circle a Ø25 mm Smart Dimension. Select the other circles and use Equal relations, or dimension them consistently. Do not combine redundant dimensions with Equal relations.
5. Exit the sketch and use Cut-Extrude → Through All.
6. On the same broad face, sketch the centraling as Ø50 mm. Its centre is 125 mm from a short edge and 50 mm from the lower long edge in the plan view. It lies on the horizontal midpoint but is offset 25 mm from the plate centre toward that lower edge.
7. Cut thising Through All. Rename the features to Plate Base, Guide Holes and Central Opening. Save as Bottom Plate.SLDPRT.

Checkpoint: one rectangular solid with five through-holes: four Ø25 holes and one Ø50ing. The centraling is not at the rectangle’s geometric centre.

Beginner mistake: drawing circles that look aligned without adding dimensions or relations. Zooming in does not replace dimensional control.

1. Create a new part. Repeat the origin-centred 250 × 150 mm rectangle and 30 mm extrusion.
2. On the broad face, create the same 190 × 90 mm four-hole centre pattern, but use Ø40 mm circles. Cut them Through All; these holes receive the bushes.
3. Select the plate’s underside and start a sketch for the central boss. Use a Ø50 mm circle aligned with the Bottom Plate’s centraling: 125 mm from a short edge and 50 mm from the corresponding long edge. When viewing the underside, identify the corresponding edge carefully because the view can reverse the apparent direction.
4. Use Boss-Extrude for 90 mm away from the underside. Check the preview direction and keep Merge result enabled so the boss and plate form one solid.
5. Save as 2. Top Plate.SLDPRT.

Checkpoint: four Ø40 through-holes and one integral downward boss. The central feature adds material; it is not another through-hole.

Why: reusing the plate datums makes the bush axes coincide with the pillar pattern when the plate orientations match.

Guide Pillar

1. Create a new part. On Top Plane, sketch one circle centred on the origin.
2. Dimension it Ø25 mm. Exit the sketch and use Boss-Extrude → 200 mm.
3. Save as Guide Pillar.SLDPRT.

Guide Bush

1. Create another part. On Top Plane, sketch two concentric circles with their centres at the origin.
2. Dimension the outside to Ø40 mm and the bore to Ø25 mm.
3. Extrude the annular region 60 mm. Verify the preview shows a tube, not a solid cylinder.
4. Save as 4. Guide Bush.SLDPRT.

Checkpoint: the bush wall is (40 − 25)/2 = 7.50 mm. These are nominal dimensions; they do not establish a real sliding clearance.

Feature order: establish the main cylinders first. Add any specified edge chamfers afterward, using the reference drawing to select the correct edges. The hand mass calculation on this page deliberately neglects chamfers.

1. Select File → New → Assembly. Browse to Bottom Plate.SLDPRT and insert it at the assembly origin. Confirm its tree entry shows (f), meaning Fixed. If needed, right-click it and select Fix.
2. Choose Insert Components and select Guide Pillar.SLDPRT. Place four instances in the graphics area. Keep the insertion tool active while placing them, or repeat Insert Components if you already exited.
3. For the first pillar, select its cylindrical outside face and the cylindrical wall of one Ø25 plate hole. Choose Mate → Concentric. This aligns their axes; it does not set insertion depth.
4. Set the seating depth with a planar mate. For this walkthrough’s reference configuration, make the pillar’s bottom end face coincident with the Bottom Plate’s underside. The pillar passes through the 30 mm plate, leaving 170 mm above its top face. This is a chosen assembly datum, not a press-load or stroke specification.
5. Check the mate preview before accepting. If the pillar points the wrong way, change mate alignment rather than adding a conflicting mate.
6. Repeat for the other three pillars. To keep these fixed components from spinning about their own axes, use the concentric mate’s Lock Rotation option where appropriate.
7. Save as Press Tool Assembly.SLDASM.

Checkpoint: the base remains fixed and all four pillars stay seated when dragged. Each pillar has an axis relationship and a seating relationship.

Selection tip: a cylindrical face establishes an axis; a flat end face establishes seating. Rotate the view or use Select Other when a required face is hidden.

1. Insert 2. Top Plate.SLDPRT once and 4. Guide Bush.SLDPRT four times. Keep the Top Plate floating.
2. For each bush, make its Ø40 outside cylindrical face concentric with a Ø40 Top Plate hole. Do not use the Ø25 inner face for this seating relationship.
3. Set the bush’s axial location. In this walkthrough, make the bush’s top annular face coincident with the Top Plate’s upper face. With a 60 mm bush through a 30 mm plate, 30 mm then projects below the plate.
4. Lock rotation for each bush-to-plate concentric mate if a rigid moving group is intended. Repeat the same seating choice consistently for all four bushes.
5. Align one bush’s Ø25 inner cylindrical face concentrically with its corresponding pillar’s outside face. Leave axial sliding free.
6. Control rotation of the moving group about this guide axis with an orientation relationship, such as a Parallel mate between corresponding long vertical side faces of the two plates. Check that the central boss remains aligned with the baseing.
7. Check that the remaining three bush bores line up with their pillars. The matching hole patterns should establish this geometry. Do not force additional concentric mates if SOLIDWORKS reports them as redundant or over-defining; investigate axis alignment and existing mates first.

Checkpoint: the four bushes travel with the Top Plate. The plate should not drift sideways or rotate. It should still be able to move along the pillar axes.

Why a bush may look “flat”: a coincident mate aligns only the faces you selected. A flush annular top face is expected for the seating choice above; look underneath to confirm the remaining bush length projects downward.

1. Expand the Mates folder. Look for failed or conflicting mates and rebuild the assembly.
2. Drag the Top Plate or use Move Component. Watch for axial translation only. A floating assembly component can be intentional; “fully fixed” is not the goal for a mechanism.
3. If nothing moves, check whether the Top Plate is fixed or whether a distance/coincident mate locks it axially to the base or pillars. Suppress only that axial-locking relationship; retain the guide and orientation relationships.
4. Inspect several positions with a section view or Evaluate → Measure. Check bush/pillar overlap, the central boss relative to the baseing, and unwanted plate contact. Dragging alone does not prove collision-free travel.
5. Measure and document a suitable demonstration travel before adding a Limit Distance mate. Do not set a stroke from the video or infer it from pillar length alone.

Create a simple motion demonstration

Open the Motion Study tab and use an Animation study for a visual sequence. Set the starting position, move the time bar forward, then position the Top Plate at the measured demonstration endpoint. Preview the sequence and save the animation using an available export format. A keyframed animation shows movement; it does not calculate contact force, stress or validated dynamic behaviour.

Checkpoint: the fixed group stays still, the moving group stays together and the animation maintains the measured engagement throughout travel.

1. Rebuild and save: confirm there are four unique designs and ten component instances, with no missing references or failed features.
2. Mass check: assign the intended material before using Mass Properties. Compare against the hand calculation only when density and included geometry are consistent.
3. Drawing: use Make Drawing from Part/Assembly. Add orthographic and isometric views, sufficient dimensions, and an assembly BOM with balloons. Add tolerances only when justified by the design requirements.
4. Presentation: create an exploded view to explain component order, then return to the assembled configuration for the motion demonstration.
5. Package: with the assembly, select File → Pack and Go. Confirm that the assembly and all four referenced part designs are included. Include drawings if you have created them, and choose the ZIP option.
6. Independent check: extract the ZIP into a different folder and the copied assembly. Confirm that its referenced components resolve without browsing back to the original project folder.

Why Pack and Go matters: an assembly file alone does not contain all the referenced part documents. Packaging the references makes the project portable.

When something goes wrong

Remember the sequence: shape the parts → locate the fixed group → build the moving group → preserve one motion → verify and package.