If you just want the clip models and not the story then please scroll straight to the bottom of this page, or click here.

The roof moulding clips on the Volvo S60 (and other models) are likely to break when the roof moulding is removed, and even if they don’t, they are likely to distort at the base or have lost positive moulding retention.  Volvo make a special tool for removing the mouldings, but if you don’t use this, or don’t use it correctly, the clip wings are likely to break off because they are the weakest part in the assembly.

Even with new clips you really only get one chance at re-fitting the mouldings.  Get it wrong and you’re likely back to more broken clips.  A full set of clips for both the left and right hand side of the vehicle have the following Volvo part numbers:

Note that the clips are not handed.  The same part numbers are used on both sides of the vehicle, but simply rotated 180 degrees when fitting.

Figure 1.  A Pillar Exterior Moulding Clips

The clips are relatively inexpensive but you’ll likely need all 30 and at say US$4 each, that’s $120 plus postage.  This is still a whole lot cheaper than a new moulding strip (there are four parts which will cost between US$400 and $1000 each depending on the colour code).

But the moulding retention clips probably cost around 10 cents to manufacture (including distributed injection moulding costs) as Volvo have made millions over time, some of the clips are used on other models, and they will have made a spare parts inventory.

The clips are rather intricate, but this is in part due to limitations of the injection moulding process including relief angles, constant width walls, and mould flow.  The dimensions, particularly for the mounting lugs, the clip profiles and height are critical for flush moulding and retention.

But perhaps we can 3D print these clips?

The clip design is no longer limited by an injection moulding process, and should provide a strong, functional equivalent part at close to the original clip manufacturing price (excluding the modeling time which I will have done for you).  Note that even the Volvo clip designs have changed over time.  There are clear differences between the old and new clips even though they have identical OEM part numbers.

Modeling the parts starting from broken clips is not a good idea, particularly when RS Lane have thrown away the broken bits.  But I have brand new parts (with one set of clips still on order) that I can model from.

The modeling process is summarized as follows.

Take a macro photograph the critical end profile.  Note that the tab extending out-of-frame is gating for the injection mould.  It is designed to be broken off.  You don’t need to incorporate this in your 3D print model.

Figure 2.  A Pillar Clip Profile

Import this into a 3D modeling package.  I use Autodesk Inventor because I am familiar with this, but there are freeware packages such as Blender that are equally capable.

Measure the height of the clip from the base where it is retained against the car body by a lug, vertically to the top of the clip.  Use this dimension to scale and orientate the image.  This becomes the benchmark dimension for the design.

Now sketch the profile of the part using a combination of lines, fillets and trimmed circles.  In doing this ensure that no feature (and particularly the clip wings) is less than 0.8 mm wide.  This ensures that all walls are at least two 3D printed filaments thick.  This dimension is specific to my MakerGear M2 printer with an 0.35 mm nozzle and a default print width of 0.4 mm, but is typical for filament additive 3D printers.

Figure 3.  Profile Sketch in Autodesk Inventor

Extrude the profile to the measured length of the clip and we have a basic clip shape.

Now using additional drawings and extrusions we subtract and add to the extruded profile to form the retention lug slots and any other functionally critical features, noting that we do not need to make an exact replica of the original clip.  My design has an almost exact profile and lug mounting recess, but provides additional strength to the part body.

Figure 4.  Prototype Ready for 3D Printing

Now export the model as an STL, import it into a slicer (I use Simply3D) and export the gcode for your printer.  In orientating the part make sure that the clip profile is in the XY plane to ensure strength with some flexibility to the clip wings.

Print the part in Nylon or ABS.  PLA is hard but too brittle where as Nylon and ABS are softer but provide increased flexibility and toughness.  And check the critical dimensions against the original.  Fused Deposition Modeling (FDM) 3D printing does not ensure that the actual dimensions of the model will be replicated in the part.  Even though machine movement can be repeated with an absolute accuracy of fractions of a millimeter, the dimensions of the printed filament (width and height) limit what can actually be achieved.  If necessary adjust the model and repeat the process.

Now test the clip retention function on the moulding strip.  They should insert with moderate hand pressure and lock.  They can be slid out of the moulding, or the clips freed with a small screw driver to prevent breaking the new 3D printed parts.

The retention lug fit also needs to be tested.  It should be firm (hand pressure only) and align the clip to the outer drip channel profile.

The final step in making the clips is to solvent seal them.  This improves the surface finish and strengthens the bond between filament layers.

I’ve got three more clips to model before I start prototype printing and functional testing.  This will take a few days.  If they work (and I’m quietly confident that they will) then I’ll be posting the STL models here.

The first two moulding retention clips (for the A pillar) have been successfully 3D printed and functionally tested.  The prints are in PLA and have not been solvent sealed but they work perfectly on my Volvo S60.   The first clip took six trial prints, primarily to ensure dimensional accuracy and adequate strength for a working part.  The second clip took just two iterations (applying lessons learned from the first clip).

Figure 5.  Failed Development 3D Prints

During the modeling process I discovered yet another RS Lane cock-up.  The top A pillar clip could not possibly engage with the moulding profile.  I inspected the moulding and it has a cutout for this clip.  This is the only clip on each side of the vehicle that ensures that the moulding strips are located correctly in relation to the length to a precision of 0.2 mm!  On re-assembly this clip MUST be engaged first.  Having only one length alignment is a deliberate Volvo design decision to allow for differential thermal expansion without causing bowing or buckling of the moulding strip.

Lesson 1.  On reassembly align the moulding strip cutout with the top A pillar clip and engage this clip first.  If you don’t do this you will likely damage the clip, moulding strip, and/or mounting lug.

Figure 6.  Cutout in Moulding Strip for Top A Pillar Clip

This cutout got me thinking about the broken mounting lug on the the top passengers side A pillar.  I doubt that RS Lane would have broken the lug and then left it loose to rattle around in the drip channel (but given their other cock-ups I may be wrong here).  I figure that the clip was retained by the lug when they tried to fit the moulding, but they didn’t align the cut-out.  The lug likely failed when RS Lane tried to forced the moulding strip to seat (kind of like driving a square peg in a round hole - something has to give).  I have witnessed RS Lane’s brute force approach first hand.

Interestingly, in RS Lane’s reply they consider this clip as ‘null and void’.  Yet this is the most important clip in the moulding retention scheme because it is the only clip that ensures the moulding strip is correctly aligned with the length of the car body. 

Figure 7.  Fully Functional  A Pillar Clip 3D Prints
(Final parts to be printed in ABS and solvent smoothed.)

Figure 8.   New A Pillar OEM Parts (left) and 3D Printed Equivalents (right)

Only two clips to go!

I’ve finished modeling and testing the parts, and they are all functional, robust and fir securely.  The roof clips were somewhat challenging because the OEM part comprises two pieces (required for strength) but 3D printing has allowed me to model these as a single piece using a similar lug engaging detail to the other clip types.  There is also a tab on the C pillar clips that I had to investigate.  Its function appears to be to prevent the moulding from rotating. The tab doesn’t deflect significantly in use.

Figure 9.   Determining the Function of the C Pillar Clip Tab

Figure 10.  Moulding Retention Test for 3D Printed Roof Clip - Perfect!

Figure 11.  Set of Fully Functional 3D Printed Clips

All of my development testing of these clips has been in PLA (my go-to resin) without solvent smoothing.  These clips work fine on my vehicle but they’ll be even better in solvent-smoothed ABS.

The cost of each printed clip is about US$0.15 (including resin, power, clearing supports, and solvent smoothing, but excluding my modeling time).  Depending on your 3D printer and print settings an individual clip will take between 30 and 60 minutes to print, but  you can save a lot of time by printing four or more clips simultaneously.  Note that the clips must be printed vertically (standing on an end) to optimize clip strength.

A complete set of 30 printed clips (both sides of the vehicle) will cost you about US$4.50 which is less than 2% of the RS Lane price without a three week shipping delay.

The models posted below are in STL format.  They are available free to non-commercial users.  Please feel free to download and use them, and if they help with your Volvo repair, consider making a small donation through the PayPal link towards modeling and testing and this website.

If you have any problems with these clips, or if you need these models in a different format, or gcode for a specific printer then please contact me.

Click on the OEM part numbers to download the associated STL Model.  Note that the models can readily be mirrored to provide handedness to the clips.  While this isn’t necessary it may improve clip retention on the lugs.
 

Do check back from time to time for any model revisions.