Montague Dock - 6 - The Dock

Mooring Bollards

A pack of 3D printed bollards were bought from Scale Model Scenery (Ref 6.3) a source I can highly recommend being a happy customer for several years now with many of their products fitted to the layout and more queued to be fitted.

These are filament printed in PLA which is unusual, scenic parts are often resin printed for the detail but these look good enough to me, I bought these nearly 5 years ago and are brown, currently sold in black. This gives some idea of the backlog of modelling I have to complete!

The underside is quite an open surface so a thicker glue is best used to get into the surface and still leave some to bond with another item. Generally I use DeLuxe Materials Plastic Magic for PLA but here I am gluing the bollards to a painted surface which I do not want affected by running liquid adhesive on.

But note I will be gluing plastic to plastic, gluing to paint is a crime many manufacturers inflict on us from locos to scenic items.

The next image shows the 'porous' underside of the bollards which is why a thickish adhesive is required. Also shown is my positioning jig which I will cover shortly.



I did consider whether to drill holes in the dock capping stones and fit pins to the bollards for strength but then again drilling into a filament printed PLA part can also be difficult to achieve accurately depending on the infill setting used, i.e. is the bollard dense or does it contain a fine honeycomb which may only be 10% solid.

So I decided to glue them in place on the PLA printed capping stones.

Being a stickler for symmetry when it would be applied easily in the prototype a simple jig was designed and printed, its key features are :-

1. width equal to a capping stone for lateral positioning
2. a 3 sided square cut out to accommodate the 8mm square base of the bollard and place it central on the capping stone. The cut out designed as 8.2mm square to give clearance and allow for slight print shrinkage.
3. a deeper front edge to locate it on the edge of the capping stone.

Using a jig means they will all be aligned the same as each other, their position along the dock wall set from the capping stones. Twelve, one per strip of capping works well for the steam packet and tramp steamer I have, they will both be able to tie up to three bollards each.

The bollards were rattle can sprayed with Expo Dark Grey Primer which gives a reasonable appearance, top or sealing coat not required as they are not going to be handled as would a wagon.

Jig Design

Starting from the capping stone CAD drawing, the lines that form the capping stone strip were grouped, the jig was drawn over it as below, the grouping prevents the two parts merging. The open frame arrangement was purely to save material and decrease printing time.



Then hiding the original part leaves the jig visible which then can be grouped as a distinct item itself which can be exported as an STL for printing, in this case with a 0.2mm nozzle using HatchBox silver PLA+ on the Raise3D E2, yes, printing simple items works fine on the E2 but using supports as in the Conflat P project was hopeless.



Fixing the Bollards to the Capping Stones

First I used the jig to determine where paint needs to be removed from the capping stone so I can directly glue PLA to PLA, paint removed with the end of a riffler file, result as shown.



UHU was then applied to the unpainted base of the bollard ensuring it soaks into the mesh of filament, too little leaves insufficient to contact the capping stone also of PLA, too much and it will squeeze out and damage the capping stone paint finish.

Whilst holding the jig in place the bollard was then pressed into contact with the capping stone.




Some weight was applied to the bollard top while the UHU set, in this case using some old pliers.




The result is as shown next






This was then repeated for the remaining eleven bollards, several shown here.



Summary

As I mentioned in another thread, printing tools and jigs is one of the best uses of a 3D printer.

Not having suitable drawings for a bollard, buying them was a good option, I shall also be fitting these to the sand and heavy ore docks.

Jim

References

6.3 Harbour Mooring Bollards

https://www.scalemodelscenery.co.uk...-for-ships-etc-pack-of-12-oo4mm176-8700-p.asp

 

Thanks Paul, Jim

 

Thanks Gormo

 

Thanks Vinylelpea

 

Thanks Andy