3D print Suzuki Colleda Drum Brake Pistons

[AlexS]

Hi!

For a motorcycle friend, who is building up an pre Suzuki Colleda 250 twin motorcycle from the 60s.

The bike has hydraulic drum brake system for both wheels. Small 18.5mm front and 14mm rear cylinders. Also a 15mm master cylinder in hand leveler to pressure rear and front what I understand.

In my 55cc engine thread I already place an post of a new set of pistons for the brake system.

Old pistons use a wide cup seals, on the bike fall apart. He did not find good nos replacement seals on the pistons.

Together designed new pistons with modern X ring epdm seals. Luckily could find great fit size x rings for all 3 different sizes. With outer size x ring mounted on pistons +-0.2mm oversize to cylinder bores.

Last week got the new pistons from China supplier . 3d SLM printed of 316L material. The print has extra material to mount the part in the chuck and use an support.

First an test part 14mm pistons. Last two photos 18.5mm piston

[Roger B]

An interesting solution 

Was it easier than machining the pistons from bar stock?

[AlexS]

Agree, these pistons could be made from bar stock. First idea was to outsource machining. Where 3d printing was cheaper than cnc machining. But the extra outsourced machining made the 3d printed parts still quit expensive compared to only printing. And I do like to machine them my self and get more practice on tight tolerances machining. Also testing on machining printed aisi parts (for other projects), where printed geometry reducing some machining.