hi scultingman and many thanks for your skilled suggestions. reading the various (enlightening) replies to my initial post, i decided to go for a microblasting unit (Renfert Basic quattro + glass beads) as well as plastic polishing compounds from Menzerna applied with dremel softcloth tools (GW16 > 495P > G52 grades).
Applied on Formlabs printed tabs (Dental Model, Black, Tough, and White resin), the process was straightforward and results where stunning. II got mirror finish where I wanted it (masking tape), with some labour though to be honnest.
Now, for the mold… I have partnered with a plastic injection company here in France , and we are busy manufacturing (CNC machining) a specific aluminium frame + ejectors to host the 3D printed formlabs hightemp resin core and cavity. We’ll mount this frame in a Babyplast injection machine (a highly qualitative screw injection machine) for our first plastic shots (Bayblend T65XF, ABS/PC blend).
The mold joint is not flat, rather contoured to follow the round shaped design of our product. We plan to use an injector battery of 5 ejectors/vents for each part. No cooling circuit for now. The two molded parts are 80x60 mm (3.1 x 2.4"). Approximately 8g (0.25 oz) each.
I admit, this is pure experimentation and results are quite “uncertain”, but the great benefit (if success), is that we’ll have some real plastic parts in hand, accounting for iplastic design constraints (ribs, drafts, bosses, grooves… and sink marks !), and with these in hand, we’ll be ready to carry-out ultrasonic welding assembly tests (20 khz) with embarked electronics for failure testings.
Then, and only then, we’ll go for big business (ultimate design refinements, steel mold, big machines and the like)
I.m currently documenting (photos)) all the steps involved and will post a full paper in a few weeks to share with the community.
kind regards
marc