Having problems fixturing a small section of a cone. Brittle material and can't use anything on the inside for support as that arc is not smooth. Trying to make a fixture that will repeat so we can use cad to measure the surface profile. We tried a magnet with a small lip but even with part against the stops we aren't sure what to use for alignment (thickness of part from OD to ID (after ID is finished) is 1.2mm which is what the 45° edges are (not much for manual hits:blah.
20230427134833855.pdf
I have made a mold of a part before with dental mold (we use it to get reproductions of parts for use on a comparator). (We primarily use Cuttersil Light, it is a green toothpaste tube and a bottle of red liquid hardener)
I will adhere to porous surfaces, but if you peel it just after it cures, it always comes off metal.
You say brittle, and it might not come off. If the parts are consistent enough, you could sacrifice one part to make the mold, then put the other parts on that mold.
The plasticene clay (the stuff for kids that is non-toxic and doesn't dry out), if you warm it up (like just above body temperature, not in an oven), it gets very soft. You might be able to make a mold to support your parts with that, and it should hold up to the pressure from a stylus.
Quick and easy, that's all I've got at the moment.
Caemgen, I will look into the dental mold right now (& you have me wondering if I could use that 'temporary crown' stuff for when one falls out) - thank you (I've tried sugru but it seems to flex too much when taking hits on the top)
Thank you Jefman, Do you use something other than the 'removeable adhesive rubber' ? only asking as I tried using the putty we clean our probe connection with & it flexed more than we felt comfortable with
Mike, thank you. We have used that for larger parts but these will crumble if we use that on these parts. We had one break just from using a piece of 3m ATG tape and (when removing it) the part cracked
Well, the temporary tooth repair stuff worked well but then chipped slightly so made another one then made a mold from JB Weld .. working well so far. Thanks for all the input