No thermal expansion at all?

[Steffen]

Sounds good to me!

https://newatlas.com/materials/thermally-stable-zte-advanced-material/

I wonder whether the material polishes up nicely. If not, perhaps it can be coated in silver or aluminium 🙂

[mura_gadi]

Hello,

Very nice, metal mirror only thick enough to avoid flex. Metal mirrors are full circle stuff, so always love that.

As you say, the big question is what level the existing or the cheaper version composite will polish too.

Steve
Ps. Looking at metal polish compounds for lapping/polishing aluminium - I'd guess easily if its the major compound.

[billdan]

The mirror is not the issue when it comes to thermal contraction at night, it's the OTA tube or trusses that shrink causing focus to go outside it critical focus zone.