urgent need of figuring assistance

[TheMan]

I am currently making my first 8 inch telescope mirror. 950 - 980 mm focal length. Figuring was going well, until I made a bit of a mistake and did a stroke for a bit too long. Around the centre zone I made a deep zone and I am unsure of how to fix it. I have a full sized & a 3 inch size lap to fix this. What stroke will help get rid of this? Surface texture is not an issue at the moment, I will smooth it out later. Any help is appreciated. 

[discardedastro]

Not an expert, but the W deepening stroke as described here? https://stellafane.org/tm/atm/mirror-refs/strokes.html#The W Edge Deepening Stroke

 

[TheMan]

1 hour ago, discardedastro said:

W deepening stroke

Yes that seems to be working. Thank you

[Astrobits]

Your 8" mirror with a f/ratio of less than 5 will need fairly long strokes to figure so the W stroke with about 1/3 dia length should get you back on track.

Nigel

[Astrobits]

Don't forget that the central zone plays virtually no part in forming the image, most of it being covered by the shadow of the secondary. Therefore , as your first mirror, errors in the central area can be left alone in preference to getting the edge good. Of course we all want to get perfection over the whole mirror but a classical cassegrain mirror performs perfectly as a Newtonian and that has a rather more drastic hole at the centre.

Nigel