crashtestdummy

That's the main reason for doing it, personal achievement and knowing what goes into making the view you see when you look up.

theres a few decent areas up near petersfield and the new forest,both about 30-45 mins away then maybe a bi monthly trip to Dartmoor/Exmoor or isle of wight.

I have a similar grasp of mirror grinding jargon ,im just well practiced ;)

have updated with some better pictures of the curve :)

It's just shadow from the angle,it's pretty uniform all the way round :) will try nd get some better pics or a pic with the tool on the edge

may pop up some time early next week if that's ok?i actually have some old tiles in the garage that wer can have a look at using if you like although probably better just to sort some mosaic tiles.may be having Friday off,if so will try and sort some out :) thinking I may definitely go for 12.5mm to make sure as its only another hour and a half grinding.

I would say the feathertouch is definately heavier than a moonlite but the sips is similar to the weight of a paracorr 2.I will try and weigh them seperately but I don't have the moonlite or paracorr 2 to compare so will need help on that.

You adjust the sips for focus after collimation and then you just focus each new eyepiece as you would without a coma corrector.there's much more yet to come grinding wise,I doubt I'm half way through yet!!!

Yeah I can't wait to use mine.the paracorr in the old scope was ok but with the sips you set it up and don't have to adjust it again all night which for me is a big plus.

Tested it out last night and initially dissapoinyed that the views aren't as bright as my 15x70 binos then realised that one eye is never as good as two on similar aperture.think I want a slightly zoomier eyepice too as the supplied 23mm at 328mm fl isn't quite enough.nice and light though!!!

Yeah I suppose.luckily I don't have many outgoings asside from about £1500 I'm spending on fixing the car over the next week :) probably do another update tomorrow and there may be a shock

When I say budget,I mean more "what I can afford" ;)

Actually I didn't factor in the coatings :( still,well within budget.

Btw we need to decide on secondary size as I massively overestimated the necessary size for visual.

Factored just about everything in no and after selling my stuff I should have much if any extra to put to it hopefully but if I have it will be worth it.

Im hoping as soon ad I get some more grit I can start hammering down to sagitta on the mirror and catch up so we start the tile tool set at a similar time

An SCT is much more glass though as it has the primary,secondary and the corrector plate hence the massive weight.mine is a 43mm thick blank,you could always use a 25mm plate glass blank and have it slumped.that would be almost half the weight.John Nichol showed me one and it's probably the way I will go for my 26".

The current 22" weighs 22kg so I would think it would be about 30kg or thereabouts.

It's a slow process,more so the bigger you go but I really wanted to do one and there's no time like the present.

John will do a great mirror for you,that's for sure but he will also give you advice about making your own.I'm sure he will run another of his mirror making seminars some time soon

I initially planned an 18" F3.9 but the 22" blank was only about £50 more so I couldn't help myself.obviously the 18" would be much less grinding.are you grinding yours yourself or buying one?

Oh and to add,my next one will be a 26" f3.something :)

I think everyone should have a go at grinding at some point,it a really interesting experience but hard work.I know that when I look through that eyepiece for the first time with a mirror that I've ground will be a great experience.

My current 16" f4.5 is 1829mm focal length,the new 22" is going to be f3.6 and 2016mm focal length.likely one small step at zenith which is quite manageable for my height.Any less than 3.6 to me is just more coma and grinding.for an 1800mm 22" would be about f3.2 which is a bit too much to me.

Enhanced coatings for the primary and secondary are £338 which isn't too bad but I need to include the price of attatching the secondary holder to the secondary.also the price of the secondary too.I'm hoping the whole scope shouldn't cost more than £2500 including a new featherlite focuser with sips coma corrector.

With smallers scopes you make them for your own enjoyment/achievement but with big scopes the savings are big too.

As a rough guide so far:

22" blank £475

10kg weight disc £20

3kg 60grit £30

3.5kg 80grit £15

1kg 400grit £13

1.75kg 220grit £12

Spirit level £8

Gorrilla bucket £12

Belling stones(6!!) £10-15

12.5kg 80grit £50

Still have 10kg of 80,all the 400 and 1kg of 220 left

and I have just ordered a 10kg cast iron weight disc which is 11" to replace my 5kg 9" one.this should be much better for hogging out the front :)

You could probably have just switched to a full w-stroke with the full sized tool to get the casting ripples on the edge sorted.a smaller sub diameter tool is definately useful too