Member postings for BW

+1 on this, its always seemed to be a fairly odd thing to me - In my twenties I tested it by setting alarm to all sorts of strange times and unless I was totally and absolutely tired out the night before I'd usually wake up just a few minutes before the alarm.

Edited By Bill Wood 2 on 06/03/2017 08:39:31

Thanks Neil - that was puzzling me.

So if your GoTo box was a tiny bit inaccurate or if there is a +/- on the repeatability or the tracking could you spend 5 hours gathering data and have not much to show for it after the data is processed ?

I imagine the horsehead itself would occupy 0.0000x of a second in the field of vision

At the opposite end of the spectrum from yourself, am currently enjoying looking at craters on the moon and struggling to line up on Jupiter unbelievable how I can see things with bare eyes and yet miss them completely with the telescope. I guess I will get better with practice.

Am off to google hints to line up a small telescope.

Bill

Hey Neil,

I like that picture.

Is that actually what you see through your eyepiece when you point your telescope at the right place ?

......... and if you cannot see it how do you know where to point the telescope ?

Bill

OK, I googled and found some diy metal cutting bandsaws. I'd never bothered having a good look beyond converting woodcutting ones.

Ive seen diy wood cutting bandsaws and diy metal cutting hacksaws but not familiar with diy metal cutting bandsaws mentioned above. Unless its the Gingery one ?

Any good photos or plans or websites I should look at ?

Bill

I've seen them called bell drills on some forums.

http://www.centerdrills.com/standard-products/centerdrills/centerdrill-r-type-radial

Thanks for all the advice. Will continue to learn on the little telescope and further investigate what I might be able to make or buy. Am off to have a look at Jupiter and Saturn tonight and not expecting the results to be as fabulous as my initial moon craters.

Bill

Thanks Neil,

Am starting to question viability of building a 6" or 8" from scratch - after allowing for some mistakes and time spent and costs of individual parts, unless I get lucky on ebay auctions, could end up costing same as a cheap one.

Couldnt see the £64 mirror on the Orion site, cheapest I could find was £120 - am I looking in wrong place ?

8" $649 here

Bill

Thanks for the replies. Its encouraging to "meet" 2 people who have done 12" mirrors.

I found this mob in Australia who seem to be the equivalent of the link in Martyn's post above. They will send a pricelist if you email them.

I also found this diy site http://www.webstertelescopes.com/silvering.htm

and being as it seems to be a backup of a site that is down, I have shamelessly copied what he has written and pasted it into a word document in case it gets lost, it seemed to be good clear instructions. Can email it if anyone ever stumbles across this post in future.

Bill

If anyone is interested page 51 of this book

**LINK**

And then googling Brashears Process opens the door to other websites

Bill

I've been googling and reading about telescopes for the last week or so ever since I bought a little Aldi National Geographic telescope that clearly showed the craters on the moon. Amazing.

I thought a 6" or 8" telescope would cost a fortune so started reading about diy telescopes and this led to mirror grinding - seems interesting, and I usually see a line that goes something like this .........................

".............. after you have ground the mirror its quite cheap to get it silvered by your local mirror silvering place ..................."

Maybe I'm not googling the right terms , I get sites that look to be specialising in expensive custom optical jobs for industrial applications and scientific laboratories.

Has the local cheap corner shop mirror silvering place disappeared just like the local foundry has ?

Once all diy costs are considered, especially silvering + protective coat, is it cheaper and quicker - but far less interesting - to buy mirrors ?

Bill

To answer my own question - This post is useful

https://stargazerslounge.com/topic/196278-what-can-i-expect-to-see/

I just bought one of these and blimey its amazing - I could easily see the craters on the Moon !! There are heaps and heaps of them ! First time I've ever looked through a telescope at the moon.

Amazing to an astronomical newb. For me its well worth the $50.

I found the 20mm lens easy to use but the 4mm lens was quite difficult to use - eventually got it working but quite difficult.

Bit disconcerting when I used it to look for parrots in the trees - everything was upside down.

Have got an idea that some of us make their own telescopes - is that right ?

What happens if I spend $200 ? Do I get something 4x better and start taking photos of horsehead nebula or is that a $2000 job ?

Bill

In my copy of " A Man and His Lathe " by Sparey, he emphasised that he encountered far less chatter when using form tools in a rear toolpost. He was writing about his experiences with a Myford 3.5" lathe.

Its on the list of things that I want to try one day. Havent done it yet.

Bill

Tim,

Am exploring the different ways of cutting the bobbles on the end of my chess pawns.

So am genuinely curious about your method for making balls using this type of cutter.

Is it similar to the boring bar idea in that link or something completely different ?

Bill

Dave and Mike,

I often visit the science museum in Oxford and gawk at all of the old scientific instruments - so if you have never done that its worth a look and ponder upon how they made all those things back in the day.

**LINK**

What interesting things can you chaps recommend that I go and have a look at next time I am over ? Any other museums or displays nearby of an engineering nature that I may not find in the conventional tourist info or internet searches ?

Bill

Am guessing that its similar to the sphere generation by boring bar ?

ttps://www.youtube.com/watch?v=BJtxfI_LKio

Bill

Thanks for the advice. Will learn more about inserts. Was amazed at those tiny little ones referred to above.

Bill

Hello,

I want to investigate a round insert for a copying jig for a small South Bend clone lathe, 9" swing, max speed 720rpm. A round cutter might be helpful for some curves that I want to try and copy whereas a straight bit can be a bit awkward.

I dont have the skills to grind an appropriate tool from HSS, unless someone maybe has some tips ?

However I was wondering about making one from silver steel.

Tried to work out an insert spec and came up with RCMG60400F (left N off the end as its not normally used)

Tried searching on this but doesnt yield any inserts.

Searching on just RCMG however does yield results.

When specifying inserts is it customary to use just the first 4 letters and not worry about the rest ?

If I managed to make something from silver steel would it go blunt far more quickly than HSS ?

Bill

Forgot to mention before, window cleaner bottle with adjustable nozzle set to very fine jet is also a favourite of mine.

You can get quite good at sending a very fine jet right where its needed.

Bill