The ED 66 Project

[Stub Mandrel]

I did an experiment on some scrap sheet, anodising it, dying blue with ink, then sticking on vinyl letters, bleaching and dying black.

Lo! It worked so I tried it on the OTA. Horror! Some of the letters looked wonky so I took them off, they and the masking tape I used to align left a residue so the bleach wouldn't get rid of all the blue colour.

Eventually got it off but anodising such a big tube resulted in >5amps from my 4A transformer and the rectifier nearly melted the case.

And then the black anodising was a disaster and awfully blotchy.

Worried about the thread (for the lens cell) eroding if I strip again, so I rubbed wax into it then bit the bullet and I did a really good strip and was scrupulous about cleaning. I put 0.33R and  0.22R resistors in series and that got the current down to 4A. The resistors got hot enough to melt the solder joining them so I joined them with a croc lead, that worked but one melted my plastic sheet and I had to put it on the alloy scrap used for the earlier test!

The good news is that, after a marathon 2 1/2 hours in the tank to compensate for the larger area, it seems to have taken the die well. Leaving it in for extra time just to be sure. Will wash down in a minute, then pop in sealing solution. Fingers crossed!

 

Funny how it starts easy (because you do everything by the book) but then as you try harder (bigger) things the process gets marginal and you (I) get sloppy and things start to go pear shaped!

[Stub Mandrel]

Ta-Daa!

More pics on the 'Show Us Your Frac' thread.

[RT65CB-SWL]

Very nice! 

May I ask where you purchased the thermometer/focus wheel from? - I would love to put one on my 're-modded' Meade ETX105 in place of the one I have, (which is from an ETX125). 

Edited September 7, 2018 by Philip R

[JamesF]

Lovely.  What it's missing now is a hand-made finder :D

James

[Stub Mandrel]

12 hours ago, JamesF said:

Lovely.  What it's missing now is a hand-made finder

James

LOL! That's exactly what I was thinking lying in bed this morning!

<Edit> Damn your black heart! There goes my weekend...

Edited September 8, 2018 by Stub Mandrel

[Stub Mandrel]

On 03/09/2018 at 21:41, Stub Mandrel said:

Gah!

Ever since finishing the scope, I've been stressing over one missing part - the knurled focus lock screw.

Just noticed the test piece in the photo lying on the floor. Picked up and screwed in underneath it...

[Stu]

Beautiful Neil! Somehow I had missed the finished pictures. I’m off over to the ‘show us...’ thread now to drool some more  

[Stub Mandrel]

An update on this project. I entered the scope in the Model Engineer competition at the National Model Engineering and Modelling Exhibition in Doncaster. I was delighted to be awarded a silver medal - this doesn't mean I came second, there were many fantastic models ons how, awards are made against standards and in this case it was entered in the 'horological, scientific and optical instruments' category, which usually means clocks!  Probably the first telescope for decades! I had to declare all bought in parts, but the judges were pleased to see photos taken with the scope. I am very chuffed!

[JamesF]

Excellent!  Well done.

James

[RT65CB-SWL]

Congratulations... 🏆🥇<---your virtual SGL cup and medal.

[Rob]

Nice one. Well done Sir!.

[Stu]

Well deserved Neil 👍👍👍

[barkis]

You deserve the highest praise for the engineering skills you have displayed here Neil.  The finished work is of a very high standard indeed.  You can justly be very proud of yourself, but I get the impression you are a modest guy, but you really deserve the Accolades bestowed on you, they are justly earned. Superb stuff matey.

Ron.

Edited May 13, 2019 by barkis

[Stub Mandrel]

Thanks for all the kind comments 🙂

[happy-kat]

Well done that's marvelous.