A New Lease of Life (Old 6" Newtonian)

[GC - South Aus]

G'day All

My name is Gavin (Gav) and I live in Adelaide SA.

I have been a member for a little while now, but I tend to sit back and read everyone else's posts, advice and in particular the buy and sell forums. :D

I thought I would share a little diy/fix-em project that I am working on at the moment. It is nothing amazing or flash, no huge apertures :( or super-computer controlled telescope mounts. It is just a simple but fairly old (I think it was born in 1975 going by a stamp on the front of the mount) 6" Newtonian Reflector!

The story behind this is that I found it on ebay (fairly cheap) and too my surprise it was in Adelaide. I believe that it had been saved during a house demolition, but thats about all I could find out about it. So I thought I would save it from a possible fate worse than death (the guy selling it was talking about making it into a coffee table, well the mount component and the rest would have probably ended on the dump :mad2:). So I put in my offer for a buy it now and won on my first go :). The original pic from ebay can be seen below in attachment 1.

I have two boys one 10 the other 5 and I thought this would be a great project that we could share and achieve together:thumbsup:. The 5 year old has been interested in Astronomy since he was about 2 or 3 years old and I have nightmares everytime he wants to "play" with my more expensive equipment :scared:. Although he already has his own 4" refractor and a set of bino's. I love sharing this hobby/interest with my children, in fact with anybody who will listen (by the way thats definitely not the wife, shes no listener on this topic)!

But I also have another motive for the purchase and this will become more evident in a later entry! ;) And I will also need everyone's knowledge, guidance and technical know how (please).

So I went to pick up the telescope I was a little dissapointed at first as I thought that the OTA may have been an 8" one (there were no real descriptors in the advert), but on closer inspection it turned out to be a 6" OTA :sadeyes:. I was surprised by the mount's weight, I had to split it into two parts to fit in the boot and the OTA had to go in the car (falcon sedan), it was a snug fit all round and I only just made it with a sedan! When I got it home I weighed the mount after struggling to get it in the house by myself, in total (not including the OTA) it weighs in excess of 75kg (approx - UPDATE: Sorry I should make mention that this includes the heavy pier) and it is just akward to carry.

So there we have it a new safe home for something that was destined to be a coffee table after almost 37 years of catching photons (or there abouts)!

Stay tuned for additional entries and futher info on my big plan.

Let the fun begin. :thumbsup:

Regards & Clear Skies

Gav

[Matt Starwave]

Quite creative some telescope makers. Half a bino by the looks of it for a finder. Must be a f9 or larger comparing height to other objects around it. Another interesting project to follow. Great mount too, looks heavy alright.

[GC - South Aus]

G'day Again

So we officially started yesterday (me and the little one) :). I logged on to my favourite website, 'Ice in Space' (of course! :thumbsup:) and downloaded the informative entry by Mr. Mike Salway - Iceman (aka Sir Post a Lot) named 'Cleaning the Mirrors of a Newtonian Telescope'. Armed with this new knowledge (without reading it first :screwy:) I started to strip down the OTA.

My aims are to:

1. Clean the mirrors to a reasonable standard (but I am not expecting mircales, this will just be a cheap family and visual use OTA!).

2. Clean out the inside of the tube.

3. Flock the tube.

4. Re-paint the outside of the tube.

5. Fix the home made guidescope rail.

6. Undertake correct collimation.

7. Some how secure it to the mount saddle (I am thinking metal worm gear clamps/fasteners)

First of all we stripped the OTA down and extracted the mirrors.

They are in a real state, both primary and secondary! :(

Significant cobwebs, marks, dirt, dust and pigeon poo. Yes pigeon poo! The OTA must have been stood-up (without a cover :screwy:) for sometime in an old storage shed or garage. There is pigeon poo on the mirrors and down the inside of the tube.

We eventually extracted both mirrors (whilst being careful as to not catch avian (bird) flu) and then I started to read the article. Oops I don't have everything I need to clean with (i.e. distilled water and some soft paper towel etc). So I will post the images below of the stripped OTA and then head to the shop and will hopefully get around to cleaning them tomorrow :).

Stay tuned.

Clear Skies

Gav

[GC - South Aus]

G'day Paul



Yes it is quite creative and the bino focuses really well too, but probably won't be staying on in the long run.

In relation to the f/ratio the OTA has 3 sets of 4 holes all in the exact same location (ie in line) and size but at different distances (up and down) on the OTA so I feel that the tube f/ratio can be altered. :shrug:

At the mirrors present location, if my calculations are correct it comes in around f8.8, so yes f9, but like I said it probably can be made faster.

Regards & Clear Skies

Gav

[Matt Starwave]

Even a mirror like that can give an useful image--be amazed how dirty some mirrors get and still work fine.- have fun.

[GC - South Aus]

Good Evening All

Well I am back from the shops and I now have all the items I need (listed in Mike's article) to clean my mirrors. I am almost tempted to do them tonight (1900 h CST now), but I think I will avoid the temptation to rush the job!

I have also just realised that I can't do it tomorrow as I am at the Footy, watching the Power beat the Swans. You are all probably wondering why the crazy icon isn't at the end of that sentence :lol:.

So what I have decided to talk about instead in this entry is my big plan!

As I said in the first entry I did have something else in mind other than a general family telescope.

Well, I have something to confess to you all that might come as a surprise to some of you. I have a very serious case of "Aperture Fever"! :sadeyes:

Unfortunately I feel that I have reached the useful capacity of my EQ6 Pro mount (for imaging) without going OTT. The largest scope I use on my EQ6 is a C9.25 as well as a range of smaller refractors. Now I know what a lot of you are thinking, your'e probably going to say "I use my EQ6 for a far greater load than that" or "I have seen some guy on the internet who carries a 12 inch Newtonian on his".

I agree, the mount probably could do so much more and I also see people do it all the time, but you see I don't have bottomless money pits as pockets and I want (sorry I need) the EQ6 to be around for a long time as I can't afford to upgrade to anything with a greater load capacity. Plus its fun dreaming day and night about a G11 or a Paramount MX (until you wake up that is! :rofl:).

I have sought advice from people that I respect in relation to pushing the EQ6 that little bit harder (with a 12" Newtonian or RC Astrograph) but I think I need to come up with another answer.

So here it is. The mount that came with this appears really heavy duty and weighs a tonne, I think it could probably carry a 12" - 14" OTA easily. It has got me to thinking, how hard would it be to make this GOTO or at a minimum motor driven for imaging purposes. I have been looking on the net for a little while now and I am seeing alot of people attempt and even succeed at this.

That's where I need everyone's help :help:, please. Could you have a look at the pics below and give me some ideas on how to achieve this, what to possibly use and where to go. Just one thing I ask you to keep in mind, I need to do this on a budget!

The mount moves fairly well, it does have some rust on the inside of the cyclinder. It needs some cleaning and is void of any grease whatsoever. The saddle is removable and could quite easily have a different saddle or puck put on it.

Thanks to everyone in advance, I look forward to your replies.

Clear Skies

Gav

[brian nordstrom]

:) Hi Gav , I think the mounts bearings , eg. RA and Dec 's bearings are from a large , I mean LARGE !!:question:,,, Machine's drive shaft . :question:.
If so the bearings will be needle rollers on both axis's and will be super smooth if cleaned and new grease is used , you might even see where the old grease nipple used to live ?? :thumbsup:.
I am a Boilermaker of many years and this mount looks to have been made by one of us ? or a fitter on the mine site's perhaps ?
Its a good piece of smooth and solid engineering .
Looking forward to the next chapter ,
Brian.

[omegacrux]

Hi Gav
That to me looks like a universal joint off a cars driveshaft that should take some serious weight , cool idea got me thinking now !

[mercedes_sl1970]

Hi Gav - what a great project. I was in Adelaide recently and went by the shop that the scope and mount was in. Was very tempted at the time but I was fairly certain it would not fit in as overhead luggage on the return flight! I'll look forward to seeing what you do with it.

Andrew

[GC - South Aus]

Hi Brian

Thanks for your input, it is greatly appreciated.



I think your right it's definitely some kind of home job, but has been solidly made.

Interesting points about the bearings and I will keep them in mind.

Glad you are enjoying the project and I will try to keep it as interesting as possible.

Clear Skies

Gav

[GC - South Aus]

G'day David

Thanks for your comments, interesting thoughts on the driveshaft.



Judging by your comments I will have to stayed tuned to your next project perhaps!

Clear Skies

Gav

[GC - South Aus]

Good Morning Andrew



Turns out to be a small world after all. Yes this item (which I originally found on ebay) was being sold in a salvage/antique shop in the Adelaide CBD. They originally wanted $295 but I got my offer through at $150. Hey some people might think I am crazy for even spending that amount on this item, but the coffee table idea of the bloke selling it still gives me nightmares :scared:!

I think you are right,it would have been a tight squeeze in the overhead luggage. I am interested to hear what you may have been looking to do with the scope and mount, please feel free to share your thoughts. Hopefully I don't destroy your ideas too much with what I am aiming to do!

Stay tuned and Clear Skies

Gav

[mercedes_sl1970]

Hi Gav

For me, it was all a bit of wishful thinking, really... I have to be able to move my astro stuff out of a shed for use in the back yard (and then still move around due to trees) so anything I have needs to be quite portable.

If I was in a different situation, I think what you have has a lot of potential. I did have visions of building a big refractor with a lens from Istar. Oh well, something for the future. The mount looks like it could take a big load!

By the way I think that's a very good deal you got.

Will watch this with interest. Best of luck.

Andrew

[Peter.M]

I think you will run into the same problem with this, I am no expert but I suspect the downfallings in your eq6 weight capacity wise are not due to the weight capacity of the actual structure.

The torque needed to move heavyer objects is what gives a mount its capacity. This comes from the motors so obviously you will need strong motors to run this mount when you put a large load on it. Im not sure the cost of the motors will be economical (I have not looked into this) but I dont imagine that they will be cheap.

[GC - South Aus]

G'day Peter

Thank you for your input.



I agree with your comments, however the difference I feel between this project and my EQ6 mount is that I can more readily adpat and change the older mount (i.e. adding motors and gears). Where as the EQ6 is limited by its design and structure.

I am looking at larger (higher ratio, maybe 240 to 360 teeth) worm drives/gears for this mount, with better motors.

Thanks again and if you have any further advice in relation to gears, best placement location or any other considerations. I would be happy to receive them.

Clear Skies

Gav

[GC - South Aus]

Good Evening All,

Well I am going to have to eat humble pie after all, Sydney Swans got up over the Power (well least they put up a decent fight for 3/4's of the game).

My weekend didn't get any better!

On the Sunday I followed Mike's (Iceman's) step by step tutorial in cleaning Newtonian mirrors. Which I must say was easy to read, follow and produced great results. Well would have done until I found that after removing most of the dust and dirt I had a mirror missing quite large amounts of its reflective surface.

So I have now put the OTA back together and will test the mirrors visually once I have an opportunity (which probably won't be for a week or two). So I may now have to get both a new primary and secondary mirror for the six inch family visual OTA. Dependant on first light views/results, the OTA may have to go on the back burner.

Still progessing on with the mount though so stayed tuned all.

All the best and ....

Clear Skies

Gav

[ZeroID]

Is it not possible to find someone to recoat the mirror ?
Long term though the mount sounds like it could be useful ...

[brian nordstrom]

:lol: humble pie for tea ,, It dont taste to bad .
It gives you energy for the continuation of the build . :hi:. Gav.
Good the see some history emerging .. much more interesting than what is on television ..:thanx: .
Brian.

[GC - South Aus]

G'day All

Sorry for my absence as I have been away from home with work on a trip to Bendigo and just got back this week.

I am now really busy with ANZAC preparations and I am just heading off to the march now (hopefully won't be another wet one!).

Will try and get back to the project soon. Stay tuned.

Regards & Clear Skies

Gav :)

[Bosi72]

Yeah it is surprising that you can buy a 2nd hand car for a couple of hundreds of $, with thousand of sprockets, bolts, shafts, wires, yet good 2n hand telescope mount starts at $2000+

Unfortunately that's market reality and I could only hope that Chinese manufacturers in the future will start producing mounts at affordable prices.

Regarding the project, I could only think of adding two (or 4) car starter motors from the wreckers. I am not experienced in either of mechanics nor electrics, however common sense is telling me the motors should be located as at the attached photo.

Pity you're not in Melbourne, otherwise I'd be glad to assist you in this project.

Cheers & good luck
Bosi

[MattT]

HI Gav.
Many years ago I borrowed a book from my local library that had lots of ATM ideas like home made mounts out of Aluminium poured at home into sand moulds!!!.... but there was an EQ mount made from the rear axel of a mini minor mounted very much the same as the 74" reflector at Mt Stromolo was (may she rest in peace) and your mount seems very much along the same lines. Absolutely Fabulous, Happy ATMing
Cheers, Matt

[GC - South Aus]

G'day everyone,

Hope you are all well.

Firstly my apologies for the late update and reply to some of the comments, like most people I have been really busy with work, study and family. Unfortunately work and study have been keeping me from not only this project but observing too (however weather has been generally poor on average).

Brian, glad to hear that you are enjoying the project (hopefully there has been some better things on tv lately). By the way humble pie tastes horrible, but I am glad to see Port getting some good wins up lately. I was even at the Port and Roo's game recently, I must say it was one of the best games I have been to.

Brent, regarding the re-coating of the mirror. Yes this probably could be done but I am not aware of many places around where I live in South of Adelaide or what the cost maybe. Additionally, when comparing to some of the prices out there for not only 6" mirrors but whole OTA's, is it really worth it?

Matt, thanks for the comments mate. I too remember the old 74" telescope at Mt Stromlo. I was lucky enough to live in the ACT for a while and had the opportunity to get up there a couple of times.

Bosi, thanks for your ideas and offer of help. Shame you don't live in Adelaide as it would be good to have advice and other ideas, but this is why I chose to use this forum. I knew I could rely on the internet to keep us (i.e. astronomers) all together no matter how far we all are from each other.

Anyway. this is just a quick update to let you all know how things are progressing/fairing, which is not too great at the moment. The bad news is the mirror is no good at the moment and will require a recoat. This will mean that this (OTA) will have to go on the back burner for now. I would like to restore the mirror but don't have the cash at the moment and as stated previously it is not really worth it at the moment considering the current prices of 6" mirrors and OTA's.

The mount is now my priority and I have managed to source a Losmandy DDS system with G11 motors and I am hoping this will provide enough power to move this thing. Like I said in earlier posts even though it looks quite hefty it does move very effortlessly when pushed. The gears/worms are going to be the biggest issue I feel, this is in cost and placement. I would like to get some Ed Byers worm gears but they are pretty pricey (understandbly) due to their quality.

Anybody got any ideas for some cheaper but reasonable quality solutions?

I have got some ideas for placements and will post some images soon for comments.

Once again my apologies for the late entry and I will try to do better over the coming months (however I do have exams at Uni this month!).

Kind Regards & Clear Skies

Gavin

[Rod]

I found Lenord Stage good to deal with. His gears are here:

http://www.gototelescopes.com/gears.htm

I think if you do a search you will find he has an excellent reputation.

Rod

[GC - South Aus]

Hello Everyone

Thanks for the advice and encouragement so far.

I am still working on this and researching gear options and placements, plus some recent purchases (albiet funded by recent IIS sales) have set me back financially.

As some of you might have seen I have recently taken on another project of upgrading my newly acquired SW 150mm (150/1200) refractor :D (see link below).

http://www.iceinspace.com.au/forum/showthread.php?t=97504

Another project to keep me going, as well as my obs that I am building at the moment (very slowly!!!!!!!!!!!). I am working on the Achro to upgrade and modify to come as close as I can to an ED telescope (i.e. focuser, v block (CA) filters, dew shield/lens heater etc etc). I know that I would have to replace the lens to truely achieve this desire for an ED/APO of this size, but hey I do what I can on a budget!

I will keep you all posted and eventually start a thread for both the SW 150 Refractor and the Obs.

Cheers and Clear Skies

Gav

[MattT]

Hi Gav,
Have just found this thread again. 6" achro's are the best! I've had mine for a while and LOURVE IT:2thumbs: Thanks to David U for doing a great job on getting the most out of this big baby.
Istar are coming out with the Raycorr really soon.....this year round December is the latest and it will turn achro's into apo's...well worth waiting for. Supposed to cost around $300-400 US. Check out Istar on my Signature.

In the mean time I upgraded the 6" with a GSO 10-1 linear bearing focuser :thumbsup:from Agena Astro in the US for $250 delivered and a Badder semi-apo filter which does amazing things to the moon, as does a William's Optics Bino viewer(thanks Meru!) Binoing a refractor is just sensational, the moon....wow. I wish there were some planets up at a decent time to bino view...
As a refractorholic:astron: I would love to hear what happens next :lol:
All the best
Matt