markse68

Hi, I bought a Tal-2m recently 🤦‍♂️ 

But I think it has some issues with its equatorial mount- particularly the dec axis which seems very rough in motion like it has ball bearings that have suffered a shock and dented their races.

So I’d like to open it up and have a look to maybe replacing them if they are standard bearings

I found Astro Baby’s excellent detailed tear down of the Tal-1 mount but the 2 seems a different beast even though it looks very similar.

I read of someone on here in the past replacing the RA bearings. Wondering if anyone ever came across information or ever took the DEC apart before? 

There are 2 grub screws that appear to lock the OTA mounting plate to the DEC shaft but I’ve undone those and it doesn’t want to budge and I don’t want to damage it anymore. It’s hard to say if that plate is threaded onto the shaft or just a press fit but it’s solid.

Any experienced help much appreciated

BTW the RA bearings feel ok though there is a definite detent when the DEC shaft is moved to be in line with the pier mount- wondering if it’s intentional to aid in putting the mount into its box or perhaps also damage 🤔

Mark

Thanks Steve and Mick. I quite like the look of the old transformer as it goes 😉 but it’s not very portable- and that old clock drive was very noisy and shaky. I had to slacken off the worm a bit as it had a tight spot and I’ve limited the winding current to 200mA on the stepper to get it really silent, and it was stalling, but now it seems to be working excellently. I was using it last night for 3hrs(!) on the first clear night in what seems like ages with all the rain. Best nights viewing since I bought the scope- Jupiter, Saturn, Moon- so crisp and clear and the drive makes it so enjoyable 😊 Tried to split Antares and failed lol- think I might need more than 4” for that- though it did look different from other stars.

Dont know if it’s because they were all fairly low but they did drift a little- I can probably tweak the speed a little but it’s so much more stable an image than with it switched off I probably won’t bother.

Yes Mick- it’s meant to be a USB charger that you clip on your battery packs but makes a great little interface to other things with a simple drilled hole and soldered wires- I should fuse it really. They’re 10.8v (3cell ) packs so 12.6 fully charged and the stepper runs down to 8 or 9V I think.

Mark

Thanks all

Carole I'm in N Greenwich area most of the time- hoping to catch the Flamsteed Society at their next viewing meetup on Blackheath but they don't seem to have had one since April.

Demonperformer yes for its size it was meant to be a good performer and certainly impressed my naive eyes with the moon- beautiful! And yes "once completed"- that is the stumbling block at the moment- designing something is the easy bit

Mark

It does look like the tube is distorted into peaks where the screws attached the old focuser- maybe from overtightening or an accident? Could you use larger washers to spread the screw pressure further from the holes and pull the peaks flat again against the Moonlite mount while tightening the screws? The tube looks quite thin so should reform quite easily?

Trying to decide myself what colour Moonlite to order - think it will be red like yours 😍

Hi, sorry I forgot my netiquette and already posted elsewhere 😬

I’m Mark from SE London where the skies are bright and you can occasionally see a constellation or 2

40+ years ago my grandad showed me Saturn through his huge to me then telescope. It was such a strange sight I was convinced he was kidding me and had drawn it on the eyepiece! That was my only viewing through his scope unfortunately.

Back in the 90’s something ignited an interest in the universe and I bought a little Tal Alcor 65mm newt from Telescope House in London. It was a fantastic little thing and the views of the moon, Jupiter and Saturn were awe inspiring but life happened and I didn’t stick to the hobby for long. Still have that little scope though

I think it must have been the images of the black hole that re-ignited interest and I was soon owner of an old first version blue 4” Tal-1m - the motorised equatorial mount appealed after the manual alt-az mount of the little Tal, and the views have been a real step up!

Now I’ve gone and bought a huge 12” mirror  🤦‍♂️ and am designing a dobsonian mount for it- dreaming of immersing myself in deep sky objects- those amazing galaxies and nebulae I keep seeing in beautiful photographs that I dream of seeing with my own eyes. Can’t wait (I know they’re not going to look like the photos - maybe that’s a future development of the hobby for me 🤷‍♂️ Baby steps at first)

I’ve already learnt so much browsing this and other forums - thank you all 🙏 Trying unsuccessfully to avoid spending too much on eyepieces and other paraphernalia ....

Mark

Just measured my Tal-1 and it's 850mm (~33.5") . I think the Tal 120 was designed to be shorter so I think you must have a Tal-1

Mark

Thanks for all the replies! Nigel and Craig there's definitely a family resemblance there so it's looking almost certainly to be a David Hinds mirror- which is great I think  and likely from a Fullerscope- did they have model names like R12, R3 etc? I'll do some more digging and contact the David Hinds webpage. 

I did find another picture on here of a Fullerscope D.Hinds mirror- looks to be similar layout though a different hand.

Mine lacks a grading letter but I chose to be optimistic and as 6" is the largest scope I've ever looked through I'm really excited and inspired to build something with this and have my mind blown

Mark

So I've caught the astronomy bug quite badly after the Tal-1m...

I saw this mirror on ebay and rather recklessly took a punt on it. It's a 12" mirror - the seller didn't have any information about it but it looked like a telescope primary- it had it's focal length written on the back anyway

I think it's a fair few years old and would love to know more about it if anyone recognises the style of inscription- if it's from a known maker?

It has inscribed on the back "R12/49" and I was wondering if that had any meaning- perhaps in relation to the figuring or a test result?

The plan is to build a dobsonian with it and get even better views of the moon and Jupiter  

Mark

Hi, I just recently bought a Tal-1m on ebay after a strange urge to look at the moon and Jupiter again took hold of me- something I haven't done for years... My previous experience had been with a Tal 65mm newt I bought brand new back in the day from, I think, Telescope House- lovely little thing but this Tal-1 is something else!

I wanted a motorised equatorial mount as that was the thing that was a bit of a pain with the 65's alt-az mount and when I looked it was there waiting for me on ebay-  and I love it

The plan is to stick it in the boot of the car and drive off somewhere with a  bit better seeing than SE London so I wanted to convert it to battery power. Plus the synchronous motor drive was very noisy...and shaky- you had to turn it off if you wanted a clear sharp image

I opted for a stepper as I knew about these Trinamic drives with built in controllers and opted for one with "Stealthchop" which gives very smooth motion at low speeds. Bit pricey for a stepper but worked out quite neat and simple. You can programme in the speed you want it to run at and it will just start up and run at that speed as soon as it's powered.

It runs off a Makita battery pack through the original connector, draws about 250mA so should last for hours, and is very very quiet. I got my measurements a bit wrong I think when I was drawing up the 30:1 reduction gears so I have to mount it slightly off line to avoid the big worm gear clutch screws clipping the new brass gears but it works fine and tracks the moon well.

Mark