sky-watcher auto focuser

[Logan Run]

hello everyone hope all is well

I bought a second hand sky-watcher auto focuser  some time back,  all working fine,  all of a shoulden,  it seam to stop working, I looked that the buttons on the controller they seam to to be sticking in , so I unscrewed it ,  gave it a spray of contact

cleaner , it works , when I come to use it again, it was back to square one, the buttons on the controller still sticking and slow coming back out, I have tried a few times with contact cleaner , sometimes it  doesn't rotate the focuser , does any have any suggestions,  what is wrong, please            

[Merlin66]

Bad news I'm afraid.....

I have and use six of these SW focus motors on my Solar scopes and found exactly the same problem on five of the controllers. The push buttons SW used are rubbish and are prone to failure.

I ended up buying a minimum order quantity of a replacement switch and un-soldered the four switches in each controller replaced them with the new switch.

That was early last year, and so far I've not had any further failures.

If needed I can check my files and supply details of the replacement I used.

Ken

 

[Logan Run]

oh dear,  it looks like an new auto focuser many thanks for advice,  ken

[banjaxed]

13 minutes ago, Logan Run said:

oh dear,  it looks like an new auto focuser many thanks for advice,  ken

You could try one of these from FLO, then you could throw that one away 😀

4tronix FocusRF - Remote Control for DC Focus Motors

[Dave scutt]

3 minutes ago, banjaxed said:

You could try one of these from FLO, then you could throw that one away 😀

4tronix FocusRF - Remote Control for DC Focus Motors

You beat me too it I was just about to mention the same

[Logan Run]

cool   thanks guys  I will next yr 

[Dave scutt]

27 minutes ago, banjaxed said:

You could try one of these from FLO, then you could throw that one away 😀

4tronix FocusRF - Remote Control for DC Focus Motors

Great minds think alike 

[Capt Slog]

On 18/12/2021 at 16:11, Merlin66 said:

Bad news I'm afraid.....

I have and use six of these SW focus motors on my Solar scopes and found exactly the same problem on five of the controllers. The push buttons SW used are rubbish and are prone to failure.

I ended up buying a minimum order quantity of a replacement switch and un-soldered the four switches in each controller replaced them with the new switch.

That was early last year, and so far I've not had any further failures.

If needed I can check my files and supply details of the replacement I used.

Ken

 

What sort of buttons do they use?

Like these?  

 

 I bought a pack of 100 from Amazon for £2.99 to fix some things which weren't working.   Not the easiest solder work, but still doable, and certainly cheaper than a new controller.

[Merlin66]

No, the push buttons are much more basic in the SW controller.

I’ll post a couple of images and details ASAP.

[Merlin66]

The ones I used were 8.5 x 8.5 x 14mm momentary DPDT 6pin DIP. Pin distance 5mm, #J31- 05-05  51771

https://www.ebay.com.au/itm/174729305484

or

https://www.ebay.com.au/itm/233766040071

Cut the excess length of the feet and use a de-solder braid .....

 

[Capt Slog]

@Merlin66 They're actually a bit more sophisticated than the ones I pictured, which are 6mm square, but the same sort of thing.

 

Well done on the fix, they stuff they use doesn't make de-soldering easy these days.

[Ouroboros]

My SkyWatcher auto focuser developed the same problem recently.  Examined the circuit using a multimeter and found the problem lay with one of the micro switches as described above.

I managed to find a UK based supplier (Switch Electronics) with these switches in stock in the UK. 
8.5x8.5mm+Momentary+PCB+Push+Button+Switch
I bought 3 (so I have a couple of spares) for 22p each +vat. Came to £3.65 with postage. Cheaper than buying a new unit anyway.

As described above these switches can be purchased through eBay, but there’s quite a wait for them to arrive from China.

I didn’t have any desolder braid so used a fine darning needle in a hand drill to drill out six small holes for the pins and soldered new switch into place. Worked a treat. Tested the unit and it now works.

Edited July 7, 2022 by Ouroboros

[SthBohemia]

Being somewhat of an antique (feeling as old as Rameses II) I had to lookup what a darn autofocuser is/does! 😞 Oh an electronic knob turner! Now I am wondering why anyone needs an electronic knob turner! Just another gadget adding to a confusion of wires and requiring a separate power supply! I am sure someone will put me on the straight and narrow and explain to this silly old fool the wonders of owning an 'electronic knob turner' 🙂 

[DaveL59]

53 minutes ago, SthBohemia said:

Being somewhat of an antique (feeling as old as Rameses II) I had to lookup what a darn autofocuser is/does! 😞 Oh an electronic knob turner! Now I am wondering why anyone needs an electronic knob turner! Just another gadget adding to a confusion of wires and requiring a separate power supply! I am sure someone will put me on the straight and narrow and explain to this silly old fool the wonders of owning an 'electronic knob turner' 🙂 

Advantage of them: you don't need to be touching the scope when adjusting focus, so no wobbles.

I bought a couple new old stock Tasco ones from the US for IIRC a tenner each, a cheapie compared to these new versions that others have. One is fitted to the Celestron Starsense LT70AZ which is quite wobble on its own and the focus motor makes it much nicer to use. The other at the moment is on the SW130-EQ2 for the same reason.

[SthBohemia]

2 hours ago, DaveL59 said:

Advantage of them: you don't need to be touching the scope when adjusting focus, so no wobbles

Thanks Dave. I have enough trouble/confusion and headaches just working GOTO controllers... Without another hand controller to confuse matters. In many ways prefer the plain simplicity of the Celestron Ultima fork mounts, Up, Down, Left, Right. 🙂 

[bosun21]

Coincidence??

 I have just placed an order for a Skywatcher electric focuser and also the 4Tronix FocusRF. I didn’t like the look of the control pad provided with the focuser as only two speeds didn’t seem to offer the accuracy i wanted. After placing my order I came  across this thread which confirms that I made the correct decision.

[SthBohemia]

2022, the year electric knob turners became all da rage 🙂 (Canna help myself I have a warped sense of humour)!

[StevieDvd]

25 minutes ago, SthBohemia said:

2022, the year electric knob turners became all da rage 🙂 (Canna help myself I have a warped sense of humour)!

No these are so 2010's - current trending is real auto focusing. 😄

[Ouroboros]

Yes, “Autofocuser” is a bit of a misnomer isn’t it? 🙂  Nevertheless, as @DaveL59 points out above, it does offer the advantage of not having to touch the scope when focusing - which makes a lot of difference when focusing by eye and particularly for imaging.  If I was looking to install a new focuser now I’d get a decent electronic version and let the software do the focusing.  But my SW focuser works and there is a measure of pleasure in mending old stuff cheaply, and keeping it going. Also, I don’t particularly want to strip the whole lot out and replace it just now.  

[Ouroboros]

1 hour ago, bosun21 said:

Coincidence??

 I have just placed an order for a Skywatcher electric focuser and also the 4Tronix FocusRF. I didn’t like the look of the control pad provided with the focuser as only two speeds didn’t seem to offer the accuracy i wanted. After placing my order I came  across this thread which confirms that I made the correct decision.

Actually the old ‘wired’ controller like mine is variable speed from fast down to limpet speed.  I agree though the controller looks a bit naff,  but it’s easy in the dark to feel for the buttons and the speed knob.  Numbered buttons, as in the 4Tronix, may require looking at to control. The advantage I think of the 4Tronix is that in being wireless it allows you to sit away from the scope to focus whilst looking at an image on a screen.  Plus you don’t  have wires to trip over.   I’ve got a long extension lead between my hand controller and the focuser. 

[FenSkies]

Jumping in on this as I have just refitted one of these to my scope after a year of disuse. I found that the motor now does not have the torque to turn the focus mechanism unless I take out so much tension that there is backlash.

Has anyone taken the actual motor/gearbox unit apart and service it. I suspect there is a slip-clutch of some sort to prevent the motor from burning out under load, as i can hear the motor turning feebly, but the shaft that connects to the scope remains stationary.

Any advice or knowledge on this will be very welcome 🙂