250pds Focuser

[KyleStoke]

Hi All 

I have just come into possession of a Skywatcher 250pds but need to add a Lakeside motor focuser to it. 

First problem is the dual speed knob is on the wrong side, it is towards the front on the scope, does anyone know if its reversible?

Also there isnt a bracket mentioned on FLO's website, does anyone know if one exists or at £50 for a bent piece of aluminium would i be best to fabricate my own.

 

[banjaxed]

I have the dual speed focuser on my 200p Dob and as far as I remember it is possible to switch it over.

[Steve Ward]

Just undo the screws and flip it.

I've done all mine as I'm left-handed ... 😉

[KyleStoke]

Thanks Both, it is set up left handed so you would of been ok on this one. 

 

[davies07]

FLO should be able to supply a bracket. Just drop them an email.

 

[andymw]

Someone already flipped the focussing wheels (probably to add a ZWO EAF or something similar which connects to the fast focusser).  As has been said:  it's easy to just remove and flip the wheels (leaving the main focusser attached to the tube).  FWIW:  I did see that the Lakeside focuser connects to the fast focusser also, so wondering why you want to flip it?

Edited September 13, 2022 by andymw

[StevieDvd]

The usual practise is to fit the motor to the opposite side of the dual speed knob.  The fine turn side is probably too fine a tune for the small increments the stepper motor provides.  I've not seen anyone fit to the dual side but that does not mean it should not be done.

Fast focus or probably more aptly named coarse focus is the single speed, the fine focus would be slower.

As well as the correct bracket I expect FLO also provide the correct replacement screws as well and the correct size coupler.

 

 

[KyleStoke]

On 13/09/2022 at 17:49, andymw said:

Someone already flipped the focussing wheels (probably to add a ZWO EAF or something similar which connects to the fast focusser).  As has been said:  it's easy to just remove and flip the wheels (leaving the main focusser attached to the tube).  FWIW:  I did see that the Lakeside focuser connects to the fast focusser also, so wondering why you want to flip it?

Hi I have swapped it over now. I wanted it on the inside because it overhung the front of the scope and also it was just neater for the cables.

[KyleStoke]

On 13/09/2022 at 18:46, StevieDvd said:

The usual practise is to fit the motor to the opposite side of the dual speed knob.  The fine turn side is probably too fine a tune for the small increments the stepper motor provides.  I've not seen anyone fit to the dual side but that does not mean it should not be done.

Fast focus or probably more aptly named coarse focus is the single speed, the fine focus would be slower.

As well as the correct bracket I expect FLO also provide the correct replacement screws as well and the correct size coupler.

 

 

Im probably wrong but I don't think the single speed side was removable. 

Unfortunately there isn't a ready made bracket at FLO but they are looking if the MN190 bracket will fit. If not I'll probably adapt the one I have. I've drilled out the coupler to fit already but it needs to have the bracket secured properly.

[StevieDvd]

12 hours ago, KyleStoke said:

Im probably wrong but I don't think the single speed side was removable. 

Unfortunately there isn't a ready made bracket at FLO but they are looking if the MN190 bracket will fit. If not I'll probably adapt the one I have. I've drilled out the coupler to fit already but it needs to have the bracket secured properly.

I doubt the single speed side is not removable see here for someone fitting a ZWO EAF to their 130PDS - hopefully your focuser is the same.  It should be a case of lining up the grub screw with the access hole to remove it.

If your coupler is narrow enough to fit inside the focuser frame you could use the same hole to secure it., otherwise the coupler will stick out a little further. Once the coupler is fitted you can then check for the bracket mounting position.

 

 

[KyleStoke]

1 minute ago, StevieDvd said:

I doubt the single speed side is not removable see here for someone fitting a ZWO EAF to their 130PDS - hopefully your focuser is the same.  It should be a case of lining up the grub screw with the access hole to remove it.

If your coupler is narrow enough to fit inside the focuser frame you could use the same hole to secure it., otherwise the coupler will stick out a little further. Once the coupler is fitted you can then check for the bracket mounting position.

 

 

Hi Stevie, 

Its more than possible I missed the grub screw, its installed in my dome so not the best light in there.

The coupler I modded fits nicely the issue is normally the bracket is fixed with the locking screw which is normally in the centre of the focuser plate. on this one it isnt its got 2 both off centre. I could drill out the bracket I have but it would be very close to the edge. 

[KyleStoke]

Just to confirm there is no grub screw to remove the single speed knob 

[StevieDvd]

On 15/09/2022 at 20:02, KyleStoke said:

Just to confirm there is no grub screw to remove the single speed knob 

If the scope was not bought new is it possible they have taken the focuser spindle out and re-fitted it with the single speed knob further in or out and the grub screw is not aligned with the access hole? In which case you may have to remove the double speed side first. There will be a grub screw keeping the double speed housing in place and  one that can  be accessed to remove the assembly from the spindle. That should allow the spindle and single speed knob to be pulled out  to make its grub screw visible.