Skymax 127 mak - Fine Focus

[PeterC65]

13 minutes ago, JDF said:

How did you find it worked before you changed the visual back ? 

I can't fit a wider knob with the 2" Clicklock in place, but I think I really benefit from the extra leverage provided by the clothes peg. The focus control is so sensitive that just a tiny nudge on the end of the clothes peg is enough to make a difference at high magnifications. I wonder now how I ever used this scope without it!

[JDF]

1 minute ago, PeterC65 said:

I can't fit a wider knob with the 2" Clicklock in place, but I think I really benefit from the extra leverage provided by the clothes peg. The focus control is so sensitive that just a tiny nudge on the end of the clothes peg is enough to make a difference at high magnifications. I wonder now how I ever used this scope without it!

Yeah, I use the peg too but it does sometimes ping off into the dark, I have just ordered one of those off ebay so we will see how it goes.

[PeterC65]

22 minutes ago, JDF said:

Yeah, I use the peg too but it does sometimes ping off into the dark, I have just ordered one of those off ebay so we will see how it goes.

My 'peg' has been remade so that the jaws clamp right around the focus knob. Only the spring remains from the original peg! The main problem I have with it is getting it off the focus knob in the dark!!

[Zermelo]

2 hours ago, JDF said:

How did you find it worked before you changed the visual back ? 

I never got to try it before I did the swap.

[Louis D]

I find fine focusing with the foam wrapped focus shaft on the 127 Mak easier than fine focusing with my single speed Crayford focuser on my Dob.  It's very smooth with next to no backlash or mirror flop.  The Crayford is a bit notchy due to the high preloading on it for heavy loads.  Thus, it takes a bit of grip on the knob to get it to move.

I love the fact that none of the visual back's load is transferred to the focusing mechanism.  It's all born by the rear cell which does not move during focusing.  No matter how much load is on the Mak's visual back, focus feel remains exactly the same.  It's such a refreshing change, especially from the fracs' focusers which can struggle at high altitudes under heavy loads.  The Dob's focuser load doesn't change much with altitude by comparison.  However, once I've got a Barlow, PBI, CC, and 17mm ES-92 in there, it starts to feel a bit boggy.

[LaurenceT]

I bought the Skywatcher auto focus unit and also had some bits made up by a fellow in Portugal specifically to fit the 127Mak with the dovetail bay positioned for an alt az mount. Works very well but because of the long focus travel of the Mak I disengage the belt from the focus knob to get rough focus quickly and then just slide it back onto the knob.

 

 

Edited January 29, 2022 by LaurenceT

[banjaxed]

2 hours ago, LaurenceT said:

I bought the Skywatcher auto focus unit and also had some bits made up by a fellow in Portugal specifically to fit the 127Mak with the dovetail bay positioned for an alt az mount. Works very well but because of the long focus travel of the Mak I disengage the belt from the focus knob to get rough focus quickly and then just slide it back onto the knob.

 

 

I always thought the Skywatcher motor focuser was too slow which is why I used a higher rpm motor. If you are interested I bought a 4Tronix remote controller for the Skywatcher motor and it gives you 4 speeds, which when used with a 12v power supply gives a much better choice of speeds. They are on sale at FLO for about £36.00 and are well worth it IMO.

[StarryEyed]

I cut a hole in the plastic lid from something (was many years ago) think it was off a tube of pringels and pushed it on. Worked a treat! 

[LaurenceT]

3 hours ago, banjaxed said:

I always thought the Skywatcher motor focuser was too slow which is why I used a higher rpm motor. If you are interested I bought a 4Tronix remote controller for the Skywatcher motor and it gives you 4 speeds, which when used with a 12v power supply gives a much better choice of speeds. They are on sale at FLO for about £36.00 and are well worth it IMO.

Speeding up the focusing on the Maksutov would be an advantage, I'll look into it, thanks for that.

I'm having a slight issue with a Skywatcher focus motor on the  Orion ST80 I bought for an excellent price recently. It came with the focus motor already installed, I wouldn't have chosen that combination but the price was simply too good.

The outward travel of the  focus tube is fine but the inward travel is prone to suddenly stop, the motor pausing. I can overcome it by reversing the direction slightly and then restarting the inward travel and it goes OK.

I think it's either some torsion of the bracket or something to do with backlash which is apparent.

[nfotis]

On 27/01/2022 at 17:56, PeterC65 said:

If you make this mod, be very careful to keep the tube objective lens upwards when you remove the focus knob as I understand that without the knob there is nothing to stop the whole mirror and focus mechanism from disappearing inside the tube!

 

It has happened to me when I tried to fit a bigger focus knob *bummer* on my Skymax 127. I had to ask a more knowledgeable guy from a Greek astronomy forum to help me because I had no idea what I was doing (the Skymax 127 was my first scope ever, bought used).

N.F.

 

[RT65CB-SWL]

+1 for the Baader helical focusser mentioned by @PeterC65

[jjohnson3803]

On 27/01/2022 at 05:05, PeterC65 said:

Many people use a clothes peg (the spring loaded type) to get fine focus adjustment on the Skymax 127. Initially I though this seemed a bit basic but it actually works really well and a modified clothes peg is now an essential part of my kit.

Not only does it allow very fine focus adjustment, but if you just gently nudge the tip of the clothes peg then you can change focus without causing the scope to wobble.

I use a small plastic spring clip on my 90mm.  It's very similar to a clothes peg but the jaw opening is a bit larger.