SCT Focuser upgrade

[Marky1973]

In my continuing quest exploring potential  MAK/SCT scopes for planetary viewing/imaging, I am looking at focuser upgrades to make life easier. I can see that there a various versions that can either replace the focuser knob, like the Starlight FeatherTouch focusers or Crayford-style focusers of various designed that complement the onboard focuser and fit into the visual back of the SCT/MAK - like the moonlite and skywatchers.

Been reading around fixing and using them and they both sound like decent options - either/or should be a great upgrade. 

I was wondering if there were any major advantages of one type over the other? If the plan is to use for planetary visual/photography and (maybe) a bit further down the line some DSO work (I still have the ED80 for that) - will one particular focuser be better than the other for planetary/DSO purposes?

Either approach seems to help with any mirror shift people may have experienced, but does the addition of a focuser on the visual back introduce any major issue with distances and achieving focus with cameras for example?

Hope this all makes sense.....

[PeterCPC]

I have the Feathertouch which replaced the existing focuser on my C9.25 and find it very good. I decided not to go for a Moonlite simply because it will add weight to the back. That may or may not be an issue for you.

Peter

[Physopto]

I had a Meade 12" LX200 for a while. Used its own focuser and was not too impressed.  If I had kept the Meade I would definitely have fitted a FeatherTouch.  I use Refactors now and have just ordered my second FeatherTouch to replace the Tak one. They are exceptional. I cannot comment on any others.

Derek

[DRT]

I use a 2" FeatherTouch Crayford on the back of my CPC1100 and it works beautifully. I have had no issues with focus travel but do not image so can't help on that score.

[Tinker1947]

I put a Feathertouch on the 11" SCT, less than 5 minutes to fit and made the focusing so much easier, the Rowe-Ackerman Schmidt have them fitted out of the box...

http://www.firstlightoptics.com/starlight-instruments-feather-touch-sct-microfocusers.html

[Colinlp]

I've been thinking of the Moonlite Crayford, I would like to motorise it to help with imaging, I'm thinking if I add a motor to the mirror focuser then I would lose manual control for fast large movements such as changing between observing and imaging. If I added a Crayford then I can get the best of both worlds and have a fine focus that will leave the mirror stationary which I hope will keep the image from bouncing around in the FOV

[Davey-T]

I have a 10" LX200 with the original Meade electronic motor focuser and frankly wouldn't even attempt planetary imaging without it.

Dave

[Physopto]

18 minutes ago, Colinlp said:

I've been thinking of the Moonlite Crayford, I would like to motorise it to help with imaging, I'm thinking if I add a motor to the mirror focuser then I would lose manual control for fast large movements such as changing between observing and imaging. If I added a Crayford then I can get the best of both worlds and have a fine focus that will leave the mirror stationary which I hope will keep the image from bouncing around in the FOV

You could go the FeatherTouch route and fit a HSM---Handy Stepper Motor with manual focus over-ride. this focus control can be simply unengaged for manual focusing.

May be worth a look. Moving mirrors can be the cause of mirror flop if not really well locked off.

Derek

[Colinlp]

23 minutes ago, Davey-T said:

I have a 10" LX200 with the original Meade electronic motor focuser and frankly wouldn't even attempt planetary imaging without it.

Dave

I can believe it, I'm still using the stock focuser and it's a nightmare without a Barlow but with, forget it! Well not quite forget it but adjust - reacquire - adjust - reacquire until you get somewhere close. I sometimes think one of the JMI attachments for the stock focuser would be worth shelling out for until I can afford the Moonlite or other

[Davey-T]

38 minutes ago, Colinlp said:

I can believe it, I'm still using the stock focuser and it's a nightmare without a Barlow but with, forget it! Well not quite forget it but adjust - reacquire - adjust - reacquire until you get somewhere close. I sometimes think one of the JMI attachments for the stock focuser would be worth shelling out for until I can afford the Moonlite or other

IMHO for serious planetary imaging (or at least something that doesn't drive you to drink) you need to get near focus, lock the mirror and motor focus.

Dave

[Marky1973]

Thanks everyone - sounds like there isn't really much in it - unless there is an issue for photography, although many imagers seem to use crayfords, so probably not an issue - perhaps weight is the main concern there.

Thinking of motor focusers (I have one on the ED80 and it is a lifesaver) I will no doubt get another eventually...thinking about it I am guessing this might work better with a crayford as you could then use the standard focuser for getting close (and quick and dirty visual use) and then use a motorised crayford to fine tune - if you have a motor locked on the original focusser, I presume you can't disengage it so easily to do the quick and dirty focus.... might need to have a look at the weight and see how different OTAs will sit on the NEQ6... 

[Davey-T]

1 minute ago, Marky1973 said:

Thanks everyone - sounds like there isn't really much in it - unless there is an issue for photography, although many imagers seem to use crayfords, so probably not an issue - perhaps weight is the main concern there.

Thinking of motor focusers (I have one on the ED80 and it is a lifesaver) I will no doubt get another eventually...thinking about it I am guessing this might work better with a crayford as you could then use the standard focuser for getting close (and quick and dirty visual use) and then use a motorised crayford to fine tune - if you have a motor locked on the original focusser, I presume you can't disengage it so easily to do the quick and dirty focus.... might need to have a look at the weight and see how different OTAs will sit on the NEQ6... 

If you splash out on an expensive if one it will have a clutch or if you're into DIY you can make your own

Dave

[Marky1973]

Just now, Davey-T said:

IMHO for serious planetary imaging (or at least something that doesn't drive you to drink) you need to get near focus, lock the mirror and motor focus.

Dave

Dave, do SCTs have any inbuilt method for locking the mirror? Or are we talking about locking the crayford when focus is set? Presumably this doesn't lock the mirror though? Or am I missing something? Just been looking on-line and can see you can buy a mirror lock to replace the standard focuser - then I guess a crayford in the visual back + motor would make imaging easier.

 

[Physopto]

My Meade had a mirror lock, you unlocked moved and locked again. As I understand it Celestron did not at that time, but since have addressed the problem on the latest SCTs. I am unaware of how good they are but no doubt some one will be along to tell you. The Crayford focusers can suffer from slippage I believe as there is no actual gearing, a drive bar rod is in tight frictional fit to the tube. Whereas the FeatherTouch are rack and pinion. They can suffer some slippage when a very high weight is fitted such as a large heavy camera. But this is because of the reduction gearing through the ball bearing contacts, not the gearing.

My FeatherTouch has been fitted with  a direct gear drive motor focuser from Starizona. But this type of motor drive can only be fitted to the 3.5" models as I understand.

The quality of the FeatherTouch is better as I am informed by web reports and everything I have read. I have heard really good things about the Moonlight though.

You really need a lot more input from other members over this decision and a lot of time researching exactly what you need.

Derek

[PeterCPC]

You cannot lock the mirror on my C9.25 but the Edge versions have a lock (more expense). I usually use a Bahtinov Mask to focus on a star, which is easily done without a motor focuser, then move the scope to Jupiter or whatever without touching the focuser again.

Peter

[Colinlp]

Trouble is there are good reports about a lot of the options, everyone who has one says they're the best thing since sliced bread, I can't find a single review saying something is lacking in some way even though common sense tells you otherwise. So many variables on which is the best for any one person, I'm driven by the final cost as well as suitability so I have to accept that I will have to make a compromise as I did buying my scope a CPC 1100 GPS, I would have liked a 14" edge but there you go.

[Marky1973]

13 minutes ago, Physopto said:

My Meade had a mirror lock, you unlocked moved and locked again. As I understand it Celestron did not at that time, but since have addressed the problem on the latest SCTs. I am unaware of how good they are but no doubt some one will be along to tell you. The Crayford focusers can suffer from slippage I believe as there is no actual gearing, a drive bar rod is in tight frictional fit to the tube. Whereas the FeatherTouch are rack and pinion. They can suffer some slippage when a very high weight is fitted such as a large heavy camera. But this is because of the reduction gearing through the ball bearing contacts, not the gearing.

My FeatherTouch has been fitted with  a direct gear drive motor focuser from Starizona. But this type of motor drive can only be fitted to the 3.5" models as I understand.

The quality of the FeatherTouch is better as I am informed by web reports and everything I have read. I have heard really good things about the Moonlight though.

You really need a lot more input from other members over this decision and a lot of time researching exactly what you need.

Derek

Definitely, Derek. As ever I am slowly moving up the budget ladder as I look at various options, so I have time to save up and read around what I need.

[Marky1973]

11 minutes ago, PeterCPC said:

You cannot lock the mirror on my C9.25 but the Edge versions have a lock (more expense). I usually use a Bahtinov Mask to focus on a star, which is easily done without a motor focuser, then move the scope to Jupiter or whatever without touching the focuser again.

Peter

More expense than I think I want to add for mirror lock! ;-) 

[Marky1973]

7 minutes ago, Colinlp said:

Trouble is there are good reports about a lot of the options, everyone who has one says they're the best thing since sliced bread, I can't find a single review saying something is lacking in some way even though common sense tells you otherwise. So many variables on which is the best for any one person, I'm driven by the final cost as well as suitability so I have to accept that I will have to make a compromise as I did buying my scope a CPC 1100 GPS, I would have liked a 14" edge but there you go.

Completely agree Colin - neither option sounds like it would be a problem - and cost is also important, which pushes me towards the replacement focuser as opposed to a moonlite/crayford - plenty of time to research some more though!

[Physopto]

The Money Pit is yawning!

[Marky1973]

Start at  127Mak and then think, I probably should get more aperture.... then a 150 PRO.... the 180 PRO - I mean, you might as well maximise FL and Aperture, surely? And then oooooh, look at the C8....hang, on there is a C9.25 as well... and then focusers....and reducers..... 

MUST

STOP 

LOOKING.....

:-)

 

[PeterCPC]

One thing that I find helps with the focuser and, don't laugh, but I use a hair thingy on the end of it which you can use for very fine adjustments and stopping vibrations. See attached - bought from Poundland.

Peter

[Colinlp]

2 minutes ago, PeterCPC said:

One thing that I find helps with the focuser and, don't laugh, but I use a hair thingy on the end of it which you can use for very fine adjustments and stopping vibrations. See attached - bought from Poundland.

Peter

What do you mean don't laugh????? I nearly threw up laughing at the thought of you using a hairy thingy on the end of it whilst out alone in the dark!

[Marky1973]

Thought that was a picture of a (H)airy disc for a second.... was going to tell you the scope needed Collimation....

:-)

Seems a lot of people use similar cheap mods...so might be the way to start, upgrading bits at a time after getting used to the scope.... it'll probably take me months to learn how to collimate.... :-)

[Marky1973]

Just now, Colinlp said:

What do you mean don't laugh????? I nearly threw up laughing at the thought of you using a hairy thingy on the end of it whilst out alone in the dark!

Or shifting uncomfortably from one leg to the other queuing in Poundland....