Crayford focusers

norm · #1 22-03-2008, 11:49 PM

Hello,

Its been a while since I've put out a thread. Can people advise what the difference is between say a standard 10:1 Crayford focuser like the one available at Bintel to that of a Moonlite or Feathertouch.

The question is really pertaining to a newtonian scope. Is the price upgrade from generic brand to one of the above noticible and worth the price? Is the feel, quality, material, workmanship etc, etc make it worthwhile to upgrade.

I'm expecting an analogy between a Commodore and a Ferrari here somewhere !

And for what its worth I drive a Commodore and apart from its usual failure of mechanical parts over x years, it does the job. Similar to aperture feature, there is no compromise for roominess in a big car.

Heaps of detailed info appreciated

!

Zuts · #2 23-03-2008, 01:14 AM

Hi,

Feathertouch or moonlite focusers can have motors attached them, to this you can attach electronics that allow automated focusing. This is irrelevant for visual use but very usefull for imaging.

All up a computerised focuser is nearly 1000 AUD, based on a particular companies fine focuser, which has stuff like brakes and guaranteed thousands of an inch adjustment which is needed for automated computerised focussing.

For visual use save your bucks and get a 10:1 GSO, it will be great to use and wont bump the scope around so much when you try and focus.

Paul

ausastronomer (John Bambury) · #3 23-03-2008, 01:41 AM

Quote:

Originally Posted by Zuts

Hi,

For visual use save your bucks and get a 10:1 GSO, it will be great to use and wont bump the scope around so much when you try and focus.

Paul

I would agree with that advice in most cases. Probably > 95% at least. If we were talking about sticking the focuser on a premium telescope, I don't know that the GSO is appropriate in that situation. For instance, if you shelled out $15K plus for a 25" dob from Peter Read at SDM telescopes, which are as good as they get, you would feel somewhat short changed if the scope arrived with a dual speed GSO crayford focuser on it. Somehow a $100 focuser on a $15K scope doesn't quite fit.

I have a dual speed GSO crayford on my 10"/F5 dob and a dual speed Feathertouch on my 18" Obsession. The GSO focuser does a very nice job for $100. It isn't remotely in the class of the Feathertouch, which are the best available for visual use IMO.

On the basis that Norm is a Commodore man, I think he would be very happy with the GSO. Conversely, if he was building a scope from premium components (Suchting mirror etc) he may want to consider a premium focuser. The Moonlite dual speed is also very good, but a full grade behind the dual speed Feathertouch IMO. Considering the Feathertouch is $500+ it should be very good.

Cheers,
John B

Zuts · #4 23-03-2008, 02:14 AM

Hi John,

I agree with you 95% as well. If you buy a Ferrari you should get the right tyres

As you say a GSO will work very well. I am thinking of getting a feathertouch or TFC-S, because with that base i can computerise it, if not for that i would be happy with the fine focuser i got for the TV85 for visual.

Mind you the TV fine focus cost 300 AUD. On my Meade ED80 i managed to fit one side of a GSO 10:1 fine focuser (the knob) for 30 bucks. So i would say this to Norm, if he wants a 85 % improvement in focusing ease, shell out the 100 bucks for the GSO and he wont go wrong.

Edit

I understand what you are saying. I have a Meade ED80 which is a good scope and a Televue 85, the left hand knob of a GSO fine focus would not feel right on the '85.

Paul

norm · #5 23-03-2008, 12:33 PM

Thanks John and Paul for the input.

I was thinking of getting the Moonlite CR2 ($400AUD) for the 12" LB, but given its 1/3 the price of the scope doesn't seem quite right.

Sounds like I'm better off asking for the GSO dual focus upgrade when I by the scope and see how it goes.

Damn, the other 1/2 already gave me the green light to buy it too!

Cheers,

Norm

Zuts · #6 23-03-2008, 01:00 PM

Quote:

Originally Posted by norm

Thanks John and Paul for the input.

I was thinking of getting the Moonlite CR2 ($400AUD) for the 12" LB, but given its 1/3 the price of the scope doesn't seem quite right.

Sounds like I'm better off asking for the GSO dual focus upgrade when I by the scope and see how it goes.

Damn, the other 1/2 already gave me the green light to buy it too!

Cheers,

Norm

Man, green light means go

If the budget is approved why not get a Parracor with the difference?

Paul

gbeal · #7 23-03-2008, 02:31 PM

I had a F/T on the 10" f5 newt, used for imaging and visual. With the completion of the 16", I swiped the F/T. and got a Bintel 10:1 for the 10". Wow, what a difference. The 10" has been lent to a mate who is scope-less for a while, and to be honest I felt awkward giving him the scope with the less than ideal focuser.
BUT........... as has been pointed out, it is hard to justify spending more on the focuser than you do on the basic scope.
The Bintel is good, but pales when you have used the F/T.
Gary

Glenhuon (Bill) · #8 23-03-2008, 02:39 PM

I've recently fitted a GSO 10:1 to my 150 newt, what a difference from the R&P

. If you can't justify the Feathertouch etc on the new scope, go for the GSO, well worth the extra few bucks.

Bill

Starkler (Geoff) · #9 23-03-2008, 02:40 PM

In short, the GSO does a good job at the budget end of the range, whereas the feathertouch is rolls-royce in every respect.
The gso is functional and works well, but the FT is oh-soooo-nice to use and look at.

citivolus (Ric) · #10 23-03-2008, 04:45 PM

To stir the pot, I use a WO 10:1 Crayford on my SCT. I have not tried either Feathertouch or GSO versions, so can't compare it to them other than to say I have no complaints.

Louwai (Bryan) · #11 26-03-2008, 11:29 AM

Quote:

Originally Posted by citivolus

To stir the pot, I use a WO 10:1 Crayford on my SCT. I have not tried either Feathertouch or GSO versions, so can't compare it to them other than to say I have no complaints.

I had exactly what you have & was very disapointed with it.
The seperate parts of my WO were not concentric, & as such, when it was swivelled, it threw everything out of alignment & I would need to collomate each time.
I ended up getting rid of the WO & went to a FeatherTouch. Have never looked back.

skies2clear · #12 26-03-2008, 02:05 PM

Sounds like the Feathertouch is excellent. Not meaning to get too off topic, does anyone have any experience with the Clement Bellerophon Focusser? These are expensive, but the idea sounds killer to me, being able to get real close in (focusser travel), without draw tubes getting in the light path. Any comments appreciated,

CSkies

citivolus (Ric) · #13 26-03-2008, 05:06 PM

Quote:

Originally Posted by Louwai

I had exactly what you have & was very disapointed with it.
The seperate parts of my WO were not concentric, & as such, when it was swivelled, it threw everything out of alignment & I would need to collomate each time.
I ended up getting rid of the WO & went to a FeatherTouch. Have never looked back.

Hmm, interesting. I'll have to check if that is why my collimation jumped so much last week.

Regards,
Eric

citivolus (Ric) · #14 26-03-2008, 10:08 PM

Quote:

Originally Posted by Louwai

I had exactly what you have & was very disapointed with it.
The seperate parts of my WO were not concentric, & as such, when it was swivelled, it threw everything out of alignment & I would need to collomate each time.
I ended up getting rid of the WO & went to a FeatherTouch. Have never looked back.

I just did some tweaking with mine. I found that the three set screws on the SCT end needed to be adjusted to prevent slop, which could explain shift in collimation with rotation. I have not actually tried it out yet to see, but there may be a feathertouch or moonlite in my future.

Louwai (Bryan) · #15 29-03-2008, 09:12 PM

Quote:

Originally Posted by citivolus

I just did some tweaking with mine. I found that the three set screws on the SCT end needed to be adjusted to prevent slop, which could explain shift in collimation with rotation. I have not actually tried it out yet to see, but there may be a feathertouch or moonlite in my future.

The very basic check that I did with mine was;

1) I got the general collimation alignment by putting a laser directly into the visual back & getting it central on the target.

2) Then I fitted the WO focuser & positioned the laser directly into it.

3) I then needed to "re-align" the laser back to the middle of the target.

After I re-aligned I loosened the single Rotating lock screw & rotated the body as it is designed to do, while the laser was still fitted & turned on.

In doing this I was able to watch the laser dot spiral off the side of the target & dissapear.
After a 180deg rotation the laser was hitting the side of the 2ndry tube.
After a 360deg rotation the laser spiralled back onto the target again.

In addition, when I had my 2" diagonal & 2" EP fitted the draw tube would "sag" dramatically under the weight, which also threw everything out of alignment.

As I said in the previous post, I got rid of the WO & bought a FeatherTouch.
What a beautiful piece of engineering.
Fitting my 2" diagonal + a 2" 2x Barlow + a BIG 1kg 2" EP there is not 1 scrap of movement or sag.
Just awesome.