Not overly impressed

[matt]

OK guys

FWIW

I'm going to post what I believe is my first and only criticism of an item I recently purchased which I thought would improve my set-up.

I've just recently bought and fitted a new GS 2" Crayford to my Skywatcher 8" f5 scope, replacing the R&P which came as standard.

Yes, the Crayford is smooth and "potentially" offers more precise focusing, but what's the point when I can't get a decent collimation with the ******* thing!!!!!

Here are my main gripes:

1: The single screw brass compression ring which secure the eyepieces.

But when I tighten it, it pushed the eyepiece or my collimation tools in the opposite direction, and you get a different result (through a Cheshire or laser) every time you tighten the ring depending on how tight you turn the screw. This offers little to no consistency and leaves the process open to image quality suffering through poor alignment.

Also, given such vaguaries in this area of the focuser's design, how can you ever be sure you've actually achieved a genuine collimation?

Why was there not a second screw on the opposite side to the only existing screw to provide a balance (and centering effect) in securing eyepieces, collimators and other accessories in the precise optical path?????

2: I also needed an extender to allow the tube to rack out far enough to acheive focus and outside focus. This extra piece of equipment only adds to the potential for all components to be out of optical "whack".

I was told (when this item was being "sold" to me over the phone) that it was a straight "plug and play", no adjustment or modification required.

Sure. The focuser only cost $150 ...

But that feels like something of an expensive mistake at the moment for an upgrade which came very highly recommended.:mad2:

Sorry to whinge, but dammit... that feels better:lol:

Anyone got a higher quality Crayford kicking around in their kit they'd care to offload?

[janoskiss]

Don't be sorry Matt. I appreciate you sharing your experiences. I'm considering getting one of these focusers, precisely to avoid the sort of problems you are talking about. My rack&pinion is sags and flexes too much with heavy eyepieces. The Crayford on my ED80 is very basic but solid, and with the tension on, it does not shift even with heavy eyepieces or SLR cameras hanging off it.

[slice of heaven]

Whinge away, we don't mind.

Yep it's a downfall all right. I shimmed underneath the compression ring with a strip of plastic to take up the slack so the eps are a snug fit without using the screw to tighten....2 eps are very snug... but the sideways shift is gone.

:confuse3: Can't help with the extension though, that's a real problem without buying a new one or making an extension to fit under the baseplate.

[Starkler]

Sounds like your gripe is with the 1.25" adapter ?
My GS crayford has two screws on the brass compression fitting for 2 inch ep's.

Re drawtube travel , looky here.
http://www.iceinspace.com.au/forum/showpost.php?p=37170&postcount=7

A few have fallen for this.

[slice of heaven]

2??? Mine only has 1 on each size.... do the 2 screws stop the sideways movement?

[anthony2302749]

I just read the thread and it made me think. When you are making any changes to a Newtonian e.g. new focuser, it becomes much like a ATM project. You must consider what changes a modification may make to the optical axis. There is a program avaliable from the net called "Newt" which will give you some idea of what will happen when things are changed (follow the link).

http://home.att.net/~dale.keller/atm/newtonians/newtsoft/newtsoft.htm

I can not comment on the GS Crayford, but I would assume that it either has a lower profile then the original R&P or that it does not have enough travel, additional if the scope was an f6 there may not be a problem with "draw tube travel". Maybe the point here is to consider the "draw tube travel" when selecting a new focuser Skywatcher 8" f5.

If the "brass compression ring" is similar to the JMI then all is required to secure the eyepiece is a gentle tweak of the screw, the eyepeice should not move. As GS is Taiwanese the manufactoring tolerances may not be as good as JMI so it maybe slightly large the 2" hence it pushed the eyepiece or collimation tools in the opposite direction. A probelm that can be fix but at additional cost.

Just my thoughts on the subject

Anthony

[matt]

Yep

Only one tightening screw per 1.25 and 2 inch brass compression rings.

What was really disappointing about this experience was the assurances I was given that this Crayford was straight forward "plug and play". I went to great lengths to make sure it was ready to go on my scope, out of the box.

I was (foolishly,as it turns out) comforted by the fact the same vendor actually sold my exact make and model of scope and assured me it was perfectly suited without any extra mods. I reckon that makes the problem of its lower profile almost unforgiveable. You'd think he'd be aware of the focusers specs?!??

Surely it's a sign of a good businessman to KNOW YOUR PRODUCT:mad2:

By the way Anthony ...I think your comment about manufacturing tolerances is pretty spot on.



I'm going to see how a little "padding" of the 1.25 eyepiece holder goes in terms of limiting the amount of movement when tightening the compression screw.

But honestly, whatever happened to the days when you got and what you paid/asked for ... with no nasty surprises?

[anthony2302749]

Hi Matt

I know I should not be asking this question and you do not need to answer it, but who was the dealer?:confuse3:

Anthony

[matt]

Anthony

I don't think it's allowed on this site to "name names"???

Mike? Your stance on this?

[iceman]

I'm quite sure I know who you're referring to - have you spoken with the dealer about your problems yet?

It's best to give the dealer the chance to help you fix the problem before naming them and bagging them.

One side of the story is a dangerous thing to take as word.

[matt]

Yep

Only about the lack of tube travel. To his credit he did send out the extender free of charge but it was still disappointing that it came to that at all.

I must say the individual in question was also quite dismissive when I expressed my frustrations over the phone. But that's a different issue altogether.

The problem with the compression ring I've only discovered today.

The Crayford I bought is apparently from a new line?

I would like to make it clear that my comments are in no way a personal attack, but an expression of frustration and moderate disbelief:sad:

[Starkler]

So you loosened the lock screw as I suggested and you still have a drawtube travel issue?

[davidpretorius]

Matt,

just a thought, have you cadjusted your secondary. I fiddled with my secondary early on in the piece and found that i could no longer focus with my toucam. I had lost nearly 1 1/2 revolutions. If you haven't got it, buy this months AS&T it has a great article on collimation!!

Get your secondary spot on and see if that makes a difference???

[matt]

Starkler. It's not a focus lock issue. I figured out how that works pretty early in the piece.

The overall height of the unit is a full inch shorter than the Skywatcher stock standard R&P focuser. So there's your focus problem:P

DP ... the seccondary's pretty much where it was prior to the mod, when it was well-collimated. I've hardly touched it, save for a very minor tweek because of the new focuser's installation.

I've got the current issue of AS&T ... but I'm pretty much OK with collimation these days.

I fear it's just one of those things. You win some ... you lose some

I'll return it and keep on the hunt for a goodun

[anthony2302749]

Hi Matt

I may have an idea (it is only an idea) to fix your problem with "draw tube travel" you need to move the main mirror towards the front of the scope by about an 1" to 1 1/2" so that you can use the focuser with out the extention.

If I remember correctly the primary mirror cell is a push/pull type configuration for collimation purpose. Replace the original bolts with bolts that are about 1 1/2" this should move the main mirror forward by about an 1"+, this will fix the focuser travel problem. This mod should cause no problem with the performance of the scope.

Anthony

P.S. Forgot about the springs they will need to be replaced. Problem can find better ones then whats in the scope now. Also should have thought about this, "Balance", by moving the mirror forward the balance of the scope in the cradle will change.

Anyway it was just an idea.

[matt]

Hey Anthony

Thanks for the suggestion but I think I'd rather not reduce the focal length of what is already a fast scope (f5 - 1000mm), even by such a small amount.

I think a speedy refund will be the best solution and I'll be a little wiser for the experience:lol:

[janoskiss]

Matt, you cannot reduce the focal length without regrinding the mirror, but yes go the refund.

[anthony2302749]

Hi Matt

You are not reducing the focal length. Remember that in the manufactoring process the mirror was ground and figured to have a focal lenght of 1000mm (f5). It does not matter were in the tube the mirrors is placed the focal lenght will always be an 1000mm (f5)

By moving the mirror foward you a shifting the focal plane.

Anthony

[RAJAH235]

Matt, send it back & save the hassle. mho. L.
FWIW. I definitely wouldn't like my heavy mirror floating around on extra long screws. I fully compress the springs then back off 1 1/2 ~ 2 turns & do coll. from there. More tension = less chance of going out of collimation. :D L.

[matt]

Of course:P

Anyway, still don't fancy that sort of carry-on for a dud focuser.

My mind's made up. It's onwards and upwards. The question is: can anyone recommend a really good Crayford other than a Moonlite or Starlight????

[bird]

JMI make nice crayfords, I've got the DX1-M and it's fantastic.

www.jimsmobile.com

Bird

[iceman]

I've got the moonlite and I love it.

[davidpretorius]

thanks, i have often wondered about this

[anthony2302749]

And they come in a range of colours.

http://www.focuser.com/storefront.php

[matt]

Am already liaising with Ron from Moonlite.

Looks like it's going to be the CR2 for me, but bird I'll also be checking out the JMI.

One thing for sure, I'll be avoiding single screw brass compression rings and making sure min and max (racked in/ racked out) focuser heights are spot on with the use of spacers etc etc

Tricky business this, but I believe well worth the effort (and cost):lol:

[Starkler]

matt , what is the total focuser travel fully racked in to fully out?

Is it this one ?
http://www.telescope-service.com/ATM/focusers.html#tsoaz2cn

[matt]

Geoff

That's it! That's the one.

Total travel is 1.5 inches.

Note the single compression ring screw on both the 2 inch and 1.25 adaptor.

I reckon that's a flaw. Just a personal opinion, but opposing screws work much better IMHO?

[matt]

Again ... it's only my humble opinion,

but does anyone think it's a bit misleading/ "naughty" to send out an item in a box labelled "GS Crayford" ... when the contents are actually a TS Crayford????

Or are they the same thing, manufactured by the same company?

Does a GS have two screws on the 1.25 adaptor brass compression ring?

mmmmmmmmm!

[wavelandscott]

Matt,

I put a Moonlite on my 8 inch GSO Newt...the Moonlite is a cracker no doubt about it.

I did have to get a tube extension...I originally ordered the standard tube but ti was not quite long enough to give me enough out focus. The extension worked a treat.

Focuser is buttery smooth...I liked it so much that I replaced the JMI on my 12.5 inch Discovery with a Moonlite too.

I enjoyed working with Ron from Moonlite...I found he was very responsive and helpful via e-mail for me.

Good Luck!

[ving]

1.5" doesnt sound like much travel, tho my understanding is that its the norm for these and many others...

I'll stick with my gs r&p :) sloppy and smooth :P

[Starkler]

Ok the crayford has a specified focus travel of 41mm.
Interestingly , the standard r&p focuser as would have been on yours is directly under it on the web page . That one has a specified focus travel of 37mm. :confused:

Have you actually measured the travel on the new one? I still have a feeling something is wrong. Either the new unit has a fault, or the lock screw issue is having an impact. Please humour me and totally remove the lower lock screw, then rack the focuser up and down and see that you dont get as much as you did with the old r&p.

[matt]

OK

Geoff ... give or take a mm, the travel is the same distance. Have measured it... ad nauseum. Approx 1.5 inches. Same as the R&P.

The problem is the unit's overall height at min and max rack. It's a lower profile unit. Which is why I needed to insert an additonal 30mm extender.

For the sake of the exercise, and to make sure you could put your mind at rest, I fully removed the focus lock screw. No diff. Is no good. Is done, dusted and over:lol:

As ving pointed out ... it appears 1.5" travel is fairly common.

wavelandscott, it's likely I'll order the CR2 with standard 2" draw tube, an SW8 install kit and additional 1" spacer.

That's Ron at Moonlite's recommendation, and it's the same arrangement I calculated.

Bottom line ... if you can afford it ... pay it!!!!!:lol:

[wavelandscott]

I got the CR2 on both of my scopes...do take notice that the fine focus on the CR2 is the one that is set up to be butter smooth...I find the rough focus is a bit "clunky" on the CR2 but still lots better than my old R&P that was on the 8 inch and comparable to what I found with the JMI...

In hindsite, I am not sure if I needed the CR2...I only do visual stuff so the CR2 is probably a bit overkill...but, what they heck, it is only money!

Do make sure that you get the "spacer" measured right...not to make you nervous or anything but I did not do my measuring quite accurate enough and in the end needed the tube extension...it was "close" and with my GSO plossl eyepieces it worked fine but I found I needed just a bit more out travel on that scope for my TV gear...and then got the tube extension...repacing the JMI was no problem (low profile to low profile)...

Anyway, just make sure that you get your measurements right the first time...measure twice cut once...Good Luck!

The Moonlite "Red" looks really cool!

[togo54]

matt

I'm was having the same problems that you're having regarding inconsistant collimation with the crayford "style" focuser that came on my dob. I have found that moving the brass compression ring so that the screw actually makes contact with the eyepiece barrel has made collimation far more consistant. Of course this may eventually lead to scratches on the eyepiece barrels. I moved the compression ring on the 2" along with ring on the reducer. Worth a try. Hope this helps.
Tom

[matt]

Hi Tom

Nice to hear from you. Thanks for the suggestion.

When you say "moving" the brass compression rings, do you mean removing them altogether?????

That's not a bad suggestion. I'm not concerned at all about EP barrel scratches.

Is it easy to remove the compression rings?

Thanks

[RAJAH235]

matt, If you use a small screwdriver, you'll find that you can simply rotate/slide the comp. ring slightly so the screw comes thru the gap. Just push on the end of the ring. I would not take it out. Might leave too much play in focuser barrel. :D L.
ps. How much play/movement is there between the E/Pc & the focuser tube?
pps. Just a thought,, try diff E/Pcs as well. NOT all same 1.25"/2" diam..............:shrug:

[matt]

Thanks Rajah

Will have a look at your suggestion.

You know, this whole Crayford episode got me thinking last night (and I meant to post earlier) that while it's unfortunate we have the occasional disappointment or bad experience, there's also plenty of good experiences as well.

I know various dealers and individuals are often praised for their service and attention to detail.

So in that vein I'd like to hand out a few bouquets myself, to make sure I make the effort to focus also on the positive and do my bit to keep some "Karmic" balance in the Universe:lol:

Here's one for Dan at Frontier Optics. Your service and prompt replies to all my questions regarding the William Optics 2" Dielectric Diagonal was nothing short of first class. Your willingness to take the time to chat was very pleasing. It made me feel comfortable in spending the money, which I did, and the item in question looks fantastic and is eveything you said it would be.

To Steve Massey at myAstroShop. Same as above. I've had at least half a dozen conversations with Steve about a wide range of topics, all averaging about half an hour each. All of it very valuable. All of it has led to a number of purchases already and more to come, including a brand spanking new Celestron 9.25 - with a view to a new EQ6 and SynScan. Again, well done Steve.

And lastly, back to the Crayford, congrats Ron Newman at Moonlite. The same again. Plenty of questions all expertly and courteously handled. In two cases Ron replied within 5 minutes to my e-mails. Nuff said. There's $$$ heading your way too, Ron:)

Good old fashioned customer service and knowing your product. It's priceless, and I reckon worth whatever premium you're asked to pay on top of saving a few bucks from someone who's not got the time or interest in you and your needs as a client.

As a footnote, I reckon it'd be great if we gave out IIS awards (of some kind) for great service etc

Even if it were just some kind of voting system which led to an announcement or some sort acknowledging their effort and expertise. Yes, I know it's a commercial endorsement etc etc and you have to be careful :P etc etc

But isn't that akin to plain old word of mouth, like in "the good ol' days" when people in a community would all talk to each other and give each other "the good oil"??? That's how good businesses got what they deserve ie more trade, and not-so-good businesses missed out coz they weren't being spoken of at all.

Just a thought.

[togo54]

matt

Like Rajah said. Don't remove the brass ring. simply "push" it til the screw is within the gap.

[xrekcor]

I have often thought of swapping out the cheap R&P focuser on my scope
for one of thos GS Crayford focusers. The only thing stopping was the R&P
I have has two seperate adaptors one for 2" one for 1.25" extending the
focuser out by about 1.5" I dont see this extention on the GS Crayford
focuser. So if I wanted to swap I would need some sort of extention or
a re-tude and relocate the focuser. I would love a nice focuser it's not
easy focusing while imaging with a ton of weight on the focuser drawtude.
Also the R&P doesn't handle the weight of my XW's very well either.
But we live with what we have.

regards,CS

[matt]

That's right Rob

Or we do something about it. Horses for courses, I guess.

Comes down to attitude.

Much of the reason this thread has run so long was also about the service and info I received from the business which sold me the Crayford.

And that disappointment's not gonna change. I'm not angry, not bitter... not looking for an argument.

It was simply ... a disappointment from which I've learnt something and moved on.:)

[xrekcor]

I fully agree with your frastration. I think probably one of the first
things the vender should of asked was the height measurements
of your old R&P fully extended and least extended positions.

I guess I just wanted to chipped in and say why I haven't gone to the
Crayford, although I would love too. But because of the difference in height
I haven't. No argument intended.

regards,CS

[matt]

No offence taken, Rob.

As I'd indicated in a prior post, the vendor in question actually sells my scope, with the standard R&P focuser that I was looking to replace!

It turns out that the only check he'd carried out was that the mounting plate for the 8" OTA had holes for screws in the same place. He didn't check max and min racked height. Didn't check draw tube length and travel.

Just told me it was right to go and took my $$$.

Poor. Very poor. Sorry, but that's the only way to describe such a lack of care or attention to detail, or product knowledge.

He had all my components in front of him. OTA, R&P ... and the Crayford he was sending out.

How do you rate that?

[matt]

Anyway...

The good news is I've ordered a Moonlite CR2 from Ron Newman in the U.S who couldn't have been more helpful.

Sure, it costs a little more than the $149 generic Crayford, but not that much more for quality and peace of mind.

Should be a great upgrade. Now, to get back in touch with Bird about installing this temp monitoring system!!!!!:lol: :lol: :lol:

And then there's flocking .... adding drive motors .....