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Meade 5000 ED APO 80mm - focuser issues

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#1 Franky

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Posted 29 May 2009 - 04:13 AM

Its my third thread today, I feel I am getting quite annoying :crazy:

I am hopeless about my Meade 5000's focuser. My meade came with two speed focuser (wonder why, I've read many posts from people who got it with one-speed focuser)

On its bottom, there is a plate, which holds the focuser arms to the body. This plate bears the locking and tension screw.

When Meade arrived, I found a little allen screw at the bottom of the case! At the very bottom - under the foam!
I did not care, but then I tried the focuser. It was quite smooth, but it was clinging when focuser knob was turned. The sound was caused by the movement of the already mentioned plate.

Then I've noticed that there is a free hole between locking and tension screws. I took that allen screw found at the bottom of the case and it fit perfectly to the free hole.

Well, now the plate no longer clings. But the fucuser is "sticky". As you turn the knob it goes smooth and suddenly comes to place of higher resistance. The amount of resistance is irregular as well as the frequency of resistance spots. I tought, it is something that can be adjusted with the "tension" screw. But this screw has no effect! I can put it out completely or tighten it like mad, the tension and "stickyness" of the focuser is still the same. It actually did have some effect before I put that lost screw to the free hole. When the tension screw was loose (and the plate was clinging) the tension of focuser was lower. By tightening the tensions screw it actually pushed the plate down so it did not cling and the tension in focuser was higher. But should it work like this? Low tension = clinging plate? And what is that lost allen screw found at the bottom of case for? Why does it perfectly fit the hole in focuser plate, if its not supposed to be there?

And now for the locking screw. I do not understand why it is there! When it is loose, the turning of focuser knob causes the crayford tube to go in and out. When I try to move the tube by hand, it is quite rigid and will move only under stronger force. Then I tighten the locking screw. I can still turn the focusing knob, but this time, the tube does not move. "So this is how locking screw work", I tought. But then I tried to move the tube by hand and I needed considerable lower force to move it! So what is the locking good for? If I attach 1kg DSLR to focuser, it makes much more sense not to lock the focuser, as ironically, when unlocked it is more rigid and will need more force to move.

I have never had refractor and crayford focuser, so I am all so confused about this. So tu summarize:

1) Why would meade ship my refractor with screw left at the bottom of case, and even hidden under the foam?
2) Should I put that screw back to the bottom plate of focuser? Or should I leave that free hole free and let the plate "cling" as I turn the knobs?
3) Why does not the tension screw make any difference when I put the lost screw back to the plate?
4) Why is the focuser tube more rigid and firm when it is not locked and more easy to move when actually locked with locking screw?

I am sorry for the long post, but as you see, I have 3 problems with one naughty focuser. I hope someone will be able to help me, as I am quite frustrated :bawling: honestly, I have never had crayford focuser, so I do not really know whether the described issues are real problems or only my own unknowingness.

Thank you very much for any help,
wish you a beautiful day and clear nights,
Frank.

#2 sctchun

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Posted 29 May 2009 - 04:25 AM

Hi Frank,

Ok, I didn't know that now have double speed focuser, of course I have a fairly early copy of the scope. You are correct on the focuser lock in the sense that it sort of disengages the focus knobs. But to prevent the tube from sliding when you lock the focuser is that you need to tighten down the tension screw.

A easy way to test this is attach your DSLR and have your scope pointed straight up (Of course you may want to do this with some padding below the camera just in case). You'll know when you have enough tension when if you try to lift the camera, it will go up. If it doesn't then you need to increase it.

The Meade is a great scope, I would suggest you may want to get a flattener for it if you are planning to do some imaging with it. The Astro Tech one doesn't add any reduction (Especially since the scope is already fairly fast to begin with).

Steven

#3 Franky

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Posted 29 May 2009 - 04:34 AM

Thank you for help Steven. I'll try to play with locking/tension setting when I come home.

As for the screw found at the bottom of the case, does your Meade have any small allen screw between locking and tension screws?

And, is the plate bearing the locking and tension screws supposed to "cling" when moving with focused knobs? As I've said, if the "lost" screw is not mounted in, the plate clings as it moves.

And most importantly, do you have any idea why the focuser is "sticky" and not smooth when I return this lost screw to the plate? I've tried many combinations of tension setting, but when that screw is in, nothing changes....

Thank you once again for your great help,
Frank.

#4 Starlighter

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Posted 29 May 2009 - 10:48 AM

Mine as well as all those sold in the US all have single-speed Crayford focusers. In fact, I ask Meade if there's a retrofit kit so I could upgrade mine. The answer was no.

It's a bit tricky getting the tension screw adjusted to where there's enough tension to keep the drawtube from sliding down when using a heaving eyepiece when the scope is pointed towards zenith. I find that if I'm using the heaviest eyepiece I own which is the two pound 41mm Panoptic and adjust it so that eyepiece remains in place, when I go to use other, far less heavy eyepieces, there's now too much tension. The focuser knob becomes too stiff so I have to back off a little on the tension. Underneath, there are two screws, one for tension and the other to lock the focuser. If I'm using an AZ mount where I slew the scope by pushing the diagonal, I find this lock screw really comes in handy.

Bottom line is, it takes a little playing with, but after a while I got to where I can pretty much know how many turns to use on the tension screw to get it to work properly. That said, this is not the smoothest focuser around. It does have a bit of stiction even when the tension screw is all the way out. But that hasn't stopped me from getting the image in perfect focus.

It's a terrific little scope that provides exceptional wide views of the heavens. I've got quite a few telescopes, but I'll always keep this one. Its build quality is great. A very solid scope. The dew shield never slides down when the scope is pointed up. The baffles work very well reducing stray light from ruining the view. All-in-all, a wonderful scope.

#5 Franky

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Posted 29 May 2009 - 12:04 PM

>> All-in-all, a wonderful scope
All I can is agree on what you've said. BTW, I was tremendously surprised that I could see Saturn's rings with this little beast. I thought that I'll need a larger scope for that. When I saw it in the eyepiece I nearly jumped over the neighbor's fence :-)

HOWEVER, no one has so far answered one of my questions. As I've said, when I unpacked the scope I found a little Allen screw under the foam in the aluminum carrying case. When I was using the focuser knobs, the plate under the locking and tension screws was moving and of course making "cling-cling" sound as it repeatedly hit the body of focuser (see attached image).

Then I took the found screw and placed it in an empty thread between locking and tension screws (see attached image). Ever since then, the plate under screws is not making sounds as it is fastened to focuser's body by the found allen screw. However, after this step, the focusing mechanism became sticky, putting irregular resistance to my hand. Furthermore, after fastening this screw the tension adjustment has NO effect at all. Without this screw all is working well but the plate under screws is moving and making sounds....

So the question is. Should the screw be there or not? I do not understand why it was hidden under the foam. As I've said, I have never had (or seen) crayford focuser before, so I don't know if the screw should or should not be there. Whats better? "Cling-cling" sound but good focusing or no "cling-cling" and worse focusing? :help: Maybe the plate under the screws is supposed to be loose and maybe it is the way how the tension is physically adjusted. I really do not know how crayford's work. Should the plate move? Should the found screw be there or not?

Also, Starlighter, I see you've got CG-4. I'm thinking about getting one for this Meade. Can you recommend it? Is it sturdy enough?

Thank you so much for your help,
Frank.

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#6 Starlighter

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Posted 29 May 2009 - 12:19 PM

Well, as you can see from the photo, my Meade with its single-speed looks entirely different. With your scope it appears the two-speed knobs are held in place by a bracket. It also looks like that screw hold the bracket in place. Not having it in front of me, it's hard to really understand the function of that small screw.

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#7 Franky

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Posted 29 May 2009 - 12:47 PM

Thanks for the picture. Now I see that I'll have to find someone with double speed focuser which is not going to be an easy task.

But I am happy that you're happy with your scope :jump:

If you know about anyone who has double speed focuser on his Meade 5000, please let me know. I'll be happy to have someone to consult this issue with.

Thank you very much for your help :bow:
Frank.

#8 Starlighter

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Posted 29 May 2009 - 01:51 PM

For what it's worth, the 127mm APO triplet uses the very same two-speed so perhaps someone owning it under the Astro Tech name or Meade can chime in. And the new Explore Scientific EDs use the same two-speed Crayford.

My best guess is that allen screw holds the plate to the bottom of the focuser. Perhaps if you slightly back it out a few turns, it might alleviate the sticky feeling you've noticed. That said, this model with the single speed does exhibit a tad bit of stiction. Mine is that was as are every single demo I've fooled with on display at local scope stores. The stock Crayford focuser is nowhere near as smooth as say a Feathertouch or a Moonlite.

#9 Franky

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Posted 29 May 2009 - 04:59 PM

My best guess is that allen screw holds the plate to the bottom of the focuser.


Right, I am almost 100% sure that the screw should be there to hold the plate in place. However the unexpected drop in focusing quality puzzled me a lot so I've started this investigation to the "should/should not use that bloody screw" topic. :thinking:

Perhaps if you slightly back it out a few turns, it might alleviate the sticky feeling you've noticed.


Yes, I've tried that. The smoothnes of the focuser increased and the "cling-cling" started to spread aroud the room once again :gottahurt: in other words, it makes almost no difference when the screw is slightly tighten or not in place at all. Without the screw the plate will not fall off, as it is held by the locking and tension screws.

Moreover, I am starting to believe that the plate should be moving and doing its "cling-cling". When the screw is not there and plate is moving a lot, focuser is really smooth and soft. Then, when I tighten the tension screw a little, the plate has less room for movement and focuser has more tension in it. When I tighten the screw completely, the plate has no room for movement and stops "cling-cling" (just like when I tighten the small allen screw). In that case the tension in focuser is quite high. Could it be that this is how this crayfor should actually work?

This teory holds in every aspect but one - what was that bloody allen screw doing in the carrying case with the scope? :looney: Plus, the free hole where I eventually threaded the screw WAS actually bearing hints saying that the screw was there before! (little scratched circle around the hole, just in the size of allen's head) :foreheadslap:.

This case is a real mistery for me. Everything says that the screw should be there, but in same time, all evidence say that the focuser works best without it. :lol:

I am looking forward to hering some more opinions about this misterious hidden-in-carrying-case allen screw :)

:thanx: Frank.

#10 Gary Honis

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Posted 30 May 2009 - 10:57 PM

Frank,

I own the 127mm Astro-Tech Triplet which is the same as the Meade 127mm and has a dual speed focuser, most likley the same as yours. I bought the scope as a demo with the understanding that it had a broken focuser. I dissasembled and re-assembled the focuser after I bought it, and it has been working well since. I suggest you take yours apart. The photo below shows all of the parts when I took my focuser apart. There's really not that much to it and you will better understand your focuser's operation. I don't know if you have a warranty on the scope....keep in mind that you may void it. Pollux Chung has a good online procedure for working on generic Chinese focusers here:

http://www.backyardv...gsofocuser.html

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#11 Starlighter

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Posted 31 May 2009 - 12:34 AM

It would sure be nice if Meade offered what's in the photo as an upgrade kit for the single-speed versions. I'd buy one.

#12 Franky

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Posted 31 May 2009 - 03:05 AM

Gary, thank you for great link! Well, I do not want to void my warranty, but this link might come handy in 1-2 year's time when I'll have to regrease the focuser. Thank you very much, in deed!

Frank.

#13 Mike Cook

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Posted 31 May 2009 - 12:31 PM

I wouldn't mind this 2 speed focuser on my Meade 80mm triplet as well. Looks a bit like some holes and screws are in different places compared to the single speed Meade unit.

Mike

#14 Franky

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Posted 31 May 2009 - 12:47 PM

Hello Mike,
from what I've heard the single speed focuser on this Meade product is smoother than its double speed sibling.

I do not remember who wrote it, but they claimed that they'd rather have single speed focuser which is smooth than worse quality double speed focuser.

But I am only referring to what I've heard, I do not have personal experience with the single speed focuser.

Wish you all the best ;)
Frank.

#15 Mike Cook

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Posted 31 May 2009 - 01:09 PM

Thanks for the hello there Frank. Mine is pretty smooth though there's a bit of 'grippiness' when first turning the focuser but otherwise I do like it very much and it is smooth through the range of min to maximum. I just never seen a Meade 80mm triplet with the 2 speed on it yet until your post. I know you'll like the viewing through the little Meade though!
Cheers, Mike

#16 Starlighter

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Posted 31 May 2009 - 01:21 PM

Hello Mike,
from what I've heard the single speed focuser on this Meade product is smoother than its double speed sibling.

I do not remember who wrote it, but they claimed that they'd rather have single speed focuser which is smooth than worse quality double speed focuser.

But I am only referring to what I've heard, I do not have personal experience with the single speed focuser.

Wish you all the best ;)
Frank.


The new Explore Scientific 80mm triplet uses the same two-speed as the one on your scope. In fact, all these 80 to 127mm triplets (Meade, ES, Astro Tech) come out of the same factory in Kunming, China. They'll sold in the Orient under the Maxvision label.

I've operated the two-speed on the Explore Scientific 80mm triplet and to me it seemed much smoother than my single-speed Crayford on my Meade.

There seems to be a problem with the consistency of quality with these Chinese-made two-speed Crayfords. I've tried quite a few in scope showrooms and with some I've found they tend to feel either very smooth, have a spot where they seem to become rough, or are stiff as a board and that's with the tension adjustment all the way out. Some companies such a SkyWatcher seem to have better quality two-speeds.

#17 Franky

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Posted 31 May 2009 - 02:34 PM

I think that the varying quality due to operations in China is problem of many brands. Take Celestron for instance. I've had their CG5 mount which has quite positive reviews across the Internet. When I've received mine it was pure catastrophe and I've sent it back to my dealer. But then again, it was about the particular unit that reached my desk...

Thats why its best when you can shop in local store. You can touch anything you buy. And that's an advantage. Astronomy shops in my country are extremely rare, and if you find some, they have few things in stock :bawling:

So I usually order everything via Internet from abroad. I envy those guys from USA, who come and say "I went to local astronomy store and after one hour of playing and trying I've picked a great piece of equipment". All I can do is order via the Internet and hope for the best :(

#18 Starlighter

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Posted 31 May 2009 - 05:51 PM

I know what you mean. But sometimes having a shop locally doesn't mean things aren't screwed up.

Back when I purchased my Meade 80mm triplet, I did so at OPT. They're about a 145 mile roundtrip from my home. The deal here was, I was going to exchange a Meade My Sky unit I bought new from OPT for the Meade triplet plus pay the difference in cost. It was that or end up with store credit and I would have still needed to exchange it for a new one at Meade. So in order to do this I had to take the defective My Sky, drive to Meade which was 3/4ths of the way to OPT, exchange it for a new one and then drive to OPT to exchange that one for the scope. When I did the first part, the people at Meade in Irvine were great. It seems that just about every My Sky ended up being defective due to a software glitch that occurred with the change of the year. I called ahead and was told by Meade it was no problem. They exchanged it for a new one. When I got to OPT and the salesman went into their stock to get me the scope, when we opened the outer box, I noticed the case was seriously dented. As luck would have it, that was the last one OPT had in stock. It appeared the scope was not damaged. The dent seemed to have been caused during the construction of the case since it was from the inside out and was done before the foam was inserted and glued into place. So the salesman called Meade in Irvine and they agreed to exchange the dented case for a brand new one. So on the way back, I once again stopped at Meade. A lot of driving that day. But had I just purchased it by having OPT ship it to me, I'd have still been forced to return the case to Meade for an exchange. That or wait until OPT got another scope in stock and that could have been a few weeks. I guess I was lucky that Meade as well as OPT were within what is still a reasonable driving distance.

Now I try to buy most major items for this hobby face-to-face. In that regard I'm once again lucky since besides OPT I have both Scope City and Woodland Hills Camera fairly close by. The last purchase I made using a shipper was my Orion AZ mount and you should have seen the outer box when it arrived. Looked like a bunch of gorillas were using it as a toy. Fortunately for me, the mount was undamaged.

#19 ken svp120

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Posted 01 June 2009 - 07:04 AM

Unless the screw at the bottom of the box was an extra that just happened to be there at the time of shipping, I would say its very disappointing that your scope would arrive with loose parts.

As for whether or not it belongs where you think it does, I would either contact Meade and ask them, or see if you can find a diagram of your focuser assembly on the internet. It seems unusual that your focuser would not work as well once you put the screw in place...

Or you could send the scope back and get another one. This would be my approach because when I pay for something I expect to receive it fully assembled and functional unless it states otherwise up front.

Good luck.

#20 meademods

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Posted 30 November 2012 - 12:40 PM

Keep in mind that the meade 127mm apo focuser might be the same as far as the parts But! It is not the same as the 80mm focuser. The 80mm focuser is a solid inclosed and does not come apart in the same manner. The loose screw you found in the case does go where you but it. Sounds like it wasent accembled right and I would send it back for a replacement one. The only correct way to fix it is to replace it with anouther 2 speed craford like you said Moonlight exc: If you keep it I would add 2 more set screws to hold the diaganl in place more scurely for bigger 2" eyepieces That's what I did to mine best thing I ever did no more worry about the diagnal slipping out. That's my 2 cents worth. FYI I also repair and up grade meade lx200 gps telescopes as well.

#21 meademods

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Posted 30 November 2012 - 01:14 PM

I found a web sight for replacement parts for a 2 speed. http://agenaastro.co...pgrade-kit.html

garry

#22 kevint1

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Posted 30 November 2012 - 01:51 PM

Have you checked to make sure the knobs aren't rubbing against the focuser housing? I had the large knob on the right side rubbing on my ES 102 and it caused binding in one area as the knob was turned. Loosening the knob and pulling it away from the housing a little cleared it up.






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