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Meade 6000 Series 70mm APO - Focus Jammed/Stuck

ZWO ASI183MM Pro Equipment Focuser Troubleshooting
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Sean Richardson avatar
Sean Richardson avatar
So I am still very new to imaging. I have been using a dslr for about a year and just got my ZWO ASI183mm pro a few weeks back. I took it out last week for the first time and got everything up and running with no issues. Last night was finally crystal clear so I was hoping to get many hours of data on my first target. While I have had many software issues in the past that I've had to learn on the go I have never had a mechanical problem with my scope or any other gear... until last night.

So I got everything set up as usual with no problems but when I go to focus on a bright star I noticed my focuser was jammed. I am only able to turn the focus knob about a half a turn before the tube stops and seems restricted and I don't want to force it. The focus tube only comes out about a quarter to half inch before it stops and I know it has a lot more room than that! I just don't understand it was perfectly fine last week and then it went right back into it's hard case until I took it out again last night. The scope did not fall or get bumped on anything at all. The only thing that was done differently was that I left everything attached to the scope (camera, wheel) when it was stored but I don't see that being the issue at all, it was very snug in a foam hard case. I have included a photo that shows just how little the focus tube is able to come out.

I don't know if I am explaining this very well either. I don't know exactly what these components are called and I can't seem to find much help online. Of course my luck it's been cloudy for a month and now nothing but clear skies for the next week, I can't win!
Any help would be much appreciated thank you!
Engaging
andrea tasselli avatar
andrea tasselli avatar
Are you sure I didn't lock down the focuser accidentally?
Sean Richardson avatar
Sean Richardson avatar
I wish it was something that simple but I don't think that's it. I made sure the screw to lock down the focuser was not tightened and I am still experiencing the issue.
Well Written
Roy Hagen avatar
Roy Hagen avatar
Can you unscrew the pinion from the focuser to inspect the gears, the teeths in the rack and the pinion gear?
Then you can carefully pull the focuser tube in and out to see if something is jamming the tube.
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Sean Richardson avatar
Sean Richardson avatar
Roy Hagen:
Can you unscrew the pinion from the focuser to inspect the gears, the teeths in the rack and the pinion gear?
Then you can carefully pull the focuser tube in and out to see if something is jamming the tube.

Thanks Roy, correct me if I am wrong though. The teeth you are referring to, they are located on the gear on the bottom side of the focuser correct? I have included a few more photos of my scope. I have a feeling my focuser is not as easy to access as other rack and pinion setups, it just looks very different to me. Then again I could be very wrong, I am a newbie. It looks like it's all part of the scope. I don't see teeth, only threads where I can see the tube and it doesn't appear to be hitting anything that I can see.
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Roy Hagen avatar
Roy Hagen avatar
The focuser is a so called rack and pinion focuser.
The pinion is the shaft that the knob is fitted to and in the middle of this shaft/pinion you will find a little toothwheel/gear that moves the focuser tube in and out by pulling the rack. The rack is a flat bar with similar tooths, like the round gear in the middle of the pinion shaft
You can see the rack in the middle of your pictures, the brass thing in the square hole.

My William Optics focuser allows me to unscrew two bolts and lift the pinion with the housing straight off, but it is possible that your Meade focuser has a different design and the pinion has to be pulled out sideways.
It is possible to unscrew the set screws and one of the knobs, with an allen key to see if something is possible to move sideways.
Do not try to losen the knob with gear. 
Maybe Meade can provide you with some instructions?
Work on a smooth table ansdtake pictures of everything in every position if you decide to dismantle the focuser.


.
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Sean Richardson avatar
Sean Richardson avatar
Roy Hagen:
Maybe Meade can provide you with some instructions?


Thanks again for the info and quick reply Roy. I have sent Meade an email but I will have to wait until Monday for a reply unfortunately. As much as I want to try and fix it and get out shooting tonight, I think waiting is my best option. The scope is also less than a year old so if anything is wrong I think it's covered at least. Just sucks watching these clear nights come and go
Roy Hagen avatar
Roy Hagen avatar
That sounds like a smart decision, Sean, and I can relate to your frustration.
Best of luck

Roy
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Adel Kildeev avatar
Adel Kildeev avatar
Sorry to hear, Sean. I do have the similar scope, Meade 80 APO triplet, never had any problem with the focuser, very robust and reliable. But I would agree with you that it is better to wait for the Meade’s reply, your scope is still under warranty. Messing up with fine adjustments could be unwise. Good luck and clear skies!
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Sean Richardson avatar
Sean Richardson avatar
Adel Kildeev:
Sorry to hear, Sean. I do have the similar scope, Meade 80 APO triplet, never had any problem with the focuser, very robust and reliable. But I would agree with you that it is better to wait for the Meade’s reply, your scope is still under warranty. Messing up with fine adjustments could be unwise. Good luck and clear skies!

Thank you very much Adel. I have the worst patience ever but I will be waiting for Meade's reply. I have had this scope since January and I agree, it seemed very reliable. So when this happened I was really at a loss. I hope it's just a simple fix that gets me back up and shooting!
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Adel Kildeev avatar
Adel Kildeev avatar
Any reply from Meade, Sean? Did they instruct you on the fix?
Sean Richardson avatar
Sean Richardson avatar
Adel Kildeev:
Any reply from Meade, Sean? Did they instruct you on the fix?

They finally got back to me on Friday. After going back and forth all day they left me hanging over the weekend again. 

This was the initial reply
1. Confirm there is no debris on the bottom of the focuser rack mechanism. If there is debris on the gear, it can prevent full travel of the focuser drawtube. 
2. Loosen the bottom focuser lock screw completely and see if the problem persists. 
3. If none of the above works, you can unthread the entire focuser from the OTA and check the focus travel. With the focuser removed from the OTA, it will be easier to see if anything inside the focuser assembly preventing the travel or out of alignment. 
4. There are two button cap screws on the top center of the focuser body. You can remover one of the screws at a time to confirm if the plate below the screws looks out of alignment. There are screw holes on the plate that need to be in alignment with the focuser button cap screw holes. 

I have done all of this with no luck. The only thing I can't do is check the gear for debris, I have no idea how to access it on this focuser setup.
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