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200mm Skywatcher Dob remount


AstroAdam

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HI all,

Im dusting off my scope, and looking at getting my head seriously back into some observing and imaging. I'm looking at remounting my 200mm dob OTA onto an HEQ5 mount.

obviously I need the mount itself, but guessing I also need a set of the 236mm rings, and a bar thingy to attach them to. Would that be all?

Had a dob mount for years, and love it but now wanting to upgrade to something that I don't have to constantly nudge, nudge, nudge :), and the scope itself is great.

Any advice gratefully received!

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I've just done exactly the same thing. I have a 8" Dob but have just bought a HEQ5.

You need 236mm rings and a long dovetail bar. The only problem with it is the round things where handles screw in get in the way when rotating the tube for easy access to the eyepiece.

Wonder if they can be removed?

post-4880-135486928304_thumb.jpg

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You're making me jealous :)

As for the 'ears' as i call them, they can be taken off. There's only two bolt/nut combinations holding each one on if I remember rightly. Means they'd be easy to put back on if needs be too. It may be a mirror cell removal job to get at them though, unless you have exceptionally skinny arms to get down past the vanes holding the secondary, or a particularly long spanner!

need to do this now. ! How have you found it?

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I love the dob but was always into the imaging side more than observing. A few months ago I sold all my imaging gear including a HEQ5 Pro but recently started to regret it.

A couple of weeks ago I bought the SW 8" Dob (to give observing a chance) and started to make a list of imaging equipment I wanted to get back into it. Last week I picked up the HEQ5 from a member here who incidently I sold my old one too and thought I'd have a go at putting the Dob onto it. Bought some rings and dovetail and 2 nights ago was ther first and only time I've used this combo. The mount was flawless but I was standing on chairs in some funny positions to get to the eyepiece sometimes but the tracking of objects was a revelation over the nudging of the Dob.

I'll have a look at removing the "ears".....cheers.

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If removing the side bearings from the SW tube, the simplest way is to remove the primary mirror and cell as a unit, so you can get your arm up the tube with a spanner. You will have to recollimate the primary after refiiting, but provided the secondary was collimated before you start, you shouldn't have to touch the secondary adjustments.

This would be easier than removing the secondary and spider.

If it were me, I'd keep the dob bearings, just in case.

Regards, Ed.

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Right! It's done! I've got hold of a second-hand HEQ5, and have just ordered the Rings and Dovetail from FLO.

Can't wat to get started :)

I think I'll remove the 'ears' on mine as I want flexibility when positioning the EP. I can always put them back on if needed, but to be honest, it's unlikley to be going back on the Dob mount any time in the near future.

Will keep you posted how it all goes :)

Cheers,

Adam.

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Well!

It's done! And I've had my first night of having a go in the back garden. All I can say is WOW.

After the initial messing around with alignment (never used an EQ mount before :) ), I'm just blown away by GOTO. I've spent the last 20 years having to find stuff myself, and to be honest, I don't miss that!

I took the 'ears of my dob after all. It was very easy, (as it will be to put them back on if required). I didnt even have to take out the mirror cell - I just unscrewed the machine screws holding them in place, with the tube pointing downwards at an angle so the nuts and washers rolled out. Easy!

Makes positioning the eyepiece a lot easier, as they don't get in the way.

After all that - it looks like this....

IMG_2068.jpg
IMG_2069.jpg

One thing I'd definitely say is don't worry about removing those ears - unless you're going to definite use it as a dob still.

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Wow, nice setup! I've a dobson myself (150p version) and I was thinking to to the same, sad thing is it's a bit costly :(

Is it hard to attache the rings and dovetail bar to the tube itself? Care for a small tutorial maybe?

Second question, is it pratical to look through the eyepiece? Looks rather high so my guess is you have to stand on an elevated position?

Anyway, nice piece of equipment again, I'm jealous :D

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Thanks!

In answer to those questions...

Attaching the dovetail and rings to the tube is simple. The rings simply screw onto the dovetail, and then open up using thumbscrews to be placed around the tube and tightened up. The hardest part is taking off the dob bearings, which in this case are simply black plastic things held on by two machine screws with nuts inside the tube. Simply tilting the tube (with the mirror at the top so the nuts don't fall onto it), and undoing the screws causes the nuts to fall out of the tube, so you don;t even have to remove the mirror cell. Easy!

The dovetail attached looks like this :-

Dovetail

Nothing actually physically attached to the fabric of the tube.

As for the height.... yes it is high (an I am most definitely not!). However, I have a cunning plan that gets me up there...

Steps

A cheap set of steps - just £12 from Argos for those in the UK. Do the job admirably!

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Just to let everyone know.. I have been able to put my dobsonian on to my heq5 easily using 236mm rings and 33.5mm dovetail. Works like a charm and if u are imaging you don't need the steps or removal or the ears. Also,I have been able to get a cheap Asia webcam and connect it to the finder scope to work as a guide scope. On twosome clear nights for testing.

200p is the best DIYable OTA I have seen to date!!

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Just to let everyone know.. I have been able to put my dobsonian on to my heq5 easily using 236mm rings and 33.5mm dovetail. Works like a charm and if u are imaging you don't need the steps or removal or the ears. Also,I have been able to get a cheap Asia webcam and connect it to the finder scope to work as a guide scope. On twosome clear nights for testing.

200p is the best DIYable OTA I have seen to date!!

It's easy isn't it! I'm using mine for visual as much as imaging, so need as flexible as possible eyepiece positioning, hence the ear removal.

Great OTA though!

Sent from my iPad using Tapatalk HD

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Very interesting.... Glad some one has managed this. I was getting a little frustrated that my dob was not going to be useful for tracking.... Now just need to save for a mount and not a new scope !

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Just to let everyone know.. I have been able to put my dobsonian on to my heq5 easily using 236mm rings and 33.5mm dovetail. Works like a charm and if u are imaging you don't need the steps or removal or the ears. Also,I have been able to get a cheap Asia webcam and connect it to the finder scope to work as a guide scope. On twosome clear nights for testing.

200p is the best DIYable OTA I have seen to date!!

Could you post a link to the rings and dovetail that you bought..... Thanks.

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Just to let everyone know.. I have been able to put my dobsonian on to my heq5 easily using 236mm rings and 33.5mm dovetail. Works like a charm and if u are imaging you don't need the steps or removal or the ears. Also,I have been able to get a cheap Asia webcam and connect it to the finder scope to work as a guide scope. On twosome clear nights for testing.

200p is the best DIYable OTA I have seen to date!!

Does the webcam only work for,planets/ moon? As I have a webcam and I am unable to see 'live' images of the stars. Just wondering how all this finder scope/webcam works?

Thanks.

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Another question :). What's the difference (except price) between a heq5 and a eq5 mount? Thanks.

There's a massive difference in sturdiness. The EQ5 can only take 9kg whereas the HEQ5 can take up to 18kg.

The H, I believe, stands for 'heavy duty'. It's basically a cross between the EQ5 and the EQ6, and sits in between, size-wise. It's designed to be more sturdy than the EQ5 but more portable and lighter than the EQ6.

Sent from my iPad using Tapatalk HD

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  • 2 weeks later...

I'm actually in a similar position to some of you guys. I have a 200P dob and desperately want to get into imaging.

From what i've read it's not a great scope for imaging even on a heq5. Have you used it for this and do you have an opinion on it?

Honestly, this is such valuable information for me and will likely affect my next purchase so as much feedback and advice as you can give would be welcomed.

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adam - thanks for those links.

Questions

1. you say unguided, so do you mean your mount was static? or was it tracking in some way?

2. you have the skywatcher - which was originally on the Dob mount right?

3. Do you have any focus issues? i have read that some people have had to may an extension tube, or change the focuser on the scope?

thanks

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adam - thanks for those links.

Questions

1. you say unguided, so do you mean your mount was static? or was it tracking in some way?

2. you have the skywatcher - which was originally on the Dob mount right?

3. Do you have any focus issues? i have read that some people have had to may an extension tube, or change the focuser on the scope?

thanks

1) By unguided, I meant that i didn't use a guidescope to 'watch' a reference star and correct the movement of the main scope. The HEQ5 pro does, however, track - i.e. it moves to counter the rotation of the earth. A guidescope, via a guiding system and a guide camera, helps to correct errors in the mount's tracking by basically 'watching' a reference star via a second small scope attached to the side of the main one, and then finely nudging the main scope to correct any tracking errors.

2) Yup! Mine was originally a dob.

Have a look here for more a bit more info on my conversion to EQ...

3) No issues with focus. With Newtonians, the issue is more usually the other way, in that you can;t get the focuser to go 'in' enough to get focus. The focuser on the skyliner has a t-ring thread on it. you can unscrew the 1.25" focuser neck and that leaves a thread for you to attach a T-ring for your camera. Works marvellously! Unless they've changed the focuser in recent times (which I don't think they have), then it should still be the same.

If you need me to post photos, let me know!

Cheers,

Adam.

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