DM6 Encoder upgrade project

[+Bino-viewer]

Its not too often i post on here, as my own DIY skills are somewhat limited.

But i've been planning what i hope is a relatively straightforward upgrade to my manual alt az mount.

 

A bit of background. About 4 years ago now, i purchased an easy to use, and beautifully engineered

alt-azimuth telescope mount from a US company : Diskmounts, based in Florida, USA.

 

Its performed beautifully and exceeded most of my expectations. It will comfortably work with a 5 or 6 inch

class refractor or upto 11" SCT type scopes. Its simple to use and works simply by using adjustable friction

on each of the 2 axis. Once correctly adjusted you can even change eyepieces without it losing balance.

Many consider it the finest alt-azimuth mount of its type available.

 

 

When i ordered it, i opted to have encoders fitted to each axis, and purchased the 'Sky Commander' DSC

(Digital setting circle) to go with it. 

This is the only thing i found at fault with my mount.

The Sky Commander is rather dated in its design, and i found the interface rather clunky and unintuitive to use.

The fitted encoders were selected to work with the Sky Commander, and are of the 4096 click type.

In short, i felt when an alternative, more modern DSC came along, i would upgrade to it.

I responded to a 'wanted' Sky Commander ad on the US 'Cloudy nights' astro forum, and promptly sold it and sent it on

its way back across the Atlantic.

 

Fast forward 2 years to spring 2017.

The DSC that i'd wished for comes along ! ?

The Nexus DSC

Its made by an Australian company : Astro Devices.

It ticks every single box.

It has a big display, is easy to set up and navigate, and will interface with modern wireless astronomy planetarium applications

such as the one i use, Sky Safari +

 

 

When it arrived i simply fitted the Nexus to the top of my mount, and plugged it in and set it up.

Everything was nearly as i'd wanted it to be, except when i entered an object, and manually slewed to it, i found out 

that the object was just outside the field of view whenever i used high, or even medium power eyepieces.

A little annoying, but it was something i just put up with, and with a little hunting around the close vicinity, i soon

found what i was looking for.

But the perfectionist in me wants high accuracy and the object right there in the field of view.

 

There is a separate issue here, and that is whether or not my set up is orthogonal ?

That is, is everything set up squarely, and things like the tube rings connection to the dovetail plate, and the dovetail plates connection

to the mount saddle needs to be correctly in line : orthogonal. There is actually a set up routine on the Discmount website which covers this

in detail. I've read it, and it advises the use of shims to make minute adjustments, which is a little out of my comfort zone, and although i made 

some adjustments, it doesn't seem to have made a difference.

I also believed, that as i was using well made rings, and a quality D type Losmandy dovetail, and Discmounts own substantial saddle plate,

that things should already be orthogonal ? Maybe i was wrong ?

 

So on to the nitty gritty of this post.

Astro Devices have recently introduced their own very high accuracy encoders, which are specifically designed to work with the Nexus.

And the best bit is they do a version especially for the Discmount DM4 and DM6.

 

Like most things in this hobby they are a little pricy, but if i'm to get the most out of the Nexus, i think its definitely a worthwhile upgrade.

Quite a chunk of the cost was the shipping and duty i'll have to pay from Australia.

But i've ordered them this evening (Wednesday 14 November) I've never ordered astro gear from as far away as Australia before ;

it will be interesting to see how long they take to arrive.

 

It should be a simple job to swap the encoders over, even for me ! ? What could possibly go wrong ???

When they arrive i will continue with this thread. Thankfully there is an excellent in depth  installation guide on the 

Astro Devices website.

 

Here below, is a picture of the inside of my DM6, showing the present encoders,

and an image of the new upgraded encoders on their way from the land down under.

 

 

Links

 

Discmounts USA

http://www.discmounts.com

 

Astro Devices, Australia

http://www.astrodevices.com/index.html

 

 

Edited November 14, 2018 by Bino-viewer

[Tweedledee]

Good luck with that Rob. Hopefully you will have no problems and the Aussie gear will solve your problem. ?

 

I've purchased astro tackle from Australia in the past and have been pleasantly surprised by the delivery times being sooner than predicted.

 

I have purchased astro gear from all around the world, and now have complete confidence in doing this, and have been very pleased with delivery times, though Chinese stuff has mostly arrived via the slow boat, and on odd occasions not arrived at all resulting in a refund.

Edited November 14, 2018 by Tweedledee

[BAZ]

I can understand your frustration that you have paid all that good money out and then find that it still doesn't work. Good luck with the mod and I hope it gives you the accuracy that it claims.

[Doc]

Fingers crossed for you Rob.

 

I found with my DIY DM6 mount the accuracy is not very good if the mount isn't level. In fact it can be a few degrees off if it is out of kilt.

[+Bino-viewer]

Thanks all.

 

Mick : i would have assumed with an alt-az set up it should make no difference if the mount is not level.

I try and keep the DM6 fairly level to my eye, but thats only because of its design with a heavy scope mounted 

on its side so to speak. But i bet with me its never bang on, and i never get a spirit level out or anything.

 

Even with the Panther, you don't need to level it at all.

 

Btw, the service i have had so far from Astro Devices has been outstanding.

I can't recommend them enough.

 

Serge (The man in charge) is even looking into getting me a set of encoders for my OO Dobsonian.

That can be another DIY / Self Mod post for the future.

[+Streetbob]

Looking forward to hearing how it all turns out.

[Doc]

That's what I have thought as well, but when I set up at home I can get 90% of my objects within the FOV as my observing patio is perfectly level, but when I set up at Belper for example and it's on a little slope my scope is never as accurate. If I do take time to level then it's a lot better so I always level now.

[+Bino-viewer]

Progress update on my new encoder project.

 

I've been in regular touch with Serge Antonov, who runs 'Astro Devices' out of Sydney, Australia

and have even spoken with him on a couple of occasions, when after placing my initial order,

he actually rang me up to discuss a few things. Hows that for customer service ??

 

My DM6 encoders are still in Australia, while Serge custom builds me another set for my 12" OO Dobsonian,

and sooner than have two separate orders, and two lots of shipping etc, he's putting everything together into a single order.

 

I think its pretty amazing that he's gone to the trouble to alter the Dobsonian encoder kits they already produce for

other scopes like the Meade Lightbridge / Starfinders and the GSO Dobsonian range  to then work with the

Orion Optics dobsonian mount which is quite a bit different.

 

Heres some pictures below of the modified altitude encoder that Serge has made for my scope.

The other encoder for the azimuth axis is pretty much the same as for the other scopes.

 

The installation of these Dob encoders will be a challenge for me, but i have a good friend who is 

an aero engine fitter at Rolls Royce, so help is there if i need it.

I will continue the DM6 upgrade thread when the kit arrives (probably early in the new year)

and start a new one for the Dob, as i have a few other mods in mind as well for that scope.

 

 

Edited December 20, 2018 by Bino-viewer

[BAZ]

It looks quality gear Rob, I'll be following with interest.

[+Streetbob]

I have an 8” OO Dob mount so I am interested to see how well they turn out. Keep us posted.

[Tweedledee]

Only just caught up with this thread Rob. ?

 

I will follow your progress with great interest. Nice to see you are getting some personal service from this guy, and all the way from Australia. ?

 

It is about time these sort of encoder systems became easier to retro fit to all manner of different scopes, since we are now well into the 21st century!

[+Bino-viewer]

Time to finish off this upgrade thread to my DM6 alt-az mount......

The encoders arrived safe and sound in only 4 and a bit days, all the way from Sydney, Australia.

Thats pretty good going i think.

Serge, who runs Astro Devices even gave me a call to check if i'd received them ok.

 

Here they are

 

 

Fitting them was simplicity itself.

First thing was to remove the large friction nuts and washers.

The old encoders are then removed. They attach to each axis via a small pin, which sits in each screw shaft and are held securely by a grub screw.

Then everything is given a good clean.

 

 

Using a supplied centring adapter, the new encoder is carefully installed, on to the azimuth axis,  and held securely down by a supplied adhesive strip.

Before i did this, it advises you plug in the cable to the encoder, as space is a bit tight and i was glad i did.

The washer and nut then go back on and are hand tightened up.

 

 

The encoder pin is then added, and tightened in with its grub screw.

It advises a 12mm pin height.

 

 

The encoder wheel then installed, which just pushes down on to the shaft.

and the whole process is then repeated for the altitude axis.

A cable clip is then attached and the pair of cables are then fed through the top mount cover to the DSC computer.

 

 

I opted for the Astro devices custom made shelf, which attaches to a small, simple ball head mount.

 

 

 

The Nexus DSC then fits securely on to the shelf, and the encoder cable plugs in.

I then fired up the Nexus, and updated the new settings for the new encoders.

All done !! ?

A simple, easy job all in all, and i wish all mods were as easy.

I'm pretty pleased so far, and quite proud of the fact i own one of these mounts.

I suspect i'm one of only a handful of others in the UK who do. An investment really.

Mine is DM6 mount number 357, so there are a good few around, but most are probably in the US.

I've certainly not regretted buying it. Its a beautifully designed and built mount in every way.

 

I've done a quick power up and test in the garage, and all seems to be working ok.

A bit of fine tuning and testing will follow in due course, but here i have a small problem.

I don't have a telescope....apart from my Dobsonian !!!  I sold them all ?

A new scope will be coming soon though. When it is ready.

 

My next job will be to turn my attention to my Orion Optics Dobsonian.

I have a set of encoders to fit to that scope too and that will be my next 'mod job' which i will start in a new posting.

 

Thankyou for reading ?

 

 

Edited January 7, 2019 by Bino-viewer

[philjay]

Very neat Rob

[BAZ]

Nicely done Rob, it looks the business mate.

[+Graham]

That looks great.

Where did you get your encoders for the dob.

Going to need a set myself soon

[+Bino-viewer]

Thanks Graham.

 

They were supplied (as was the DSC Nexus computer) by 'Astro Devices' based in Sydney, Australia.

 

http://www.astrodevices.com/index.html

 

The chap who runs the company, Serge Antonov, went out of his way to modify their existing sets

to work with my OO Dob mount.

 

It depends on what your plans for your scope are...?

As an imager, you will be putting together a good GEM to cope with your imaging demands...?

Unless its a computerised go-to set up, i assume you want a 'push to' setup with encoders to 

locate objects before your tracking motors do their thing ?

 

If you do that, you will need a DSC to work with them ??

I'm sure Serge could advise you, but the stuff they do is really designed to work with the

regular Dobsonian mounts you see ie from Meade, Skywatcher, GSO etc.

 

Another company that supply encoders are US Digital.

 

https://www.usdigital.com/products/encoders?gclid=EAIaIQobChMIvuWzl-Lc3wIV6LDtCh23zgFMEAAYASAAEgImz_D_BwE

 

Like i say, it all depends on the set up you have planned.

 

Considering everything, have you discounted simply buying a used EQ-8 ? 50Kg payload capacity i think ?

They do come up used from time to time, and perhaps that would be an easier option.

 

[+Graham]

Thanks Rob. 

The mount will be a fully  computerised goto running eqmod. 

Although the eq8 is a great mount at 50kgs it is not large enough. 

My mirror and cell will come close to that on their own. 

I have all the bits I need to make an eq. 

The drives I will recycle from the old fork mount.

I want to fit encoders to improve the accuracy. 

Thanks I will give that site a look. 

[Tweedledee]

Very nice Rob. ?

 

Looking forward to hearing more on this when you get your new scope.