Another beautiful old mount, likely an R Miller design?

[VaguelyAmused]

Hi All,

With a risk of similar threads being started, I have an old mount that we (my Dad, mainly, and I) aquired many many years ago. At the time we retrofitted (in a way that could be removed) a Sitech Servo system - this was fairly bleeding edge at the time, and we worked to test/develop the Sitech Servo board and software with Dan Gray and Mel Bartels. This unfortunately failed recently and has been replaced by an OnStep system which is actually excellent.

We have never really known the history to the mount. When we first got it, we saw similarities to it and the AP900/1200 range and a bit of reading started to paint a legend in the form of Rob Miller, who seems to have had his hand in a lot of the class leading mounts we drool over. 

Later, we found the Astro Promotions PM1 information/discussion forum and we are pretty sure it is indeed a Rob Miller design, and based on some recent posts perhaps also a collaboration with Peter Drew, both names I would be thrilled to have associated with this mounts design. A recent post by yuklop including the pictures of their mount, and they look almost identical. 

She is a real beast, with a 9" 180:1 brass RA wheel and a 6" 180:1 brass DEC wheel and came with 34KG of counterweights. Absolutely lovely, oozes quality and has been superb. 

It would be great to know a little more about it, it seems quite refined to be a prototype, but equally, its much much bigger than the PM1 so could have been a custom/commission back in the day? There may be more out there than I realise, and I hope Rob knows they are all still going strong and being loved.

Kind thanks
Chris

PS: The Observatory Build is covered in a recent thread "Nerd Shed Observatory Introduction"

 

[Paul M]

That's some mount. I don't know OnStep, do you still use PHD2 or such like for guiding or is it a bespoke ,self contained system? What guiding accuracy do you get?

[VaguelyAmused]

Thanks Paul,

OnStep is an interesting project. It is (IMHO) slightly inaccessible just due to the number of different variants, generally centred around which board design you decide to use but well supported and there is forum support. There are, I believe, kits you can buy which come with the majority of the components including the PCB but you can go your own way too. I chose the "STM32 Blue Pill" variant as it was one of the best described and documented however for the price difference, I would probably recommend the MaxPCB version and a Teensy 3.6 at the moment, also because chip shortages mean getting an STM32 development board can be tricky.

It is quite remarkable how feature rich it is, I am very impressed. It uses a mini wireless dev board to host a wireless server, acting either as its own access point, or connected to an existing wireless network. An ASCOM driver is then used to allow control from pretty much any program if you are so inclined. Alternatively, the Android application can be used to control it, including alignment, sync, goto's via an inbuilt catalog etc. Finally there is a handpad you can build (with a little OLED display!) that can do all the same as the android app and that can either be a wired or wireless handpad.

I've had it connected to Stellarium for point and click Gotos (though will be moving away from Stellarium I think due to its crazy CPU usage on my little i5 NUC). PHD works very well with it and on the first night with a "that will do" polar alignment and no fine tuning I was getting +- 1 arcsecond accuracy, I honestly can't remember what I was getting with the Vixen GP but I don't remember it being as good, or as easy. I've attached a PHD graph (sort of, its N.I.N.As display of the PHD data, scale is in arcseconds). I think it will do better when I spend time properly polar aligning it.

Cheers

 

 

 

[F15Rules]

That's a stonking mount Chris!! I only realised it's real size when I saw it next to your Vixen!

Peter Drew is a regular visitor to SGL, so I hope he will see this thread and chip on with anything he knows about your mount 👍.

Thanks for sharing,

Dave

[Stu]

Mount looks amazing Chris, and I really enjoyed your obsy build post.

I’ll tag @Peter Drew in the hope he does see this thread and add any background he has.

[Peter Drew]

I'm always up for chips!  🙂  This mount is also one of Rob's.  These mounts were experimental and custom made rather than production and as mentioned were the forerunners of some of the legendary Astrophysics mounts.  I've added some photos of the giant mount that Rob made, it had been stored in a shed prior to being donated and I am gradually refurbishing it back to its former glory.  The eyepiece position is over 7 feet high when vertical.  I also show one of the smaller ones I made for my 12.5" Cassegrain, you can see the similarity, most of mine were made for fork mounts.  The blue Cassegrain is underneath.

[VaguelyAmused]

F15Rules yeah its not until you place it next to something more standard that you realise its size. It is still all slightly sinking in a bit quite what I have. The observatory build was so long and had so many challenges that there were points I just wanted it to end. The mount I have been out of contact with for a while, my Dad and I spent many a night with it before I moved away to Uni and that was coming up to 20 years ago now. He is still very much around and well, but the dome he had built for it was on its last legs and the mount needed a new home (shh don't tell him about this thread, I don't know if he realises what he's given away yet!  ) 

It was hard not to treat it like it was a museum piece at first, not for its age just the "don't touch in case you break it" sort of awe I had of it. The original drive failing, and having to swap out the motors and drive for an OnStep system probably did me a favour as it now feels a bit more "mine" and I am relaxed with using it. 

Of course the forecast is cloudy for a while now (sorry all!) but I can't wait to get out under more clear skies with it all.

 

[VaguelyAmused]

Hi Peter,

Fantastic pictures, thank you for sharing and the history. The nostalga is too much and an honour to hear from one of the makers behind the mounts 

It reminds me slightly of the Blackbird Pilot reciting the story of the speed check radio comms. I now feel like the little cessna! 

EDIT: And thanks Stu, apologies I got excited about seeing the pictures from Peter I forgot to say thanks for the tagging

Edited November 12, 2021 by VaguelyAmused
Forgotten thanks

[Mr Spock]

Lovely mount - real beast as you say. Well made though.

BTW, is that a KEF 103.2 I see in the background?

[VaguelyAmused]

Mr Spock you know your vintage audio sir  

[Stu]

11 hours ago, VaguelyAmused said:

EDIT: And thanks Stu, apologies I got excited about seeing the pictures from Peter I forgot to say thanks for the tagging

No problem at all. Excitement is good 👍🤣

[Mr Spock]

10 hours ago, VaguelyAmused said:

Mr Spock you know your vintage audio sir

Indeed. I'm an avid amateur speaker designer/builder dating right back to the '70s. I know a KEF B200 SP1075 and T33 SP1074 when I see them  I've used both these drivers in the past.

[CCD-Freak]

I found these pictures on the internet some years ago but there was no info as to who made them....sure look like yours.

 

 

[Peter Drew]

They are all Rob Miller mounts.     🙂

[VaguelyAmused]

CCD Freak, brilliant thanks for sharing. The picture of the big fork mount and scope, in what I assume was the workshop is warming, I think I spy a lathe in the far background  Its funny, it was in the back of my mind, weight loading further out from the axis, when mounting the little ZS61 on top of the primary scope rather than side by side. Those fork mount photos make my "concern" somewhat farcical! 

Peter, almost as farcical, expecting technical support on a mount somewhat outside of any warranty period but could I ask, short of any full teardown, are there any "preventative maintenance" or recommendations such as oil/grease points I should be aware of? The mount is still smooth as butter and working brilliantly so I have no intention of touching it, which in itself probably already answers my question.

Cheers
Chris

[CCD-Freak]

I did a search on Rob Miller mounts and found a few more pictures...  Many of these are right here in Texas.

Edited November 17, 2021 by CCD-Freak