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VIXEN SUPER POLARIS GEM


paulastro
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I bought my SW 120ED a  new present, well, an old present to be accurate.  I couldn't resist it when a fellow SGLer advertised a Vixen Super Polaris GEM.  The mount could well be thirty years old or more but its slow motions are as smooth as the day it was made, and much smoother than the many cheaper clones of this scope and the Vixen Great Polaris which came in its wake.  These Japan made scopes are probably some of the very few mounts ever which can easily exceed the manufacturers stated maximum load.  At any rate this one will certainly be in good working order a lot longer than I will 🌝.  In the mean time  I'm delighted to be it's custodian.

 

1484732339_20200613_141238SW120EDonSuperPolaressideon.thumb.jpg.a6d9cf552de9d8a164bc7c6d39d53a9f.jpg

 

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Congrats - yes I saw that sale.  That set-up looks lovely.

You're right about those mounts: my elderly father recently gave me his old Vixen 102 on an SP mount (well we swapped scopes - he uses my little PL72 on a Porta mount now).  Those SP mounts are so smooth!  I've been doing some tinkering these last two days and have put some old Vixen motors (w manual clutch releases to disengage the motors if needed) on both axes.  I think I'm going to use it normally as a motor-driven alt-az mount though it can always be switched back to EQ :)

May I ask what saddles you got to attach to the old SP mounting cradle so that they're flush (because of that 1-2mm rise, or did you use washers)?  Right now I've got to screw in the 102 rings each time which is fine, but if I can securely mount some saddles that can allow other scopes to also be slotted in, that's going to be even better.

Anyway, enjoy - just need the clear skies to come back now!

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Very nice indeed Paul.

I picked up a manual GP2 earlier this year and although of a vintage about a decade younger than your SP (25'ish years from what I gather) its beautifully smooth and is a cracking setup with a pair of original MT-1 motors and the clutches.

The Vixen mounts are so much better engineered than the later clones, though I have t confess that I didn't believe it until I experienced it for myself.

I hope that you get many happy hours of use from your new mount.

Ade

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Thank you vineyard.  It's good to hear of other people out there still using an SP.

It's still a work in progress for me re saddles, I only had the mount delivered yesterday.  At first I did what you did and just mounted the rings on the SP top plate, I only did it the once and that was enough for me.  Also I want to use my other scope with it.  As you can see in some of the pics if you enlarge them, I now have two Tele-Optic-tecnica small saddles in place which came with my Ercole altaz mount. The trouble is that there are only two holes on the top of the SP so each of my saddles is only attached by the one hole.   I thought they might keep rotating because of this but they don't  and it works well.  They are very good singles and one would hold my 120ED.  The problem is there is no way I can attach one in the centre of the SP top plate as there is a round depression and  nothing to fix it on with.  I am looking for a dovetail with a channel going the length of it in which case it would be easy.

If you have the dosh you can buy an ADM plate from FLO or elsewhere which would work  just fine and is all you need.  The roblem for me is it costs £104 and this is too much for me.  I will let you know if I solve the problem - without spending £104 hopefully!

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Many thanks Ade.  Yes, the Vixen SDs and GPs are a class apart in this this type of mount, they are superbly engineered compared with the Chines clones.  I've told many people over the years how good they are, and it's often the case that people aren't very convinced - unless they get to try one out for themselves. Amazing considering the SPs have been around for over forty years.    The same thing happens when I tell some people how good biinoviewers are compared with the best single eyepieces for observing the Moon and planets!

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Many thanks John, that's very kind of you.  I have to admit I do find it rather cool looking.  In fact, to my wife's angst it's still set up in the lounge as I write this - though at least I have folded the legs down 😄

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The SP is lovely. They are so nice to use, especially with clutches if you need to stop motors or GOTO 'getting in the way'.

I've re-acquired a GP, a GPDX and SS2k over the last six months or so, along with quite a few spare parts, for the reasons in posts above - I actually sold the DX on buying an iOptron, but missed it and bought it back. Lovely smooth motions, without any tuning etc., can turn the drive shafts without the knobs quite easily.

I'm guessing that both will easily be getting on for 20, and yet will see me out! Same with my old G11.

Edited by Richard
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18 hours ago, paulastro said:

vineyard, here are some pics re the saddles I'm currently using.  As I said, they do work well, but not the final solution yet.

 

And here is the solution if you have over £100 to spend.

https://www.firstlightoptics.com/adm-replacement-saddles/adm-vixen-style-saddle.html

 

 

 

Hi Paul, thanks that's v helpful. Crikey re the more expensive solution - for some reason reminds me of crab claws!

I'm going to try the first solution you show - luckily @Ant was just selling two Vixen DPAs from ADM for a v reasonable price so I've snaffled them and will thread them on and see 🤞🏾

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1 hour ago, vineyard said:

Hi Paul, thanks that's v helpful. Crikey re the more expensive solution - for some reason reminds me of crab claws!

I'm going to try the first solution you show - luckily @Ant was just selling two Vixen DPAs from ADM for a v reasonable price so I've snaffled them and will thread them on and see 🤞🏾

vineyard. They may be all you ever need.  I'm sticking with the two tele-optic ones in the pics, they are the final solution for me 😄.

Despite only each being held by one bolt, they dont seem to rotate and they cant move anyway when you put a dovetail across them of course.   The ones you have bought will probably work just as well.

Regards, Paul

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I had Vixen's little sibling, i.e the 'GP' and that too was a joy to use. In my opinion they are the benchmark of how an GEM/EQ mount should be.
I now regret selling it, but as I 'mostly' dual mount; it was a real pain to accurately balance a C6/SCT-xlt and an ETX105 side-by-side. (images below).

IMG_0050.thumb.JPG.0e83cba8a43fca7212f2ea43c0df5c0f.JPG  IMG_0051.thumb.JPG.216a619401be6d13bc865743a8b5d7da.JPG

 

note: it was OK to balance with either the C6 or ETX and a TV Ranger.

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  • 2 months later...

Thanks for posting, I recently picked up the same mount, with an old 6" reflector at an auction a month or so ago for £45 and am just starting to see how it works and whether it does everything it should. It came with the same tripod as yours as well; I note your tripod cross-support also has rust on it - I was wondering what I should do with that.

Until seeing your post, I wasn't exactly sure what model mine is, however it looks exactly the same as yours, so i assume its a Vixen SP GEM also.

I have stripped the telescope down and cleaned it - it was very dusty (probably sat in a barn/garage for some time. I have also partially disassembled the mount, but won't go too far with it. The RA worm screw shaft is a little bent, so I need to do something with that and it has an RA drive, however I don't have a controller so can't test it.

The mount appears to move well on both axis. Hopefully it will work okay once I reassemble.

 

 

 

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50 minutes ago, ibraidwo said:

Thanks for posting, I recently picked up the same mount, with an old 6" reflector at an auction a month or so ago for £45 and am just starting to see how it works and whether it does everything it should. It came with the same tripod as yours as well; I note your tripod cross-support also has rust on it - I was wondering what I should do with that.

Until seeing your post, I wasn't exactly sure what model mine is, however it looks exactly the same as yours, so i assume its a Vixen SP GEM also.

I have stripped the telescope down and cleaned it - it was very dusty (probably sat in a barn/garage for some time. I have also partially disassembled the mount, but won't go too far with it. The RA worm screw shaft is a little bent, so I need to do something with that and it has an RA drive, however I don't have a controller so can't test it.

The mount appears to move well on both axis. Hopefully it will work okay once I reassemble.

 

 

 

765468_0.jpg

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In case it is of use to you, here is the original Vixen manual for the Super Polaris mount:

 

super_polaris.pdf

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  • 3 months later...

Astro Systems back page.htmlHello Ibraidwo, 

      Firstly I'll mention the fact that I used to work at Astro Systems / Astro promotions during the 80's. I can confirm that this is an Astro Systems 6" F6 newtonian. Of course the mirrors are from David Hinds. While I was experimenting with some things, I asked him for any optical flats as seconds as they were not going to any customer. What too him was a huge casum of a defect was so tiny that it just goes to show his high standards and why he had such a reputaion.

  I noticed this scope has a different focus mount to the Vixen mounts we fitted. Can't tell if its one of the ones we played round with as a prototype with the idea producing our own ones. Or if its a reto fit someone added at some point. The tube assembly is a Collimation free design. In that we thought we're making the tube assemblies over and over using Ali tubes. So why cant we just fabricate everything so that the primary is aligned just as most refractors are. This simplifies the primary mirror cell. So reducing weight, the thermal mass and the cost. The remaining Collimation is done via the Spider and the secondary. This was all made with the idea of being sturdy enough to survive being shipped, then have a life of being constantly moved and driven around. Then reassembeled on the mount. Through all of this  getting rid of the need to Collimate it. The final idea is to enjoy the views and not get tangled in managing the instrument. We had a 6" on the Alt Az mount in the showroom. For years the best I could demonstrate how well it held collimation to each customer was to hit it hard with my hand. That poor scope endured this day in day out, over and over.  Yet it never lost alignment 

Some hints i can see tells me its one of the earlier 6" tube assemblies when the Super Polaris mount was released. Most for instance had the finder sprayed the same grey finish as the tube. Also soon after in order to get the mount to acceptably take the load of the 8" and 10" tube assemblies we made our own tripods. plus only on the first few 6" models did we make our own counAstro Systems back page.htmlter weight using the Vixen ones later as we were too busy at that time.

A very important accessory you have on this SP mount is that Grey plate for the altitude/latitude adjustment. In order to get polar alignment. We found this was the Achilles heal of the mount. Where as it looks as if the RA body is clamped from both sides by the tines between the tripod and RA body in fact this mount is not. From the factory under the original adjustment plate there were 2 small grub screws. These are intended to stop the whole mount loosely swinging about its latitude adjustment. These screws pushed one of those tines side away from the RA body. So the weight and torsion from the scope and mount was mostly loaded through the tine to other side of this plate.  That modified plate removes those two small grub screws. Our grey plate was much thicker. I have to say that was the one item of cast aluminium we ever used in any fabrication and I hated the finish quality of them.

Incidentally the casting was done by a local Blocker, as in Hat manufacturing 'Blocker'. Luton being famous for its once dominant hat industry and from where the expression Mad as a hatter comes from. (mercury was applied to felt hats to give them their sheen and often smoothed in by hand. Hence the health implications for many workers.) A Blocker is someone who maufactures the Block around which a hat is shaped.

The three grub screws you see from the outside of that plate apply pressure to a thick washer underneath. This pushed hard against the redundant tine thereby clamping the RA body firmly from both sides. The improvement to a loaded mount was dramatic. Without the combination of this plate and the tripods that we made there was no way we could feasibly expect the 8' or 10' assemblies with accessories to work.

One tip with the adjustable tripod you have (this tip goes for any similar tripod including camera tripods) is once everything is assembled. Using your foot push each of two legs outward. One leg at a time.  With about half a kilo pressure. If try this on a lighter set up like a camera tripod, less force is needed. This removes any lash on the legs and their attatchment points. With a resulting slight inward tension into the ground, this helps with a little bit more stability and damping.

One thing to watch is when packing the whole assembly away is always remove that rigid dec handle as soon as possible. While being transported this can have the risk of being knocked and then bending the worm gear. Removing this first you're less likely to forget. 

As for the rust on the braces that span inbetween the tripod legs, try rubbing with wire wool, even with a bit of alcohol as well. This works well on that finish unless its deeply corroded. Wiping after with a cloth or tissue that's lightly coated in an oil like WD40 occasionally  will help protect it from further rust.

if Memory serves the basic 6" Newtonian on a Super Polaris mount retailed at $545. The single axis drive (I do hope you have the hand controller) was another $98. The slipring/camera platform was an extra $35 I think ? The fact that you got this for how much ! Well that is a truly amazing find. I would like to ask that should you ever think of selling it would you give me first refusal. Also I would not be expecting to pay such a ridiculously low amount, and nor should you ever accept anything below a reasonable amount for such an instrument (I'll just have to work out how to ship it from My parents home to Colorado)

Edited by Eryk Mozejko
adding a photo of an old ad including one of the instruments mentioned in this thread
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Welcome to SGL.

Me thinks you may know Peter Drew who is a member of SGL?!  🙂

I'm still using the SP, I also have a GP on loan from Peter and a DX which is on my profile pic with a 102mm refractor.

Thanks for posting, it was a great read.

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Hi Red dwarf

Yes I did know Peter, although lost touch with Him as well as a whole bunch of people. Exchanged a few replies on another chat forum recently. 

I just had to edit what I wrote as I spotted that I typed Your instead of You're then noticed some gobbeldigook so had to straighten some sentences out

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  • 2 weeks later...
On 04/01/2021 at 03:59, Eryk Mozejko said:

Hi Red dwarf

Yes I did know Peter, although lost touch with Him as well as a whole bunch of people. Exchanged a few replies on another chat forum recently. 

I just had to edit what I wrote as I spotted that I typed Your instead of You're then noticed some gobbeldigook so had to straighten some sentences out

Eryk, as seems you know a lot about this mount... 

I have it as well, and have been "hypertuning" it roughly, to the point of getting average RMS of 0.70" :D but problems with Dither in DEC and backlash.

Recently checking on some exploded drawing of it, realised I am missing 2 plastic bearings (or washers...don't know anymore since I've seen them called both ways )  Thoe ones marked by the arrows in the drawing. 

The two I have are 1.5mm thick, But I wonder how thick the other ones should be. (asked same question at CloudyNights but can't find exact answer yet ) it is strange I am missing them both (bought it 15years ago from a friend, original owner, and he never dissassambled it ) 

Last night I tried swapping the one washer I have from the bottom of the barrel to the top on DEC, is too thick so it doesn't fit well,,but dither and backlash worked better, kinda confirming (or I believe so ) that the lack of this washer there creates friction (i might be wrong but it seems so.. )  

So, do you or anyone else with this mount happen to know the correct size and thickness of those plastic (teflon?) bearings? 

Thanks! :D 

Carles. 

Vixen SP ex.jpg

PHd2.RMS.jpg

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Hello Carles;

I'm trying to remember how that washer sits in there. its been quite a few years. 

The Material should match the other bearing you moved. Cant remember which plastic it is. 

PTFE is distinct in how solid white in colour it is. Its also one of the highest density plastics, weight similar to that of Aluminium. if not Teflon then its either a high molecular weight polyethylene (500 grade known as HMWPe or 1000 grade known also as UHMWPe). A PE will float in water. Nylon6 will be off white with a hint of yellow slightky denser than water. 

its intended to be as much a support to spread the weight, taking up torsion perpendicular to the shaft axis as much as reducing friction. 

Either of the three materials are available in sheets from 0.5mm thick.  Personally I would opt for a HMWPe or UHMWPe although 1000 grade Pe would be harder to source in very thin sheets. Ptfe would come a close second. Unfortunately Acetal (POM) is not readily available in thin sheets and I'm sure 3mm is the thinnest. 

PTFE is usually stocked in smaller sheets and is reasonably easy to cut to shape.

Incidentally as you posted the diagram of the mount. The part I was refering to that we reworked is listed as part 1-9. this image doesnt show the two grub screws that go into part 1-2. But looking at the part 1-2 the right hand vertical part (tine) of this casting is the part which is pushed away from the RA body (part 1-3). So the bearing/washer 1-28 is where most of the load from the weight of the OTA,counterweight and the mount go through on the from factory set up.

By getting that right tine of 1-2 to be pressed up against the RA body 1-3 so the load goes evenly through both bearing washers 1-28 and 1-29, the capacity and stability of this mount is greatly increased.

If I had an SP mount today and had it stripped down. Nothing to do with its performance and purely from an asthetic point of view. I would strip that paint and have a hard time deciding wether to spray it the current Mazda metalic red or a pearlescent white similar the current Lexus colour.

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Hi Eryk, 

thank you for your reply! very helpful :D

my washer is white I would say, but not sure  which material would it be. I still don't understand how are both missing, and perhaps the size of the missing ones would be half of this one, or perhaps this 1.5mm distribuited in two?

 Washer.jpeg.b3f64f6f35e6937c81325930909307bf.jpeg

about what you are comenting of the 1-9 mechanism, that attached to an screw that goes through 1-2, i've found that it tilts the RA axis even visually, and if looking through the polar finder, the tilt is more pronounced.  I had the feeling that withouth this sort of "latitude locking mechanism" the latitud could shift a bit during the night while changing targets/areas of the sky, and after seeing that models after the SP, including the SP-DX and forward (including modern copies like the eqm35 ) all had a dual latitud locking mechanism; back and front, I've added this screw on front of it with the intention of locking it up. I think it does work. Although is not flat to push, but well..

1386573455_LAtadj.thumb.jpeg.d6c5b37546451822bd8f0ef40f7f1b50.jpeg

In order to find the right size of the washers to be inserted, how would you recommend me to measure it? 

 

Carles

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Looking at the photo il guess the material is either a PE or PTFE. drop it in water , if it sinks its PTFE, floats is a PE.

probably the best thing would be get a 0.5mm sheet of PTFE and cut 3 or 4 bearings so you can try them stacked like a shim to get the right results. 

I would think !.5 mm would be the right thickness as the part number listed is the same. The end ring on the shaft should dictate how much gap is taken up to get both bearings to mate with each surface.

At least with shimming layers of 0.5mm sheet you can experiment with which gets you the best results. otherwise by a small ball of a putty like substance. Something like Blu-Tak or what ever equivalent is available locally to you (its a product used to stick things like posters on walls temporaily. usually obtained from office stationary suppliers. stick the ball up against where the bearing should go. then fit the shaft in place without turning it. then pull it apart. hopefully the putty with have bee squashed into the thickness of the smallest gap between the two surfaces the bearing is to fit between.

I like the idea of the return screw you have to stop the RA body from slipping in its altitude adjustment. by taking off the plate 1-9 there should be two small grub screws, silver in colour now visible in the 4 and 8 o'clock positions. tightening these applied pressure in order to help stop the whole mount from tilting on its altitude axis on its own. But these two screws also stopped that side of the part 1-2 from clamping part 1-3 properly from both sides. Which denied the mount its full capacity to carry heavier equipment.

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  • 4 months later...
On 14/01/2021 at 02:23, Eryk Mozejko said:

Looking at the photo il guess the material is either a PE or PTFE. drop it in water , if it sinks its PTFE, floats is a PE.

probably the best thing would be get a 0.5mm sheet of PTFE and cut 3 or 4 bearings so you can try them stacked like a shim to get the right results. 

I would think !.5 mm would be the right thickness as the part number listed is the same. The end ring on the shaft should dictate how much gap is taken up to get both bearings to mate with each surface.

At least with shimming layers of 0.5mm sheet you can experiment with which gets you the best results. otherwise by a small ball of a putty like substance. Something like Blu-Tak or what ever equivalent is available locally to you (its a product used to stick things like posters on walls temporaily. usually obtained from office stationary suppliers. stick the ball up against where the bearing should go. then fit the shaft in place without turning it. then pull it apart. hopefully the putty with have bee squashed into the thickness of the smallest gap between the two surfaces the bearing is to fit between.

 

Hi Eryk, 

 

sorry for the delayed reply. I finally gotten PTFE washers from UK , but weather here in spain has been awfull so couldn't test much till recently . 

I have ordered 1mm 0.5mm and 0.25mm . and played with it a bit, but indeed in Dec with the addition of the washer, tracking kind of improved a bit, but specially dithering has had a massive improvement. 

Attached are PHD2 logs from a session from last month. Same night,  just different parts of the sky (South-East and North-Zenith)  dithering movement and recovery was pretty fast (before it took around 2minutes or more.. ) backlash seemed to improve too :) I don't know exactly why Polar Alignment value changed throught the night..perhaps flexure of some kind , no idea. 

Quote

I like the idea of the return screw you have to stop the RA body from slipping in its altitude adjustment. by taking off the plate 1-9 there should be two small grub screws, silver in colour now visible in the 4 and 8 o'clock positions. tightening these applied pressure in order to help stop the whole mount from tilting on its altitude axis on its own. But these two screws also stopped that side of the part 1-2 from clamping part 1-3 properly from both sides. Which denied the mount its full capacity to carry heavier equipment.

 

That is something too...the screw I've added somehow helps, but not a lot. I was thinking if there would be a way of changing the whole latitude adjustment base . The silver colour screws you've mention, I have adjusted a bit but as you say, too much will refrain the mount from moving..and I have to Polar Align often since the mount is outside, but the telescope I mount it each time and it might move. 

 

Eitherway, the washers did it's job. Indeed it was weird that it was missing in both axis... in DEC I think I've ended up with 0.50mm. And also added one to RA.  Still a bit more to tune up but so far, so good :)

 

Guiding first.jpg

Guiding second.jpg

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