AdeKing

25 minutes ago, Robindonne said:

Did it come unharmed?    Did my best to protect it.   The dutch transporters are always in a hurry and the majority thinks throwing with packages saves time😑

It arrived in A1 condition. It was nestled snugly in the air cushioned box.

10/10 for your packaging skills, I was very impressed.

I'm fairly confident that the courier's could have kicked it around like a football with no damage.

Very pleased indeed with the delivery.

Ade

Delivered today by a friendly DHL driver a very nice example of a TAL Gen 2 25mm Plossl, the one with the lovely purple coatings courtesy of @Robindonne.

I've been after one of these for a while and figured that it would go very nicely with the Towa 80mm f/15.

Just need some clear skies to test it now as it not only arrived with clouds, but rain too .

Posted elsewhere, but here is a shot of my recently acquired Vixen GPD mount, sporting my also recently acquired Towa 80mm f/15 in solar guise.

The GPD2 came complete with a working Skysensor 2000 PC which interfaces nicely with my SkyFi unit and SkySafari. 

I was pleasantly surprised that it was actually significantly less effort to get the 25 or so year old SkySensor unit to work with SkySafari than it was to get the relatively new AZ GTi to work.

20 minutes ago, mikeDnight said:

I used smootright wild thyme as a close enough match for my liking. I painted a couple of counterweight and a blue polar scope cover, which I think pretty close. I wouldn't hesitate to paint the entire mount in this colour if it needed it.

Thanks Mike

I'm pretty sure Smoothrite Wild Thyme is a close match for the original plastic parts.

But hopefully @mikeDnight can pop in as I'm pretty sure he's used some to restore parts of a GPDX fairly recently.

There is a thread on here somewhere, I'll see if I can find it.

I think Orion Optics will sell a primary cell, though they're not cheap.

Alternatively, have a word with Beacon Hill Telescopes, I think he's still working.

I approached him about a primary cell for the 22" Dark Star that I had at the time, but then never did anything about it.

http://beaconhilltelescopes.org.uk/

He only works via snail mail and telephone, but certainly seems to be well regarded.

I think he's semi-retired now but still building telescopes to keep him out of trouble.

Hope this helps,

Ade

10 minutes ago, Mark at Beaufort said:

Very nice Ade it makes me think why did I sell my 80mm Towa.

Thanks Mark,

I'm very pleased with it and am amazed at the quality of all parts of it it given that it was a department store type telescope.

Just need to switch the fixed finder for a vixen finder shoe so that I can use my solar finder with it.  The actual finder is lovely though, so need to get some small guide rings with a vixen foot so that I can carry on using it.

Regards,

Ade

Since FLO started stocking the Scopetech long focal length achromatic refractors, I've had an urge to try an f/15 refractor to see what observing with a traditional long focal length telescope is like as I've seen loads of praise of them even though the current trend tends to be for shorter focal length ED doublets.

I do have an Altair Starwave 102 f/11 already, but it doesn't see a lot of use as I feel that my Vixen GP is about at its limit with this setup due to the weight and long moment arm.  Its just a little too shaky for me and needed a motorised focuser fitting for me to find it usable.

Anyway, @Dave1 posted an Ad in the classifieds for a Circle T 80mm f/15 refractor complete with most of the original accessories and the original mount and tripod in its original wooden storage crate.  After much deliberation, and changing my mind every 5 minutes, I eventually put it out of my mind and decided that I didn't need "yet another telescope" until I noticed that it had popped up on SGL classifieds again recently at a lower price, so I decided to give it a go and got in touch.

I collected the not insubstantial wooden crate and its contents at the weekend, and was surprised to find that despite being probably about 35 years old that the box still contained clouds.

Considering that these telescopes were essentially Department Store telescopes, I was really impressed with the build quality with everything being solid and not a sign of plastic parts anywhere in the construction of the OTA.

The OTA was quite scratched, something that I was expecting from the description in the Ad, but the optics were absolutely spotless.

I knew that the scope had been modified to accept 1.25" eyepieces and I also knew that Dave had flocked as much of the tube and focuser drawtube as was possible.

The focuser only has about 50mm of travel and to reduce the length of the tube the focuser employs a telescoping drawtube which extends the drawtube length by 210mm in addition to the 50mm of focuser travel.  I was quite excited by this as I hoped that the OTA would allow me to use my Binoviewers natively without needing a GPC element, so allowing lower magnifications.

First Light - Terrestrial

First light was to view a group of starlings on top of an electricity pylon about 200m away and I was pleased to see a nice clean and sharp view at 48x using one of the nice Skywatcher 25mm stock eyepieces (not the plastic one) and my Tak prism diagonal.

Next I removed the GPC from my binoviewers and put them into the diagonal and confirmed that I could just reach focus on the clouds, but needed a proper astro target to confirm.

Second Light - White Light Solar

Early yesterday evening saw some relatively large clear parches between the clouds so I added the GPC back into the binoviewer and put in my Lunt 1.25" wedge to view the sun.  After adjusting the focuser to a point at mid travel I then adjusted the extending drawtube to get a sharp image and was blown away.  The detail visible was impressive, three small spots in an arc (AR2772) with some associated pores and lots of obvious texture in the macro-granulation with some faint faculae also visible.  This was very pleasing and I can see this OTA becoming a solar favourite.

Third Light - Jupiter & Saturn

It stayed clear last night and I managed to get about an hour of viewing of Jupiter and Saturn in before I nodded off and woke myself by nearly falling off of my observing chair.

Performance on Jupiter was impressive at 48x with the moons cleanly resolved and details visible in the north cloud bands with the GRS being immediately obvious.  I was also pleased to see that there was almost no discernible CA, which was to be expected given the focal length, though CA doesn't actually bother me that much, even in my little ST102 that plenty of people complain about. 

I tend to prefer observing at lower magnifications as the contrast decreases as you increase magnification and although I did get a nice view at 114x through my Pentax XL 10.5mm the view at 48x through the Skywatcher 25mm was somehow more satisfying.

On to Saturn and again, a crisp sharp image presented itself.  I increased the magnification slightly and was able to resolve the Cassini Division but was too tired to put in the effort and try to pick out the subtle bands in the clouds.

Finally over to Capella to do a star test, not the ideal target due to its low elevation but it Was getting quite hazy by this time and Capella was nice and easy to pick out.  In focus there was a nice airy disc and on diffraction ring.  Defocusing revealed a perfectly centred bullseye target pattern, so I'm very pleased.

One thing that I did notice is that the Dewshield is rather short and things did start to dew up at the end.  I shall have to make a foam extension to the dewshield or get another dew strap, but I'd like to keep this setup as simple as possible so I'll try a dewshield extension first I think.

 Here is a photo of the Towa 339, I'll add more photos showing details of the sliding drawtube and clean objective once its stopped raining.

4 minutes ago, JeremyS said:

Maybe a low cost wife and a friendly observing area, @AdeKing?

🙂

@JeremyS, you made me double check what I'd written for a second.

The second part is right, I only wish the first part were. 😃

Collected locally yesterday a nice classic Towa 339 80mm f/15 under the Topic brand with most of the original accessories, flocked, and converted from 0.965" to 1.25" by @Dave1.

Photos to follow.

Really excited to observe with this one based on Dave's planetary observing reports from 2018.

Now I REALLY do need to slim down my telescope collection as I fear that it's very much getting out of hand.

Edit: Photo Added

Edit: From tests on scudding clouds this morning, this OTA looks like it can natively reach focus with binoviewers without the need for a GPC. 

This photo shows my Tak prism in place, but my Baader T2 prism diagonal and quick change adaptor have a shorter lightpath, just need to test on an astronomical target to be sure.

6 hours ago, Graham Beamson said:

A very clever idea and helpful write up. Thank you !

I'm thinking of setting up a small back yard observatory and an important requirement of the project is not too much in the way of earthworks or big engineering so as not to upset Mrs B. So rather than digging a hole for a pier I'm looking into the idea of using one of the Skywatcher pillar mounts standing directly on the block-paved patio.

I would have a Skywatcher EQ6-R Pro mount and a Skywatcher Esprit 120 refractor on top of the pillar. The total payload on the pillar would be about 40kg. I would be doing visual and astrophotography. The Skywatcher pillar itself is only 900mm high and I would probably need an extension - I believe that a 200mm extension is available from Skywatcher. Ideally I might need a bit more than that.

It looks as if you have an extension on your pillar mount and possibly one that is more than 200mm - is that correct ? Also, in the light of your experience, what do you think of my proposed payload of 40kg ?

Thank you, Graham.

Thanks Graham, this solution has certainly worked for me and the holes in the upturned pots make re-positioning the mount accurately fairly easy, normally with a small tweak required to polar alignment.

I'm not sure on the payload the pillar is capable of, as I could never find any numbers.

I'm now using a Vixen GPD2 mount and the heaviest setup I have is an ED120, so I'm probably working with about 24-25kg max load on the pillar myself with about 8kg each for mount, scope and counterweights.

I was using the 16" extension, but found it too prone to vibration, so switched to the 8" extension instead.

I preferred the height with the 16" extension, but the stability is much better with the shorter extension in place so I make do with the lower height.

6 hours ago, CraigT82 said:

Thats a great idea Ade! I've got the same pillar and have driven 3x 500mm permanent ground markers into my front lawn and I set it up on those, haven't managed to get permission to leave it our there semi permanently though, still have to set up and tear down each session 🙁

Thanks Craig, that sounds like a good alternative.  Being able to to leave the mount set up permanently has made a huge difference to my observing.

Mine is in the rear garden, I'm not sure I'd be happy with it left in the front garden.

3 hours ago, mce said:

Just a word of caution. I have this kind of setup which is more less permanently outside. We had some very violent storms earlier this year, and it blew over in the night, fortunately with fairly minor damage. However, I am now rather paranoid, and I check the weather forecast every day for wind speed. If it looks bad, the pillar gets a bag of garden compost draped over its legs, and then it isn't going anywhere (touch wood)!

 

Thanks for this tip, I haven't suffered from that problem, but I do have a couple of 25kg bags of ballast handy that can be deployed in bad weather.

4 minutes ago, HollyHound said:

You've inspired me to listen again to this album, first time in years 😀👍

Seeing the @Philip R post made me dig it out of storage and listen again too.

Glad my post had the same effect on you @HollyHound

7 hours ago, Philip R said:

Jeff Wayne's musical version of 'The War of the Worlds - The New Generation' on vinyl LP to accompany the 'original'.

  

Wonderful, I really like The New Generation version.

Those opening three boom, boom, booms still make the hairs on the back of my neck stand up.

A pair of albums that I will not part with.

Hope you enjoy.

Ade

32 minutes ago, Alan White said:

Green cover over the mount Ade?

Actually I do have a green cover on it already, its apparently the three white legs sticking out from underneath the cover that she finds offensive.

47 minutes ago, Alan White said:

To blend the Observing Area and 'Khazi' more with the garden, it has gone green.
Shame the garden has gone brown of course!

The garden fence is slowly being treated with green as well.
All blends well with the shrubs and trees.

And of course I have upped my 'Green' credentials too 😉

That looks incognito now Alan and blends in with the garden nicely. 

My wife has recently requested that I paint my white pillar mount green to blend in with the garden, that was a possibility with the Green GP on it  but seems wrong now it's got a white GPD2 mount attached to it.

I tend to do most of my observing from home on the outskirts of light polluted Poole.

However as I mostly use refractors that are fairly easy to transport I'm able to take them to dark sky sites within a 30 min drive from home.

But like @rwilkey says it's best to go out with others so attending a local group will introduce you to fellow astronomers that would give you someone to observe with.

Not the postie, but collected locally last night by myself after 5 months of shielding at home.

A new to me Vixen GPD2 and Skysensor2000PC. 

I can't believe how much heavier duty this is than the standard Green GP that I have.  Hoping that this will cope with my Starwave 102 f/11 a bit better.

The GPD2 will stay on a semi-permanent setup in the garden and the GP will be used as a mobile Setup on my TAL Wooden Tripod for when I finally venture out.

15 hours ago, John said:

Slow motions are very useful I agree. I can cope OK without if the mount motion is smooth on both axis.

I'm delighted with my T-Rex which suits my 130mm F/9.2 perfectly. The Ercole and the Skytee II carried it OK but the T-Rex showed me what a top end alt-az mount can do. Unfortunately the T-Rex is out of production and getting on for AZ100 in terms of pricing if you can find one:

Thanks for this John, the T-Rex is probably what I would opt for if it was still in production I think as I'm not an avid user of a dual scope setup.  However, after my dual scope solar session yesterday, this may well change.

It looks like a fantastic mount and its such a shame that it is no longer in production.

15 hours ago, Macavity said:

When I had a nice (Red!) Giro III mount, I used to measure the distance from
the center of the scope (and centre of that the counterweight) from the axis.

The distances are not always equal in Giro mounts. It is not as easy to judge
balance across the Azimuth axis (as it is in Altitude). So I would WEIGH the
scope (including the rings, disgoneal, finder, eyepiece etc.) and then do a
(back of envelope!) "See Saw calculation" (Weight x distance etc.) and then
CALCULATE the *required* counterweight to balance the system exactly.

A bit excessive? lol. But it worked for me. (Sorry if this has been noted!!!)
I could even play "silly beggars" and SPIN the axes around and around! 🥳
But then such *precise* balance can become an issue in it's own right...

I do find that my SkyTee II has a slight wobble on the Azimuth axis. So I
tend to use a slight *imbalace* so that it does not suddenly "slop" over!
As is the case with these mounts it is a tad non-obvious how one might
even tighten up the Azimuth axis. 🙄

Thanks so much for this, this post has actually been the lightbulb moment for me and the GCSE physics refresher has proved invaluable.

After reading this post yesterday, I decided to approach things a little more logically and follow your methodology and its revealed that I am absolutely useless at estimating weight. 

I had no idea that my double stacked LS60 and Baader zoom weighed 4.5kg, I'd estimated it at 3.0kg.  What was more of an eye opener was that the little ZD66 solar setup was 3.1kg and my ED120 was 8.1kg, no wonder I'd been struggling.

So basically I was using much lighter counterweights than were needed. A bit more googling around the see-saw calculation to refresh the "little grey cells" yielded this:

So when I realised that I could work out the distance of the second weight from the pivot point by using L1 = L x W / W1 I was good to go.

And what a result, with the ED120 loaded on and balanced in Alt and by using a combination of counterweights closer to the actual (and not my badly estimated) fully loaded OTA weight I calculated the distance required and BINGO a balanced mount with very little initial stiction indeed.

Basically with the counterweights I'd been using, to balance the ED120, the centre of the weights would have needed to have been placed about 200mm beyond the end of the counterweight bar, D'Oh!!!!!!!!!!!

I'd been blinded by the fact that I'd considered an Alt Az to be foolproof, but obviously not resistant as as bigger fool as me.

Anyway, result is that I had a nice session on Jupiter and Saturn with the ED120 and Ercole last night.  A little stiction is there, but barely noticeable compared to what it was.

So thanks again for providing the light bulb moment.

14 hours ago, steveex2003 said:

I would be interested to know what you find here. I have said head, and think it such a wonderful little thing other than similarly not having complete confidence in the tension adjustment screws.

I'll keep you posted, but having had a quick look at these mounts at the moment I have no idea where to start dismantling them.

14 hours ago, Solar B said:

I think this is a SUPERB 👍 thread as we are perhaps really getting to the crux of what 

is important to the individual with regard to Alt Az mounts , I am sure your Ercole is a 

great mount  Ade and one that you will enjoy and it's like everything you won't really 

know unless you try , I for one am leaning toward a certain mount (yes that one) but 

I currently do not require that capacity however probably will next solar season.

Brian 

Thanks Brian, see above for the lightbulb moment.

14 hours ago, John said:

Getting at the azimuth bearing of a Giro mount is not easy !

There is a trick to it - I'll try and find a link to the method.

 

Thanks John, that would be very much appreciated.

7 hours ago, HollyHound said:

I’ve definitely found that both my SkyTee and Castor work much better when loaded with two scopes. I’ve setup a lightweight grab and go dual scope setup using the Castor mounted on an AZ3 tripod. With just the C5 on one side, it needs the counterweight bar, but even then it’s not super smooth in AZ, but with an ST80 on the other side, it’s remarkably smooth 👍

Thanks, I'm beginning to get the picture that these mounts really come into their own when used for a dual scope setup.

6 hours ago, John said:

I think the lesson is clear with these "T" type mounts - balance is the key to getting the best from them and that needs some experimentation to get "just right". Even more so than I originally thought.

This has been a real learning experience and I think that never a truer word has been spoken John.

It has been a real eye opener for me.

3 hours ago, TerryMcK said:

I find the magnetic base spirit level very useful when getting the counterbalance shaft horizontal. 

Me too for my Alt Az mounts.

Stick it to counterweight shaft and adjust tripod to get it level once then rotate by 90 degrees and level again then good to go.

Oh blast, this thread seems to be reinforcing what I've probably known all along that I need slow-mo controls.

It's not doing a very good job of convincing me that I don't need one of those fancy bells and whistles AZ100 mounts, which is what I hoped the Ercole would do.

In the meantime here is the solar setup I've been having fun with this afternoon.

Deleted: Duplicate Post

6 hours ago, Mark at Beaufort said:

@AdeI had the original SkyTee mount and I did become frustrated that the Az side did not always move slowly. In the end I used a handle on the one side to make things easier. I attach the only photo I can find to show the handle in situ.

In the end I bought the SkyTee 2 which I felt was much better because of the slow motion controls.

Thanks Mark, this is the type of thing I'm sure I've seen commercially available, but looking at that I could drill and tap a hole into one of my dovetails and use the handle from a cheap old Slik Prototype tripod I picked up recently.

At one point I had two SkyTee 2 mounts but moved them on as I found the controls awkward to use when I had Newts. Now I'm using Fracs it's looking like an attractive option once again.

Ummmm, here we go again.

18 hours ago, Alan White said:

Ade, it could well be the lightness of the scopes used, sometimes more mass makes things run more smoothly.

Thanks Alan, I tried with the 102 f/11 today so a completely different beast, quite a bit heavier and almost 4x the length, but similar symptoms.

It is definitely improved by adding a counterweight and by gradually moving the weight along the counterweight shaft I found a sweet point where the Stiction was much reduced though not eliminated but much more tolerable.

17 hours ago, John said:

That's a good point Alan. I remember having both my ED120 and an ED150 on the mount when I was testing the latter and the mount seemed very smooth on both axis then.

8 hours ago, iPeace said:

I now recall that one of these mounts I used worked as close to perfection as one could hope for - but only when two particular scopes were deployed in a particular configuration. It was a real 'wow' moment for me. The only useful explanation must concern weight and balance. In your situation, I suppose I would be trying to determine whether this 'perfect point' exists, with the scope on one side and the empty counterweight bar on the other, gradually applying downward force by hand until the mount (almost) starts moving by itself; if that point exists, then it's a matter of re-creating it with counterweights, adjusting one millimetre at a time.

I'm sure the above reflects at least in spirit your efforts so far.

John and Mike, I think this is something I need to investigate further. Watch this space.

5 hours ago, Solar B said:

That set up looks superb Mark with a wonderful solution 

Ade I personally could not do without slo mo controls as I require them to glide over 

the solar disk ... and I guess that's the main reason I like my ST2 , it's far from perfect 

but performs well enough and I like the ability to mount a longer FL refractor on top 

but tend to use the sides for normal solar obs.

PS I do like the look of your new Giro though 👍

Brian 

Brian, I do love the slow-mo controls. I had a ST2 off you ages ago though it was under utilised so got moved on to fund something else, something I'm now regretting.

4 hours ago, John said:

I'll say it again, there is still a niche for a good capacity alt-azimuth mount, with slow motion controls, that is priced somewhere between the Skytee II / Ercole and the £1K plus units like the AZ100.

I'm glad that I hung onto my Skytee II. Far from perfect but it does what it does competently and has a good capacity for it's price once the saddles are replaced and it's on a stronger tripod.

I hear you John, there is still a gap in the market for a mount with slow-mo controls at that price point. 

3 hours ago, markse68 said:

Does the Gyro use PTFE thrust bearing for the AZ? Interestingly ptfe coefficient of friction reduces with load up to a point. So if it does, a couple of thoughts- you could try a heavier counterbalance weight closer to the pivot point to try to reduce that cof. Or maybe a lighter weight further from the pivot to increase the rotational inertia (it increases by square of distance from pivot) which might help smooth out the motion and make the stiction less noticeable? Worth an experiment perhaps.

I'm not sure, I found this earlier which suggests polymer bearings, but I couldn't see a date when the page was last updated browsing on my phone.

http://www.donelasci.de/mounts.html

Spec sheets on other sites suggest normal bearings.

2 hours ago, Stu said:

Like John, I have always found these mounts work best with two scopes on them. Somehow the imbalances seem to cancel each other out, and perhaps the additional moment of inertia helps to damp the motions down a little. There’s nothing I enjoy more than say an Ha and white light scope side by side, or widefield and higher power scopes at night.

The AZ100 is better, obviously because of its overall size and rigidity but same as for the SkyTee2, the slow motion controls really help.

Even the Scopetech Zero Mount is better in this respect because it has the slo mos and the bearing clutches.

Stu, thanks for popping in. I saw your post and have just spent a pleasant half hour observing with the LS60DS on one side and the ZS66 and Cool Ceramic wedge on the other and it's like a different mount.

There is still a bit of initial Stiction that needs to be overcome but nowhere near as much as with a solo scope.

I know neither of the attached scopes need such a heavy duty mount but everyone says that it's better to be over mounted 🤣.

A bit more effort to set up but it's been a real eye opener and much more pleasant to use.

I clearly need to do this more often goodness knows, it's not like I haven't got enough Fracs to choose from.

I don't understand the reasons for it. It's kind of like suspending a weight from a tripod for added stability. Doesn't look like it'll work, but it just does.

Thanks all, I'll have more of a play and report back.

Welcome to Dorset, there are a few of us Dorset residents here on SGL.

Regarding clubs, there are groups at Weymouth (http://www.weymouthastronomy.co.uk), Wimborne (http://www.wessex-astro.org.uk/) and Crewkerne (http://www.cadas.net/monthly-meetings/).

I know that Wessex and Weymouth are running monthly Zoom meetings at the moment but looking at the Crewkerne website it just states that meetings have been suspended due to Covid 19.

Wessex Astro have an observatory at Durlston Country Park at Swanage, but monthly meetings are suspended due to Covid at the moment.

I can't help with decent observing sites local to Dorchester I'm afraid as I'm further east in Bournemouth, but once you get onto the coast and away from the towns the skies are beautifully dark, likewise to the north of Dorchester as it's pretty sparsely populated.  You've chosen a great area for your move.

I'm sure someone else will be along in due course.

Ade

Thanks Alan, I did wonder whether this might have an impact, I'll try it with the ED100 or ED120 and see what difference it makes.

I knew it would be a re-learning curve as I haven't used a manual Alt-Az for a while.

More tinkering and playing, then tinkering and playing is in order I feel.