Posted 15 February 2013 - 04:36 AM
Would be interested to know if anyone has experienced problems with the opening and closing of the hatch/shutter.
Clearskies and good observing
Posted 15 February 2013 - 02:19 PM
What specifically is your problem ?
Posted 15 February 2013 - 03:54 PM
I have one, Oldtimer, but have no problem with it in this direction. The only problem I've got/had is with splash water as a result of heavy rainfall penetrating the door sill. Pulsar have recently addressed this though by introducing a sealing strip.
What specifically is your problem ?
Posted 16 February 2013 - 05:44 AM
Here's a shot of mine. 2.1 metres in diameter: ca. 2.3 metres high. Houses two OTAs, (Nexstar 8i and a 4" achromat parallel to each other on a "Gemini" bar, all on a cast iron pier mounted Skywatcher HEQ5 Pro GEM.
Posted 17 February 2013 - 05:27 AM
Opening and closing the shutter,requires much care to ensure the cord does not touch or disturb the guidescope and OTA on the tall CGE PRO Mount. Moving each side of Mount whether opening or closing shutter sometimes results in the cord sliding off the twin pulleys.(Does this happen with your pulleys ?)........
A tall stepladder is then required to carefully reach up and replace the cord on the pulley.Obviously the stepladder does not remain inside dome.....
Looking at the Pulsar Dome at the recent Astrofest I saw that the twin pulleys have been replaced by a single, much larger pulley system, which I tried out on their display dome.Gary told me these have been used on all their Domes since last Summer.So!! I have ordered one hopeing this will improve my existing twin pulley system.
Incidently reading of your rainwater prob, which is now resolved I would be interested to hear if you are troubled by rainwter entering the Dome floor via the open 'bottom locking hole'.
Posted 17 February 2013 - 03:44 PM
Many thanks for the very kind comment. It's just a great pity in as much as the "Dome" had to be placed so close to the house because of the small garden, hence the vista is limited to the high, (as a result of roof tops) Northwest to the, (as a result of roof tops) Southwest through East.
However, as they say, what goes around: comes around !
I think Pulsar must have modified the pulley system since I bought my "Dome" from them in 2010. Inside and at the top of the dome, mine has but a single wheeled pulley.
However, when Gary and Dave asked me to test it, I found that at 5'4", I didn't have enough physical height to be able to put enough leverage behind this to open or close the shutter.
To eliviate the problem, they fitted an extra jockey rider next to the point at which the shutter assumes its closed position which, in turn, providing me with the extra leverage I needed.
But with this, (as you mentioned and unknown to me), dual pulley system in place, I'm not at all sure that any recommendation for you to install such an extra leverage point would be in any way effective. (?)
For what it's worth however; although my shutter cord runs close to my two, side-by-side mounted 'scopes, I can certainly avoid its contact with them when operating my shutter in both directions via the described means.
As to your currrent situation, I hope the single pulley solves your problem, but it sounds somewhat as if Pulsar are regressing to something more akin to that which I have.
BTW. It's a pity we didn't meet at the Astrofest this year !
I was there on Saturday at the Pulsar stand, tapping Gary and Dave for a solution to my door/rain water problem which, as a result. I now hope to have resolved by means of the piece of sealing strip I managed to scrounge !
Do you then have the same water ingresss problem via the lower bolt hole ?
Posted 20 February 2013 - 06:46 AM
I hope the sealing strip you obtained resolves the rainwater ingress problems. My own problem of rainwater ingress related to the open hole at the bottom of the dome into which the locking bolt fits.
When opening the door after a rainfall I found the water had seeped along the base edge into this bolt hole and flooded onto the dome floor, I know there is the rubber floor installed but nevertheless this rainwater adds a level of dampness and condensation…. Our enemies!
However I have now ‘fibre glassed’ the bolt hole bottom thus preventing water from entering the dome floor.
I believe this to be a design fault but which Pulsar do not seem concerned about.!
Seems strange that Pulsar have now reverted back to a single pulley, which was the system in place when you purchased your dome in 2010.
Pulsar assembled my 2.7m dome in March 2011 at which time it was fitted with a double 1 inch stainless steel pulley system which was easy to operate in an empty dome but as previously mentioned once I had the tall CGE PRO and OTA assembled in the dome, it proved awkward to operate,
Having ordered this nylon / plastic single pulley system and chasing Pulsar last week Gary phoned to explain that it would be delivered on Tuesday but I am still waiting for it.
I agree this does seem inferior to my existing one inch double stainless steel pulley and perhaps Pulsar should have increased the diameter of the stainless steel pulleys allowing for a thicker cord to be used: So much easier to pull.
Yes indeed, pity we didn’t have this “exchange” before the AstroFest as we could have met up and discussed matters more fully and probably redesigned the dome for them!!
I see that Wallingford is not far from my address in Bledlow Ridge so perhaps when the weather is more settled you may care to meet up to discuss equipment, techniques and the difficulties of observing in these perennial cloudy skies, although there has been a few reasonably clear night skies this month.
In the meantime happy observing.
With Best Wishes
Posted 21 February 2013 - 06:47 AM
From what you say, it sounds as if we had/I have an identical problem; namely water ingress resulting from splash-back rainwater from the patio surface, getting onto the floor of my dome via the door lock bolt hole in the bottom sill. As I mentioned however, I managed to scrounge a length of sealing strip from young Dave at the Pulsar stand which I have placed in position. True to form though, it hasn't rained since ! Just when it's really needed ....... !
I hope by now your new pulley has arrived and you've been able to fit it. If so, has it improved the situation ?
It seems to me though that your problem may have been better solved by that second leverage point Gary and Dave placed in my dome for my convenience in opening and closing my shutter.
As I mentioned, I'm only 5'4" tall so couple this with the original single pully point at the top of the dome, a relatively hight 8" Celestron SCT/ Skywatcher HEQ5 Pro all on a cast iron pier assembly, and you can imagine it was nigh on impossible for me to put enough purchase behind the cord and single pulley to effect opening and closure of the shutter.
Thus in realisation of my plight, they overcame this by providing an extra wheel like cleat, close to the shutter closure point so that now, I have two points over which the cord runs when it comes to opening or closing the shutter. And when not in use, the cord can be removed from the cleat when the roof's open and tied out of the way. With this little device, I have no problem in opening and closing the shutter.
If you wish or you think it may help, I can photograph it.
Changing the subject, yes, I'd like to meet up with you when the weather (hopefully) improves and the days get longer: (I'm not so keen these days to drive in darkness) ! I note that indeed you're not too far from my address here in Wallingford: near to Stokenchurch, I believe. (?)
Perhaps drop me a PM when the climate improves to perhaps arrange a "get-together" ?
Posted 22 February 2013 - 11:28 AM
Well! The single pulley system was eventually delivered yesterday.
The attached bracket for bolting to the roof spur of the dome has a flange which sits over the top of the 2inch dia.pulley wheel presumably preventing the ‘two cord runs’ from jumping off…improved design!!
I was disappointed there was no cord included as indicated on Pulsar’s accessory page, the unit being priced at £39 +delivery costs, but as Gary asked me for £35 cash with no delivery costs I suppose the deal was good, particularly as the 2 inch pulley wheel is designed with a ball bearing race, another improvement perhaps!
Yes! I would very much like to see a photo/ picture of your pulley system including if possible the additional ‘wheel like cleat’ that Pulsar attached to the closed end of the dome. Many thanks Tel.
Great that you are keen to meet up when the weather is more ‘friendly’
I share your comment about driving in the dark. Car journeys in winter months can be very tiring.
However if one wishes to continue visiting friends, Family, Grandchildren in the winter months then one has little choice. My son and daughter live in Beenham, Berks and Welwyn Garden City: both being an hour’s drive away from Bledlow Ridge.
Hope your nightskies are improving. Mine have of late but boy! its still freezing after midnight.
With Best Wishes
Posted 23 February 2013 - 05:22 AM
I will try to post a few pictures of my pulley arrangement as soon as possible. (I have yet to take them) !
Descriptively though, I would not put the diameter of my own pulley wheel, (ca. 2010), attached to the roof of my dome as 2". From what I can see of it, it is not much more than 1" across and is contained with metal on either side of it which, in turn, prevents the cord from coming off the wheel. (Compare perhaps one of those simple washing line pulleys).
The thickness of my cord incidentally, is about 0.75cm.
The cleat, (for want of a better word), is, if you can imagine, something like, --- (although in this case, plastic), --- one of those old, wooden, wide topped, thinner waisted cotton reels with a bolt passing through the central hole. This is then attached to the dome just below the shutter.
When opening my shutter, I merely have to untie the cord from its resting place, lift the shutter a little by hand, and then start pulling the cord with one hand while keeping it taught with other, (lest it catch on the 'scope assembly). Then, with the shutter fully open, the cord is once more tied out of harm's way.
To close the shutter however, the cord is once more untied from its secure position, but this time placed over the "cotton reel". Thus it now not only runs over the pulley wheel in the roof, but also over a second fixed point (the "cotton reel"), near to the shutter's closure point.
This gives me a lot more purchase, enabling me to lift the shutter initially against gravity until it reaches the point on its way to closure, where gravity takes over.
Does this make sense ?
As said though and as we all know, a picture paints a thousand words, so I will endeavour to post some !
Still true to form, good night skies are few and far between. Likewise, it's rapidly becoming the season of galaxies while I'm just getting into Ha and Olll imaging of, (now diminishing in supply), emission nebulae !
What did Patrick Moore always call it? "Spode's Law" ?
Look forward to meeting up with you sometime when the weather improves and there's a little more evening light !
Posted 24 February 2013 - 05:20 AM
The series of images I promised, relating to my Pulsar shutter arrangement. I hope they speak for themselves.
No1. Cord rest position. Shutter closed.
Posted 24 February 2013 - 05:22 AM
Posted 24 February 2013 - 05:25 AM
Posted 24 February 2013 - 05:34 AM
Hoping the foregoing helps.
EDIT: Please note that it is not necessary to use the "cotton reel" fixture at the shutter opening when opening the shutter. It is only used to give (me) more leverage when closing.
Posted 25 February 2013 - 08:21 AM
Many thanks for interesting message : Yes it all made sense.
At 0.75cm thickness your pulley cords are thicker than mine and I am sure this must impact favourably on the ‘pulling’ power when opening and closing your dome.
Have now downloaded and looked at the pics you so kindly sent me.
Interesting set up, Tel, and I am pleased it makes the shutter opening and closing easier. Nothing worse after a cold night and early morn. observing than to struggle with closing the dome shutter.
I am away from home at present but will return for the day on Wed and armed with your ‘pics’ and my new ball bearing race pulley wheel I am looking forward to improving my set up.
Looking at the gear in your dome it looks as if you have some interesting astrophotography set up! You mention getting into Ha and O111 filters for Galaxies.
My attempts at astrophotography have been confined to the planets using the Orion Guider and a Phillips webcam
Last years observing opportunities were few and far between and this year to date hasn’t been inspiring, so I am beginning to doubt my wisdom in spending so much money over the last 2.5 years, (especially at my time of life) purchasing a dome, Celestron SCT, guide scopes, cameras and numerous gadgets all of which the mags say you must have!!!!!
Prior to moving to Bledlow I lived in the Chalfonts for 30 years and in my large garden I built a dome and installed a 12.5 inch Newtonian with Circles which was mounted on the now famous Rob Miller’s PM1 Mount with electronic guiding facilities.
It all worked very well, so I constantly ask myself why did I upgrade to Celestron SCT amd Mount 2 years ago?....... Is it old age stupidity?
I meant to mention my astonishment at how many posts you have made to the Forum since you joined in 2006…I believe they total about 7730, compared to my 42 since 2011.
Also, I believe you very kindly replied to a problem I posted on the Forum early last year, although I cannot seem to trace it.
The Forum is a really great place to exchange views and discuss matters, long may it continue.
Stay in touch and I will look forward to meeting up in the Springtime.
With Best Wishes and clearskies.
Posted 26 February 2013 - 07:21 AM
I'm afraid I was a lttle out on my guesstimate of my cord thickness. I took a micrometer to it this morning and, although as you can appreciate such soft material is not easy to measure due to its ability to compress in the jaws of the "mike", I must revise my original figure to somewhere in the region of ca. 4.7mm. My apologies if I mislead you.
Moving on to imaging, what I was trying to say was that with the Spring approaching, so too is what I call the galaxy season, many of which are of course photogenic, but far less suitable for employing Ha and Olll filters which come into their own particularly in photographing emission nebulae which in turn, for this coming season will be in shorter supply; more so, considering my relatively restricted back garden vista !
Still, and with regard to your own imaging, Saturn will be with us within a few more months at a more congenial time, (although not a particularly favourable altitude), which should, (given good weather of course), allow us to make good use of our webcams: (I, like you, also use a Phillips' webcam via Stark Lab's "Craterlet" software).
As to the number of posts I've made over the years, I don't know I can rationalise it ! I suppose it stems from working in a scientific environment in both product development and, more interestingly, product support where I had to deal with all manner of technical problems on behalf of customers/reps. etc. Thus I think you'll find that most of what I've contributed to CN has been along the same technical problem solving lines which, in retirement, has become merely an enjoyable extension of what I did when at work.
BTW: Do you have any plans to visit the "Sky at Night" magazine sponsored "International Astronomy Exhibition" at Royal Leamington Spa in May this year ?
Posted 28 February 2013 - 08:09 AM
Many thanks for last post.
I have never used filters for astrophotography as apart from the high cost, I have always believed there is a learning curve to maximise the benefits of the type of filter.
I acquired a Canon 550D last year with the intention of trying to capture the many wondrous nebulae around Orion, besides M42 : all of which require the removal of the Ha blocking filter in the Canon camera
I did consider sending the camera away to be ‘modded’, as they say: however ivo the dreadful night skies I decided to postpone the idea.
Many galaxies are visible for observation and photography in the coming Spring ie Leo and the Plough but the ‘enemy’ is always lurking around, suddenly drifting in and obscuring the ‘sights’ you have patiently set up….
Yes! Saturn will soon be visible but unfortunately considerably lower in the sky than the ‘King’ has been these last 2 years……….Hoooray for Stark Labs!
I exchanged the new large 2 inch pulley for the existing smaller double pair yesterday, not without problems: the accompanying instructions indicated another hole may be required to secure the assembly…..what a joke! Standing on tall steps precariously balanced over the ‘scope and mount, I had to unbolt the existing fixing plate from the dome roof, drill two more holes in this plate, then another in the fibreglass rim.
Finally securely bolting the new assembly and plate back to the actual dome and returning to ground level from the dizzy height of the dome roof I tried opening and closing the shutter.
To my delight it was very easy and all accomplished by remaining on one side of the dome……… Previously I had to walk around the mount holding the cords taunt.
The complete exercise only took me 3 hours!!! Well! when you reach my venerable age everything seems to take longer.
I am sure the huge amount of technical support and advice you have imparted within the 7800 CN contributions since 2006 have been greatly appreciated by the many posters myself included.
I am not sure about the "International Astronomy Exhibition" at Royal Leamington Spa in May this year.
My Son and Family will be visiting from California for a brief visit including the Friday and Saturday so regret cannot give you a firm answer.
Hopefully we should be able to meet up before then, perhaps in April some time and I will PM you nearer that date
Best Wishes and Clearskies
Posted 02 March 2013 - 07:30 AM
Sorry for the slow reply.
Well it looks as if the new pulley system has effected a cure to your struggles with the shutter of your Pulsar dome !
Looking at your last image though, ("Inside the Dome"), I note you are working from the original tripod. Have you any plans to install a pier ? They do provide extra room to the limited space these domes offer although in my case, I think I have lost such that I gained with mine by mounting my two 'scopes horizontally parallel to each other !
Also, is that also a dehumidifier I spy at the back ? If so, I did consider one for my dome but thought they were somewhat expensive; (Sky at Night magazine advertised one once for £170+). Does it do a good job ?
I have since got around that potential problem by use of a simple 1KW fan heater which is timed to "kick in" for a quarter of an hour in every hour through out the night, (when the dome is not in use of course).
My humidity gauge appears to indicate that it does indeed keep moisture at bay; evidenced too by laying a hand on the iron counterweights. Any moisture around and these are the first to allow it to condense !
Anthony, I wish you all success with your dome, with your coming family visit and to a meeting with you, hopefully in April. And, should you be able to attend the IAS in Leamington after all, then I'm sure you'll let me know nearer the time.
Hoping that these eternal grey skies eventually pass: (I think so far this year, we have had less than half a dozen clear nights ,let alone seen the Sun in the daytime) !
Posted 05 March 2013 - 05:02 AM
The interior does look rather cluttered and that’s before I bring in the comfortable observing chair!
Normally the de-humidifier lives indoors but ivo the high humidity levels in the dome during the last few months it has remained in situ. Actually this appliance is extremely efficient, with many settings.
I will often switch it on, having set the timer for 2hrs then switch off the power from its source indoors, so that it can be switched on when necessary & controlled indoors without entering the dome.
The 1Kw dimplex heater seen on the table is a permanent feature remaining on 24hrs per day it uses v.little power and keeps the chill off the dome interior. Obviously it is removed several hours before a planned observing night.
Incidentally I always keep the ‘scope and mount covered with a heavy poly/foam sheet as in the past, heavy condensation on the dome roof has dripped on the equipment.
Your comments concerning the amount of room taken up by the existing v.heavy weight tripod are indeed valid but I have no current plans to replace the set-up with a pier because of the huge amount of work involved.
Originally it took, ‘forever’ to set up all the equipment, balancing the OTA in ‘three dimensions’ to provide for exchanging eyepieces with cameras and other gear all affecting weight differentials.
Achieving the GOTO facilities to a reasonably accuracy required much time and patience in setting the 6x star alignment process. Then finally working through the ‘drift method’ for accurate sidereal motion can take a while....all of which requires a good clear night sky at least for several hours!!!
For photography I additionally use the ‘Orion Star Tracker’
So many tasks before one begins to actually use this expensive equipment I sometimes I wonder if I chose the right hobby/pastime but having read a book on astronomy aged 10yrs I was completely smitten with the subject and couldn’t wait to own my first telescope.
I am currently living with my friend Jane in the wilds of Woodend nr. Marlow and checking the night sky at 7pm on Sunday was amazed to see a sky completely devoid of clouds, this ‘phenomenon’ remained until a large cloud bank began rolling in from the East at 10:30pm.
Jane’s house has almost a 360 deg vista allowing views of all the winter constellations in the South and clear views of the rising Spring Constellations. Leo etc in the East.
Absolute magic!!!...My location is quite restricted.
Were you also blessed with a brilliant night sky?
The downside was of course being away from my observatory on an exceptional night not seen for months.
My son Steve now tells me that due to his Company’s re-organisation plans in London he is unsure of his visiting dates this year: could be June or even July, so I may well be able to join you in a trip to Leamington in May, buy I will of course let you know asap.
In the meantime I will look forward to seeing you perhaps at ‘my house’ in April a date we can arrange idc. You are welcome to come in the morning or afternoon and can return home before dark fall.
With Best Wishes,..Anthony
Posted 07 March 2013 - 03:04 AM
Many thanks for the invitation to visit you when the days draw out a little more. April, for example, would be a fine time. I'm normally free most days, so if you can propose a date nearer the time, I'm sure it would be acceptable.
I agree entirely with your comments on the number of tasks one has to undertake before even getting to use the equipment.
Even with a permanent set up and with one single imaging target in mind for capture, I would guess that on average it takes me somewhere between one hour to one and a half hours to get the main 'scope aligned, .... camera focused accurately on a bright star, .... guide 'scope equally camera focused on a bright star, .... move to target, .... review exposure levels, .... centralise target on screen if necessary, .... set up guiding system and then eventually, .... with fingers crossed .... GO !
And all this with a anxious eye on the weather.
Oh that we might have more than one clear night occasionally, since part of the problem in my case, is that such are so few and far between, I tend to forget the routine !
Posted 15 March 2013 - 08:02 AM
Lady luck has given me some reasonably clear night skies this week and situated here in Woodend nr Marlow.
As previously mentioned such is the high isolated locality of my friend Jane’s large garden it allows an almost 360deg vista of the night sky. Not wishing to ‘crow’ it is truly wonderful and majestic to see so many constellations at the same time, all slowly moving westward allowing one to easy understand how the Earth rotates.
Although the temp was below freezing with a cold north easterly howling and requiring much warm clothing, the low humidity in the air provided incredibly sharp views: Andromeda could be seen very easily.
Wishing that my observatory and ‘scope were with me I had to be content lying back in a chair with low power binoculars, albeit with a good FOV.
Unfortunately this wonderful experience lasted only an hour before dense cloud banks from the N.E sky rolled in, slowly and menacingly moving across the night sky until within 10minutes that wonderful stellar vista had been removed.
The forecast seems to show a week of wet and windy weather and its times like this I dream of moving to places with sunnier climes and great night skies!!!!
What have the night skies been like in Wallingford these last few weeks Tel and have you been able to do any astrophotography?
I hope the weather improves during April!
Best Wishes and clearskies but one has to agree this web forum is well named!!.
ps Thought I had better change the title to something more appropriate