Platform FAQs

 

 

  • What exactly is an Equatorial Tracking Platform  ?

 
It is a motorised platform, which  converts your manual Dobsonian Mounted scope into a telescope that automatically tracks celestial objects, holding them stationary in the eyepiece field of view for up to an hour.
So your Dobsonian mounted telescope behaves like a motor driven polar aligned equatorial scope.
This allows very detailed observation, reduces fatigue, also allows limited astro-photography with your Dobsonian, and above all removes the annoying need to constantly bump the scope to keep up with the Earth's rotation .
 
Please visit our “ what is an equatorial tracking platform ? ? ”  page for a full explanation of the theory behind these platforms.
 
Once adjusted to match your home latitude (which only needs to be done once), setting up your platform for an observing session is very simple,  (1) Align to North with the attached magnetic compass, (2) Stand your Dobsonian on the platform  (3) Locate your target object then switch on the drive (4) Now enjoy observing objects stationary in the eyepiece !
 
In the field the whole set-up takes less than 5 minutes total.
 
The platform will track for an hour with out needing to be re-set.
 
You can move to other targets whilst tracking is engaged and the telescope will continue to track the new object seamlessly.
 
Re-setting takes 10 seconds only.

 

  • Will it fit my Dobsonian Mounted telescope ?

Our standard platform takes all commercially available Dobsonian mounted telescopes in the UK up to 12 inches aperture and 120lbs weight, and most 14 inch scopes too. This includes Meade Lightbridge, Skywatcher’s Skyhawk and Flextube models, all Orion-UK models , GSO models , Orion-US models – both truss and classical skyquest models, etc . The platform is also suited to many home made and speciality made telescopes, including larger aperture models, eg those made by David Lukehurst which fall within the 120lbs weight limit and have a Centre of Gravity of  22 inches or below.
 
 (The CofG of your classical Dobsonian setup will normally be several inches below the altitude bearing central pivot point, due to the mass of the Dobsonian base, CLICK HERE for instructions on how to calculate this exactly) )
 

If your Dobsonian is 
BIGGER  than this, ie 16" to 20" or up to 24" if an ultralight then a Watch House XL platform may be the answer,  please click
HERE
 
 
Please contact us to discuss if you are in any doubt of its suitability for your scope. 

 

  • Can I use it to take photographs etc with my Dobsonian?

Yes.
 Motorised tracking for your Dobsonian will allow you to enter the world of astro-photography, with some limitations, as with any non-guided equatorial mounted polar aligned telescope.
You will be able to use short exposure prime focus techniques for bright objects with an SLR for example, or direct short exposure eyepiece photography with any digital camera/video camera.  
You can also  use basic non-guided CCD imaging using short exposures and stacking of images using freely available software programs to observe and record deep sky objects. This is a very cheap introduction to imaging, as a basic phillips web-cam with free software can cost less than £20 and gives great results.
 
 
There is a fantastic new generation of reasonably priced Minitron CCD cameras for example that integrate frames on the fly to provide effective exposures of up to 5 seconds, and cameras of this type have been successfully used with Equatorial Tracking platforms in the US.
 
We have used these Minitron cameras with our Watch House Platform and a 12" Orion xxt12 scope with success for both deep-sky objects and also the moon and planets. See the photography pages for details 
 
These integrated exposures can themselves then be aligned and stacked off line using free software like registax to generate exposures equivalent to many minutes .
 
Please see our photography pages for more information and lots of web links.
 
You can also place a normal tripod and SLR camera directly on the platform to take relatively long exposure ( several minutes)  wide field sky photographs of constellations etc, as an alternative to piggybacking the SLR camera on an equatorial mounted driven telescope. Again examples of this on the photography pages.
 
 
  • How long will it track for ?

Depending very slightly on your latitude, at least an hour before requiring a manual re-set  ( which takes less than 10 seconds to perform ).
This tracking time is physically engineered into the design and geometry of the components.
It is physically impossible for the platform to track for less time than this when the sidereal rate is correctly set.
  • Can I  use it to track the Sun too ?

The simple answer is YES you can.
Although the Sun's apparent motion across the sky is different to that of the Moon, planets and deep sky objects, the platform will effectively correct for the element of this motion due to the Earth's rotation. In practice this means that for visual observation and web cam videos you can eliminate virtually all of the usual eyepiece drift by using a platform.
This is equally true if you are using a Dobsonian mounted telescope, an equatorial mounted telescope, or a specialist solar telescope on a fixed tripod mount.

REMEMBER NEVER, NEVER, NEVER observe the Sun without using a dedicated solar filter.
Please see our photography pages for more information on how we set up our 12" Dob for solar observing, for about £20 !
 
  • How much is it ?

The Standard size -UK Watch House Equatorial Platform is currently priced at £480 
+ Your contribution to Packing & Delivery is £20.00 by insured courier to any mainland UK address,  and normally takes 2-3 working days from dispatch
 
The XL-size- UK Watch House Equatorial Platform is currently priced at £570 
 + Your contribution to Packing & Delivery is £30.00 by insured courier to any mainland UK address, and normally takes 2-3 working days from dispatch
 
We will contact you when your platform has been shipped, with a courier’s tracking number.
 
 
NON UK - based  customers please note :
 
For customers in Southern Europe we also offer a Southern Europe model which is engineered to be suitable for all latitudes between 400 and 500 North, ie the whole of France, Italy etc. Please see  our  pages for European customers for details.
 
Courier delivery (DHL or TNT  normally) can also be arranged outside the UK to any mainland European address, BUT as these rates vary frequently, YOU MUST  contact us for specific shipping rates before ordering, and to ensure that your home is at a suitable latitude for the platform.
 
 If you dont follow these steps to get our agreement before ordering, we reserve the right to reverse any payment made to us from outside the UK.
 
 
  • What about after sales service ?

As we manufacture the platforms ourselves, we always have all spare parts in stock for next day delivery, in the very unlikely event you should need a replacement part.

We have never had a platform returned for repair yet !!!

  

  • How long after you accept my order will I get my platform ?

We will aim to ship your platform 20-30 working days after receiving the cleared funds from your deposit. 

Please contact us for the current situation at d.c.billington@btinternet.com
 
In the unlikely event that we feel that this lead time is not possible, we will contact you immediately with the option to reconsider your order or accept a slightly longer lead time.
 
You may however be lucky and hit the point in our production cycle when we have platforms in stock for immediate shipping.

 Please contact us for the current situation at d.c.billington@btinternet.com
.

 

  • Is it REALLY safe to "balance" my precious telescope on this ?

Yes of course it is ! ! !
 
Platforms like this are used in the US for huge Dobsonian telescopes of 24 inches aperture and more, up to 30 inches in some cases.
 
It really is TOTALLY SAFE because :
  • The overall North/South tilt of the platform when set up anywhere in the UK from 470 North to 57North is only a maximum of 5 degrees from level.
  •  
  • The overall movement of the platform table , ie the East/West tilting motion as the platform tracks during one hour  involves only a maximum of +/- 8 degrees from the mid-way horizontal & level position at each end of the tracking arc.
SO PLEASE IGNORE  rubbish comments like "  But it can't work, I mean,  how can you balance a scope on a board tilted at 470 from horizontal ? ? "
 
These remarks  just show the "knowledgeable person" (we are too polite to say ill-informed, and opinionated idiot) has not bothered to take the time to understand the theory of how a platform works !
 
It is totally safe, and the theory works beautifully in practice.
 
Literally  thousands of Equatorial platforms have been built and used over the last 20 + years since the idea was first published.

We have supplied over 100 platforms to date and have NEVER heard of a case of the scope 'falling off' a platform.
 
Our platform has also been very carefully designed such that the Centre of Gravity  (CofG) of  the telescope always remains well inside the base of the platform's feet throughout this movement. Additionally the Platform top surface is coated with a high friction marine deck paint to ensure excellent grip by your telescope's feet.
 
Please see our gallery page for images of the amount of actual movement during a tracking run, using our 12" Orion Telescope and the images below which 
show the centre-of-gravity at both ends of the tracking movement.

Photo: This photo clearly shows that at the end of the tracking the centre of gravity still falls well within the platform feet ensuring maximum stability.  Photo: This photo clearly shows that at the beginning of tracking the centre of gravity falls well within the platform feet ensuring maximum stability.
                Start of tracking run                                           End of tracking run

The "stopped motion" animation below also shows the arc that the tracking platform describes over one hour of tracking which involves only a maximum of +/- 8 degrees from the mid-way horizontal & level position at each end of the tracking arc
 

Watch House Platform movment over 1 hour

 
 
To get an idea of just how stable equatorial platform mounted telescopes are, just have a look at the gallery on Tom Osypowski's site in the USA, which shows Dobsonians up to 30" aperture on his premium quality platforms :
 
 
 .
  • I see it’s powered by just one small 9v battery, what about battery life ?

The platform has been designed to operate in an in-balance geometry state and to be in kinetic equilibrium and so needs very little power to move it in its tracking arc.
We ship your platform with a single Duracell LR9 9v battery ready for use. In our experience battery life is between 20 and 30 hours, with a 12 inch scope , depending on many factors  which include, ambient temperature, frequency of use, humidity, make of battery etc. Battery life is a little shorter with larger heavier scopes.
We suggest you always keep a spare battery handy when observing  (we do) , but please don’t buy  your batteries from the chemists ( expensive), or worse still cheap Chinese batteries from the market.
Duracell are by far the best and  they are available in 5 or 10 packs on Ebay at a fraction of high street retail price.
They last 2-5 x longer than cheap Chinese batteries.

 

  • How about portability ?

The platform is very portable, the standard platform weighs only 18lbs ( , the XL weighs 27lbs) and is easily carried in 2 pieces, taking less than 5 minutes to set up and align.
 
Additionally the Platform requires no external power supply, just its own small 9v battery, so no mains lead tethering you to the house, and no heavy expensive 12v Powerpack either to lug about (and forget to re-charge).
 
In our experience battery life is between 20 and 30 hours, depending on many factors  which include, load ( ie size of scope) , ambient temperature, frequency of use, humidity, make of battery,  etc.

 

  • Will it work at my home latitude ?

The standard Watch House Equatorial Platform has been designed to operate in a perfectly level condition at a latitude of 52 0 , ie about Banbury in the UK, Warsaw in Poland, Berlin in Germany and Rotterdam in the Netherlands.
It is easily adjusted (in less than 5 minutes) to any  desired latitude at + or - 50 degrees from 520 North, ie for operation between 470 North and 57 North simply by  tilting the groundboard using its 3 precision height adjustable feet.
 
The home observing latitude set-up only needs to be performed once, on first setup of the platform, and we will pre-adjust your platform to match your home latitude before delivery.
 
So, the standard platform covers the UK from down South in Cornwall up to as far North as Glasgow, Edinburgh, and Inverness,  all of Ireland North and South, and central / Northern Europe.
 
For customers in Southern Europe we also offer a Southern Europe model which is engineered to be suitable for all latitudes between 400 and 500 North, ie the whole of France, Italy etc. Please see the pages for European customers for details.
 
To find your latitude from your UK post code, click here.
 
  • Can it be adjusted for other latitudes outside 470 North to 57North?

For latitudes outside the range 470 –  570 the North or South end of the platform would need to be raised further, eg on a wooden block, but this is  not recommended  as eventually this could make the platform unstable, as eventually the CofG of the telescope could possibly fall outside of the base at maximum tilt.
 
Our +/- 5 degree range of adjustment only requires a maximum of 31mm height adjustment of the base board from the level position.
 
Please note some overseas manufacturers have been known to ship platforms to UK astronomers which are built to operate at 450, which is the standard latitude setup in the US,  ( we have seen one ) with instructions to put a large 3 inch  wooden block under one end to achieve the desired offset.... POTENTIALLY UNSTABLE please don't do it !
 
 
For customers in Europe we also affer a Southern Europe model which is engineered to be suitable for all latitudes between  400 and 500 North, ie the whole of France, Italy etc. Please see the pages for European customers for details.
 
 
 
  • How do I find out my home latitude ?

There is a very good site HERE that will give you your home latitude  by pointing to a UK map in degrees and minutes/seconds eg 52 degrees 45 minutes 0 seconds . The site also gives information on the correction needed for your simple magnetic compass reading to indicate true North for all UK locations, and a nice an explanation of why all magnetic compasses are inaccurate, and how this inaccuracy varies as you travel around the globe.
 
Alternatively, to get your latitude from your postcode just click here
note that this site gives your latitude in degrees and decimals of a degree ie 52.75 degrees.
 
  • How accurately do I need to align the platform for normal visual use ?

A simple alignment by eye with a basic magnetic compass (supplied) is normally quite sufficient for visual observing. As with any polar aligned scope however , the more accurate the polar alignment, the more accurate the tracking, ie the less drift you will see. We also give full instructions for more accurate drift alignment type method using Polaris as a guide star if you want to be more precise, for example for photography purposes.
 
  • What are the advantages of using an equatorial platform ?

 
  • Basically, no more nudging the damn scope to follow objects across the sky ! !
  • Greatly reduced eye fatigue for the observer.
  • Much higher powers become possible for lunar, planetary and DSO observing, 300x and 400x become routine and up to theoretical 600x with the object remaining in the eyepiece.
  • Much finer detail is then appreciated, as your brain processes an essentially stationary image.
  • Sketching becomes a pleasure, as an object remains in the eyepiece as you move between sketch pad and eyepiece view.
  • You can now use your scope for photography, with some limitations ( of course !), and with the new generation integrating CCD cameras, see our photography pages for more information.
  • Very portable and totally autonomous power supply,  so take it to your favourite dark sky site or star party.

 

  • Can I move between objects whilst tracking ?

Yes.
You can reposition your Dobsonian telescope to new targets as normal whilst the tracking drive is engaged. When you have found your new target you will find that your system simply continues to track it.
See below for use with computerised object location systems.
 
  • Will I still be able to use my Digital setting circles or my Orion Intelliscope object locator ?

 
 In short, Yes.
Almost all modern DSC systems have the option to turn off the sidereal clock, which allows you to use them with a tracking platform. The Orion Intelliscope object locator system for example has this function specifically designed in. With the sidereal clock turned off, the initial alignment of the object location system will remain accurate throughout a tracking run as your object location system effectively ignores the platform's movement, as the sky is in effect standing still relative to your scope .
 
Alternatively you can align your telescope object locating system with the platform drive switched off and the platform at the beginning of its tracking arc position, use it to locate your target as normal and then switch the drive on and track your object. 
When you want to move to another object, switch the drive off,  reset the platform to its initial zero position and your location system is re-aligned and you can then locate your next object. Now switch the tracking drive back on again and tracking will recommence.
 
We use the Orion Intelliscope system ourselves for personal observing with the platform and find it very accurate.
 
  •  How much will it raise the eyepiece by ?

 
The platform has been very carefully designed to be as low profile as possible only raising the base of the Dobsonian mount ( ie the eyepiece ) by about 4.5-5 inches.
You can reduce this even further by removing the 3 feet from your telescope base board and placing the telescope  ground board directly on the platform table.

 

  • How robust is it ?

 
We have constructed the platform from the most robust and appropriate materials available, stainless steel, aluminium alloy and premium Baltic Birch 18ply plywood,
 
 All adhesives are Lloyds approved marine grade epoxy resin based and the platforms wooden parts are fully waterproofed with Lloyds  approved marine paints .
 
We have chosen a Vertical North sector design as this places the load directly over the bearings rather than at an angle, giving greater stability.

 

  • Where can I see one ?

 

There are lots  pictures here on the website in our gallery pages , or you can see one “in the flesh” at various astronomy events around the UK. See the side bar for where we will be .

 

  • What else will I need to buy ?

 
A warm coat, and more eyepieces probably !  This is because you will be enjoying your eyepiece time much more once you have a platform, and you will therefore be spending much more time outside under the stars.
 
Nothing beats sitting down and spending 20 mins really observing your target without nudging the scope every 2 mins.
 
 
  • It looks rather simple doesn't it ?

 
 It may look rather simple, as we have gone for function over form to keep the costs down, but Looks can be very deceiving !
The mathematics involved in accurately designing a Vertical North Sector Equatorial Platform with a low profile, in kinetic equilibrium, for a given latitude are actually very complex.
No fewer than 25 interdependent complex trigonometric equations have to be solved to provide the exact sizes, shapes angles and positions of the component parts. and these component parts then have to be cut, finished, machined and assembled accurately to achieve efficient tracking.
As an example the 2 Vertical North Sectors are actually not arcs of a circle at all, but complex developed elliptical sections of a canted 3D cone, whose axis is centred on Polaris at 520 latitude.
 
Another example is the radius of the circular south bearing sector, which is given by the following equation

 

rs =((zs -Ts/2)sinq + Zlow)/cosq - Drs

 
The construction of each Watch House platform requires more than 100 separate operations to complete the manufacture of this robust and complex, if simple looking, piece of astro-engineering. 
 
 

 
To place your order please click here.
 


 
 
 
 
 
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