I am selling my permanently mounted 16 inch Equatorial Newtonian and replacing it with a number of Celestrons - 14, 11, 9.25 and my old 8.
Okay, they each have a purpose. I use the 14" for occultations and high resolution stuff, the 11" with F6.3 adaptor is great for various imaging jobs, and my new 9.25" has remarkable resolution, clearly superior if the atmospheric conditions are a bit 'iffy'. (We could have a long discussion on how the larger instrument suffer under medium to poor 'seeing'.) As for my old 8" classic it is light and portable, and I can easily pick it up andtake it outside the observatory, or wherever as the occasion requires.
Now my 16" took up a fair bit of space with quite an arc of swing, close to 4 metres diameter, and I will have a fair bit of space when it is gone. I had made my 11" and 9.25" wheelable within the observatory to get to a usable spot and then wheel away when not required, and a week ago I posted details on a $62 wheelable stand for the 9.25" courtesy of Bunnings parts.
Anyway on this occasion, I thought that rather than plonking the C14 down centrally, it would be nice if I could easily move it. However the problem is that any wheeled mount would add around 120mm to the height, perhaps more.
Then I saw these little dollies for $10 from Bunnings and rated to 90kg. (The C14 all up is a few kg lighter than this.) I bought three dollies. I just dropped a heavy washer in each to spread the load a little. No work, no drilling, and for $30.75 it is easily movable if required and only adds around 20mm to the height.
It does not run as smooth as the nice wheels for the C9.25" but there is a lot of weight here. particularly over the polar axis. It seems to work well on a smooth floor and is not that free that it will move when you don't want it to. Time will tell.......
The castors are lockable 3" rubber-tyred, which makes it very capable of negotiating slightly uneven ground such as pavers, exposed aggregate concrete, etc (but it is not an "off road" dolly!). The only problem is that the dolly arms are not quite long enough to allow the tripod to spread fully, but the dolly acts as a bottom spreader, so it is quite robust. If I needed a more permanent solution, I would mount the same 3" lockable castors onto slightly longer arms (or buy a larger diameter dolly), so that the tripod can spread fully.
For optimum stability, it helps if you align the wheels radially outward before locking them, as this increases the "footprint" and it has very little movement at all. If you lock the wheels when they are tangential, they can tend to want to rock slightly, and if they are oriented inwards, it is a bit less stable.
(Just a few notes for anyone else who is looking for a way to make a heavy telescope more mobile.)
Hello Julian,
I appreciate your comments. About 10 days ago I started a new thread in this section doing a 'show and tell' about a dolly I made for the C9.25. In that case the existing tripod did not have stabilising crossbars at the base, and so I made a simple wooden 'T' shape to capture and hold the legs and preventing them from moving and splaying further. The 3" wheels I used then were rated to 50kg each, but to my thinking (say for my C14) the leg under the polar axis would take close to 40kg and the other two about 25kg each. This makes me uneasy since I always like to over-engineer when possible. So heavier wheels etc. would be called for if making a frame for the C14 and the cost would soar... Also a frame such as this adds to the height - in the previous case 120mm.
For my purposes with the C14, I didn't want it any higher, but I wanted it mobile. I have a nice flat floor. Imagine my joy when I found these little dollies, and found they were constructed of solid pressed steel, rated to 90kg each, and only raised the height by(say) 20mm. (In the unlikely event that anything goes wrong, it only has 20mm to drop or sag.) No drilling, scewing or painting required, just a few minutes to fit, and only $30 all up. WOW!
Hello Julian,
I appreciate your comments. About 10 days ago I started a new thread in this section doing a 'show and tell' about a dolly I made for the C9.25. In that case the existing tripod did not have stabilising crossbars at the base, and so I made a simple wooden 'T' shape to capture and hold the legs and preventing them from moving and splaying further. The 3" wheels I used then were rated to 50kg each, but to my thinking (say for my C14) the leg under the polar axis would take close to 40kg and the other two about 25kg each. This makes me uneasy since I always like to over-engineer when possible. So heavier wheels etc. would be called for if making a frame for the C14 and the cost would soar... Also a frame such as this adds to the height - in the previous case 120mm.
For my purposes with the C14, I didn't want it any higher, but I wanted it mobile. I have a nice flat floor. Imagine my joy when I found these little dollies, and found they were constructed of solid pressed steel, rated to 90kg each, and only raised the height by(say) 20mm. (In the unlikely event that anything goes wrong, it only has 20mm to drop or sag.) No drilling, scewing or painting required, just a few minutes to fit, and only $30 all up. WOW!
For my purposes with the C14, I didn't want it any higher, but I wanted it mobile. I have a nice flat floor. Imagine my joy when I found these little dollies, and found they were constructed of solid pressed steel, rated to 90kg each, and only raised the height by(say) 20mm.
Yes, those little three-wheel dollies are ideal if you only need to move the telescope across a flat floor. I considered something similar, but my father had to negotiate a few slab joints etc, so the larger wheels were a "must-have" for me. I designed a new "dolly spreader" which would pick up the tripod at full spread, and only raise the tripod by about 25 mm, but never got around to making it.
[QUOTE=
For my purposes with the C14, I didn't want it any higher, but I wanted it mobile. I have a nice flat floor. Imagine my joy when I found these little dollies, and found they were constructed of solid pressed steel, rated to 90kg each, and only raised the height by(say) 20mm. (In the unlikely event that anything goes wrong, it only has 20mm to drop or sag.) No drilling, scewing or painting required, just a few minutes to fit, and only $30 all up. WOW![/QUOTE]
Great find, went out and got 3 myself.
Ultra simple solution.
OK they don't have any breakes or locks - so what.
Once rolled into the observing location it's just a small tilt to remove the dollies to avoid knocking the legs out of alignment.
I put them back when the scope needs to be rolled under cover.
At least I don't have to dis-assemble the entire set-up when it needs to be moved.
Sure a fully automatic solution would be better. But then, so would a dome. My bank manger thanks you..
Hi Menno,
The issue about lockable wheels and possible vibrations in the mount when the three little dollies are in use have been raised by a friend. To tell you the truth, I believe there IS a little more vibration, but I don't have a problem with movement.
I haven't tried it, but I would suggest sliding a chock (perhaps a heavy duty cheap rubber door stop chock wedged directly under the base of each leg. There is probably something like 15mm clearance so this would be ideal, easy to place, and worth a try.
Firstly, it would stop any movement, (though you need to bump against it for it to move anyway) and
secondly the rubber wedged underneath should assist in damping out vibrations.
Thirdly, it is simple and straightforward just taking a few seconds and I am all in favour simple solutions.
Hello Menno,
I thought I would apologise. I went out and measured it and it is not quite as straightforward as it would appear. (Like so many things, it seemed like a good idea at the time.) The main problem is that the curved sides of the dolly prevent a conventional shaped chock from being inserted. D'OH!
Any chock as I am suggesting would now have to be a particular size.
You can slide a chock in from the direction of any of the three wheels in the dolly, providing it is not more than 30mm high and 30mm wide. The height directly under the leg is ~20mm. - So it is still eminently do-able. However you would have to have enough purchase on the chock to force it in, and then remove it later.
If you can find or fashion such a chock, I would suggest somehow attaching a string to the end of it to help pull it out.
So it probably involves a bit of work with a Stanley knife if you want to go this way. As I said, I haven't tried it, but the concept is simple and you have the rounded base of the dolly sitting 20mm over your flat floor, begging for something to steady it.
Sweet , might look for these here , my fully loaded CI-700 and C9 are quite heavy as well .
