Dobson 400mm telescope

In September 2009 I purchased from Astroshop an Orion XT-10 25cm Dobson and had lots of fun with it. But my aperture fever resulting in a lingering wish for a 40cm put me on scanning webshops for a reasonable 40cm. This size is just the largest size for a 'grab and go' as a telescope of such size (focal length 180cm) does not require ladders to reach the eyepiece and the scope is not too heavy. Although a cart on wheels can be extremely useful for the 65kg and even for a 25cm which still weight 27kg. A 25cm is 2 magnitudes brighter than a 10cm and a 40cm 3 magnitudes.

On 17 Nay 2013 I found an offer on a Dutch astro trade mart for a 40cm f/4.5 Dobson with a GSO mirror. The owner had it enhanced with a smaller and lighter rocker box of plywood which has better quality than the original particle board. The focuser was replaced by a 1:10 focuser. So I went to Hengelo to inspect it and decided to buy it. It has a very smooth horizontal motion and the balance is adjustable.
Then I put setting circles into it for easier finding of objects. Apps like Skysafari show live altazimuth coordinates for the selected object.

GSO 400mm Dobson telescope
The 40cm Dobson in the garden

Old and new Dobson
The Orion XT-10i (foreground, sold) and the GSO 40cm

Pictures of the installation of the setting circles

Like the Orion XT-10, I installed azimuthal setting circles on it.
Altitude setting circle on side of telescope
Azimuth setting circle in bottom rocker box
The azimuthal setting circle made from an aluminum disk with A4 papers printed on it covered by plastic foil

Pictures of the construction of the wheelcart

As this telescope + rocker box is too heavy to carry once (65kg) I decided to make a wheel cart which carries the handles on the sides of the box and can be moved on wheels with air pressure tyres. The all-plastic massive wheels induce too much vibration which causes decollimation during transport. So I purchased a wheel cart at a consumer building supply shop for only $30. And got a two 2m long steel tubes of 33mm x 2.65mm wall thickness for making the frame. I welded the frame of 60x60cm and attached it. Then I cut the wheel cart into two pieces. I welded the wheels part onto the frame which should embrace the box. Sorry, professional welders, the blobs do not show a good quality weld but strong enough to hold the weight. As on the rear (wheels side) it appeared that the nicely laquered box got damaged, I put an aluminum strip on it (over the scratches) to prevent this further.
It has to be primed and painted yet, but it is ready to use and works conveniently.
The tubes and the wheel cart
The tubes and the wheel cart
Partially welded in the vise
Grinding the welds
Cutting the wheel cart
The wheel cart into two pieces
Ready for welding together
Welding the frame onto the wheel cart
The wheel cart (to be primed and painted yet)
The setup with the Dobson