A Quick Remove Wheel Barrow Handle System for a 20-inch Dobsonian

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Last touched 2002 January 19

I was part way through rebuilding TJ, my 20-inch Dobsonian in 1999 when the Kriege/Berry book on building large dobsonians came out. TJ was pretty much an Obsession clone anyway since I had been a student of Dave's ideas for some years. Nonetheless, the book provided additional clues and saved time and effort in dealing with many details.

One of the details was the attachment of wheel barrow handles for moving the rocker/mirror box around and loading into the car. For the sake of speed, as I wanted to get the scope out under some dark skies again, I copied Dave's handle method right from the book. While it works and is an extremely secure system, it had a major drawback for me.

When loaded into my Jeep, there was only a couple of inches to spare on either side of scope. To make it more interesting, there were times that I had to take the handles off in order to fit the scope into the car. This was normally when the back seat of the jeep was raised. When I did this, the handles and wheels rode on the roof of the jeep with the ladder and ramps.

It proved extremely difficult to reach in the back of the jeep and unscrew the eyebolts that held the handles to the rocker so I could put the handles on the roof. It was painful and took forever. I think I did it once.

I decided there had to be a better way, a way that could be done from the back of the scope, once the scope was in the back of the car/jeep.

This page includes images of my system. In brief, the weight of the scope is transferred to the handles by a couple of blocks of wood. A pin/dowel system holds the handles on at the front of the rocker. The old eyebolts slide through a block of wood and into a hole in the rocker at the back of the scope.

In operation, once the scope is in the car, the eyebolts are pulled out. I pull the handles outward a couple of inches and push forward. This disengages the pins in the front and the handles are free to be lifted out over the top of the mirror box.

It takes about two seconds. For attachment, I lift the handles back over the mirror box. The handles are slide in between the alignment blocks on the rocker and the front pin engaged. The handles are pushed in and the eyebolts inserted into the hole in the rocker. Takes about a minute.

This system works great! I love it. I've been using it for several years and it has held up well under use. There is a draw back, though. It blocks the use of spring counter weights, if the springs are used in the traditional sense. I would either have to mount the springs inboard, or carefully thread them around the blocks. The latter would be difficult since I often observe with the scope while the handles are still attached.

Click on most images for a larger/high resolution version of the image

back view
The handle is attached, viewed from the back. The eyebolt is inserted in the travel position.

back view
The eyebolt has been removed, and the handle pushed out. To disengage the front pin, I only have to push the handle forwards and the handle falls off the rocker. I hang the eyebolts from hooks on the rocker for storage while observing.

back view
The handle is attached, viewed from the back and off the side. The eyebolt is in the travel position, but here you can see the blocks of wood attached the rocker that support the weight of the scope while I'm moving the scope with the handles.

front view
The handle is attached, viewed from the front. A steel strap support the wood that holds the alignment pin. The scope is ready to be moved with the handles. You can see the holes in the handles for the original system.

back view
The handles have been removed so you can see the alignment pin/dowel as well as the hole in the rocker that the pin inserts into. Note that there is a third block under the handle. This block is for alignment... it carries no weight. It helps support the handle while I'm inserting the pin. While moving the scope, it helps to keep the handles from twisting under the weight of the scope.

front view
A view of the pin from the other side. It's a 1/2-inch oak dowel rod. The wood it is attached to is also oak.

bbunge@ladyandtramp.com


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