It's all about degrees really.
The thing with DIY camera cranes is they can be really simple, so long as your need is to have one with sensibe height, say eight feet. And as I'm a great believer in keeping things simple, and in the fact that if it's behind the camera it doesn't matter what it looks like so long as it works, the design I have in mind will use wood as the base material.
There really is a load of tosh talk when it comes to cranes for most uses, fancy bearings and such are only needed on really large ones, or where rapid movement is wanted, as using a basic principle in all of the moving joints a steady controlled movement can be achieved cheaply in most cases. Stupidly most designs I see use a pair of paralell jibs to provide the camera levelling, which really is daft as it doubles the weight of the jib, and the smae thing can be achieved with a piece of strong string, and as I said earlier you can arrange it so that the camera gradually pans up or down as the crane rises. As a Manufacturing Engineer by profession I'm struggling to understand why commercial cranes cost so much, including consideration of
all of the cost and safety implications.
Ok, so a wooden crane might not impress people much, but the results will, and that's what really matters.
I've made three cranes so far, but out of aluminium, this one............
.......which has a three jibs for different applications, and ones I've made for other folk on the same principles. The top cost for the biggest version shown in this pic is only about £120, and no special tools needed to make it (the shot above was taken a couple of weekends ago on the location used for my video in the User Video section).
You can see the first version of this crane through the link in my sig, though I must update the site as it's been improved since then with more bracing that you can see in the pic above.
Anyway, getting back to the one I suggest you go for I know it will work, and to be honest with some faffy after build care it could actually be made to look ok for a woody, matt black paint does wonders

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Anyway, enough hijacking of this thread. I'll get on with it.
In the mean time, am I right in assuming your camera is a Canon XL? Knowing the approximate weight helps to configure the design, though mine was built to take a PD150 with WA converters and a large battery, so not too far away.
And, there is one thing you'd be wise to start looking for now, as it's a must have that can scupper things. Either an old pan/tilt tripod head, or simply the screw needed to fix the camera. For your reference you are looking for a screw which is a 1/4" BSW (British Standard Whitworth). We can either fix the tripod head to the camera plate with the old tripod head, or screw the camera direct to the plate. Ebay helps here.