Adapting a Thedolite Tripod for LF Use

[Garen]

This has been a useful project in converting a theodolite (surveying transit) tripod (picture 1) for LF use. The top of the tripod (picture 2) has an opening of 2.5" diameter with 22 tpi thread (picture 3). More pictures to follow.

[Garen]

I machined a 3" aluminum disk (picture 1) with a 2.5" shoulder threaded at 22 tpi (picture 2). To mount the pan tilt head a 3/8" - 16 tpi stud and a knob is required. I also added a wing nut to provide a second tightening fastener to stop the main knob from becoming loose during transportation. More to follow.

[Garen]

The adapter threads onto the tripod top. The 3/8" stud threads into the base of the pan-tilt head (picture 1), then mounted onto the adapter (picture 2) and tightened down using the knob from below (picture 3). The camera mounts onto the pan-tilt head (picture 4).

Transit tripods are sturdy. There are lugs on the tripod feet to stand on and push them down into soft ground. The camera is rock steady in mild windy conditions. The total cost of the project including the purchase of the tripod is around $45. I have not included the cost of my machinery or my time in the $45!

[Dave Wooten]

Nice!

[Archphoto]

Great job !

These tripods are designed to take abuse, I even wonder if you could just replace the top plate of the pod with a new one with a piece of 3/8 thread, so you would not need the insert that you made.

Peter

[reellis67]

Nice work. I did the same thing, but yours look like a cleaner job. That thing will take ALL kinds of abuse - have fun!

- Randy

[Len Middleton]

OK, so there is someone else out there who knows what a thedolite is...

I managed the easy way out. My surveyor's tripod had a threaded cap that fit onto the male threads on the top of the tripod and it had a 3/8" stud on it.

Cheap and robust, and the legs on mine are wood, so it has that additional dampening effect over an all metal one.

Nice work, but yes I would not expect that the $45 would include the cost of the lath to turn the bits or the equivalent of your time as a lath operator / machinist.

Len

[Garen]

Oops! There is a misspelled word in the title of my post. The correct spelling is "theodolite".

To answer Peter's question, more modern tripods have 2.5" opening and are not threaded. The adapter plate does not need to have a threaded shoulder. Securing it to the tripod will have to be done differently. Bear one thing in mind, the more sophisticated the design, the more expensive it is to make. Keep it simple and cheap. Spend your money and time on the picture (not the equipment).

The legs on my tripod are wood (like Len's). The color is beginning to irritate me. One of these days, I will spray it with gray or black paint.

It is reassuring to hear from everyone that these tripods have served them well. What remains to be done is to take more pictures. Fall is around the corner for landscape photography. I needed this tripod to shoot jitter-free long exposures.

[jim kitchen]

Nicely done... :)

The bolt insert is a good idea, since a male thread could shear if attached to the original plate, causing the owner to replace the entire plate periodically. A few folks may not like the replacement cost for a new plate, such as myself. Shearing points are best if the point is separate from the original plate, where the shear point could be a softer bolt placed through the port in the plate. Standard threaded bolt sizes could be accommodated if the bolt were placed within a manufactured bushing designed for a specific bolt thread or diameter. A set of opposing locking pressure points, such as a set of threaded keys that fit into the base of the tripod head, may be useful too to prevent the tripod head from rotating on the plate. Threaded keys that simply apply pressure to the base of the tripod head's plate are ineffective over time, where a circular opening within the tripod head's baseplate that accepts a threaded key, or the insertion of a threaded key, would be more secure. Lock washers are most useful between the lower threaded nut and the bottom of the plate, allowing the user to tighten the bolt with finger pressure, without stripping the bolt's soft threads.

I have a similar set up that is currently under construction...

I did use a transit leveling head as the intermediate stage on the surveyor's tripod, but I found this to be a very weak point in the tripod system. The leveling head's locking mechanism was not foolproof nor as secure as I thought it should be. Rigid connections with a weak shear point may protect the camera in a fall allowing the camera to break free from the tripod head.

jim k