Kern Tripod Details

If no one else responds, I'll get you some pics in the next day or two. I'm on the road at the moment and hope to be home later today.

I have one at the office. I can send some photos early next week as well.

Thanks to you and Dave!

I adapted by Kern centering rods to the newer Leica GST120-9 tripods. I had to fabricate a mount to keep the head on the tripods, but they work very well. What exactly are you looking for in regards to pictures?

> What exactly are you looking for in regards to pictures?

I'm wondering if there's a mechanism that allows the domed head at be slid around on the top of the tripod and then locked once the pole has been plumbed. It isn't obvious to me how this would be arranged. It seems like without that capability the only means of plumbing the pole would be via the tripod legs, which seems a little coarse. I'm hoping that photos would show how all that is done.

Basically you replace the current tribrach mount with a fabricated piece

> Basically you replace the current tribrach mount with a fabricated piece

Aha! I'll have to take a closer look at my Kern pole to see if it'll allow for that. I'm not sure it has the clearance between the dome and the clamping screw, but I may be misremembering.

Thanks!

That's really cool. I still wonder why the Kern concept didn't take over. It's elegant.

When Leica bought Kern, the salesman for Leica said that Leica would continue to make and support the Kern tripod. He lied.

There's good and bad with the Kern centering system, but I have been using them since 1986. I believe that using the Kern legs has prolonged the life of my instruments as the legs are already over the point and the plate level before you put your instrument on the legs. The centering rod also makes a good plumb bob.

> Basically you replace the current tribrach mount with a fabricated piece

Here's a rough-out of the piece I plan to use. I didn't have time to finish it today -- I need to remove some more material around the axle hole in order to clear the underside castings on the Brunson tripod I'm converting -- but it's getting close.

Not sure what kind of details that you are looking for, but here a few snapshots. Let me know if there is something else that might help you.

Those photos show a real Kern setup. It occurred to me last night that the modification I'm making -- like the one that Berk shows above -- will probably work fine, but will put all the stress on a small portion of the clamping screw face rather than distributing it evenly. This is because the screw won't be perfectly normal to the fabricated bracket.

In the Kern setup shown above there are two additional pieces, one with a spherical contour, between the clamping screw and the tripod head that corrects for the non-normal angle of incidence between the screw and the head.

I do have the two underside pieces from the Kern setup, so I'll see if I can incorporate them to address that issue.

Jim,
I am attaching 6 photographs.

The first three are of a real Kern Tripod.

The only difference I can see in the Leica set up from the bunch of photographs already shown on this subject. The difference is my Leica adaption shows a small metal piece that allows the cover to be hooked onto that and the other end of the rubber belt that runs through the cover to hook on one of the leg opposite, this holds the cover for storage and transportation. The three photos show the tripod legs spread and it shows the attachment fitting for the strap to hold the tripod cover on. The other two show the tripod cover installed and how it is attached at both ends of the hold down strap.

The second three show the Lecia adapted tripod.

I don't know if you have the cover or not but it sure is good protection for the Kern mechanism on top of the tripod. If you have a cover it should be simple to make a hook ala the Leica photographs.

Jerry M. Davis

The lower of the two Kern pieces is concave on the inside, to a slightly smaller radius than the upper convex plate. When they tighten the lower one slides against the upper until the edge of the rim makes equal contact all round. It'll twist around as necessary.

If the ones you have don't fit the tripod you are intending to use you could probably turn up something similar from a couple of small squares of half-inch aluminium fixed to a bolt held in a decent drill. Thinking back many years to when I last used the Kerns I don't recall that the plates were "high-precision". I'm sure they suffered a number of dings over the years and had to be "reshaped" with a hand file.

I used KERN Instruments/tripods for 9 years on USFS Cadastral. The only time I didn't like using it was if I had to set up on a point that was higher than the rod would allow clearance for. The worst setup I recall was a very tall rock Section corner in a rock mound on the side of a steep mountain. My partner and I spent 3 hours building platforms of rock stable enough to set the legs on and stand next to the instrument. We were able to shoot the 1/4 corner to the south direct and saved a day (or more) of traversing. The rodman did have to cut down 10 lodge pole pines to see the 1/4 corner, it gave him something to do while were building our flat top pyramid 😉 .

The rod is removable, is it not? Of course, then you'd need a plumb bob attachment I suppose...

Jim Your adaptor looks a lot like mine. Made it out of aluminum stock. I have 7 working Leica tripods with the Kern centering rods. All have the aluminum and none have failed. I presumed that you had the centering rod, locking handle with the concave washer that would go against the aluminum. The handle has a convex face that nestles into the washer in most cases.

Using a Leica on the tripod and needing to set on a point that protrudes out of the ground more than the shortest length of the centering rod (or visa versa, deeper that the centering rod will extend, allows me to unscrew the centering rod and use the laser plummet.

Jim
If you are looking for a set of legs I may be able to help.
I think I have about a dozen or so in the shed.
Let me know.
Email is good.
Jim in NH

> If you are looking for a set of legs I may be able to help.

Email sent.

I had some photos to post of the completed conversion, but Picasa crapped out during the import process and failed to store them on my computer. It did, however, manage to erase them from my phone. What kind of dimwit designs something that makes that possible?