Korona 11X14 Front Rail Replacement Ideas

Last summer I purchased a Korona 11X14 camera bones missing a few key components for a great price (Minus a back, bellows and the front extension rail.) I have nearly finished the camera with the exception of the front extension rails. I am pretty handy with wood and woodworking tools so it is the geared rails that are attached to the wood extension rails that I need ideas for. I looked at other extension rails for sale but like the film holders and backs there is no standardization among the various manufactures nor within the various camera models of different sizes. One would think that a manufacture would standardize on one size and pitch for racks and pinions.

I have looked at McMaster/Carr and various manufactured racks and pinions available on ebay but have not found a suitable replacement of a similar size and at a reasonable price. I would like to hear how anyone else has solved the extension rail replacement issue or how you have created a new method to move the front standard backwards and forwards for focusing. Thanks, appreciate your ideas.

Robert

Hi Robert,
I had nearly the same problem some 15 or so years ago. I bought an 11x14 Empire State that had the front rail, but no back rail. I found a local woodworking shop and found some old, wrong-sized orphan rails on eBay the pro woodworker could cannibalize to use on the new rail. You just have to match the pitch, etc., of the gears on the camera. I happen to have some parts from an old Korona 5x7. I'll check and see how much of the rail I have. It's yours if you want it.

Another idea is to forego the rack and pinion for the new rail. Just make the rail with the groove on the sides. Use friction focusing (instead of rack and pinion) and the already-in-place locking mechanism on the Korona front standard to lock the front standard in place when in focus. This is what I would do today, assuming the front standard will lock down tight.

Update: The two tracks are 14 1/4" long.

Mcmaster has gear rack in acetal plastic for a fraction of the steel or brass prices. (you DO need to correctly identify the pitch and pressure angle though)

Michael, thank you for the offer of your spare parts. I have decided to go with buying matching modulus spur gear and rack from China. I am trying .5 Modulus for the metric equiv for pitch. I just hope it is not too fine a modulus/pitch for the purpose of a view camera focusing/extension rail. As it is the gears on my other cameras occasionally want to jump a tooth. I chose the number of teeth so that the diameter of the spur gear was slightly larger than the original on the camera. I will have to adjust the depth of the rack on the rails as the rails available online are much deeper than the original and same for the width.

Thanks again for your offer.

Best regards,
Robert

Tracey, Thanks for the McMaster and Carr recommendation. They do not have the needed pitch and pressure angle for the older camera. The ancient gear racks are very squared-off toothed and so the modern pressure angles are hard to convert. Any way I used their filters and diagrams to choose .5 Modulus and 20 teeth to get the diameter spur gear that I wanted. Modulus 1 with the larger tooth on the spur gear was either too large or small a diameter based upon the number of teeth that were available online. Thanks for your advice/help.

Best regards, Robert

If you have the measurements, you could get them 3D printed (there are some exotic filaments that work well for rack and pinion assemblies). However, if you don't have the CAD skills, you'd need to pay someone to create the model for you first, which might be prohibitive.

Here is the front rails I made with red oak balusters purchased from HD and the spur gear and rails purchased from China on EBAY. I purchased the spur gear and rail from China as I could not find anything that matched the original or even came close at a reasonable price. So I purchased a set of metric rails and gears from the huge selection online. (I used Modulus 0.5) The wood used for the rails were red oak balusters that I plained down to match the original rails. (I had the original base for the camera but not the front rails, so I matched the thickness of the base for the rails) The steel rails were drilled and tapped and screwed from the back of the wooden rails. Korona originally used nails to attach the geared rails but I wanted something a little more secure. The hardest part was tapping (threading) the steel rails as they were partially hardened. I broke several taps while cutting the threads and so you may see several screw holes that were not used in the photos. I don't have the greatest wood working skills or tools, but the extension rails do work smoothly. FYI, I also had to replace the steel rails on the base as well because the new rails/gears are metric. So it is possible to make your own extension rails if you have the tools.

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