4x5 diy view camera rack/pinion question

[Pfsor]

Engineers designing nylon racks and pinions for printers don't have to allow for what photographers are apt to do to those mechanisms.

That's true, a camera is different from a printer. The printer nylon pinions get much more wear than a camera ones - and how useful they are! What do you think the nylon examples of the OP are good for?

[Pfsor]

I can't be sure without taking it apart, but this appears to be exactly the type of gearing driving the focus on my new Intrepid 8x10, on a close-to 2.5mm rod (with the reservation that I can't see how the track is fastened--only the teeth), with two gears and tracks, one on either side of the bed, and It's very smooth--I initially thought it might be friction drive with an O-ring until I started looking.

In the Intrepid the whole system appears to be fed through long grooves in the wood taking most of the pressure and acting as a bearing for the rod, with metal bearing surfaces only at the end, under the knobs, only needed for the lateral clamping to lock the focus..

Your comment should not be overlooked. The Intrepid camera is probably the closest to a homebuilt camera the OP wants to have. What is more, the Intrepid you mention is even a bigger camera than the OP wants to build. Yet it uses - despite all the naysayers - a nylon rack and pinion. Isn't it a sufficient answer to the OP question?

[Colin Graham]

At that price, they look worth experimenting with. I'd look for a spur gear that has a protruding hub though, to simplify attaching them to the shaft.

Hello all,
I'm reading this website since time and now I'm starting thinking to build a 4x5 view camera.
I'm looking for parts, in particular racks and pinions and I've found:

Plastic gear width 4,2 mm diameter 10 mm and hole of 2,5mm as you can see in the picture
Mod is 0,5

The rack is
Mod 0,5 length 125 mm, 4mm wide, 7 mm high as in the other picture


Do you think they could be used for a 4x5 lf camera with dimension 18x18 cm ?
Or 2,5 inner diameter of gear is too thin ?

Thanks for help
AndrewAttachment 177132

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[barnacle]

On my sapele camera, the slide is between wooden surfaces; the nylon gear is used *only* to provide for and aft focussing movement.

The pinion gears have a short shaft, and I drilled through that and the brass focussing shaft and locked them with a pin.

(I have a plan to rebuild that camera; some of the wood has started to split - courtesy central heating, I suspect - and there were aspects of the brasswork with which I was not overly happy. But that's what prototypes are for.)

Neil

[Pfsor]

On my sapele camera, the slide is between wooden surfaces; the nylon gear is used *only* to provide for and aft focussing movement.
...
Neil

Which means that your nylon gear is strained even more than it would be in the common rack&pinion construction.
That is a good sign for the OP!

[Andreafotosg]

Thanks all for suggestions and opinions and links
Really useful

I'll look for a different type of gear

Also great the link to Neil's camera, I'll study his idea and solution

Andrew

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[Bob Salomon]

Thanks all for suggestions and opinions and links
Really useful

I'll look for a different type of gear

Also great the link to Neil's camera, I'll study his idea and solution

Andrew

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Why not just buy the parts from a Linhof, Sinar, Arca service center?

[Andreafotosg]

Hi Bob,
It's the challenge, the hardest way for sure, It's a hobby and the final satisfaction for diy is priceless!!


Andrew

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[Jim Jones]

The Noba camera http://www.largeformatphotography.in...8-NOBA-Cameras cleverly avoids the use of rack and pinions.

[Sean Mac]

Also great the link to Neil's camera, I'll study his idea and solution.

Practical experience is more useful than theoretical opinion

I hope you have looked closely at the Phillips / Chamonix approach using linear rails and ball screws.

It is well tested.

Best wishes