Mamiya C330 Focus Knob Problem

Les Berkley · Sep 13, 2014

Hello!

I have a very nice Mamiys C330f, which works beautifully. It has one odd problem. The right-hand focus knob was badly manufactured. It is 'canted' about 20 degrees, and 'wobbles' as I turn it. Nothing is broken. The splined shaft and the stud onto which the knob screws are perfect, straight and true. The threads in the knob are clean and undamaged. It's definitely a manufacturing defect. Does anyone know where I can get one of these knobs? It's pretty annoying to feel the 'woble' as I focus.

Thanks to all.
Les Berkley

Gerald C Koch · Sep 13, 2014

APUGuser19 said:
It's NOT a manufacturing defect. Somebody has dropped the camera or some other sort of damage. I't possible the shaft was bent. It didn't come from the factory that way--I promise you.

I agree. If one were to drop this camera this is the sort of damage one would expect.

Les Berkley · Sep 14, 2014

It is a manufacturing defect. The shaft onto which the knob screws is absolutely fine. If I remove the knob and turn the other knob to rotate the shaft, there is NO wobble. Focusing is perfectly smooth. Looking at the defective knob, you can see that the threaded (female) hole is at an angle to perpendicular.

fotch · Sep 14, 2014

If you cannot get a replacement knob, try a machinist, maybe the can fill & re-tap the hole. They should be able to check & see if it is made wrong.

jadphoto · Sep 15, 2014

Hard to believe that Mamiya would let something like that out of the door. But the made a ton of the CXXX series so it's certainly possible. I'd think the best bet is as fotch said, "find a replacement knob" or a cheap "donor" camera.

JD

Ken Nadvornick · Sep 15, 2014

From your very detailed descriptions it does indeed sound like a defective part.

Have you tried contacting Mamiya directly? Perhaps they have a few replacements hidden away in dusty boxes in a corner of their warehouse. Or if they disposed of all previous TLR stock, maybe they can tell you who purchased it? Perhaps an independent repair service?

Calumet hung on to parts for their Monster/Beast 8x10 cameras for years and years. They didn't advertise that. You had to call and ask. But if you did and they still had it, they'd sell it to you for a fair price.

[Edit: Or take a look at this auction on eBay. It's for a large lot of various Mamiya camera parts. Do the zoom thing on the second (or third) photo. Look in the far upper right corner. Are those C-series focusing knobs in the plastic bag? If so and they are C330 knobs, perhaps the seller might be willing to break them out for you? (Note that I have no connection whatsoever with this seller. I just searched on the term Mamiya C330 parts.)]

Ken

Gerald C Koch · Sep 15, 2014

You might be able to use a knob made for electronic equipment. They are available for several shaft dividers.

Another possibility would be to have a machinist re-drill the hole correctly (making it a bit larger) and then make a bushing to make up the difference. This has the advantage of not changing the appearance of the camera.

Surprised this bad knob made it past Mamiya's quality control.

Rick A · Sep 15, 2014

Try contacting Mamiya here, they were able to supply me with a couple of parts a couple years ago.
http://www.macgroupus.com/

Les Berkley · Sep 18, 2014

Thanks to all. Auction did not include correct knob, but I will contact Mamiya directly. It's just an annoyance in any case.

Mamiya C330 Focus Knob Problem

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