Replacement knob for Hella cabin fan

[tudorsailor]

I seem to be missing the knob for 2 black Hella marine turbo fans as are found on many boats

Does anyone know where I might get a spare?

The shaft of the male part is 15mm. Would any knob with 15mm diameter thread work???

Thanks

TS

 

[rogerthebodger]

Is it the big knobs on the side.

I do meen the adjusting knobs not the knob that does the adjusting.

Most electrical knobs have a 1/4 inch hole with a grub screw to lock the knob to the adjusting shaft

15mm die thread would be quite a big thread. I would also measure the thread pitch ass the thread could be non standard.

I would try hella for a replacement knobs.

 

[chris-s]

Once you decide the sizes etc, check out ebay.

 

[tudorsailor]

Once you decide the sizes etc, check out ebay.

Not the knob that controls fan speed but the one on the side that you loosen to adjust tilt (and vibration) and tighten again
Hella don't seem to have spares.
I guess if it's an M15 I could embed a nut in a 3D printed knob. Just need to find a M15 nut!
Thanks

 

[RichardS]

I tried to find a new speed adjusting knob for mine for years as the contact retainer had split. It proved impossible to find one so in the end I had to bodge it.

Richard

 

[rogerthebodger]

M15 is not a standard thread size. The closest standard is M16 or M14 but M16 is the most common size.

Do measure the thread pitch before going any further.

Tou could also look for a knurled knob in brass or stainless steel.

 

[penberth3]

M15 is not a standard thread size. The closest standard is M16 or M14 but M16 is the most common size.

Do measure the thread pitch before going any further.

Tou could also look for a knurled knob in brass or stainless steel.

Probably a quick and inaccurate measurement, but no - I didn't think there was such a thing as M15.

 

[chris-s]

Not the knob that controls fan speed but the one on the side that you loosen to adjust tilt (and vibration) and tighten again
Hella don't seem to have spares.
I guess if it's an M15 I could embed a nut in a 3D printed knob. Just need to find a M15 nut!
Thanks

If it’s a nut and you can 3D print it, include the thread in your model. I’ve printed threaded parts many times. With a good amount and of infill they can be pretty strong. And you could print several spares.

 

[tudorsailor]

A friend in Greece has confirmed that the nut is 16mm with 1.5mm pitch. I am in London. Boat is in Greece. If I 3D print an M16 nut or knob, could someone kindly test it on a fan to see it it fits if I post it too them?
TS

 

[penberth3]

A friend in Greece has confirmed that the nut is 16mm with 1.5mm pitch. I am in London. Boat is in Greece. If I 3D print an M16 nut or knob, could someone kindly test it on a fan to see it it fits if I post it too them?
TS

Wouldn't it be easier and quicker to order what you need off e-bay?

 

[tudorsailor]

Wouldn't it be easier and quicker to order what you need off e-bay?

Maybe but...... None of the knobs on eBay have the wide base as the fan knob has. So I have designed and printed a test knob. I have ordered am M16 screw on eBay and wait to see how it fits. Oh and more satisfying to create the knob and print it - if it works

TudorSailor

 

[tudorsailor]

Printing the thread was not successful. So decided to embed the M16 nut in a knob



This should work

TS

 

[RichardS]

It looks just the job. Is there a technical reason why the orientation of the flats on nut do not match the orientation of the plastic holder?

My instinct is that a parallel orientation would be stronger.

Richard

 

[tudorsailor]

It looks just the job. Is there a technical reason why the orientation of the flats on nut do not match the orientation of the plastic holder?

My instinct is that a parallel orientation would be stronger.

Richard

No reason for the orientation other than it snapped that way when I was designing it in Fusion360. Strength is not a factor here so I will probably leave it as it is.
I will now print it in ASA as that is more durable that PLA. I intended to glue in the nut but the fit is so tight that it is not necessary!
I printed the knob on my new-to-me baby Ultimaker2Go printer which I have modified/upgraded. So not only am I please the design works but pleased the printer performs too.

TudorSailor