Looking for rotary switch knobs to suit a 411 dash

[Kevin H]

Having installed an air con system on my 411, the original rotary heater controls are now redundant, so I have set about intergrating the air con controls in the dash, instead of using the tacky add-on panel that came with the VintageAir AC system.

I have rotary temperature and mode controls but the original switch knobs from the Bristol do not fit the D shaped shafts on the new switches.

Does anyone know where I can get rotary switch knobs to suit a 411 dash?

the attached pictures show the old control and knob alongside the new switch, plus another view of the knob I want to replace. So I'm looking for something similar that fits the new switch.

[Janne]

A question: is the new shaft bigger or smaller than the old one?
Is it also d- shaped?

[John Simmons]

If you can't find anything suitable, you could possibly modify the original knob to work with the new shaft. Assuming that the new knob has a metal "D" ring embedded in the plastic. You could retrieve the "D" ring and install it in the old knob using epoxy. I've done similar fixes in the past. The issue is how much force is required to turn the new switch. If it requires too much force the modification might fail after a while.

[Janne]

That is the reason for my question, about the relative sizes of the shafts. New shaf smaller - remove ring or if no ring, clean inside with a burr, get some 2-component hard filler (I would use Cold cure Acrylic) , put some vaseline on shaft, put knob on shaft, let harden, remove, remove excess, etc etc.
It is easy.

[Kevin H]

Thanks for the responses.

The new switch shaft diameter (D shaped, max 6.35mm) is smaller than the old one and a different shape - the old shaft is hexagon shaped. Unfortunately the new switch shaft is also considerably shorter than the old one.

I don't have any D ring clips, but I don't really think embedding a clip in the old knob would hold for very long, because the mode switch is quite stiff.

My preference would be for metal knobs with a grub screw which could provide a very solid fixing.

[GREG]

I have A/C control knobs from a 603 or the plastic Bakelite one for the wipers on an earlier V8 if any use. Or maybe some round chromy ones from a Radiomobile radio !

So I have quite a few knobs and like Janne mentioned , you could even put Vaseline on my knob if you want !!

[Kevin H]

Originally Posted by GREG

I have A/C control knobs from a 603 or the plastic Bakelite one for the wipers on an earlier V8 if any use. Or maybe some round chromy ones from a Radiomobile radio !

Chromy ones wouldn't suit, but the other ones you mentioned could if they have a D type fitting. Any chance of a picture?

RS Components appear to have something reasonable. RS | Hardware | Knobs, Levers, Handles and Handwheels | Knobs | Round-Knobs They're not metal, but then nor were the original ones.

[GREG]

The wiper one looks a bit like this

GENUINE LUCAS JAGUAR HEATER SWITCH KNOB XK 120 & 140 on eBay (end time 23-Mar-11 17:40:05 GMT)

I will take a picture of the rear tomorrow with some measurements.

[Janne]

When I restored my 411 I looked on web companies that supply British Vintage cars. Bristol used parts that are common with the other british cars of the same era.
The square rear light assemblies were usedby Aston Martin (chromed surround) and British Leyland (blacksurround). Bristol used the cheaper black surround.
I found NOS assemblies.
It takes time to find bits like that, but once I found about 6 or seven companies that sell that stuff, it was fairly easy.
Unfortunately the motherboard on my UK laptop got fried, so I lot every piece of info.
Most of those companies are in the mag Classic Car. Some of them I got from the clubs for each make in UK.

Good luck, Kevin!
I will try to see what I find.

[Kevin H]

Thanks for your help with this guys - please don't go to too much trouble.

I think I will order the ones from RS Components (see pic) as it appears they will do the job for the time being. They're also very cheap so I can always replace them later if I find some nice ones.

[Janne]

Check out Elma Electronic - Complete housing solutions and components for the electronics manufacturing industry.

Plenty of knobs (without vaseline) with setscrew fixing.


Your shaft is 1/4 inch. Not easy to find in this Metric world!

[Janne]

A better oner?

Check out item number (RS stock number) 223-742 on your site

[Kevin H]

Thanks Janne, Elma looks like a really good source!

If I use one with a grub/fixing screw the imperial shaft size shouldn't matter.

The switch is from the USA which is probably why it's an imperial size. it would probably be illegal to do that in the EU

[Janne]

Kevin, any possibility of you telling us the source of the Aircon unit, and the installation?
I will need to install one myself.

Your shaft is 6.25mm, but some of the knobs have a 6mm hole. Not even Vaseline will help.....

You can drill it out gently. 0.25mm ic nothing in Plastic. Lots of lubrication (to prevent overheating and discolouration) if you choose an Aluminium knob.

[Kevin H]

Originally Posted by Janne

Kevin, any possibility of you telling us the source of the Aircon unit, and the installation?
I will need to install one myself.

Vintage Air - Inventors of Performance Air Conditioning - www.vintageair.com they sell generic systems as well as ones to suit specific cars

They also have distributors/resellers in many countries.

Your shaft is 6.25mm, but some of the knobs have a 6mm hole.

The shaft is aluminium so it won't take much to remove 0.25 mm from it, or as you say I can drill the hole out if it's a knob with a grub screw.