Replacement cogs for traction control actuator.
 

Over time, the plastic teeth in the traction control actuator are prone to break. The damage occurs where two of the cogs intermesh at the point where rotation is stopped (rather suddenly) by a buffer.
This actuator was inherited from the 5 and 7 series B*M*W - hence plastic.
I have taken measurements of the workings and my son-in-law did the Cad drawings - being a biomedical engineer / electronics engineer he is familiar with this type of work and I believe the drawings to be accurate.

We had planned for the commercial division of a local university to run a production of these cogs in aluminium (their recommended material as titanium was too expensive).
However, they informed us that there is a difficulty in manufacturing these.
My son-in-law doesn't see a problem, but then we do not have access to large commercial 3D printers.

Does anyone have any recommendations as to an alternative manufacturer? Could the company that manufactured gears for the folding door mirrors be a possibility?

We are not aiming to make a profit on this project - just to help fellow 75 KV6 owners (a little) to keep our cars on the road. Our local Rover Car Club has designed many items eg. lower rail suspension enhancements for the P6B and other non-attainable parts.

How many KV6 engined 75 and ZT cars in the U.K. are fitted with the traction control system - believe that not all were fitted with this system. Also, is this (traction control actuator) a problem in the U.K.

I am attaching a photo of part of a page of our drawings to indicate what we are aiming to achieve. In all, there are 17 diagrams / sections in our drawings. This attachment may lack some detail as we had to reduce its pixels - apologies if this detracts from the drawing.

Hope you may be able to give me constructive recommendations.

Kind regards to all,

egremont.




http://www.the75andztclub.co.uk/foru...584170b1ab.jpg

I don't know of one car with that installed! (not that that might mean much:getmecoat:)
Most have a lonely looking connector under the battery, which I believe was supposed to connect to this.

I am very surprised why the Australian cars would have this fitted!

All launch cars have this fitted, mine did indeed break the stop off the gear wheel. A correctly positioned small nut and bolt through the body of the gear wheel sorted the problem until a replacement could be found.

The early type Cruise control actuator from the E39 is the exact same item for those who are looking for a replacement. :)

One here for example

http://www.ebay.co.uk/itm/M18799-BMW...0AAOSwZ8ZW4JOS

I have had 2 of these go on 4 of the 75 models I have owned. Managed to get a secondhand unit from a wrecked 75 and another from a BMW. Both my Tourer's have traction control, so I for one, would be very interested in this project going ahead.
Graeme

When I had the apparent problem with the traction control a few months ago, Dave (Stocktake) pointed me in the right direction.

The picture below is the original in my Connie.

http://i369.photobucket.com/albums/o...le%20Rover.jpg

The picture below is the BMW one that I got off fleabay.

http://i369.photobucket.com/albums/o...dule%20BMW.jpg

As you can see, the main numbers on both modules are the same.

Fifer

Kaiser is right, every Rover 75 Ive seen over here has traction control,even base models.
The cogs all break eventually,the small bit with the rubber stopper on it always goes but if the cog bits are fished out it will continue to work.
If it gets clogged the cable sometimes gets broken as well.
I read some where BMW did once offer a cog replacement kit but no one ever seems to have seen one !!

So Nice to see that someone puts their effort on making upgraded parts to keep our cars on the road! For all I know, my car may also suffer this issue sometime in the future.

I do not know the details of this part but I guess it may be possible to simplify the design to make it easier to manufacture? Molded parts do often have geometry that is hard/complex to manufacture by machining, hence why they are mounded and not machined. Since you are changing material from plastic to aluminum, which is stiffer, you may skip the ribs between the center hub and the "rim". I guess that the "tab" sticking out may also be able to be made in a simpler way? It would be interesting to see how this part is fitted inside the actuator which would give me a clearer picture of how an upgraded part would look.

All this is only thoughts from a mechanical design engineer from the other side of the world :)

Perhaps I'm too simple but I'm wondering if anyone has approached BMW on this to find out if the cogs can be manufactured? I imagine they are in possession of the original drawings and would have details of the original manufacturer.

Or do they just have 1000 complete new units sitting in stock and they just want to sell those?

Looking at that cad drawing, there is only one method you'd be able to use to recreate those gears.
Machining is out of the question, especially in a soft metal such as aluminium. They will be too difficult to Hold therefore very costly to make. You could possibly mill it out of a solid piece of ally but you'd have a lot of waste.
Only way I could see you recreating them exactly is die casting. You could have a mould made from an original but to make it viable you'd have to produce in a large number. I'd be surprised if a die cast company would take on anything less than 1000 units but you could approach the BMW forums too and sell them there as well.

3d printed cog
 

Hi, did you ever resolve this? I have been running a 3d printed cog in my 75 now for about 6000km with no problems. Not sure how long it will last but they only take me 3 hrs to print so I can replace them as needed.