Home made pinball tilt switch. You will not be able to break this easy and will only need one wire.

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Hi all, late reply due to field service work. Thanks for the idea dingo, but the environment of the application would ruin that type of switch in fairly short order. The mode of operation is 90 degrees from level, deflected by gravity.

It has been accepted by the customer that mercury switches are OK at the moment as long as they are labeled as such. Probably I will use the metal envelope type, as suggested by captainkirksdog, I have found a suitable supply.

I think that in future designs, Hall effect will be the way to go, I have done some "crude" experimentation that shows this to be viable.

I really appreciate everyones efforts in this, thanks for contributing!

 

In your eagerness to comply with new enviromental regulations
are you confident your modification will not fall foul of existing
Health and Safety requirements.

machinery aboard a vehicle, operator unable to observe deployment, sounds bad enough, but what puzzles me is the phrase
"using a limit switch is not possible, due to the small size of the equipment being deployed, and various mechanical limitations"

It does sound like some kind of "homebrew" vehicle modification as opposed to something it left the factory with , rules for this vary around the world and would advise checking with local govt vehicle inspector.

 

I understand what you are saying, and it does sound like this project is "bandaging" at the risk of making things worse. The equipment is from the customer, and meets all of their requirements for regulations, this is merely an added feature they asked us to incorporate.
The equipment is on the roof of a large cube-van, so it is not possible to see it from inside the vehicle, and you would need to be several metres away from the vehicle to see it while standing on the ground. The mechanical limitations are the result of the way the equipment colapses in onto itself. Think along the lines of a small telescoping arm that folds into a recess when closed. The vehicle it is mounted on is kept in a building with a rollup door that just clears the roof of the van, so the operator needs to be sure that the device is down and stowed properly before driving into the building.
This is a municipal utility works department truck, the only things that it left the factory with are the chassis and the cab. It has everything from diesel generators to a microwave oven ( so the crew can eat while staying at a worksite )

Don't get me wrong, I appreciate your input and agree the whole thing sounds weird. It's one of those challenges you have to see to believe. The project started with operators wishing they had a simple way to tell if the equipment was actually down so they could drive into the garage without ripping the thing off the roof or causing damage. Once the proposed solution was presented, the fact mercury was involved raised the ire of the Health and Safety people. Being a government controlled entity, they have strict hazmat rules. We have to provide MSDS sheets for all materials and products that are used in everything we build for this customer.

Ah the joys of red tape

 

having driven off with the roof of my old bedford cf camper van
still erected on more than one occasion i understand only to well

i guess it is one of those problems that has to been seen first hand
in order to comprehend just how awkward a simple request can be to implement in practise.

my own brother has a similiar request for me to build a 'pop up'
air scoop into the bonnet/ hood of his car.