Aug 27 Fort Macleod Scores???

[Midnightsky]

Um, how do you align the units when wrapped in bubble wrap?  The IR emitter is easy -- it sprays a very wide pattern, but the receiver need some precision.

Trial and Error? It won't be perfect, but should provide better protection than current setup for both car and timing equipment.  There must be a way to figure out some sort of compromise that works to improve the situation.

[MurrayPeterson]

I may personally hate building new timing gear, but to be very honest, I consider the current situation to be pretty good.  We get no car damage at all, and the replacement cost is reasonable.

It may be possible (via styrofoam or bubble wrap) to make something that bounces away and doesn't get destroyed when hit.  Not a guarantee though -- cars hit things pretty hard and fast.

And, really, does the club really want to pay for a complete redesign to lighten the equipment?  I can't give you a firm dollar figure right now, but I can't see it coming in much cheaper than 5 to 10 thousand.  And once the development and testing is done, the actual units are going to be much more expensive.  I don't see a payoff here.

[Jackal]

I just read this thread and am assuming there was a timing related incident on August 27. 

I'm just going to do a bit of spit balling here as I've never really looked at the radios themselves.  Just thinking of this in a way that may sprout some ideas as I actually break things professionally for my living. Realistically we can't prevent it from ever breaking,  but maybe we can increase the ability of it to survive.

If interested,  I'd love to take on a project like this.  I also mentor at a Junior Engineering Lab,  and have access to much of what's needed,  and a group of youth that need projects to keep them entertained. Smashing cones in testing situations could work off some of their energy before they settle into anything else.  lol Besides...  the Milk carton egg drop is sooooo 1986.

Driving forces, and considerations.
-If the unit gets hit and the whole device is together,  we have some major repairs on the line. 
-Units require three main components. Radio transmission,  battery, and some sort of IR sensor correct? Missing anything?
-The heavier the equipment is,  the more damage there is to the cars in an incident.
-The circuit boards have extremely limited survivability without some sort of housing.
-To minimize the cost,  using the current electronics is best.



Spitballing

Separate the components, minimize the repair?
-do the radio, battery and sensor all absolutely need to be co-located? What if the battery and the radio are in a separate safer place,  and the sensor is the only susceptible item?  It may reduce the cost when a repair is needed?

-The sensor would need a remote line,  and a very small housing (Or cone... See below).  The remaining equipment can be as far as the tether physically/electrically can be.

Hitting Cones anyway.
-What about using a cone as a vessel?  Some soft foam and a small flexible structure inside the cone may work.  Cut a hole in the cone for the sensor to shoot out of.  A couch foam could be cut to a cone shape and little cutouts in that foam could house the battery radio and sensor. Using strips of foam glued together gives a bit more structure to the whole foam piece,  that could be cut to fit in a cone. 
The cone withstands the brunt of it,  and the foam disperses as much of the force as it can.

This idea would be basically placing the circuit boards and the battery somewhere in the middle of the foam that would fill the cone.  A sensor pocket could be made and just needs to line up with the hole cut in the cone. Leave the foam as a separate piece for ease of removal from the cone. Maybe as two separate halves with the weight in the middle.

Pilon by Duane Jacka, on Flickr

Both
-Maybe putting a remotely tethered sensor in a cone is best,  and the remaining hardware is elsewhere.

Maybe this post will spur on the best solution through further discussion....  Thoughts?

[MurrayPeterson]

Driving forces, and considerations.
-If the unit gets hit and the whole device is together,  we have some major repairs on the line. 
-Units require three main components. Radio transmission,  battery, and some sort of IR sensor correct? Missing anything?
-The heavier the equipment is,  the more damage there is to the cars in an incident.
-The circuit boards have extremely limited survivability without some sort of housing.
-To minimize the cost,  using the current electronics is best.

Major components are:
1. Circuit board with a small CPU (Atmel) and support components
2. Radio transceiver
3. Antenna
4. IR sensor
5. Battery

Right now, the radio and IR sensor are attached directly to the circuit board.  The entire package is about 5cm x 10cm, and uses the radio antenna socket to attach to the case containing it and the battery.  The IR emitter has no radio, so it uses the 6 IR LEDs to attach to the case.  If you want exact details (and pictures), this file contains a do it yourself manual on building an entire system:
https://drive.google.com/open?id=0ByeFbiNdvLbGdHB4VnBKWVFhSEk

I think the problem of survivability comes with several problems:

1. Crushing.
Without a solid steel case and some sort of "break-away" antenna connection, the system won't survive being run over by a wildly spinning tire backed up by the entire weight of the car.  I do know that 1/16" thick steel cases just get crushed (Race America hardware).

2. G-forces from a strike and bounce instead of being crushed
To prevent being run over, the unit's case would need to be too large (and stiff) to go under the car.  Body damage is now a likely outcome unless we are really careful with materials and weight.
Here is where your foam might help, but I am not sure about the g-forces.  I do know that they are enough to shatter the case and gell cell, as well as rip any socketed components out of their sockets (or just destroy the socket).

3. Antenna connection
The antenna is attached to the radio (directly or via a cable), and any strike will (usually) rip the antenna socket right out of the radio circuit board, thus destroying it.  We would probably need to use different antenna attachment methods (different model of radio) that are more likely to separate under strain.

4. Must withstand wind up to Fort Macleod levels (100 kph?) as well as torrential rain.  No spikes allowed in the surface of the runway
We have a Farmtek system that uses light tripods to mount the equipment.  In Fort Macleod, I need to tie a brick to the tripod to keep it upright.

5. IR sensor must be at least 3-4 inches above the ground and protected from direct sunlight.

[Pat S]

As it stands right now, are the units generally a total loss once they have been struck or can they be rebuilt? With the large impulse experience by the unit in a collision, it seems like it might be a losing battle to protect it and it might be more effective to just minimize rebuild cost.

I like the idea some people were working towards with of making the units have a remote sensor which could be "sacrificial" and put the bulk of the equipment in a safer spot (seeing as the stop box it straight, a few cones up would probably be sufficient for a lot of situations). If an incident occurs, plug in an new emitter/receiver and you're back racing.

On the "Egg drop" topic, I've seen some electronics filled with epoxy or basically hot glue when it is expected they will experience vibration (such as tire pressure monitors). That may help keep the components in place in an impact, but at the cost of serviceability and mass. The photo Murray posted looked like they shifted quite a bit in an impact.

[Reijo]

Make it thinner (e.g. not as tall) if possible?  And then strengthen the sides so a car can run over it directly without damage.  A sideways tire would still send it flying though ... and that might be another story.   Could also put foam or styrofoam around it to minimize damage to car bodywork.

[MurrayPeterson]

They are almost always a total loss, with the odd low speed "bump" that just cracks the case.  The cost of replacement is fairly low for something that is hand-built (I only charge $20/hour for my labour).  I really can't afford to get into large volume production, where the costs can drop dramatically.

Don't forget that adding connectors and cabling can boost the cost, sometimes significantly.  For the IR emitter, those items would probably be too expensive to result in money savings.  I always place the emitter in the place most likely to get hit, since it is much cheaper (no radio or antenna).  I also use the cheapest batteries I can get (about $14 each).  LIPOs run about $70 for the same voltage and capacity.

[Pat S]

Another way to go is to be mindful of the timing equipment in course design, similar to a clutch saver start, a equipment saver finish. Such as a gate ahead of the finish line that forces you to finish on a mini straight. The course designers may already take this into account, the work they do is beyond me