Lap Timing System

cathurga wrote:

Greg...you're aliiiive!! good to know feller.

We can always use your car

I dont think anything less than a decent power supply will do. One concern I have is that the timing system takes it's power from the USB port, and this means that whatever battery we use...is going to get drained, pronto.
Therefore, I think we will need a power inverter connected either directly to the battery of a car that is charging it. Alternatively, find a power source nearby....and that is not going to be easy.

Yeah I'm still here. I've had a couple weekends away camping, but hopefully make it on Sat.

I understand your concerns. I'm sure it would flatten a car battery quite quick, but that's mostly because all the power is lost in the inverter, turning it into 240V, and then back to what ever the laptop input is, then charging the internal battery as well as running the PC.

USB draining power - I think it will not draw much. I notice you can have upto 24 ft wide bridge (20 sensors) and we are only using 5. USB power output is quite limited and we are not pushing the limits with this setup.

Anyway, suit yourself. Just my two cents.

what happened to you Greg?!!!!! we need more mini's on the track, please try to make it by sat, cant wait for this thing to kick off

Greg,

I have a battery that was left over from the starter for a plane engine, I think it was 12V....I will check, we could at least do a trial run. I will bring it on Sat, lets look into this...would rather that than the car and a power inverter....Not sure how to charge this thing though...dont think I ever used it...

Greg,

Just found a PDF on the battery I have, it's this one....

http://www.elv-downloads.de/service/manuals_hw/48264_WP72_12_um.pdf

I have just put it on to charge with a 12V household charger that does a max ov 12V at 1000mah....or 1amp.

I will leave it on overnight and see if it takes a charge.... I am not good with these lead acid units...but it says it is a 7ah so assuming the laptop draws 7A or less, it should give us an hour....

I think.

Yeah that is the type of thing I was thinking of.
It all depends on what your PC uses really.

As a guide, my laptop has a 5 Ah battery and lasts maybe 3 hrs, so this would suggest my laptop uses less than 2 amps max. Yours is older laptop so who knows.....

Saw a cheap inverter at Carrefour in the camping section (80-90 dirhams) with the standard plug socket on the one end and cigarette plug on the other, you could just plug the laptop charger straight in and run it from the car - no need to worries about batteries, just fuel to run a car at idle....

Just a thought....

The inverter seems to be the best option when you absolutely have to have 110 ~ 220V but on reflection it seems overkill in this case.
If Gregs laptop is using no more than 3A then a car battery rated at 60Ah should be able to power the laptop for 20HRS!!! so I think a std car charger rated to run the laptop should be MORE than enough, without having to run the car....or even get close to running it flat....even at TWICE the Amps it should run for 10 hours....I think we have a winner...where can I get a shop with knowledgeable staff who can recommend a good quality car charger......Dubai? Not likely....best I try the internet.

hey guys.....are u looking for inverter from 12v dc to 220 ac?....

i have one inverter in the shop that convert 12vdc to 220ac (i hope it still kicking)...

wish that could help...

UPDATE:

Lap timing system will be delivered to me this afternoon. I will start creating names and details on the software.
I will also look into how we mount the transponders. It is recommended that we have the units under clear glass for best results, so in mini and touring we need to consider these factors. I can devise a way to mount for the M-03 but I dont have an M-05 so I cannot check that, if one of the guys with these chassis have a look at a possible mounting solution.
I think the best way might be a plate on the chassis that we can apply some velcro to and then attach the transpoders like that. Velcro is tough enough and will make it easy to transplant ...
Paul, if you have a chance, would you be able to have look at the parts requirement for the bridge? If not, send me that drawing and I will try to get a cost....

Thanks again to everyone in the raffle, you have all contributed.

Andy

Andy,

Will try and get hold of some pricing on the PVC tubing and connectors.

Essentially what we need is:

PVC Pipe (+/- 1 inch diameter)

2 x 1500mm
2 x 600mm
4 x 560 mm
8 x 200mm

CONNECTIONS

16 x T-pieces
4 x Staight (180 degree) pieces
4 x 3 way piece (90, 90, 75 degree) or (90, 90, 90 degree)

If anyone knows a decent pvc pipe supplier let me know, will check at ACE and a couple other places.

M-05 comes with a transponder mounting plate which sits above the servo towards the back of the chassis.

does that apply to the m-05 pro kit as well? didnt see any mountings.....

Paul, thanks for the equipment list.

With regards to the transponder mountings, they recommend visibility through windows....might have to fashion something other than the transponder mounting...

Regards

Andy, okay i see not so easy then....

Ahmad there are two holes on the chassis where it extends to protect the servo arm, see the picture below with transponder mount installed.

[img][/img]

paul@play wrote:

Andy,

Will try and get hold of some pricing on the PVC tubing and connectors.

Essentially what we need is:

PVC Pipe (+/- 1 inch diameter)

2 x 1500mm
2 x 600mm
4 x 560 mm
8 x 200mm

CONNECTIONS

16 x T-pieces
4 x Staight (180 degree) pieces
4 x 3 way piece (90, 90, 75 degree) or (90, 90, 90 degree)

If anyone knows a decent pvc pipe supplier let me know, will check at ACE and a couple other places.

M-05 comes with a transponder mounting plate which sits above the servo towards the back of the chassis.

hi paul

i'm not sure wether those 3/4-way fittings are easily available..
but for sure we'd find tees, couplings and elbows..

maybe we can just incorporate what is available even in the hardware shops in satwa or karama..

i'll try to come up with something within the day..

@ orange alien

Agreed the 3 way fittings will be difficault to find, but will make a lot easier if we do find them....More than likely we will need to make a plan and adjust the design to suit what we can find.

I will got hunting for parts later this week, but let me know if you find anything suitable in the meantime!

Okay, I went passed Speedex (next to Oasis centre) on the way back from a meeting and they have pretty much everything we need with exception to the 3 way angled connections (as i thought)

Pricing is as follows:

3/4" diameter PVC pipe 3m - 9 AED
T piece conncetor - 2 AED
90 Degree Connector - 1 AED
Straight Coupling - 1 AED

All in all its pretty cheap, in total it should come in at around 50AED for everything. I will need to modify the design slightly to make do with out the angled connectors.

I will go back and buy everything tomorrow (didnt have my parts list with me today) and build the bridge in time for this weekends session.

I will cover the costs of the bridge!

Nice work, great gesture. Thanks feller!

Thats pretty good value then, I know PVC is not that expensive. I am a little concerned that the 3/4" piping might be a little small? We may at some point have to extend the width of the bridge if we add transponders, will the design you have not be subject to some sagging? Also, if we add a banner/advert across the top it may cause some problems.

I am certainly not questioning your engineering capabilities....just curious....I would have thought something thicker like 1" or between 1 & 2"....I dunno, I only know of 2" piping, and the fact that it fits on a std Tamiya rim..lol

Andy

Cool, I will have a look when I go back and see if they have what we need in 1 inch (anything bigger will probably be serious overkill - lets save the 2" for spare dift tyres....lol). That should give us some extra strenght if we want to extend the length of the bridge.

Naturally there will be some tendancies to sag, to over come that I have come up a clever way to cross brace the structure and reduce the sagging. But will need to build it first to test how effective it is and how much weight the bridge will handle.

The other idea I have is to build the bridge in 5-6 managable sections, each section would be glued together for strength (while maintaining a compact portable size). The sections could then be quickly and easily slotted together on site.

My gut feel is that it should easily handle the weight of the sensors, cabling and banners, but we'll find out soon enough.....

it's definitely gonna sag if we're putting up banners as well..

i have an idea but it's going to be really hard to construct and a bit expensive as well..
why not try a triangular frame like so: (not completely done but i hope you can imagine how it would look like..



will not be as portable as this one though..

clearances: same as paul's

h = 0.5m
w = 2.0m



and yes they should be made in sections to make it sturdier and we should come up with something to make the base stronger to withstand possible impact and avoid damaging the sensors..
i'm thinking of putting an impact barrier in the bridge's feet area..

after all, it's not going to be the bridge's fault if somebody hits it right?

hehe..

@ Orange alien,

Great work there! and some nice ideas!

I agree the ideal situation will be to build a triangulated bridge - but like you say not easy to build, gonna cost a lot more and take up a lot more space when storing!!!! I barely have enough space for another m-05 in my apartment....hehehe

I have had a look at the design and i think with some cross bracing we should be fine.

impact barrier at the base of the bridge is a good idea - also might be worth placing the bridge on a slower part of the track....slower impact less damage...

@andy

Have we got anywhere to store the bridge when not in use?

If it is built in sections, and can be dismantled, I can store it. My spare room is my MAN-CAVE!!

I really like Lances idea, but it is going to be a bit more 'intense' to make, assemble, dismantle and store. Would be well cool though.

The cross bracing idea seems to be the most practical...

me likey....................ALOT

@cathurga

decided to mini until sundown, then head over to the more sideways part of life, thats gonna be my schedule for RC on the meets so that i can get a hell of alot more mini action, one things for sure, i want to get a hold of gerg and get him down there this coming meet