garmin gps?
 

hey guys i saw one of these at circuit city for 150 bucks and ive seen other people use these to see how fast the car can go.

how do they work?
whats the max speed it can rate?
what kind of things will it do with speed? (top speed... lowest speed... avg speed)
is this the right one?
http://www.circuitcity.com/ssm/Custo...etailReview.do
i cn get a actual radar thing for 80 bucks... would that be better than this?
can the e-tex gps do anything other than speed for rc people?



will probably be buying it today because i wanna see how fast my revo is!

thanks for any help!

The Garmins are nice units. My car-based one will measure at least 118mph. :)

They work of triangulating from several satellites to get position. From multiples samples of position over time, they calculate speed (both average and top), travel times, etc.

Radar requires someone to "shoot" the moving object, while the GPS sits in the vehicle being driven. Just make sure your GPS is VERY securely attached and it isn't exposed if you get into a crash. It would suck to have your new GPS all scratched up!

so its a good worth while unit to buy?

thanks brian

That's the one I have... they are nice little gadgets. There is a newer one wiht color screen etc I think... but I'm not fully up to speed on what's out now.

For r/c car use you might want to check out he smaller ones like the garmin gecko... if one of those has the waas capability then I would pick that for it's size. The waas just allows it to be a little more accurate sometimes. For speed measurements it's not critical though... but it can make a differenece if you need to find a buried treasure and not dig too big a hole... :)

This is the one Ive been using. This one is perfect for top speed runs. Small, Light, and the built in strap makes it real easy to attach to the truck and its less than $100. Seems to be able to take some abuse too.

http://cgi.ebay.com/Garmin-Foretrex-...QQcmdZViewItem

I've often wandered about those things- now I see how they work exactly it might be worth my while getting one- cheap second hand one mind but as long as it works & has instructions its all good.

The smaller the better too as any added weight might reduce the top speed you'd get without it. The armband one looks nice and small and only weighs 2.72oz (77g).

Alternately, if you already have an eagletree unit, you could get the rpm sensor and then calculate speed based on gearing and tire size.

well i went out and bought it so im going to go use it now!

woot!

the armband one would be cool... I didn't know what the name of it was... really any of het garmins will work fine and be accurate on speed as long as the accuracy meter reads a decent #

well i did it to my revo and rusty. revo hit like 25 and rusty hit 38. i couldnt top out the rusty because my street was cluttered with cars...

I take it then that you got your MM ESC issue and glitching squared away?

No offence to the GPS guys, I like the radar, because even though you need a second guy to operate it, it doesn't effect the weight distribution.

Radar is nice cuz you dont have to carry any additional weight on the truck during the speed run. But, you only get a speed reading as it passes the radar gun. With the gps you get a top speed snapshot no matter where it happens. Right in front of you or on its way away from you.

Besides that, I have read that a cheap radar gun isn't that accurate and is even less accurate in the hands of somebody who wasn't trained to use them...

ya i used a radar gun with my rusty with a 7 cell and it read 43 mph... then a couple months later (today) with my 3sa123 cells it only read 38.5 so... im guessing the radar gun wasnt too accurate and it was an 80 dollar gun...