TomTom GPS unit as tractor speedometer?

[lhfarm]

Just for fun, I put my Garmin GPS on my tractor while I mowed the lawn. When I was done the trackback feature showed an exact pattern of where I traveled. I also found that to mow my approx. 1.5 acre lawn with a 60" MMM I traveled almost five miles. I also use that GPS on my boat. In addition to knowing the present speed it also tells you how far you have traveled. Not many boat speedometers have odometers. too. I have also used it in my trucks to check the speedo. Most vehicle speedos are off a little bit. Interesting toy/tool.

Which model were you using? So it would show your speed as you were mowing? That is what I need.

I spray only once a year and I'd like to use the unit in the car the rest of time. I may end up with two units, but would prefer to spend more money on a unit my wife can use.

 

[GinNB]

I don't have a TomTom but use GPS all the time at work (I'm a farmer). Any kind of consumer gps that shows the speed down to a tenth of a mph will make a good spraying speedometer. If the TomTom will show you that level of accuracy and give you a toy for travelling in the car then I'd say go for it. I use a Garmin handheld but it's not as good at the street navigation end of things (no voice directions, no touchscreen and the screen's too small). You'll need a foamer or some other way to flag where you've sprayed though.

Consumer GPS units are almost useless for navigation (certainly row-to-row navigation). Been there tried that. Static accuracy standing in the open is one thing, but moving accuracy dealing with reflections from trees, trucks, buildings, hills, your tractor bucket etc is a totally different kettle of fish. Even things like the Outback Lite will most likely give you strips in your coverage, and that's if you can guide the tractor as accurately as the unit will show you to. Something like EZSteer is needed to get the most out of GPS guidance except under the easiest of conditions. Foamers are much better, and I find them better than even my Trimble EZGuide Plus for many things. I use whatever's better in each situation, but then I spray commercially hundreds of hours a year.

 

[nbennett]

I have a TomTom and think that it would work great for giving even low speed readings. My concern would be protecting it from vibrations because they don't seem to be too tough if abused. Some of the car navigators are not recommended for motorcycles for the same reasons?

 

[Mickey_Fx]

One unit you might give consideration is the Magellan Crossover. It has 3 modes of operation, highway, marine, & off-road.

As for WAAS and increased accuracy, I don't think it buys the avg user anything. Believe it is intended for aircraft nav and the sat that provides the data for it is located low in the southern sky. On my Nuvi I can turn WAAS on/off and I don't see any difference. Out in the open, accuracy is reported between 15' and 19' regularly.

 

[Hookblock]

I have a lowrance Ifinder h2o, I use it with my truck,motorcycle,boat,snowmobile, and in the woods, new use tractor I like it, it works great,water proof, expandable memory, I think between 200-300$. Down side is battery life.

 

[ihookem]

I have a Garmen Etrex. It might not be what you want but as for a spedometer it's very accurate. My spedo went out on my pickup and they want 463 dollars to fix it. It keeps mileage too and is exactly 3.3 % of of my odometer.

 

[Steve in IL]

Barry - I put a bike speedometer on my TC21D. It has a magnetic pick up on one rear tire. You'll need to find one that the wheel diameter can be programmed to something close to what is on your tractor. $10 or so.

 

[PILOON]

Well one of my new toys is a Garmin 350.

For the heck of it I mounted it in my Mitsubishi MT180D since I always wanted to confirm that it was faster than walking, LOL !

I blow snow from my 3 properties, hence move around a bit.

Simply stuck it to the windshield with the suction cup mount and it works great.

Suprised the heck out of me as I had forgotten that I was programed for 'home' and it bleeped to tell me that I'd arrived!

And, oh yeah, I do a whopping 7.5 mph top speed flat out!

For your purposes I did find it very sensitive to throttle settings with very reasonable response time.

 

[mjncad]

Barry - I put a bike speedometer on my TC21D. It has a magnetic pick up on one rear tire. You'll need to find one that the wheel diameter can be programmed to something close to what is on your tractor. $10 or so.

I like this idea as it is simple and cheap. I still use a foldable 2D navigation system in my car and truck (a.k.a. a map).

 

[GinNB]

Barry - I put a bike speedometer on my TC21D. It has a magnetic pick up on one rear tire. You'll need to find one that the wheel diameter can be programmed to something close to what is on your tractor. $10 or so.

Been there, done that on my ATV sprayer. Works fine with a few weak points. Precision on the ones I've seen and used is .5mph (or .5 km/h) at lower speeds. I just picked a spraying speed (5.5 km/h) and sped up until it just started ticking over on that value so that I could repeat it. The wire was vulnerable to sticks and branches, but wireless ones are available. having the correct wheel diameter available in the bike computer is optional, too. Just don't use the speed it gives to calibrate the sprayer if you know what I mean. Use it like a tach when you don't know what gear your tractor is in (for repeatability).