# GPS guidance system



## vhaby

"Tattle Tails" after planting or spraying in bermufagrass sod show that I am not able to properly overlap passes. I can see the previous pass when drilling only in one drection and cannot see the previous pass at all when spraying. Please point me in a direction to locate a reasonably priced, and accurate, tractor mounted (or other) GPS guidance system that will keep me on track when spraying or drilling.


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## mlappin

We used to use a lightbar from centerline, while it worked for burndown and spreading fertilizer I'm not sure how good it would work for drilling. We had two of em and this spring the one started acting up and losing signal all the time, we were told a new antennae for it could be as much as $600. A guy that I've pulled out of the mud a few times at teh hay sales cut us a deal on a used Raven Envizio. Supposedly with the addition of a tilt sensor this unit can be set up for auto steer. Tells you how far off you are in tenths of a foot. Paid $500 for it and the only difference I can tell from this one and the newer models is the newer ones have a touch screen twice the size.


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## charlesmontgomery

We have had a Centerline 220 for about 4 or 5 years. We use it for spraying, applying fertilizer as well as broadcasting ryegrass and fescue. It's accuracy is within 1'. It uses the WAAS (free system).

We paid about $1200 for it. I don't think that you are going to find one that is accurate enough for drilling that's inexpensive.
Deere's Autotrac StarFire 2 gives you 4" accuracy without a correctional signal. Used ones are selling for $6-7K. I don't know what new would cost. If you want the sub inch accuracy you can add a RTK signal.


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## Grateful11

It's a shame these GPS system are so expensive. If they were under say $1K I could see them paying for themselves pretty quickly for the small guys. I wish someone would develop an App for the iPad for GPS farm tracking, there's Apps that'll show a track as to where you've been but it's not configurable as far as width of spraying or drilling. They make road GPS for $100 it's too bad the farm GPS's are so high but I also realize that it's a limited market and they're never going to sell anywhere near as many as road GPS systems.


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## Blue Duck

I use an Outback S2 that works well. I always have it in the tractor when drilling or planting row crops. It is not accurate enough to go only by GPS but it will keep you in the ballpark. Outback has discontinued the S2 but I saw at the local dealer an Outback S-Lite for $850. The dealer said it was as accurate as the one I have but he would say anything to make a sale.


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## haybaler101

I have 3 of them now. Started with an Ag Leader EZ-Guide 6 years ago. Plain, simple lightbar used for spraying and spreading fertilizer. Runs WAAS and is within 6 to 8" most of the time. Paid $1200 then for it. Use it for tillage work now. Added an Ag Leader EZ Guide Plus 3 years ago, paid 900 for it off of EBAY. Moved it up to sprayer tractor. Only difference was a screen that showed you where you are in relation to where you are supposed to be. Still runs WAAS. This one is now used for tillage and anhydrous ammonia application. Bought a new Ag Leader Integra this spring. This one is basically an on-board computer system with guidance added. It tracks chemical applications, seed variety applications and will go in the combine this fall as a yield monitor. Running On-Trac steering with it in the sprayer/planter tractor, so I just push a button and leave the driving to it. Also as boom control on sprayer to shut sections off automatically to prevent overlaps on the ends. Still running WAAS on this unit but can be upgraded to RTK sub-inch accuraucy. I planted both corn and beans with the auto-steer on WAAS, BUT it could not be done with a planter larger than a six-row. I had to manually correct my guidance line occasionally and I could do this because I could see my middles were too close or too wide. A 16-row, or 36-row like our new neighbors have would not allow you tell were you where or how far you where off with the 6 to 8" accuracy. Got about 15 grand in this one and still adding to it.


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## LeadFarmer

I have three of them as well. We have an old John Deere Starfire 2 that we use for tillage work, or anything that doesnt have to be exact.

One of my swathers has a Trimble system on it, it does auto-steer, but the tolerance for error is pretty high. If the operator isn't pretty diligent it will leave tags of alfalfa throughout the field.

The HW345 that I will be operating today has a John Deere RTK system on it. I can cut hay all day long and it stays within it's tolerance. This unit is our main workhorse, we use it on the big swather, and I use it for listing cotton/lettuce beds and for planting/reseeding.


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## vhaby

Thank you mlappin, charles montgomery, Grateful11, Blue Duck, haybaler101, and LeadFarmer. You've given me encouragement, discouragement, and most of all, a greater insight into GPS units. Now I have better information with which to continue my search for a useable, reasonably priced GPS unit. My quest would be much easier if forage production was as valuable as corn currently is.

vhaby


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## charlesmontgomery

Looks like the Centerline 220 can be had for about $1000. The Outback Light for about $850-900. I have never used the Outback Light but have checked the accuracy of my Centerline several times and it's always less than 1'. I think that we paid for the $1200 cost for the centerline on savings in chemicals and fertilizer. Before I got it, we tried to look at previous tire tracks and/or find some tree in the fence row as a landmark. Still we would have skips or overlap as much as 10'. With the price of chemicals and fertilizer it wouldn't take long to get your money back. We had to have extra fertilizer in the spreader to make sure that we had enough. Now if I buy 2 tons of fertilizer and set the spreader on 200 lbs/A I can actual cover 20 acres or real close. I don't know how much fertilizer you have put out but you have to get the co-op or feed store to weigh a cubic foot of it, it every time you buy, as the weigh will vary due to moisture, etc. Then you have to keep the rpms at pto speed so that the spreader throws the full 40'. I set the gps for 37' which gives me a 8.5% overlap. (If you are a young guy with fast reflexes you might could get a 1.5 to 2' overlap or you can drive 3 mph which would give you more time to react.)To compensate for this I select a rate about 10% less than I actually want. For example, if I want 200 lbs/A of 46-0-0 I set the gate for 180lbs/A then my 2 tons will be enough to cover the field. or you could buy 2 1/4 tons so that you wouldnt run out.

other things to look for. If you have hills you need a unit that corrects for tilt. If you take a normal gps and drive on a slope the centerline underneath the gps will be over toward one side not directly under the center of the tractor. The greater the slope, the greater the error. Also at least on the Centerline 220 if you are getting older you need to wear your glasses so that you can read the track number that you are on. If not, as you make the turn in the headlands, you might accidentally skip a track or get back on the previous track and give it a double dose.

one other trick: if you need to measure a fence row or calculate acreage for a field. Set the gps for a 10' track width. Make one pass from end to end to mark your a & b points. Then turn and drive perpendicular to your first pass. Every 10' the gps will change track numbers as you pass them. At the end of the field multiply your number of tracks by the track width and you have the length of the field. Then do the other side, multiply the two together, divide by 43560 and you have the number of acres. Great for custom work if you and the guy you are working for disagree on the acreage. Also good if building a new fence as a way to know how many fence posts and how much wire to buy.

BTW, I don't remember the company at the moment but someone makes an external gps that you connect to your laptop. You use it and their software and you have a gps guidance system. I think the company was called "farm works". The larger screen on the laptop would be good but I didn't buy their product because I don't think that their accuracy was as good as what I got.,


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## charlesmontgomery

I found this but its not very cheap. FarmerGPS - Welcome!

doesn't appear that the farm works company offers the cheap gps unit any more


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