My company only runs Topcon, but its is user friendly. I have a rover and base that I have been running for the past three years, and in general i have had little problems. My first job was in Northern NH and with the tree cover it was not very useful. In 2009 i was on an airport job where we had a base, rover and GPS dozer and grader with MM. The paving foreman said it was the best fine grade he has ever seen on a runway, and he has been paving for 40 plus years. We had no problems getting the P209 to quarter inch tolerance. This past season I was on a landfill and he had a base, rover, and new Cat D6N LPG with 3D MC2, we had no problems with grades but the machine automation is only has good as the model.
Well lets see here
1 year on a quad track 450 with trimbles old version- very slow had a hard time keeping up with you if you were gojng to fast, accurate to within 5 tenths
3 years on a 627 with the latest version of trimble- very fast kept up with 27 no matter how fast you went and was accurate to within a few tenths, took lots of abuse
spent a few weeks on a 6t with trimble dual head system- it was faster then the old topcon but no where near as fast as 3Dmc2, when in auto the fstest you could run was full throttle first gear, was nice have the dual heads since even when you angled the blade it still knew where the blade was, and you didnt have to worry about breaklines and shoulders and things like that, and was accurate to within a tenth
6 months on a 6t with topcons old system- hated it, very very slow, auto would only keep up in 1st gear, was easier just to free hand it, accurate to within 5 tenths
6 months on 6t with topcon 3Dmc2- Loved it, kept up with me no matter how fast i went, auto works great, but had to be careful when you were finsihing and had the blade angled, since its only a single head it doesnt calibrate when you have the blade angled, can get you in trouble fast if you forget about it and ur cutting a slope that has break points in it, and also had a hard time with the blade chopping if i didnt have a 1/4 blade full, accurate within a tenth
1 year on 8t with 3Dmc2- same results very fast, exspecially in auto, but the 8 was more balanced and auto would cut smooth as glass even if i was pushing half a yard of dirt, accurate to within a tenth
about a month on a 14M with topcon MM- when using MM had to run about 1st gear half to full throtle, accuarte to with a few hundreths, now they have 3Gmc2 would like to run one with this sysyem
That really depends on what you like. We just went to a product demo and there were 2new contractors who wanted 3d machine control. Both Trimble and Topcon had a demo set up with Blade and excavator running the respected systems. Both contractors left with Trimble orders... Just sayin.... If you have only used Topcon then that's all you know. If you have used both then chances are, you like trimble. If you are new to the game and want the best.. Trimble wins out almost every time. Just sayin..
ANY machine control is better than no machine control... But given the chance to compare, side by side, Trimble will win out, almost every time.
Im willing to bet that the topcon system on the blade was not 3Gmc2, and a trimble gps dozer cannot finish as fast as a topcon 3Dmc2 system, trimble will even admit this
The original question was about laser augmentation of GPS machine control. Here's how Trimble/Cat and Topcon's system differ:
GNSS-based 3D grade control systems have made a major impact on how earthmoving is done, but they still have limitations when it comes to meeting tight vertical tolerances.
The GNSS system will give you a horizontal accuracy that is pretty good for most earthmoving and grading task so the challenge is to find a way to improve the vertical.
For this purpose, we can combine the GNSS position with a terrestrial vertical reference such as a rotating laser.
This system will use the GNSS signal to position the grader horizontally and the laser signal to get a very accurate vertical position – to within a few millimeters.
There are two ways this can be done:
1. By using a conventional, construction grade laser.
2. By using a purpose-designed, 'fanned-beam' laser.
With a conventional laser, you have the benefit of being able to use a laser you already own, but you will be limited to working within a vertical range that cannot be wider than the physical length of the laser receiver you put on the grader.
Trimble's GCS900 system with an SR300 is an example of such a set-up
The laser receiver on the grader is physically 1m long so the elevation of the moldboard must be kept within 50 cm from the height at which the laser is set up. (Assuming the laser is set up to hit the middle of the receiver at the start of operation).
Topcon Millimeter GPS and Trimble GCS900 with SR300
Topcon's Millimeter GPS (left) and Trimble's GCS900 system
The other way to solve this is to use a fanned-beam laser such as the one use by Topcon's Millimeter GPS system.
Instead of sending out a single plane of light like a standard grade laser, this laser sends out a “fanned” beam that lets the operator work to high vertical precision within a 10m elevation range.
A fanned-beam laser allows for the use of a much smaller laser receiver on the top of the grader mast, but the drawback is that this special laser costs more than a grade laser and cannot be used for other construction leveling application.
A strong selling point for these systems is that an unlimited number of machines can run off of a single laser. This not only lowers the cost of achieving high vertical accuracy, it also reduces the potential for set-up errors, because all machines are working from the same laser.
One thing to be aware of with such a combined GNSS/laser system is that you are now faced with maintaining two lines of sight to your grader: One from the GNSS antenna to the satellites and one from the laser receiver on the grader to the rotating laser on the job site.
-From The Kellogg Report Learning Center: http://www.kelloggreport.com/3D-mach...mentation.html
I work for a Topcon dealer but I can definitely tell you that Trimble is very good at marketing just like Cat is very good at marketing.
But, hands down, the Topcon 3DMC Squared Twin Antenna system outperforms Trimble all day. Just sayin...
I have been at head-to head demos where the Topcon machines were cutting better grade at a much higher speed. The smoothness, accuracy and speed where unmatched on the crawler-dozers. On the JD764HSD it's no comparison at all.
FYI the twin-antenna product solves the blade angle vs. machine heading issue with single-receiver systems.
Mark my words - Trimble will release a product soon that has inertial sensors. All companies that develop products that control vehicles and machines are incorporating inertial sensors, accellerometers, gyros, etc.
If you look back at the timeline, Trimble has been playing catch-up all along when it comes to the key machine control and GPS innovations: GLONASS, touch screen, color screen, high-contrast screen, BlueTooth, cable free, integrated batteries in GPS, user-friendly data collection software, forwards-backwards and cross-machine compatability of components, dozer boxes that can be used on excavators and vice-versa, high-speed, millimeter GPS.
Also, I am under the impression that Trimble charges you a $500 per receiver per year fee to receive firmware updates. That's $2,000 per year for a base/rover and single machine purchase. A large firm with a dozen bases, rovers and machines is paying $24,000 per year.
Lastly, when Topcon came out with their new platform, they offered an upgrade/trade-in path for users that got them a new control box and mag box for $30k.
Evaluate the whole investment including all of the other costs, and make sure to include the service you will get from your dealer.
I consult and build models for both. They are both good and any machine control is better than none, but I personally have my bias. For my own staking I use trimble heads with carlson data collection and carlson for models. I used Topcon Hiper Lite+ and then switched to trimble before playing with machine control. I think Trimble has the edge with both hardware and ease of use. As far as accuracy goes I have two customers that have built runways with dual mast trimble and no laser augmentation. Both projects were built and graded strictly with machine control. I only set stakes to mark edge of pavement and centerlines for striping. On both airports, grading met tolerance that was checked by conventional surveying with levels and required no rework. We have data collectors for both to do site calibrations and create the necessary files. I don't think you can go wrong with either, but my vote is trimble.
Using both systems side by side
We are currently using a brand new cell based dual mast gps system on our 140M blade and an 8 year old topcon system on our older 140H blade. So far on the job both blades have been within a couple of hundred's within each other over the whole job. The topcon is running an onsite base station and the trimble is running a remote cell base station that is located at the Cat dealer 13 miles away. We just had to set up a repeater for the trimble though. We have both been at least within a half a tenth of the 3rd party surveyor. Its a federal job so tolerances are tight. I Still think the Topcon is still a little bit better technology. We are still running our 8 year old fc100 data collector attached to a Hyper light plus. Trimble is more operator friendly, but the Topcon is better tech.