Spectra Precision Focus 30

They work fine for construction layout. I prefer to use a standard prism instead of the 360 when doing "tight" layout. I also use it in standard, as opposed to tracking.

The Spectra Precision Focus 30 is a great, economical Robot. To me, when looking at something like the S3, or S6 (without Multitrack) it is a more reasonable choice. I believe the multitrack on an S6 though does make quite a difference. Without it though, you are looking a basically the same quality optics, the same type of tracking, the same accuracy, the same speed (although the servos are different - Im not a fan of MagDrives-we see too many problems with them) and you can run Survey Pro, not stuck in the all inclusive Trimble Software world.

Trimble/Spectra Precision make some great tracking robots. They have a mentality that they want the instrument to track, and never lose track. This makes them a great stakeout tool. I am hopeful that they will evolve their search process though. Geolock, while it can work well, doesn't work out of the box (it needs time). I believe Leica and Topcon instruments still have them beat there.

These sell for under $20k with a Data Collector. For that price, you'll be happy with it and about $10k richer then buying the "upgrade".

>Geolock, while it can work well, doesn't work out of the box (it needs time). I believe Leica and Topcon instruments still have them beat there.

As far as Geolock, I've used it on a Geo600 and Trim5600, and I've used the RC2 on a Topcon, (Never used Lieca), but I think Geolock is way better than what Topcon has. The problem with Topcon is that you had to put the extra attachment on the prism, it required a clear line of sight to even turn in your direction, about 1/3 of the time the robot wouldn't even respond, and about 1/2 time it wouldn't find you, even after a long search pattern.

Geolock (with a DC with GPS built in) does not require any attachments, is typically ready to go after a couple of sideshots, and it will turn in your general direction no matter what is in the way. If a moving van is between you and the gun, hit GeoLock, and it will still turn close enough in your direction that it should find you with a simple search, once the van has moved out of the way.

Now, Geolock is not the perfect solution. For one thing, doing a field rotation of the coordinates seems to throw it way off, but it's easy to fix. Just hit the reset button on Geolock and after a couple of side shots it is back on target. The other major problem is that it does not handle hilly areas well. I have mine set for 2D, meaning it will hold the last vertical angle when it turns to look for you. If you are much higher or lower, it won't find you. There is a 3D setting, but vertical in low-grade GPS is not very accurate, so it doesn't work well. 2D works fine in most of Florida.