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Layout Advice
Posted by devo on July 6, 2018 at 11:53 pmHey everyone. Just ran across this board and its a great wealth of information. I’ve been reading here for a while and am looking for some advice.
First, I’m a general contractor, not a surveyor. We do mostly heavy civil and architectural work. I’ve been using some machine control and GPS gear for a few years. All Topcon. It’s really revolutionized the way we build things and I can’t imagine not having it on a jobsite. I’m pretty comfortable with it for civil work.
We’d like to start using newer tools to help us on the architectural side. For nearly 40 years we’ve been constructing buildings of all shapes and sizes using tape measures, batter boards, plum bobs and chalk lines. The usual procedure is to have a surveyor layout building corners, setup batter boards, excavate footings, use a laser for grade, plumb bob and transit for alignment.
It works, but its slow. With today’s technology we can do it better and faster.
I’ve looked a lot of different options, different brands, etc. Since I’m familiar with Topcon and we already own a bunch of that equipment I’m leaning towards that. The two options I’ve been considering are the LN-100 layout tool or a real robotic total station.
Here’s the problem: we only have a couple people who can use a total station. We have an older one now that most of the guys just use to turn angles. I’m trying to speed up the process and don’t need another expensive instrument to gather dust.
What would you recommend? A layout tool like the LN, or a real instrument? How do contractors you work with do the day-to-day layout for foundations, anchor bolts, etc?
We don’t really have the option of using an outside survey company for this type of work. Our projects are almost always in remote areas. Like, a 2 day drive and a ferry ride kind of remote. We’ll have surveyors setup the control and layout the building, but they’re not there every day to align formwork, set bolts or check grades.
I’ve been wrestling with this issue for a month or so and some advice from professionals in the field would be appreciated.
luke-j-crawford replied 5 years, 3 months ago 14 Members · 15 Replies- 15 Replies
How do contractors you work with do the day-to-day layout for foundations, anchor bolts, etc?
I do work for a half dozen contractors doing building construction. I’ve noticed that many of the trades (plumbing, electrical, etc.) are doing their own layout using total stations and not one of them uses Topcon. This in spite of our area having a very active Topcon dealer (There is also a local Leica Dealer). They are all using Trimble or one of the Trimble rebrands. I’d just suggest that you see what Trimble has before you commit.
Devo,
Perhaps demo each Trimble and Topcon. Most areas have a local vendor that people prefer because the vendor can properly support the product. Trimble and Topcon are just like Pepsi and Coke, in the end, they are both colas. Personally, since you are already vested in Topcon, then I suggest you stay with Topcon and consider either the LN100 or the DS203 Robot. The difference depends on your application. LN100 is very easy to set up since it has auto leveling. The DS Robot can work as a hybrid system with your GPS. Both will run with your current Topcon controller. Today there are very few software applications that sufficiently work across vendors platforms on the same controller. Best to stick with what you know. I work with dozens of concrete contractors whom never used an instrument, but are now using an LN100. The key is good training and support. The software can be a bit overwhelming at first. There are Topcon routines that are specific to your application, which very few know how to use correctly. For example, the Setup Reference Line is a tool designed to align the instrument with two points measured on an existing wall line. Unlike other survey applications, you need to know the distance of just one of the points to a column center or a corner of a building. The second measurement is just for rotation and alignment, then allows the end user to define where to make the adjustment. Many controllers use a similar routine called resection, which is very difficult to use for none surveyors, and must be done with extreme caution as this can create an erroneous scale factor affecting the entire job site..
Also preparing the CAD file for use in the controller is a unique and challenging part, but when done correctly supplies you with the entire plan set in the palm of your hands. Allowing you to layout any part of the project at any time. Learn to work with the line work. You can use the LN100 as a virtual and very accurate invisible line string. You do NOT need to create hundreds of survey points for Layout. Use the linework, once it is verified by your self or a surveyor. Use a local surveyor to set up the baseline, and offsets and have the verify your CAD file and points before you import into the controller.
Feel free to visit my website http://www.LeeGreen.com and contact me for help. Some may feel this is a sales pitch. It is NOT. You asked, therefore I answered. This just happens to be what I do. I support contractors specifically with Topcon equipment. Only because that is the vendor I have vested in and it is what I use every day.
My advice would be that if you do not know the difference, hire someone that has the training and/or go back to school or find and get the training to gain that knowledge.
Make sure you know to use something in your back yard as an expert before bringing it to the jobsite.
I’ve seen what happens when advanced tools are brought to the job by people that do not really know how to use them and the crew was not ready for the change either.
The boss would have some new toy that never left the yard until someone had perfected and schooled him on it.
Look out for the guy that says “I know how to use it” and then says “if you want to now, learn how on your own”. The jobsite is for teaching too and while a part of a crew, there is no keeping trade secrets.
For example, I hired a college grad that knew everything about GPS and could talk it all day long. Found out he only knew the book end and could not apply any hands on use of any GPS.
It took me months to self teach GPS before I was able to implement into my work with desirable results.
You appear to not have skimped on tools so far, so don’t start now. Don’t use a small hammer to drive a large nail.
so, “DO NOT WHIP IT UNTIL YOU CAN WHIP IT GOOD” sry could not resist
Listen very close to what Lee Green tells you. Reach out to him directly for specific guidance and direction as needed.
Thanks for the input everyone. I really do appreciate your time.
I do work for a half dozen contractors doing building construction. I’ve noticed that many of the trades (plumbing, electrical, etc.) are doing their own layout using total stations and not one of them uses Topcon. This in spite of our area having a very active Topcon dealer (There is also a local Leica Dealer). They are all using Trimble or one of the Trimble rebrands. I’d just suggest that you see what Trimble has before you commit.
The nearest dealer is Topcon and they’re 800km away. For that reason I haven’t spent much time on the Trimble stuff, even though the layout tools look to be better. Hilti has some nice stuff too. For me, I think sticking with one brand will make life easier.
My advice would be that if you do not know the difference, hire someone that has the training and/or go back to school or find and get the training to gain that knowledge.
Make sure you know to use something in your back yard as an expert before bringing it to the jobsite.
I agree with you 100%. Right now I’m pretty comfortable with the Topcon hardware and software. I do the modelling for machine control, linework for piping, excavation layout, etc. Been using the Magnet office software and it’s pretty user friendly. I’ve spent a lot of time over the years learning the basics of surveying and I haven’t really ran across anything that I couldn’t accomplish with the total station and GPS. It just takes me a long time to make sure I’m doing it right.
You appear to not have skimped on tools so far, so don’t start now. Don’t use a small hammer to drive a large nail.
This is exactly why I’m asking about these devices. I don’t want to end up with a product that can only do half of what I need, but I also don’t want to end up with a tool that only a couple people in the company can use. Choosing between a layout tool and a robot are really about the guys in the field. The end goal is to help the guys get the information they need to construct things as quickly as possible.
From my experience with the GPS equipment and machine control I’ve found that it has taken a lot of the skill off the jobsite and into the office. Operators that could use the machines well, but lacked the ability to visualize a finished product were always relegated to a pit or quarry doing bulk work. I have trained some of those guys with the technology and now they can produce finished jobs almost as good as our best operators.
The flip side of that is now all that skilled work comes back to the person developing the DTMs and information for the machines. Errors get amplified. Small mistakes in the design can cost a lot of money to fix. Attention to detail is critical and we’ve been doing very well with it so far.
I’d like to expand this approach to the architectural side. Allow the office staff to crunch the numbers, create the layouts and then let the carpenters focus on actual carpentry. No more waiting for alignment. Eliminate plumb bobs swinging in the wind. Don’t worry about batter boards being knocked out of position.
For example, the Setup Reference Line is a tool designed to align the instrument with two points measured on an existing wall line. Unlike other survey applications, you need to know the distance of just one of the points to a column center or a corner of a building. The second measurement is just for rotation and alignment, then allows the end user to define where to make the adjustment. Many controllers use a similar routine called resection, which is very difficult to use for none surveyors, and must be done with extreme caution as this can create an erroneous scale factor affecting the entire job site..
Thanks Lee. This kind of information is really helpful. I envisioned using the LN with resections. The methodology I had in mind for architectural work was:
– Surveyors place building controls and offsets
– Carpenters setup LN-100 in the area of work then resection with given control points
– Use LN-100 to align footing formwork, rebar setbacks, wall alignments, anchor bolts, etc.
Is this similar to how your customers use the product? I can see how the ‘Setup Reference Line’ would work better. Once a crew is comfortable with the LN-100, do they continue to use other standard methods like I mentioned, or do they rely mainly on the instrument? Obviously we’re going to have to do a lot of manual checking to ensure things are right. Have you ran across any issues with limitations of the instrument? For example, the usable angle range seems to be pretty small. The accuracy isn’t as good as a full fledged total station, etc.
Again, thanks everyone for your input. As a contractor it’s sometimes difficult to figure out what equipment will work best in a given situation. Most sales people are interested in selling the most expensive product, not necessarily the best fit.
The thing that stood out to me was ??We only have a couple of people that can run a total station?.
I have worked on staff for a couple of construction companies and from experience let me tell you, what ever brand or type of equipment you decided to purchase you need to dedicate the persenell to that equipment.
Do not put them on the new equipment in the a.m. and then put them on the ground crew in the p.m.
With this purchase you should be building a dedicated survey crew (even if it is 1 man). You do not want the liability of a mistake because your crew is pulled in too many different places.
If you’re doing concrete layout, get a Spectra Focus and Layout Pro. Nothing Topcon or any of the other brands offers is even close to the ease of use that setup offers. Where are you located? I might be able to help get you setup with a demo unit if you’re in the states.
On the projects I’ve seen where I work we will give building corners, gridlines, and a benchmark and that seems to keep the contractor rolling.
My experience is most are using Trimble stuff. I have been setting up CAD files for one contractor then they do statekout with a Robot. I agree with Lee, learning the software and setting up the CAD file are the hard part.
Thanks everyone for your input. Thought it would be good to update this thread. I ended up renting a robotic total station for a while. I just couldn’t decide which was going to be the right solution for us.
We’ve gotten a Sokkia IX-505 for a couple months to see how it works out. I just started using it today and it’s pretty user friendly. This was my first time using a robot, so its going to take a bit of time to decide what features i like or dislike.
I’ve prepared all the data for the foundation footings and will start layout of it tomorrow. I’ll post a few updates later on how it works out.
I would look into retro reflective targets also they are handy if your setting up a lot of times in one area. Also we have 3 IX??s watch your tilt and collimanation and backsight when there are temperature changes
Me personally if all your GPS and data collectors are Top Con then I’d stick with Top Con. I am a Trimble user and would not care to have trimble Gps, Leica total station and a Top Con controller.
I think getting into the layout aspect I think there’s more behind setting some building corners and calling it a day. If I supply you some control point coordinates and you lay out your building and then find out its 0.5′ over the building minimum set back after you have a footing or more built, you will be taking on a lot of liability. You would be surprised that kind of thing happens or a drawing has property lines drawn n-s, e-w and the property is a parallelogram.
So I guess what I’m getting at is weigh your options. laying out a building isn’t just stake some coordinates and be able to say that’s where the auto cad had it, and is it worth paying a surveyor to set up the building then handing it over to you and putting that liability on the surveyor that he did his checks and balances.
A lot of good advice above.
Don’t leave your common sense on the shelf…
N
Late but ….New here.
Check your risk management/Bonding companies. I too was a commercial contractor and found out after 18 yrs of laying out bldgs that my umbrella coverage would be basically void if we had a claim. No marking up / change/ red line drawings, no layout – leave it for the licensed. All about liability. Same reason why many companies hire PE’s when they have em on the payroll. CYA .
All my bldgs were “as built” and filed by professionals and found to be located accurately but it could have been different. Plus ,when I hired – it went much faster and I slept better. Stuck with locating the utilities, lot lighting and out bldgs for the as built drawings.
Loved my TS almost as much as my T-2. NO Batteries !!
We use SurvCE & Captivate but recently set control for a concrete contractor on a large university building who was running LayoutPro, my 1st encounter with it. It seemed incedibly easy and intuitive for his tasks. Usually I will give column lines/intersects or pre-planned axis lines for the concrete guys, this foreman says to me “I’m going to walk the site, mark 3 spots I want points then you’re going to set rebar, locate them & I’ll tell YOU how good you are @ your job” I was taken aback but went with the flow, set the #5×1.5′ bars, capped them and spun 4 sets to each from a single point, then set up on each, checked A&D to each other, original station & to a 2nd point in my loop (SurvNet adjusted), everything dead on for all intents.
He then says to me “ok, give me Up & Out from line A & 1, (sta & off i quickly figured out before asking a question to which he surely would’ve scoffed). Run what i though was a quick COGO on SurvCE for the Up & Outs, he enters them and checks twice as fast than I extracted and says “Stay here, my guys will be back in a few minutes”. I wait with my instrument guy in the job trailer, his guys come in, grab equipment and run out to points and begin checking in a manner that would make Dr. Seuss proud. His guys come back, they chat quick and he says “they found a heavy 32nd of play, better than most of you guys (meaning surveyors)”.
I will say, out of over 150 bolt patterns he has set and I’ve checked, the worst I’ve found was .06′ out, 90% are ?ñ.02′, make sure I always tell him “not bad for you guys”.
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