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Job Modeling
Posted by burnormj on November 23, 2020 at 1:17 pmHello community,
I’m not sure how many of you create models from cad files but i have been task with looking into it. My question is; if I have a full cad drawing of the existing conditions and proposed conditions both with surfaces what file types am i trying to extract to get the full job in the controller? I’m using TSC3 and have successfully been able to create the job as a DXF so that all the line work is in. I started to dabble in TTM files then got a little lost. As I understand it a TTM file will give me my surface in the DC correct? So then if i wanted to stakeout a contour line it should tell me not only location of the line but also cut fill to the line in question, right?
Any sight would be be helpful
mike
ncsudirtman replied 3 years, 4 months ago 7 Members · 8 Replies- 8 Replies
Normally, the models are created from the CAD files in the office software, with much checking and editing, then converted / exported to the DC in the desired format.
Yes, you can create a TTM of the surface for use in the data collector and get cuts and fills to the surface. A contour line is a 2d line (x,y) with a height (z), unless the dxf file has been flattened- all drawing objects at 0 elevation.
I am not sure of your software steps- (probably Trimble Survey Controller), but what your are asking can be done.
I would export the contour lines as simple linework with elevations, if you are looking to stake directly to the line.
TTMs are Trimble’s proprietary format for DTM surfaces, and the staking routine is basically “stake to DTM” – you will get a cut/fill for your current location.
TTMs are great for staking if they are generated correctly. I see a whole lot of poor grading in the files we get. In this part of the world, the vast majority of engineers do not actually create a design-grade CAD drawing. Or, if they do, there are enough last-minute changes and corrections done by hand (i.e. text or multileader with specific elevations that do not match surfaces or feature lines) that I end up basically creating the grading in CAD before we can go to the field and stake. I haven’t seen a single project that can be built straight off the paper plans for several years.
The other thing to be aware of is the TSC3’s operating system can easily get overloaded with even smaller TTMs, so even if you get a solid stakable surface, you may get bogged down in the field. The newer DCs handle TTMs like a champ, because they are running full Windows 10 with recent processors.
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil PostmanTo me, it seem’s to work better if you recreate it from the rawest format you have, not from an exporting a DXF. Recreate a point file, linework breaks and faults right off the CAD file you have. It takes longer, but seem’s to work better.
@rover83 thank you for the information, i have noticed that the tsc3 does get bogged down easily I tried and clean the file as much as possible when i got out with a dxf. I have to do a small house lot tomorrow, not much happening on the site so i have created a simple dxf with contours and elevated them as a trail.
I use Civil 3D with the Trimble extension installed and have an S6 with a TSC2 running Survey Controller 12.49. My only experience went very well with this, but was quite small so may be moot. It was a somewhat complex concrete ADA parking area, though, at the top of a steep driveway – 5 stalls with appropriate access lanes and an adjacent 5′ wide ramp at the “nose” of the stalls that allowed perpendicular access from the lanes and ramped up to the back of a convention center patio. The complex part was that it warped from the steep end of the drive to ADA grades in both directions with the ramp and small retaining wall ultimately rising about 6′ above it all (about 1600 sf total).
I modeled the surface, checked it thoroughly a few times, created a data ref, opened a new dwg and purged it completely – I started from a new 2d acad dwg, purged it and just imported the c3d settings desired to display the surface. Then referenced the surface in, saved it and use the Trimble tool to export the surface to the data collector as a ttm. Also had a clean dxf for the site and was able to set sub base/base, check form height/location and set bench elevation pins anywhere the foreman wanted for his power screed. Also final check of the finished grades before inspection.
I thought it was cool.
I have had glitches with this setup in other areas, though. Seems it doesn’t import (or correctly read) all curves in an alignment rxl and pipe alignments to rxl format don’t seem to export (or read) the associated profile info from them. It may be the older data collector software or a capability of the collector itself, idk, but hope to upgrade when the times right and see better use of these tools, too.
ddThe workflow I’m currently using on a long corridor project is as follows:
1. Export alignments with attached vertical profiles as XML files from Civil3D
2. Export final design surface as XML file(s) from Civil3D
3. Import XML files into Trimble Business Center
4. Check everything thoroughly, including with the TBC 3D drive view to get a good visualization of the site
5. Export alignments as RXL files for Trimble Access
6. Export design surface as TTM file(s) for Trimble Access
This has worked well for this project and our survey crews have been pretty happy!
That’s what we have found to be the best way too. If the design entities are correct the conversion process works great.
If I have to build alignments and profiles myself, I use TBC. Much easier workflow than Civil 3D. I still find Civil 3D easier for surface generation.
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil Postmancan you go straight from Civil3D with the exported Trimble Link XML files to Trimble Access on the data collectors? I don’t have TBC currently
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