pipe lasers lining up

Yea the pipe lazers are ok and we have two of them and they do work, but its the prep time it takes to set them up, and having the pipe strait , what do you do when you have a 30 degree bend to make tho, it takes a long time. Click to expand... then you install a manhole! i have found, even with a blower, that pipe lasers do not give me acurate elevation. i trust it for side to side alignment but not for elevation. we use the LTU and line it all up then trust the laser for alignment. i shoot every pipe with an auto-level before it is covered.

Setting up Laser dayexco said: here's a pic of how we do it Click to expand... Gee thats the way we have always done it. Just because. Never considered it to be too much work. :usa

rshackleford said: i have found, even with a blower, that pipe lasers do not give me acurate elevation. i trust it for side to side alignment but not for elevation. we use the LTU and line it all up then trust the laser for alignment. i shoot every pipe with an auto-level before it is covered. Click to expand... my 35+ yrs with pipe lasers, grade control once they started making self leveling units has NEVER been an issue if you have control of your air. if you don't trust your laser, i'd go back to 50 yr old technology using batterboards and a plumb bob.

dayexco said: here's a pic of how we do it Click to expand... That is how we always did it.

I have used a line level with success, but we have a different toy we use to accomplish the same task... We use dual axis self leveling/plumbing rotary lasers, we set the pipe laser in the invert, set the rotary laser w/ tripod on the cone on its side (main beam alligned vertically) pumb down to the pipe laser center, manually or remotely rotate the beam up to hit the next structure center then dig out a couple of sticks worth of trench and make the beams hit at the end of the trench. Its essentially the same process as the LTU, but can be done remotely for all the crew to verify, instead of only the person looking throught the instrument.

We use dual axis self leveling/plumbing rotary lasers, Click to expand... brand and model please.

There are a lot of brands and models that can do this. Both of my CST Bergers are capable of this, ALGR and LM800. The laser will the normal mount on the bottom plus one on the side, and when you look for one it is generally called laydown mode. Then they will have a selectable rotation and spot mode and usually a remote control to adjust the beam.

yea here when there is a bend a manhole has to go in.

Ours are Trimble Spectra Precision GL522 or 525 and yes they are manually or remote controlled, so you don't have to stay on the cone section looking down line. one person can allign both lasers at once from the side of the trench, or in the box or whatever crazy position one might have to get in. I prefer Topcon Greenbeam pipe lasers, and have been considering trying one of topcons new lasers with the laydown feature.

how much time do you spend lining up your rotating laser? i get frustrated using remote controls on either pipe or rotating laser. they are the worse things to set. 2 person job saves alot of mucking around. my 2 cent

bigcatpip said: there has got to be a faster way Click to expand... The fastest way is to take your time and set it up properly so you don't have to dig it up and re-lay it.

manual slope calculation question I have a Rotary CTS Berger ALH. It has Y axis slope only- not a fixed laser and it does not have the % setting that can be set on the laser. It is not dual axis and cannot be laid on its side. How is the best way to set the slope to lay drain tile? I assume: measure out 100' , find level, then drop the laser to the measurement you want to match the % slope desired. Is there a better way? Thanks, Greg

man, you people waste waaaaaaaaaaaaaaaay too much time with this...i've dealt with sewer lasers since the early 70's..i'd have 60' of pipe in the ground before you guys even get set up

I have a number of ways I line the pipe laser up. A lot of it depends on where I'm working (how critical being exact is, depending on city or inspector) and/or if I'm having to tie into an existing manhole. I've got a job going on right now, where we're replacing an 8" clay tile line with 10" ductile. I'm replacing all the existing manholes in between, instead of re-habbing them, so hitting them dead center isn't that critical. But the one where we are ending was. I have a Topcon AG-30 Theodolite surveyor transit that I use most of the time to line up. It just takes me a couple of minutes to set it up, and it's dead on accurate. I've also stretched a stringline, and hung a plumbob off of it, or even just eyeballed down a straightedge such as a level. Something I always do, that I know a lot of guys don't, is shoot my grades either with the transit, or rotary laser, and check to see if the percentage is right. We ran the percentage the engineer gave us on this job to the next to last manhole, then had to change the percentage on the last run, because we were going to hit the manhole .8' BELOW the manhole. I told the surveyor that when we started, and he supposedly checked it, and said they were right... Well, turns out I was right, so we had to change it. Which didn't surprise me much, since their centerline stakes were off too. We would have hit the existing manhole 1' south of center if we had used their stake. Have I mentioned I don't get along too well with most engineers or surveyors??? They tend not to like you much after you prove them wrong...

Here's a shot or two of my setup. It's pretty simple and straightforward, and very accurate.

Plomb stringline tied on the laser has to be the fastest. The only constraint is waiting on the machine to get the first cut opened.

dayexco said: we just use a string tied to center of laser, most have a notch built into the center of the laser already to put string line into. stand up on top of manhole, hold string tight, eyeball ahead to hub on center of next manhole...use your remote, move laser until the beam lines up with string line, drop string down in manhole til you retrieve laser when you're done....nothing to this silly game Click to expand... Can you explain step by step to me how to align etc

rasit said: Plomb stringline tied on the laser has to be the fastest. The only constraint is waiting on the machine to get the first cut opened. Click to expand... Can you show me step by step after placing manhole?