just want to see how ppl line up there lasers after setting a box or a manhole
have been work with a couple of different pipelayers and each one lines things up different , some use a tri pod, or a plumb bob, how have you seen it done or do it thanks
Cut me open and I bleed cat yellow!!
Set line transit up on top of manhole, plumb bob down to laser, line the transit up to the center line stake of the structure I am digging to, paint lines to dig by, make first cut, set trench box, and finally line up laser to transit. I always check line on the first three pipes, after that I do not move the laser anymore because it will cause the pipe to have a bow in it or even worse the laser could hit the side of the pipe.
If the run is over 250LF I put a blower in the pipe to help keep the light stable.
If it is really dusty, we cover the end of the pipe with a rag to keep the dust out.
I use my David White LT8-300LTU line tranfer unit.
Last edited by Kgmz; 03-29-2010 at 01:42 AM.
there has got to be a faster way
Cut me open and I bleed cat yellow!!
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
do you teach best what you need to learn the most?
Do you guys ever switch from a pipe lazer to a regular one?
We had one before but now we have several of the tripod ones that we set in the center of the manhole and use the sights to line up with a stake then we run 2 rods one for the top of pipe (just to double check) and our main one that is set for the invert.
I find them way easier to use because you can also use them to set your benchmarks and check other grades.
ever had to lamp a line after you've done that? i can't believe you can rifle barrel a line with that methodOriginally Posted by Deeretime
do you teach best what you need to learn the most?
We also used the string method before we got the LTU. I bought the LTU after I did the string method and was a little off, my eyes are getting old. Now with the LTU we are always dead on and can tilt it as we go to make sure the pipe is still going straight.
Deeretime we have used a regular slope laser when our pipe laser died one time, lucky we had a laser with slope mode and didn't have to stop the job that day. You could do it with a non slope laser but would have to figure out the rod for each end of pipe. And a laser in slope mode setting pipe wouldn't be of much use for checking other grades because if the slope. But a pipe laser is definitely easier and faster.
And to the OP, I don't know what could be faster than the string method with the LTU coming in close behind it. It doesn't take me that long to set the LTU up and then I leave it for the day just to check and verify, and I don't know what could be more accurate.
Day, that half day we used our slope laser the line did come out perfect, but it was not easy. We had to use the rotary slope laser and the LTU, the rotary to keep the slope of pipe right and the LTU to keep the pipe straight. And then you have to have a couple of extra guys helping, one to help bar the pipe up and hold the rod and the other to look through the LTU. Deeretime like I said it is definitely easier with a pipe laser, for most of our jobs with pipe in the 12" range I just have one guy in the ditch gasketing the pipe, then setting the target and lining up the pipe to the laser
Last edited by Kgmz; 03-29-2010 at 08:56 PM.
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.
I have fell inlove with the rotary slope lazers because ours are self setting and leveling so I set in in the M H , push the setting in and im off. when i need to set a mh off of a bench mark i move the lazer up top, set it to level and it works perfectly.
Its also more bennificial to us because we use the same lazer to run the hoe we just set it to dig 2 inces deeper to leave room for our rock. Which eliminates the need for a guy to run a rod. also with the dual slope i can use the same lazer to grade for the services comming out of our mains.
And usualy we only have one guy in the ditch unless we are double ditching.
Its just preference to what you use so i was just currious to see if you guys had used the system like ours.
I have seen pipe lasers used on storm and sanitary sewer. That kind of pipe has no bends, it goes straight from one structure to another. Pipe with bends in it, like water or gas, no laser is used. They just use the surveyors' stakes. Or if it's in an existing road, saw cuts are made where the surveyors' paint marks indicate.
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I know that but we have done sanitary and storm with bends in it our regulations are that we have to install a structure only if the deflection in the pipe exceeds 5 degrees.
so when we have an arc to make the pipe lazer don't work
It may be completely different where you are from but i have done a few of those mild bends.
when im setting up if its in a new road i will just use a plumb bob and string over the pipe laser if its in an existing road or on a site with alot of utilities i will set my total station over the laser use the laser plumb and plumb over the pipe laser then line up to the target down the road. i don't usually spray lines for the operator the lenght of the run just use the light as we go and keep it in the center of the trench
A string and plumb bob. make sure you set the string dead center at the end of the pipe where you have the laser, and run the other end to youre MH stake. I set the first piece of pipe and adjust it untill its close, setting alignment using the plumb bob, takes a little bit of adjusting as moving the first stick moves the laser. then pull the target and make sure the laser is hitting my plumb, this makes sure my laser is hitting dead on, as the first stick may be off a tiny bit, usually check the second stick as well. We also paint a line and if it looks like the pipe is getting off center we throw up the string and double check. We have replaced lots of sections of pipe between existing manholes and we usually end up nuts on every time. Takes a few minutes to set up but the extra time is worth it when all your runs are straight as an arrow.
How do you guys line up the laser if you are over 20' deep and don't have the manhole all put together or backfilled around? We like to backfill around the manhole evenly so you do not have to worry about it tipping and add the last couple of sections as we get dirt compacted around it. By doing this we are too low to see the next manhole stake if it is a long ways away (300-400'). Do you just go to the first stake you can see? If you do this you will probably hit that stake but could still be off a long ways when you get to the target manhole if the manhole that your laser is set in is not perfectly centered.I am making this too hard? We usually shoot over the top with our lasers, but on deep jobs it would be nice to shoot through the pipe. Any input is appreciated.
sometimes you woud have the hoe dig out a small cut right on center line so you can see the next stake,you may have to hold a grade rod on the stake your shooting for so u have something you can see .
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