I have a rover rod where the bubble level got loose and needs to be adjusted. Obviously it needs to be centered when the rod is plumb but any tips on the best way to do this? I was thinking maybe lightly clamp the rod vertical in my bench vise and get it as level as I can using a ?ÿcarpenters level and then center the bubble? I took four shots on a point yesterday rotating the rod 90 degrees each time and the shots are all about a tenth out in different directions depending how it is rotated.?ÿ
Door frame and a plumb bob.?ÿ Take a tip and put on the top screw, extend and there you have it.
I use a total station to plumb the pole.
How about a stedi-rest or hold-a-pole on a tripod?
Or the correct tool: https://www.surveying.com/en/pole-peg-adjusting-jig.html
Neither is very expensive.
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This is a skill that should be among the first things that entry level field hands should be taught but a lot of PLS's have never learned.
Pretty good video. In lieu of the bipod arrangement this fellow uses?ÿ I often use the angle between the tailgate and the bumper of the truck, or between two table tops, to brace the pole.
Scotland's method of plumbing between a point on the floor to one above, and running the pole between them, is a good one, but a bit rough.?ÿ You will get pretty close, but not perfect. Good for a first step or a quick check.
As Mark says there are several good jigs available, but they do cost a bit, and they are never with you in the field when you need them.?ÿ ?ÿ?ÿ
Flagging, sturdy tripod, plumb bob or instrument for leveling.?ÿ
The last pole I plumbed had the Trimble active target so I centered the electronic bubble on the controller and checked it with the total station....it was within half a hair of plumb so I centered the rod bubble.
In the video I'm surprised the manufacturer didn't have something equivalent to the bit of rubber band in there initially.
I use the pole pegger. All my rover rods and prism poles are the same diameter. I set it up one time on a wall out of the way of office traffic. I keep my rods and poles in PVC with a foam sleeve. ?ÿI check them all regularly. ?ÿUsually only one or two require a minor adjustment if any. The PVC and foam insulation sleeve work great at keeping the rods/bubbles from banging around in the truck.?ÿ
Two bubbles on the rod
Park the truck on asphalt and open the tailgate. Plumb the rod with the bubble holding against the notch formed by the bumper and gate. Firmly push the tip in so it doesn't drift. Rotate the rod 180. Adjust the bubble halfway to the center. Move the rod and flatten the asphalt with a hammer. Repeat the process until rotating the rod shows no bubble movement.
With a bit of practice you can do this faster than setting up an instrument....
Two bubbles on the rod
This is what I use with robotic setup. I have one low bubble and a second at normal height.
Here is a bit of a bar trick, or when you don't have a plumb bob. Set a nail or screw in top of door way. Then dip a bowl or hand full of water in the screw until it forms a single droplet of water. Then the droplet falls to the floor to create the bottom plumb point to level your rod. The bar trick involved a knife at top if doorway and a mark in floor. Closes to hit mark wins. Water droplet always wins.
You mean we are supposed to adjust them there bubbles.... ??ÿ
Am I the only one who cringes every time someone uses the term "level" for a vertical rod?
Licensed Land Surveyor
Finger Lakes Region, Upstate New York
Thinking level for the bubble while the rods plumb ??ÿ?ÿ?ÿ
I use a staff bubble on a pole held in an alligator clip tripod thingamajig.?ÿ
Clamp pole vertical then run the bubble around the pole to check. Fine tune till satisfied then adjust screws to centre circular bubble.?ÿ
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Another variation on the corner and 180?ø rotation technique here.
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I screwed a couple of blocks of wood together that sit stable in the vice.
Hold the pole tight against wood and slide the tip of pole around on concrete floor till pole bubble level. Rotate pole 180?ø and if not level adjust out half of difference. Keep repeating till you turn the 180?ø and bubble still level.
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Cheap, no real manufacturing skill, and I find a bit more accurate than bipod method as clamp sometimes slides up or down pole ever so slightly when you turn the pole 180?ø.
He mentions not over tightening, which means at some point you may need to loosen a screw a bit to make the adjustment. I didn't notice him doing that. If you keep tightening you could warp the bubble capsule.
Also, I would want to put thumb pressure on the bubble and tighten the screws a bit after putting in the rubber, so as to make sure it stayed in the middle while I was setting things up with the bipod or other jig.
This is a handy little item I picked up many moons ago. I don't even remember who marketed it. It's simply a machined cap with 5/8x11 female threads with a bail. Works on the plumb bob principal that the rod always hangs plumb when attached. The nice thing about it was I used to carry it in my truck in case of a hard fall with the pole in the middle of a job. You could pound a 60d nail in a tree and check the plumb without risking losing a busted traverse.
I always thought any competent machinist could pop these out without too much trouble.
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I have used the inside corner of a desk and return over carpet. ?ÿPut the pole in the corner, center the bubble and stab the point into the carpet (don't do this with your wife's heirloom handwoven wool Persian rug). Holding the pole tight in the corner rotate it 180 degrees. Adjust the bubble halfway to center if it is off. Repeat as necessary until the bubble does not move as rotated (except for inertia). You can also use a truck tailgate, bumper and soft ground.
