could i please get a recommendation on a pole bubble level adjuster?
-thanx
Paul was always pretty good at it! But he's not working in the land surveying field anymore. And I don't mean PA Paul 🙂
This is what we use. http://www.hayesinstrument.com/st_prod.html?p_prodid=2137
Just a suggestion. If you double the angle to the prism pole, you can use reversion to get a true reading. When you observe the prism in the direct mode, have your level in the usual position, then when you are taking the indirect reading make sure that the leveling bubble is 180 degrees from the first sighting. What errer you have in tour bulls eye level will be canceled.
rplsntx, post: 322257, member: 8904 wrote: could i please get a recommendation on a pole bubble level adjuster?
-thanx
Poles are pretty easy to adjust without any "hamburger helper".
Mine are on bipods. I have a mag nail in the ground set from a long string plumb bob on an overhead nail. I set up the pole without the prism, hang the plumb bob, center the pole brass mount under the plumb bob point and check/adjust the bubble. The more expensive jigs can be set up more precisely indoors.
Scott Ellis, post: 322274, member: 7154 wrote: This is what we use. http://www.hayesinstrument.com/st_prod.html?p_prodid=2137
We use this as well.
I use this.
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Seco Pole Pegger
I have the Sokkia version. Exact same thing, half the price.
rplsntx, post: 322257, member: 8904 wrote: could i please get a recommendation on a pole bubble level adjuster?
-thanx
There are lots of effective ways to do it. Most of the devices available for the purpose work well, but I prefer to use a door frame. Put an eye hook in the top of the frame and drop a plumb bob from the hook to the floor. Then make a dimple on the floor where the plumb bob hits. Remove the eye hook and put an extra prism pole point of top of your prism pole. Then put the base of the pole in the dimple on the floor, and raise the top of the pole to the hole made by the eye hook. If the pole is not bent, it is now plumb and you can adjust the bubble accordingly. If it is bent, you've got bigger problems. Once it's adjusted, slowly turn the pole to be sure the bubble doesn't change.
This is what I have:
SECO Prism Pole Adjusting Jig
http://www.tigersupplies.com/Products/Seco-Pole-Peg-Adjusting-Jig__sec5195-01.aspx?gclid=CIjpzrHXlcYCFVKIfgodKR8ATg
Google: Prism Pole adjustment
I have no relationship with Tigersupplies, other than I bought a battery from them once.
^That's the one we use as well, cant say I like it all that much but it works.
We have the seco jig on our wall in the hall and Hold-a-poles in the rigs. Both work. The inside one is nice for a check in the morning during the brisk months.
-Drill a hole in the top of a door jamb and plumb down.
-Mark the point directly below the upper hole and drill a hole there.
-Now you have a hole in the top of the door jamb and one in the floor that make a plumb line.
-Take an extra prism pole point (or take one off a spare pole) and put it on the top of the pole.
-Insert the bottom prism pole point into the lower hole in the doorway and extend the pole until the top point is in the top hole.
-Rotate the pole and adjust the allen key screws beneath the bubble accordingly.
We use two instruments at 90° to the pole and raise it all the way up, taking line at the tip and pulling to the top. Both instrument men tell the other guy which way to go and then we adjust the bubble. Then rotate it 180° and check. It's always good.
Similar to Kris...using one instrument...
1. Put the pole in a push button tripod and center the bubble.
2. set up the instrument about 15' away.
3. Look up and down the side of the pole with the cross hair. If it isn't plumb, plumb it perpendicular to the line of sight. Adjust bubble perpendicular to the line of sight. Recenter. Check it. Lather, rinse, repeat.
4. Rotate pole 90 degrees.
5. Center the bubble and repeat step 3.
6. Check it both ways.
If it is way off, you can get it close by putting the pole in a push button tripod, center the bubble, rotate 180°, adjust out half the error, repeat.
Finally, often the bubbles come from the factory with the screws too loose. Run those in a few turns then adjust the bubble. This way there is more pressure on the foam pad under the bubble and it will stay in adjustment better.
Mine are on bipods. I have a mag nail in the ground set from a long string plumb bob on an overhead nail. I set up the pole without the prism, hang the plumb bob, center the pole brass mount under the plumb bob point and check/adjust the bubble. The more expensive jigs can be set up more precisely indoors......
well...i tried the above. got all the things together and tied my plumb bob to the ceiling, lowered it to the floor and made a small dot then raised up the bob. i set my pole up with the bipod and leveled it using the bubble right over the dot.
after several hours i could never get the plumb bob to settle directly over the pole no matter how centered the bubble was. :-S.
Dave Karoly, post: 323065, member: 94 wrote: Similar to Kris...using one instrument...
1. Put the pole in a push button tripod and center the bubble.
2. set up the instrument about 15' away.
3. Look up and down the side of the pole with the cross hair. If it isn't plumb, plumb it perpendicular to the line of sight. Adjust bubble perpendicular to the line of sight. Recenter. Check it. Lather, rinse, repeat.
4. Rotate pole 90 degrees.
5. Center the bubble and repeat step 3.
6. Check it both ways.If it is way off, you can get it close by putting the pole in a push button tripod, center the bubble, rotate 180°, adjust out half the error, repeat.
Finally, often the bubbles come from the factory with the screws too loose. Run those in a few turns then adjust the bubble. This way there is more pressure on the foam pad under the bubble and it will stay in adjustment better.
What happens when or if your axis is off on the totalstation?
Kris Morgan, post: 323063, member: 29 wrote: We use two instruments at 90° to the pole and raise it all the way up, taking line at the tip and pulling to the top. Both instrument men tell the other guy which way to go and then we adjust the bubble. Then rotate it 180° and check. It's always good.
Kris,
I have to wonder if you believe this to be the best method for adjusting prism pole bubbles or if it's just the way it's always been done. It seems as though there are multiple bubbles involved in this procedure; many points of adjustment that need to be relied upon to get the single adjustment you're after. Plus, it seems as though it takes a longer period of time to accomplish.
The Seco jig that has been referenced in this thread has been the tool I've used for years now and it's fairly quick to not only check the bubbles but to adjust them as well.
I'm not expecting you to change your method, just wondering, that's all.
