I had a "friendly" discussion the other day about what can knock a prism pole bubble out of adjustment. They argued that placing the bi-pod, data collector bracket, and prism pole into the carry bag will knock it out of plumb. My first thought was that vibration is what knocked it out of level, any vibration over time.
I am curious of other peoples thoughts on this subject. I know it seems a bit frivolous, but my curiosity remains.
Thanks in advance for any input.
A field hand can look at it, from 50' and it will "Go out".
I run HIXON poles, and they need checked once a year. Adjusted once every 3.
🙂
N
When you get a brand new pole, turn the adjuster screws 1 or 2 turns tighter then adjust it. The bubbles will stay in adjustment a lot longer that way. Often they come from the factory loose.
I would think along the vibration lines and rough use in the field by the user.
Bouncing around on roads etc or stabbing them in the ground.
I pack poles in either a foam gun case and fishing rod tubes with foam inserts.
Btw foam pool noodles that can be bought at dollar stores are very good protection.
One can try a locktite purple thread treatment if something unforgiving is happening
If you drive past a "Realtor", on a dirt road, at 10:00 in the morning, it can tweek all the bubbles in the truck!
If you drive past a "Lowball" surveyor, doing the project you "bid" on, it can also loosen the screws holding them.
If you place the Pole in the office, in front of one of Kent Mc's posts, it will torque the screws to 18-24 Ft Lbs. This has been known to break screws.
If you let the pole sit beside the computer, with Holy Cow's posts up, it can bend the pole. But, if you remove it from the office, it will go back straight!
🙂 (sorry to OP)
N
I know that swatting a rattlesnake will affect the bubble. I strongly suspect using the pole as a machete will affect the bubble. I have tried experimenting with poles, dropping them from horses and ATVs, and have had mixed results so far. The amount the bubble disagrees with itself by rotating the pole 180 degrees seems to vary proportionately to how far away from the truck (and a spare pole) I am. I really cuss when I realize I left my hand held rod level at the truck too.
I can't think of any reason that simply placing the rod in a carrying bag would knock the bubble out. Whacking said bag against various and sundry obstacles while carrying it might. They might be thinking that carrying the rod in a bag encourages rougher treatment of it.
Dissimilar metals (such as the stainless steel the screws are made of and the aluminum bubble housing in which they are screwed) don't get along very well. That is usually due to uneven expansion and contraction due to temperature variations. Since a lot of equipment resides in a truck and is used almost exclusively outdoors; that can equate to -10å¡F to possible +150å¡F (inside an enclosed truck in summer). That's a good range.
As things expand and contract, they move. And as they move, the bubble's position is affected. If they were merely there to cinch things together, regular tightening might be the answer. But they are calibrated and set at the factory, probably at somewhere near 68å¡. Frequent checking and readjustment is your only answer.
I have determined that apathy is the biggest reason rod pole bubbles get out of adjustment. I would suggest an experiment where the crew checks the bubble everyday and throughout the day everyday from now on to determine what causes the bubble to get out of adjustment. That way they can prove their point and more importantly the bubble is being checked. Never let them know that you agree with their findings. It should always be an ongoing experiment to determine the truth. :innocent:In fact, I always assume that the rod is out of adjustment and they need to prove that it isn't. The cause is actually less important than the measurement being wrong.
I have six total prism poles & 2M GPS poles; some aluminum, some composite, some carbon-fibre - all with Seco 8' vials.
I check them in a SECO fixture every day and always at least 4 of them are out of adjustment to some degree, usually the composite and carbon-fiber are the worst. It usually takes about a minute each with the jig, and I think it's time well spent
I have removed & reinstalled the vials from the holders, removed & reinstalled the holders from the poles, tightened, loosened - you name it - no joy.
And, no, they don't bounce around in the back of the truck and, no, I don't drive hubs, clear line, stab snakes, spear 'em into the ground, lift MH covers, or any of the other abuses y'all might think to throw at me.
I do know that the older 40' vials I have pivot on a ball bearing in the holder, while these newer 8' vials just pivot on a little dimple projecting from the bottom of the vial enclosure. Obviously the 8' are 5X as touchy as the 40', so I think it's just the nature of the beast.
Wow. I have the HIXON poles. They are MUCH better than that. I take them apart, and grease the cone, and clean and re assemble every few years. They are WAY better than that. I can count on 0.02' accuracy at 8' up, ALL the time. I did have one go bad about a month ago. The bubble started GROWING.
N
Using it to find where the edge of concrete is because the party chief is too lazy to use a shovel.
Bouncing around loosely and being subjected to impact messes with the bubbles the most.
IMVHO, These new poly products have their limitation and being survey grade is well beyond their expectations.
😉
Sergeant Schultz, post: 381968, member: 315 wrote: I have removed & reinstalled the vials from the holders, removed & reinstalled the holders from the poles, tightened, loosened - you name it - no joy.
Among the prism poles I've owned, the weak link has consistently been the foam pad beneath the level vial. It acts as a spring against the adjustment screws, but over time most of them seem to lose their springiness. The best fix is just to replace the pad and everything is suddenly better.
The even better than best fix is to use a prism pole tripod that allows the user to rotate the pole on the point, at the setup. That way, maladjustment is immediately detected and can be partially cured by field adjustment.
I have 2 similar poles from pre 1991 and neither have needed any adjustment.
Not sure of brand, anodised red aluminium poles, not graduated, just a screw ferrule to tighten, about 20mm Ìü.
They are amazing poles and whilst never abused haven't been handled with kid gloves.
Later, graduated poles not so good. I constantly check and adjust perhaps every year.
Thanks everyone for your replies, it was both amusing and interesting.
maybe...just maybe, there's a reason they have adjustment screws...:)
paden cash, post: 394921, member: 20 wrote: maybe...just maybe, there's a reason they have adjustment screws...:)
Holy mother of God! They'd been there the entire time. Absolutlely insidious plot! :smarty:
Metal fatigue to an extent. It's recommended when you re-use bolts to torque them to spec, back them off, and then retorque them. Not so sure about a fine thread #4 or #6 hex socket head though. The plate could stress though, if you over tightened them.
If it happens to be a collet-style prism pole, most people grab the level while loosening the collet, tending to make it spin around the pole if the level isn't tight enough.
