I acquired a Talyvel Level outfit. Today I was checking calibration and adjustment. So far I have not been very successful. Any owners out there that would care to converse with a 'grasshopper' (new user)? I can use some help.
Gary Repesh
I snagged one on eBay last year. I had only seen them used before.
What model do you have? To use it as an absolute level, turn the two micrometer dials on top fully counterclockwise. It should read zero within a very small amount. (Mine didn't, either.) You need a very flat surface level in two axes to really set up the level. Even if you level it in one direction, very small errors in the other direction will throw it off.
Of course, when you get something truly level, you can turn the level around and the reading will be the same, regardless of the absolute zero.
I have a Talyvel 3 with one sensing head. The setup for that is to set the adjusting dial on the readout to 500 (that's a 5 in the little window, and 0 on the dial). Then, using a known level surface, you adjust a little screw in the side of the sensing head to get it to zero. This would be with both mocrometer knobs all the way out.
You secure the sensing head by screwing both micrometer dials all the way in (clockwise). This pushes the sensing "carriage" down until it bottoms on a damping fixture that keeps the pendulum from banging around. the pendulum is a tiny piece of aluminum suspended by 5 hair-thin wires. An iron plate on top of the pendulum moves back and forth between two inductive sensors.
If you are measuring relative alignment, you can bring the reading into range by turning the micrometer dials down a bit, and then twiddling them back and forth to tilt the carriage.
If you are not familiar with the Talyvel, they are REALLY sensitive! I can walk from one end of my lathe to the other and see a change of 1 Arc Second. That's the concrete floor slab bending under my weight.
If the sensing head has been placed on its side, it may take 10 minutes or more for it to recover. There is an oil drop between the pendulum and the carriage for damping. If the head is on its side, the drop runs to the side, and the instrument behaves a bit oddly until the drop is back in the right place.
You can call up your national Taylor-Hobson factory reps and they will gladly send you out a manual. Just tell them the model you have.
Jon
Jon,
I have a Talyvel 1. From your write-up the leveling units appear to be the same. My display has three ranges: 50, 100 and 8. I have the original manual. The needle on my display flickers very noticeably unless I am making and adjustment for zero or balance. Does yours do that? I'll probably check it some more tomorrow.
Mine came with two leveling units. One is in an 8" square fixture.
Thanks for the reply.
Gary Repesh
The Talyvel 3 has a digital readout, and a very uncalibrated small meter for help bringing it into range of the digital display.
Do you mean yout needle flickers unless you are turning the knobs on the readout box? Could be a sign of dirty potentiometers. There is a spray you can get for those, usually used to clean noisy volume controls.
Mine is VERY steady and quiet, when properly placed on a good surface. If it is on a rough and unflat surface, the sensor can rock which will cause unsteady readings. Just a very light touch on the level will cause it to rock, and you can pretty easily detect that problem.
Does it do the flickering with both sensors? That would pretty much point to the meter unit as the problem.
Jon
Yes. The needle flickers on both sensors.
Is yours battery powered? Batteries for mine are not available anymore. I hooked up a small transformer used for small items like radios. I found 7 1/2 volts put the needle in the red zone which means good batteries.
If the meter is bad this project would be history.
Gary Repesh
Gary, Is the 7 1/2 volts regulated or not? It may just be that the unit needs reasonably constant dc not the rectified ac some perhaps even most of these power supplies put out. Batteries what ever there faults do ok at this. Alan Wood
Yes, it uses two big Varta triangular Ni-Cd packs. These are available, but would cost a bundle. Fortunately, putting them on the charger for a couple of days brought them back to life.
Batteries for mine are not available anymore. I
Maybe you need more filtering. Did you put a capacitor on the output of what I assume is a "wall wart" supply? If that doesn't work, you might try putting 5 Alkaline D cells in series. If that works well, you might also try 6 Ni-Cd D cells, and you could use your wall-wart as the charger.
Remember, these are REALLY expensive tools. The current price for the Talyvel 4, last time I looked, was about 3750 GB Pounds!
Jon
Another possible consideration -- how far are you from a major road? You may be reading vibrations from passing semi-trailers and such.
As a way to check that out, get an old inner tube, and half inflate it, and place a big slab of steel (or a surface plate) on it and put the sensor on it to see whether it still flickers.
If you want to (or need to) level it, try three smaller inner tubes (say for something like a wheelbarrow tire), and inflate each half-way, then use a gentle flow of air to bring it up to level.
Vibration isolation on inner tubes is common in vibration-sensitive optical work. There are even big optical tables (6" honeycomb between two plates of steel, with the top tapped in a regular grid, and the bottom mounted on three or four legs with inflated supports (connected to dry nitrogen, and valved by a set of sensors which add or remove nitrogen to restore precise level after you add or remove something heavy to the table near that leg.)
Enjoy, DoN.
I'm going to give the five batteries a test.
Gary Repesh
OK guys! As a long retired surveyor, I'm familiar with dumpy levels, engineers levels, quick-set levels, and have heard of (cheap-for-builders and DIYers!) automatic/self-levelling "levels", (not that I would have been involved in such imprecise gadgets!).
I've used everything from chains, tapes, bands etc to 1" Kern, Microptic, Cooke and other theodoloites (Computer and laser stuff came in after I retired), but what on earth is a "Talyvel" level. I know of the great firms of Watts, Taylor Cooke & Hobson, Kern etc, but never heard of this device.
Would any kind soul please enlighten this aged guy?
Many thanks,
Dave - UK.
Dave,
They are probably right down the lane from you. And they are made by Taylor-Hobson.
The level system for the most part is two pieces. A meter with needle reading on a scale and a sensitive level unit that incorporates a pendulum and is electrically connected to the meter. The level unit is put on a surface. If the surface is level the meter should read dead center. Any deviation left or right and the needle moves in that direction and indicates the amount from level. It has other features too.
Gary Repesh
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.