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Just got a Tesa-Hite 700, need some advice.

Spud

Diamond
Joined
Jan 12, 2006
Location
Brookfield, Wisconsin
Just bought this yesterday



Been wanting a Tesa Hite 400 or 700 (not Magna) for about a year now, as it is the one I loved using at Tech College. At college, they have Starrett and Mits eletronic height gages but I prefered the Tesa.


At college this is the steps I follow for measuring a part:

Turn on machine
Use handwheel to move the probe up and down per the arrows on the screen. Is this called clearing the scale?
Then when prompted by the screen I set the datum plane, which 90% of the time is the surface of the granite surface plate.
Every now and then I would use a gage block to check to see if the Tesa was accurate.


The Tesa Hite 700s I just bought does not come with the power cord, probe, probe holder and the calibration setting piece seen below.

TESA Setting Piece for MICRO-HITE - 00760236 - Penn Tool Co., Inc

So here are my questions:

* Do I need the calibration setting piece? Couldn't I just use a gage block to check that the gage is accurate?

* Do I need to have a Calibration lab calibrate it? There is a local Lab that I have used for calibrating several of my instruments.

* Can I take the gage to the Lab, or do they need to calibrate the gage at its end-user location? Does calibration on the gage need to be done as it sits on the specific granite surface plate I intend on using?
 
1. I'm making a few assumptions because I've only used the Mahr and Mitutoyo equivalents. It might have something about Tesa not responding to any of my inquiries when I went to buy a height stand. Pity as they make awfully nice indicators.
2. Yes, it's just a group of gauge blocks in a fixture. The Mahr one (and this looks similar) has 3 blocks in a stack, with one sticking out a bit farther. This lets you go around the outside (the block that sticks out) or the inside (the lower surface of the upper block and upper surface of the lowest block). Mitutoyo does it a bit differently. They have a gauge block hanging off the side of a taller one. You touch the top of the bottom block, then the bottom of the upper block, which should be on the same plane. This has the side benefit of providing distance from the table as the lower piece is a long gauge block. However you make it, you will want the blocks to be *very* parallel to the base. If not you'll get an erroneous measurement.
2b. At least with the Mit. and Mahr setups you can also use a high accuracy micrometer and measure the ball size, then manually enter it. IME this always results in the stylus entry being too large because it doesn't take into account deflection between the stylus and the actual location the measurement is being taken within the machine.
3. Calibration depends on what you need to do with it. I've never formally calibrated mine. Partly because it isn't that old and has been well cared for, but mainly because I don't have any customers that expect it (closer to a home shop). I'll occasionally sanity check on a nice grade 0 gauge block set, but that's all. On the other hand, if I had customers expecting NIST traceable inspection results and I was not equipped to provide such in house, you bet I'd have an external lab handle it.
4. Ignoring the cost of transportation, it's typically cheaper to have a calibration lab perform work in their own facility where they have control of temperature, humidity, etc. For something like a pair of calipers it will cost more for them to come to you than to do the work, and environment won't be all that critical. For something more accurate, it's easier to let them operate in their own controlled environment.
4b. I don't know that specific unit, but the Mit. and Mahr height stands I've worked with have an internal counterweight that must be secured before tilting or transporting the height stand if you want to avoid damage. I'd also wrap the feet on the bottom as dings on those would result in damage to a granite surface and perpendicularity error of the stand until any raised spots on the feet are removed.
 
Yes, you need the calibration piece, or to make one in the same vein (C-shape gage blocks). On the tesa hites (and micro hites) the probe does not have a consistent deflection force control inside the probe arm, so in addition to calibrating the distance of 1” travel, it also “calibrates” your hand pressure on the wheel.

During calibration it will take about 6 tries, and you can test this by moving more forcefully or less forcefully with the wheel on a couple tries than others. It will not take the reading, and the probe symbol will start flashing on the lcd.

In a busy shop with many users, standard practice is for whomever just sits down at the plate to calibrate the probe, since your hand is going to be different from the previous user’s. Enjoy it, I love these tools!
 
Yes, you need the calibration piece, or to make one in the same vein (C-shape gage blocks). On the tesa hites (and micro hites) the probe does not have a consistent deflection force control inside the probe arm, so in addition to calibrating the distance of 1” travel, it also “calibrates” your hand pressure on the wheel.

During calibration it will take about 6 tries, and you can test this by moving more forcefully or less forcefully with the wheel on a couple tries than others. It will not take the reading, and the probe symbol will start flashing on the lcd.

In a busy shop with many users, standard practice is for whomever just sits down at the plate to calibrate the probe, since your hand is going to be different from the previous user’s. Enjoy it, I love these tools!


Does the Tesa have a counter-weight inside like the previous poster said of the Mahr and Mits?

When I collected my Tesa from the auction location, I just picked it and placed it inside a box whose bottom was padded with about 6" of stryfoam peanuts and then bubble wrap. I did not tilt the gage, always kept it oriented vertical. Had it in the backseat area of my pickup, and like you see in the photos the gage was surrounded by stryfoam peanuts and the box didn't move about because it was sandwitched between the front seat and the rear seat.

Tesa-gage-pic-1.jpg


Tesa-gage-pic-2.jpg
 
Yes, there’s a counterweight, that (i believe) the ribbon reader is directly attached to. I’ve never had one apart though.


Is there a way to lock the counterweight? So is it more or less likelty I damaged the gage while moving it? How rugged or delicate are these, would picking and moving it damage it , even if you don't bang it on anything?
 
Is there a way to lock the counterweight? So is it more or less likelty I damaged the gage while moving it? How rugged or delicate are these, would picking and moving it damage it , even if you don't bang it on anything?

On the Mahr and Mit. options you fully lower the carriage/probe (which raises the internal counterweight to the top) and then tighten a screw in that hole on the top. If the carriage doesn't want to return up, you're good to go. If it still moves freely, you probably didn't engage the screw. It only needs to be barely snug, not really reefed on. I've seen the company reps not even use an allen wrench, just snug a SHCS by hand and call it good. The idea is that it keeps the counterweight from banging around in transportation. If you can find a manual, it'll probably be mentioned in there along with what size (probably metric) screw you should use.

The good news is that these things are generally pretty robust. I wouldn't intentionally ship one UPS/Fedex without the counterweight secured, but honestly it might even survive doing that once. In your case I wouldn't worry at all so long as the carriage goes up and down properly and the gauge passes calibration.
 








 
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