Level Gauge Faulty

[norm nortonParticipant @normnorton75434]

[norm nortonParticipant @normnorton75434]

I purchased this level gauge back in 2012 and have used it several times. The other day I was trying to set 5 deg on a mill job and the display was jumping from 5.2 deg to 3.2 deg.

As a test, I slowly elevated it from zero and the reading would slowly increase, then suddenly jump to a different value for the next 0.2 deg, then revert to its correct value for a reasonable arc, and suddenly read in error again for 0.2 deg.

Obviously it is going in the bin. But what worries me is that it could have been like this for a long time – if I was using it at the OK values I would not have seen the jumping.

Are these units inherently unreliable? Do I pay £40 for a replacement or are there good ones from the many to be seen on eBay?

Norm

 

Edited By norm norton on 31/10/2016 14:37:18

[Les Jones 1Participant @lesjones1]

I think all these angel gauges work on the same principle. They are basicaliy a pendulum mounted on a ball bearing and they use eddy current damping to stop the reading taking to long to stabilise. The bearing could be sticking or there could be dirt between the capacitance sensing electrodes. I have put some information about the working of these gauges here on my wesite.

Les.

[Chris Evans 6Participant @chrisevans6]

Have you tried replacing the battery? I personally would not rely on one of those gauges if I wanted accurate work. I have one of the old analogue Starret ones but it is only a rough guide, I think they where originally made for building/roofing trade but they have there uses.

[Tony Pratt 1Participant @tonypratt1]

These type of angle gauges 'talk a good game' but I would imagine they are not very accurate.

Tony

[Michael GilliganParticipant @michaelgilligan61133]

Norm,

I certainly wouldn't spend £40 on one

… not when things like this are still being listed on ebay

http://www.ebay.co.uk/itm/Hilger-and-watts-clinometer-/302124002153?hash=item4657fe6b69:g:rvwAAOSwcUBYFkbM

MichaelG.

[Neil WyattModerator @neilwyatt]

They are actually quite accurate, 0.1 degree isn't a hugely demanding level of accuracy and they work on a similar principle to digital verniers..

A jumping reading is a fault, not a sign of inaccuracy and is probably wither a sign of dirt or a sticky mechanism.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

The [not Wixey branded] one that I bought from CPC for about £7 was good value for money, but I stand by my previous comment.

MichaelG.

[norm nortonParticipant @normnorton75434]

Tried the battery – no different.

It seems like the encoder is dirty/malfunctioning, the way it jumps repeatably to wrong values at specific angles.

I like your write-up Les taking one apart. I might as well undo mine. But is it a rotating sealed encoder or will I be able to wash it? Or does it use capacitance across a gap, hence a cleanable gap?

Sorry MichaelG… the Clinometer is a bit big to use! These magnetic scales are very handy as you can clamp them to the job and then adjust stuff. I have a whole set of angle measuring protractor type scales, including fancy ones with a vernier, but often you cannot access the angle between the work and the reference surface.

Hmm.. I cannot see one on CPC Farnell. eBay has a non-Wixey identical model at £25 +p&p.

Norm

[Michael GilliganParticipant @michaelgilligan61133]

Posted by norm norton on 31/10/2016 20:26:18:

Sorry MichaelG… the Clinometer is a bit big to use! These magnetic scales are very handy …

Hmm.. I cannot see one on CPC Farnell. eBay has a non-Wixey identical model at £25 +p&p.

.

1. Point taken, Norm, regarding size.
2. Sorry, I should have mentioned it may have been a couple of years ago that I bought the CPC cheapo.

MichaelG.

[Clive HartlandParticipant @clivehartland94829]

If this thing has a pendulum and swings between copper dampers it must be used level across the table as well, if it is sticking or jumping then that indicates that the suspension or bearings are touching the frame inside. They must be very much like automatic optical levels inside.

[Les Jones 1Participant @lesjones1]

I did not take the encder part appart as I was only interested in being able to output the position information a read it remotely. As you can see from the picture I achieved this via a Bluetooth ling to an Android tablet running Yuriy's DRO software. My feeling is that the bearing could be sticking causing the pendulum to jump past the sticky point. I think when CPC were selling them for about £7.00 they must have been an end of line product.

Les.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Norm, I have just the basic Wixey and I had a similar condition to yours. When I opened it up, I found the encoder part had come loose and all I had to do was glue it back in place with a bit of Araldite. So it may just be worth a look and see if you have the same kind of problem before you pull the encoder to bits.

Regards Nick.

[Neil WyattModerator @neilwyatt]

I think I must have picked up mine on a similar CPC offer – it's Duratool a brand CPC often sell, often comparable with Blackspur etc. although it works well enough and has an adjustable level on top.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 31/10/2016 21:49:22:

I think I must have picked up mine on a similar CPC offer – it's Duratool a brand CPC often sell, often comparable with Blackspur etc. although it works well enough and has an adjustable level on top.

Neil

.

Yup … That's the one: **LINK**

http://uk.farnell.com/duratool/d01906/digital-bevel-with-vial/dp/2444476

MichaelG.

[duncan webster 1Participant @duncanwebster1]

Posted by Les Jones 1 on 31/10/2016 14:47:25:

I think all these angel gauges work on the same principle. They are basicaliy a pendulum mounted on a ball bearing and they use eddy current damping to stop the reading taking to long to stabilise. The bearing could be sticking or there could be dirt between the capacitance sensing electrodes. I have put some information about the working of these gauges here on my wesite.

Les.

I think I'm about to start on a big learning curve here, as I know little about serial data! I've had a read at Les's link, and it mentions one count being 0.02 degress, but then saya that the data is the number of 0.04 degree increments, so I'm confused. Can anyone enlighten me?

[Les Jones 1Participant @lesjones1]

Hi Duncan,
It just means that the least significant bit from the encoder is not sent out in the data stream.

Les.

[duncan webster 1Participant @duncanwebster1]

I see. Does the sensor give quadrature output? If so can I access it? I'd be much happier with that as I've messed with quadrature encoders and Arduinos before

[SamsarandaParticipant @samsaranda]

Has anyone tried the app available for an IPhone called Clinometer, developed by Plaincode, it's free to download and more importantly would appear to be accurate; no problem with the batteries as long as you keep your IPhone charged. Another very useful app available is I-Engineer. .

[Les Jones 1Participant @lesjones1]

Hi Duncan,
These gauges do not give quadrature output. I have some notes on the BIN6 protocol that I can send you. I can also send you the source code for the interface. The code also reads 2 x 24 bits scales, 7BCD scales, Bin6 scales and iGaging scales. If you would like a copy of this information then PM me with an email address.

Les.

[norm nortonParticipant @normnorton75434]

OK I have taken it apart, partly out of curiosity, with little expectation of fixing it. The nature of the fault, being data jumping to a wrong value at certain levels, implied an electronic error rather than a physical malfunction.

So here is a picture of the component parts:-

On the left is the rear cover with a ring of magnets, that damp the copper pendulum, with a shaft that slides into the two bearings carried in the middle of the green, square pcb that is still attached to the display in the main body. The green pcb circle affixes to the pendulum shaft with the nut and washer and I guess carries a set of capacitive elements around its circumference. The final square pcb on the right carries a web of fine traces and a few components. I presume that this senses the capacitive changes. The odd thing was how this pcb connected to the main one with the display. There was a plastic/carbon rectangular section that was compressed between the two when assembled.

The good news is that having disturbed all these parts and reassembled them, it now works without error!! I can only guess that the plastic/carbon connector has changed its behaviour, as that was the only electronic item disturbed, but how it transmits its signal I cannot see.

Obviously the absolute zero level had been disturbed by taking the circular disk off and putting it on in a new, random location. But the device has a 'reset absolute level' sequence of button presses and this was successful. I put it on a metal block bolted to a vertical Rotary Table and slowly rotated it through a full 360 deg. The display seemed to smoothly follow the rotation with no jumping of displayed digits.

I shall now continue to use it, but perhaps keep an eye out for any repetition of the fault. Thank you to those who encouraged me to have a look inside.

Norm

[Neil WyattModerator @neilwyatt]

That's good to know if mine ever starts playing up.

Neil

[Howard LewisParticipant @howardlewis46836]

Some years ago, I bought one from Allendale. When it stared playing up, as the O P describes, I took it back, at a show.

The chap that I spoke to said something to the effect of "I can fix it, but not here. Take this one" and gave me a new one which has worked well ever since.

When my digital Depth Gauge misbehaved, they fixed it and posted it back, F O C. (By the looks of the paperwork, it needed stripping and cleaning)

As you might imagine, today, I have placed another order with Allendale, they have provided good service on both occasions that their products malfunctioned.

Howard

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