Thread: A Novel Idea For Those That Can't Afford A Sensitive Level

Originally Posted by Machtool

Are we back to real Levels and not gizmo's / talking points?

It surely cant be for breakage. You said precision level. It's not a clay duck.

Surely you would have to mis-handle a true level to break a vial. Thats hammer and chisel work

It's mechanical protection. The windows / shutters / glass / perspex over lays, are only there to prevent your and mine fat fingers from touching the vial. Touching the vial will upset the applecart.

Phil.

Phil, I suspect in a precision level like the one I have below, the Perspex dome around the vial is both to protect the vial from mechanical damage, and more importantly to keep away the warm breath of the user. The black plastic around the body is, exactly like on a good micrometer, to insulate the level from the heat of your fingers. Like precision micrometers, precision levels do not like temperature changes.

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In the case of a homemade level like in the video, such a half-round perspex dome could take care of concerns regarding sharp glass should it break. And to some extent flammable vial contens in case of breakage. This whole breakage fear is possibly exaggerated out of proportion. What if the wooden block under the vial was made of soft Balsa wood, would it not compress way before the glass breaks? Just thinking.

Model Engineers Workshop issue 36 on page 36 has an article by Peter Peters titled "A very sensitive level". Over 7 pages he describe in detail how he makes a level using a glass tube that is bent by mechanical force from below. The principle is EXACTLY the same as our friend in the video uses. But Peters model is beautyfully finished and much improved. He does not simply use a wooden block at the center, but two contact points to achieve a more circular curvature of the glass tube. He also separated the adjustments for curvature (=sensitivity) and level adjustments. A very interesting read. And proof that the idea is not as crazy as some people here want us to believe. Here some extracts for the non-believers:

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Originally Posted by cba_melbourne

Model Engineers Workshop issue 36 on page 36 has an article by Peter Peters titled "A very sensitive level". Over 7 pages he describe in detail how he makes a level using a glass tube that is bent by mechanical force from below. The principle is EXACTLY the same as our friend in the video uses. But Peters model is beautyfully finished and much improved. He does not simply use a wooden block at the center, but two contact points to achieve a more circular curvature of the glass tube. He also separated the adjustments for curvature (=sensitivity) and level adjustments. A very interesting read. And proof that the idea is not as crazy as some people here want us to believe. Here some extracts for the non-believers:

Thanks for that, his design looks much better than crazy eddie's, I bet that his vial isn't full of pressurized butane either

As Stuart posted earlier, let's see what would have to be done to make the design work.
First ..the aluminium block is not required. A base that can be machined and scraped flat would be a good starting point, tilting the whole assembly to zero it seems dumb to me, so a seperate zero screw that adjust the tilt on the vial only... companies like Wyler/Tesa go to great lengths to ensure the vial is not stressed, (why?) the idea of bending a glass tube seems counter to that? Maybe buy a replacement 0.05/m vial and build around that...

Dunno, Seems like a lot of trouble...

Pretty soon the cheap chinese levels start to look attractive... 0.02/m for $US35 http://www.aliexpress.com/item/200mm...118443097.html around $70 landed

Or if you want Swiss quality, it's hard to go past this Wyler 0.04/m for $198+postage. http://www.swissqualitydiscount.com/...products_id=41 No idea on postage?

Ray

I posted this thread as I thought it might interest and inspire other members as it did me.
I did NOT post it for members to belittle the poor fellow.
80% of the responses will make me think twice before posting here again.

IT SADENS ME TO THINK MEMBERS HERE ARE SO CRUEL !!!!!!!

Originally Posted by matthew_g

I posted this thread as I thought it might interest and inspire other members as it did me.
I did NOT post it for members to belittle the poor fellow.
80% of the responses will make me think twice before posting here again.

IT SADENS ME TO THINK MEMBERS HERE ARE SO CRUEL !!!!!!!

I understand what you are saying Matthew. I cannot see any reason for the behavior shown. The video is still on UTube for the whole world to see. Constructive criticism is ok, but anything more than that is demeaning. I believe that these posts were out of context, in this case.

I found the video useful and I don't believe that I was at risk of falling into any of the traps that were mentioned.

I was pleased that the most recent posts were back to normalcy. There have been some informative posts that I have also found useful. It has been a positive learning experience, but it was a shame that it was marred by well meaning people and their criticism.

When you are reading an "ABC" children's book discussion's on philosophical literature are premature.

Dean

Originally Posted by RayG

....................................
Dunno, Seems like a lot of trouble...

Pretty soon the cheap chinese levels start to look attractive... 0.02/m for $US35 http://www.aliexpress.com/item/200mm...118443097.html around $70 landed

Or if you want Swiss quality, it's hard to go past this Wyler 0.04/m for $198+postage. http://www.swissqualitydiscount.com/...products_id=41 No idea on postage?

Ray

Ray,

sometimes it is not about arriving, it is about the journey. Think about all the fools wasting time building model engines, when one could buy them ready made..... But there can be great satisfaction by "I made this myself", even if it does not run as smooth as the new chainsaw.

There is also the learning effect. I am sure the majority of people that use precision levels, have no idea how a vial is made in the first place. Being forced to think about what glass curvature is required for a given sensitivity, is certainly highly helpful at better understanding the magnitude of the errors that will cause say a lathe to turn taper.

Cheap Chinese: 0.02/m accuracy for $US35

Quality Swiss : 0.04/m accuracy for $198

Quality aside, if accuracy is your goal, and this seems to be the case amongst the 'well meaning' on this forum, why would you buy quality?

Does this equate to form before function?

Please explain.

Originally Posted by cba_melbourne

Ray,

sometimes it is not about arriving, it is about the journey. Think about all the fools wasting time building model engines, when one could buy them ready made..... But there can be great satisfaction by "I made this myself", even if it does not run as smooth as the new chainsaw.

Quite right, but I have read the article you mention and as you say it is many pages long... Very well explained with lots of engineering calculations mixed in like the modulus of elasticity of glass.. It is quite well written, like most articles you find in the model engineering magazines..

I have nothing wrong with people doing rough work to serve a purpose, but you need to know the limitations of such a device, and if you want to show the whole world then at least explain the limitations..

I live/work on a farm, I come across quick, rough, cheap fixes all the time..It is wonderful coming across jops where ye olde farmer has jammed a 1/2" whitworth nut on a 1/2" UNC bolt with the aid of a 15" shifter, and rounded the nut off in the process. You try to explain and all you get is "damn brumby bolts/nuts, you would think they would standardise everything"....

No point explaining to them, they would not understand..

Originally Posted by cba_melbourne

Ray,

sometimes it is not about arriving, it is about the journey. Think about all the fools wasting time building model engines, when one could buy them ready made..... But there can be great satisfaction by "I made this myself", even if it does not run as smooth as the new chainsaw.

There is also the learning effect. I am sure the majority of people that use precision levels, have no idea how a vial is made in the first place. Being forced to think about what glass curvature is required for a given sensitivity, is certainly highly helpful at better understanding the magnitude of the errors that will cause say a lathe to turn taper.

I think we are on the same wavelength here, I agree that the enjoyment and satisfaction you get from the journey often outweighs the end result, I recall showing the wife the scraped block after the Melbourne scraping course, all I got was blank looks and you must be mad... I tried explaining that it was flat to better than a few microns, what's a micron?

I happen to like making my own metrology stuff, cylindrical square, master squares, haven't done a decent straight edge, but one day I will. I've been toying with the idea of making a precision level for some time, but I plan to use MEMS sensors and make it variable sensitivity.

If you are going to make something yourself, you should aim to make it as good or better than the commercial units, at the very least it should work properly and have a bit of integrity about the design and construction, this is where I fail to get excited about a glass tube full of butane bent over a wooden block.. Maybe as a starting point for a design.

Ray

My problem with the video is simple.
If he had said "i thought i'd like to have a go at making a level, here is my first attempt", then good on him for having a go, and i'd have to say well done, even if it has issues.

But he said "look at me, i made a sensitive level", hence my problem. It is neither sensitive or will it repeat well with that big block of ally.

Ew

Originally Posted by th62

Cheap Chinese: 0.02/m accuracy for $US35

Quality Swiss : 0.04/m accuracy for $198

Quality aside, if accuracy is your goal, and this seems to be the case amongst the 'well meaning' on this forum, why would you buy quality?

Does this equate to form before function?

Please explain.

Price and quality are two different concepts.. I'm sure I don't need to explain.

That $198 for a Wyler/Tesa level is cheap. That model normally retails for over $1000.. so that's cheap AND quality.

The chinese one is just cheap. ( Incidentally that's the model I have, and it works just fine, I scraped it flat and fiddled with calibration for a while, but it will do until I want something better (that's function )

The precision level is one of the most important tools for machine survey, and for those of us who like restoring old machines, a precision level is essential. Just like a good surface plate, an accurate square and good straight edge. A good level is up there with the essentials.

Ray

Originally Posted by th62

Cheap Chinese: 0.02/m accuracy for $US35

Quality Swiss : 0.04/m accuracy for $198

Quality aside, if accuracy is your goal, and this seems to be the case amongst the 'well meaning' on this forum, why would you buy quality?

Does this equate to form before function?

Please explain.

It's about the reliability of that claim and the likelihood that the claim is still valid in a a few year's time. While a randomly selected cheap level may indeed check out, if the design and production of the item is poorly executed the chance of the next level also achieving that specification is lower than if it was from a recognised quality supplier. It is why people concerned with metrology commercially still buy the more expensive Swiss and Japanese offerings even though they can buy cheaper.

Michael

I have edited some posts and removed one other, could we please keep this debate at a non-personal level without stooping to personal insults?

We seem to have at least one member (with previous form) here, who is hell bent on upsetting the apple cart.

Please cease and desist or firmer action WILL be taken.

You've missed my point: If the cheap Chinese level is only $35 and accurate to .02mm - why would you pay $198 for something with a nice brand name if it is only half as accurate?

Originally Posted by th62

You've missed my point: If the cheap Chinese level is only $35 and accurate to .02mm - why would you pay $198 for something with a nice brand name if it is only half as accurate?

Yes, I see how that could be confusing, the 0.02 and 0.04 relate to sensitivity NOT accuracy, I'd back the Wyler for accuracy. For a machine survey, accuracy is just as important ( if not more so ) than sensitivity.

I'd probably argue that 0.02 is too sensitive for most applications, 0.1 mm/m is more than adequate for lathe levelling type jobs.. 0.02 you just go crazy chasing the bubble..

Ray