precision piezo: difference between boards

garyd9

@lakko said in precision piezo: difference between boards:

@garyd9 I think that your best choice is the universal kit and 3 undrilled piezo for the under bed piezo, take a look here
https://youtu.be/UVoCARDOoxs

No, that'd be the easiest choice, not the best one.

I already have underbed FSRs and I'm trying to eliminate the complication and variability of different probe heights at different locations. The best way to do that is to have a single sensor at the nozzle instead of 3, 4 or even 20 scattered under the bed.

I have some different ideas of how to do what I want, but having a vague idea of an end result is quite easier than making an idea into a physical object.

I'd also have to mount the piezo control board on the effector - which was why I was hoping I could order a "kit" with the piezo20 board instead of the universal one. The "kit" has multiple piezo's (in case I destroy some in trial/error) and most of the wiring I'd need, while the piezo20 appears to be a physically smaller board (and with the plug orientation, would take less space overall.) Yet, when adding in currency exchange rates and international shipping, it starts getting expensive to order a kit AND an extra board, etc.

I was hoping they'd be willing to just swap boards in the kit being that they are the same price.

Dougal1957

@garyd9 what size/type effector is it and which hottend?

Moriquendi

@garyd9

There's nothing in the kit except the board, three piezos and the endstop cable, the difference in price is £1.47

Piezo Kit = £19.99
Piezo20 board + 3x20mm piezos (w Dupont connectors) + Endstop cable = £21.46

The Piezo20 board is about 2mm shorter than the universal board (excluding pins)

@garyd9 said in precision piezo: difference between boards:

I was hoping they'd be willing to just swap boards in the kit being that they are the same price.

You didn't make it clear that was what you were asking, I'm happy to do that.

Idris

garyd9

@dougal1957 It's a E3D titan aero with the standard (non-volcano) hot end. The effector is... I never measured it. It's the ultibots d300vs+ effector. Here's a model of it: https://github.com/UltiBots/D300VS-PLUS/blob/master/d300p_effector_bca_aero.stl

I fully expect that I'd have to modify it (or just start from scratch.)

garyd9

@moriquendi said in precision piezo: difference between boards:

Piezo Kit = £19.99
Piezo20 board + 3x20mm piezos (w Dupont connectors) + Endstop cable = £21.46

Okay, now I feel stupid. For some reason, I thought there was a significant price difference. I just checked and shipping would be the same 10.5 squiggle marks additional. Actually, doing in it parts might even be better for me - so I can mix piezo sizes.

I'm going to claim that the differences in currencies is what messed me up. I expected Euro's, but you seem to be using a different squiggly that looks suspiciously like a hash mark here in the US (# - pounds.) It doesn't matter that my claim doesn't make any sense whatsoever. It's the only excuse I could think of at the moment.

Sorry about giving you a hard time.

garyd9

Just placed Order No. 11100: 1 piezo20 board, 2x 27mm piezos and 2x 20mm piezos. That'll let me try the different sizes and give me a couple of spares in case I break something.

I should already have plenty of dupont connectors and ribbon wire to make my own endstop connectors.

Moriquendi

@garyd9 said in precision piezo: difference between boards:

I expected Euro's, but you seem to be using a different squiggly

We've also been experimenting with the metric system but I don't think it'll catch on

Your order should go in the post today and with any luck will get to you soon.

Idris

garyd9

@moriquendi said in precision piezo: difference between boards:

@garyd9 said in precision piezo: difference between boards:
We've also been experimenting with the metric system but I don't think it'll catch on

Speaking of that, I'd like to register a complaint. Here in America, we inherited our system of measurements from... YOU. (Not you personally, of course, but from England... or the "United" Kingdom.. or Britain.. or whatever you call yourselves these days.) Now that you dumped the illogical system on us, and FORCED us to use it under threat of death and more taxes, you go and change to something else.

I could go on about how America is great again and the center of the world and anything we do must be perfect, but the simple fact is that 12 inches in a "foot" doesn't make sense - and made even less sense 200 years ago when people's feet were smaller. 3 feet in a yard? Really? Oh, and don't even get me started with temperatures. What in the world were you damn Red Coats thinking? Did you guys invent those systems solely to screw up colonies???

At least here in the US we had the good sense not to confuse our money with weights or violent actions. A pound is something heavy or something you do when frustrated. It makes no sense to pound your finances (unless they're bad.)

How is it that you folks didn't convert to some metric form of money? Wouldn't it be nice to get paid in kilomoney and make change with millimoney instead of pounding things? Here's a place where you just can't compare to America. We have no sense. Only cents.

I suspect this thread is going to get locked within hours, or perhaps milliminutes, of me posting this.

SupraGuy

@garyd9 said in precision piezo: difference between boards:

Speaking of that, I'd like to register a complaint. Here in America, we inherited our system of measurements from... YOU. (Not you personally, of course, but from England... or the "United" Kingdom.. or Britain.. or whatever you call yourselves these days.) Now that you dumped the illogical system on us, and FORCED us to use it under threat of death and more taxes, you go and change to something else.

Here's a little (veering off topic) history for you that I'm just old enough to remember. in the early 70s, the USA set up an initiative to adopt the metric system. At that point, Canada was NOT going to do so, however pressure was brought to bear from the USA threatening trade relationships if Canada did not follow suit. At least this is how it was told to Canadians who did not want to change. I was pretty young at the time, so the timeline is a little hazy, but starting in 1975, American cars started having km/h printed on the speedometers, with the setting that there would be a complete conversion by 1978. The television started running PSAs telling us about metric temperatures, litres, and kilometers. The Canadian government made the commitment to go completely to the metric system, then the USA... didn't.

The resultant mess here is still a mess 40 years later. Canadian grocery stores charge for produce by the kilogram, and kg is what is on your receipt, but they still post the price per pound on the signs. Hardware stores have metric fasteners in a tiny little corner of the store, while the fractional inch fasteners take entire aisles. Most people here know their height in feet and inches, and look at their driver's license if asked what that is in cm. Similarly, we probably know our weight in pounds, and convert for kilograms. Carpenters still build their walls with 16" stud centres. Measurement gets pretty weird here, but that's also our own damned fault for not going all in one way or the other.

This has caused some pretty serious problems here, up to and including an airliner running out of fuel (The pilot asked for fuel in kilograms, and received fuel in pounds, resulting in having less than half the required fuel in the tank.) https://en.wikipedia.org/wiki/Gimli_Glider

Anyway, the USA made the decision to stay with the English imperial system, Including your very own units of measure that are only valid units within the USA and nowhere else on the planet, just to add in a little more confusion, pretty sure you can't blame anyone else at all for that.

The imperial system is more inherited from the Romans anyway, though it also got a little morphed. the word mile comes from the Latin "mille" for thousand, and was supposed to be a thousand paces. We're still stuck with a lot of Babylonian math (Base 60, which is why there's 60 seconds to a minute, 60 minutes to an hour, and also 360 degrees in a circle -- and why there are so many 12s in things as well, including inches to the foot.) The Romans weren't much for math themselves, thankfully. No wonder though when you consider Roman numerals. At least they had the good sense to grab numbers from the Arabs, but they left a lot to be desired in the actual implementation.

Anyway...

I've been looking at my V2.75 board, which is slightly different from my V2 board, and it's pretty nice for use. The mass of either one isn't really much of a consideration for me, but neither one is exactly heavy. I was playing with wire length. It does say to keep the wires as short as possible, but I think that you could probably use some longer shielded or coax leads. They use long coax leads to piezo pickups in studio-grade audio equipment, after all, so it should be possible for the relatively low-frequency signals that we care about as a contact sensor. (I wanted to have some space between the discs and the board so that I could easily observe the LEDs on-board.

I was also considering mucking about with some of my own, based on the schematic here: https://docs.wixstatic.com/ugd/29e72c_b6fa4fdff11440fe90f1559a85cbd61e.pdf

Mine would be large and clunky, in part because I'd probably substitute parts that I have, since I have a bin with things like quad op-amps, resistors, diodes and breadboard. I should be able to make a functionally identical circuit, but it would all be through-hole components instead of tiny little SMD devices. No idea how it'll work, but I found a pile of little breadboards with TL074s soldered on each, I think I was going to use those for a graphic equalizer at some point (I think I built it using NE5532s instead.)

Sorry for the meandering powt, I didn't get enough sleep last night.

dc42

I think the most logical approach is for the world to adopt a new unit of measurement derived from one of the fundamental physical constants, for example the speed of light in a vacuum. Obviously the distance travelled by light in one second would be far too large a measure to be practically useful. So let's use the distance travelled by light in one nanosecond. As it happens, we already have a unit of measure very close to that distance, so let's redefine and use that. It's called the 'foot'.

SupraGuy

If only the "second" weren't so arbitrary, and no longer connected to what it actually measured in the first place, that being 1/86,400 of the rotational period of the earth. As such, anything based on time is be definition arbitrary, and no different than any other arbitrary measure.

I do like how the metric system ties everything through water, though there are some SI prefixes in place that don't always make sense. Water is of course the easy basis for temperature (Though still arbitrary, since it depends on "standard" atmospheric pressure) 1cm^3 = 1mL = 1g. (This is what I mean by weird prefixes) 1 calorie of energy will raise the temperature of 1g of water by 1 degree (Provided there are no state changes) It's still arbitrary, but at least it's all based on the same stuff.

I demand a new standard of measurement for time! We can implement it when the world starts speaking Esperanto.

garyd9

@supraguy said in precision piezo: difference between boards:

I demand a new standard of measurement for time! We can implement it when the world starts speaking Esperanto.

When do you expect that to be, and which standard (of time) will you use to answer this question?

About that thing of 1 foot being the approx distance that light travels in a single nanosecond, and assuming that the measurement of "a foot" was around long before the human race started trying to calculate the speed of light... that's actually quite a significant coincidence (and something that never occured to me to wonder about until now.)

veng1

@dc42 No doubt when the ancient runner, Phidippides, ran across the plain of Marathon, he simply used his GPS enabled Garmin to log the distance and number of steps. Then, by simply dividing the distance by the steps, he was able to define a "foot". Those Greeks were clever! But they didn't readily have a vacuum available.

Just remember, if Edison hadn't invented the electric light, we'd be watching television by candle light.

garyd9

My God, what have I started?

deckingman

Geography lesson. England is a country - so are Scotland, Wales, Northern Ireland and Southern Ireland. Great Britain consists of the countries England, Wales, and Scotland which are all part of the same mainland but excludes Ireland because that is a separate island. However Great Britain does include the Scottish islands and the Isle of Man and the Isle of Wight. So sometimes it is also known as The British Isles although it excludes the island of Northern and Southern Ireland. Just "Britain" (without the "Great") can refer to either all islands in Great Britain, the largest island, or the political grouping of countries. The UK, or to give it it's full name is the United Kingdom of Great Britain and Northern Ireland can also be called just "Britain".

It's quite simple

deckingman

On the subject of measurements, here in England/Great Britain/the UK, we have adopted the metric system. Previously timber would be sold in sizes such as 4" x 2" or 6" x 2" (often shortened to simply 4 by 2 or 6 by 2) etc and in lengths of 6 feet, 8 feet, 12 feet etc. Now we are metric, timber is sold in sizes such as 95mm x 45 mm, or 145mm x 45mm and in lengths of 1.8 metres, 2.4 metres, 3.6 metres, 4.8 metres etc. Only DIYers ask for 4.8 metres of 95mm x 45 mm timber, a tradesman would ask for 16 feet of 4 by 2 - much easier. Can you buy 2 metre or 3 metre lengths? Can you hell. Standard sizes of stuff like plaster board are 2.4 metres x 1.8 metres because it always used to be 8 feet x 6 feet. You can't buy sheets of (say) 2.5 metes x 2 metres - they don't exist.

deckingman

@dc42 said in precision piezo: difference between boards:

I think the most logical approach is for the world to adopt a new unit of measurement derived from one of the fundamental physical constants, for example the speed of light in a vacuum. Obviously the distance travelled by light in one second would be far too large a measure to be practically useful. So let's use the distance travelled by light in one nanosecond. As it happens, we already have a unit of measure very close to that distance, so let's redefine and use that. It's called the 'foot'.

Actually that's not far from what happens now. Back in the days of the British Standards Institute (remember Kite Marks?) there was a lump of metal kept in a room at a stable temperature and humidity which was the definitive "foot". In theory, all rulers and tape measure could trace their calibration back to this standard "foot". Then somebody decided that the standard "foot" could degrade over millennia or get damaged and so it was re-defined as so many wavelength of light in a vacuum. I can't remember the time period but I thing it was a second so it was a large number.

However, are we talking the English Foot, the International Foot, the Survey Foot, the Metric Foot (yes there is one) or one of the other "feet"?

wilriker

@supraguy said in precision piezo: difference between boards:

If only the "second" weren't so arbitrary, and no longer connected to what it actually measured in the first place, that being 1/86,400 of the rotational period of the earth. As such, anything based on time is be definition arbitrary, and no different than any other arbitrary measure.

I think you missed the update over there in Canada - it now is defined by Caesium-133.
But hey, 1/86,400 of earth's rotation is still precise enough for everything a human would ever need anyway, so you might as well keep it like that.

SupraGuy

@wilriker said in precision piezo: difference between boards:

I think you missed the update over there in Canada - it now is defined by Caesium-133.
But hey, 1/86,400 of earth's rotation is still precise enough for everything a human would ever need anyway, so you might as well keep it like that.

Yes, I am aware of the Atomic clock standard, thanks. Because if the need for more and more precise measurements of time, a moving target like the rotation of the earth (Which is slowing, hence the need for leap-seconds, and my comment about it becoming disconnected from what it originally measured) but the original definition was based on a solar day, which because of Babylonian base-60 math ended up with this weird system of 24 hours to the day, 60 minutes to an hour, and 60 seconds to a minute.

dc42

@deckingman said in precision piezo: difference between boards:

However, are we talking the English Foot, the International Foot, the Survey Foot, the Metric Foot (yes there is one) or one of the other "feet"?

A medieval English foot, as used to measure the airspeed velocity of an unladen swallow. Don't ask me which type of swallow.