tag:blogger.com,1999:blog-1634572204034071649.post2706141467443327480..comments2024-02-23T06:05:30.927-05:00Comments on Pete's Blog: Train Whistle DoorbellPetehttp://www.blogger.com/profile/10432659350949374712noreply@blogger.comBlogger35125tag:blogger.com,1999:blog-1634572204034071649.post-21769876988721595522010-05-21T02:39:46.898-04:002010-05-21T02:39:46.898-04:00Pete
I'm using some javascript I found online...Pete<br /><br />I'm using some javascript I found online to post code on my blog. Take a look at the source code on my blog.<br /><br />http://blog.jasongarland.com/Bloggerhttps://www.blogger.com/profile/13946867092188502749noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-26410857507279523752010-05-19T13:37:40.645-04:002010-05-19T13:37:40.645-04:00@mr
I'm glad you like the project; it was jus...@mr<br /><br />I'm glad you like the project; it was just a quick afternoon project to blow off a little steam, hiyo!!Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-62260033210573532162010-05-19T13:21:02.323-04:002010-05-19T13:21:02.323-04:00@Pete
Well, I do need to say I was wrong about the...@Pete<br />Well, I do need to say I was wrong about the "not" part and I am sorry if I haven't admited that before. I just had to say something against the statement that it is highly compressible.<br />But I don't mind to be proven wrong.<br /><br />And forgot to say: cool project anyhow. If I have time to do it I would love to use the whistle from a steamboat ;-)Unknownhttps://www.blogger.com/profile/15236369047678226404noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-42504692285341707042010-05-19T13:12:17.613-04:002010-05-19T13:12:17.613-04:00I just wrote a blog entry about how I made my twit...I just wrote a blog entry about how I made my twittering doorbell.<br /><br />http://blog.jasongarland.com/2010/05/twittering-doorbell.htmlBloggerhttps://www.blogger.com/profile/13946867092188502749noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-81600730602820659182010-05-19T13:05:51.463-04:002010-05-19T13:05:51.463-04:00@mr:
I dont know who "Dilbert" is unles...@mr:<br /><br />I dont know who "Dilbert" is unless you are referring to the cartoon.<br /><br />You also need to remember you typed:<br />>Water is NOT compressable!!!<br /><br />And you have to know this is wrong. Your point about <br /><br />>It is barely compressable, especially not at the pressures used in this project<br /><br />Is not really right; I know what you meant to say but, water is just as compressible at 100 psi as it is at 1000 psi.<br /><br />Also, just as a blanket statement, as dbeierl correctly pointed out, hydrostatic testing with fluids 'less' compressible than air have an inherent safety advantage if something ruptured. Pressure is pressure if it is air or another fluid, the concerns about safety on my tank testing after wit was welded by a professional welder can be laid to rest as I tested it under water in a stainless steel basin with me around the corner. I'm not sure what else to say at this point.Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-25430706537946508232010-05-19T12:40:24.683-04:002010-05-19T12:40:24.683-04:00@dbeierl
But when you have water in the brakeflui...@dbeierl<br /><br />But when you have water in the brakefluid...well it's boiling point is much lower than the fluid.<br />That's the reason why it should be changed regularely.Unknownhttps://www.blogger.com/profile/15236369047678226404noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-27213728122085256342010-05-19T12:36:53.826-04:002010-05-19T12:36:53.826-04:00@Pete
It is barely compressable, especially not at...@Pete<br />It is barely compressable, especially not at the pressures used in this project:<br />@40MPa you will only see a decrease of volume of less than 2 %<br /><br />http://en.wikipedia.org/wiki/Properties_of_water#Compressibility<br /><br />So stop patronizing me; you are worst than Dilbert.Unknownhttps://www.blogger.com/profile/15236369047678226404noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-60659908483254397922010-05-19T09:11:53.624-04:002010-05-19T09:11:53.624-04:00@Pete
>I do not care to indulge your fantasies...@Pete<br /><br />>I do not care to indulge your fantasies.<br /><br />I'd ask for clarification on what these were - but I suppose you don't want to play.Mekonhttps://www.blogger.com/profile/12619491545055275303noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-83415405388642453612010-05-18T14:00:03.627-04:002010-05-18T14:00:03.627-04:00@dbeierl
The ty-wrap may affect the sound. I was...@dbeierl<br /><br />The ty-wrap may affect the sound. I was concerned about that in the beginning but it sounds fine, the tywrap is pretty far up the bell so I am sure that helps. Also if you were curious, I tywraped it and put a bit of tape on the plunger because I took the spring and valve out of the whistle.Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-40261344837976129922010-05-18T13:46:04.606-04:002010-05-18T13:46:04.606-04:00@Pete --
>I can't really argue with anythi...@Pete --<br /><br />>I can't really argue with anything you said there. but I think @nelson is right, calculated risk should be considered. I also think we are saying the same things I am just more confident in the welds than you are. Hence the previous "meh"<br /><br />Spoken like a gentleman. I don't agree with you but I definitely respect your calm answer.<br /><br />And as I said to @Nelson, it's a great hack. One thing I'm curious about -- does the Ty-rap on the whistle bell affect the sound noticeably?Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-76658523421090656342010-05-18T13:20:56.765-04:002010-05-18T13:20:56.765-04:00@dbierl:
I can't really argue with anything y...@dbierl:<br /><br />I can't really argue with anything you said there. but I think @nelson is right, calculated risk should be considered. I also think we are saying the same things I am just more confident in the welds than you are. Hence the previous "meh"Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-44774034676811286772010-05-18T13:15:29.051-04:002010-05-18T13:15:29.051-04:00@Nelson --
>looks like a fun concept and proje...@Nelson --<br /><br />>looks like a fun concept and project. <br /><br />Hey, it's a great hack, no question about that. Although running on compressed air is a bit whimpy, they don't sound the same as on steam. ;-)<br /><br />My personal preference would be for an actual fog signal (compressed air by design) or ship's horn, but that's just me. If I did *any* of those things where I live the neighbors would get pretty excited.<br /><br />Darn -- now you've got me thinking about one using a whistle buoy as the output device. That would be lots safer, have all sorts of cool mechanical interface, make a great lawn ornament and have a volume control. (As a sailor, I really admire whistle buoys. They'll sound in a flat calm if there's the slightest bit of swell, they get louder and louder as the weather kicks up and will shriek like a lost soul in heavy weather as the whistle overblows and goes up an octave. And they depend on impedance mismatch to work. See the whistling buoy section at http://www.gutenberg.org/files/14041/14041-h/14041-h.htm#6 .)Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-21206768767399763832010-05-18T12:39:00.633-04:002010-05-18T12:39:00.633-04:00Holy cow you guys, this is turning into a super-ne...Holy cow you guys, this is turning into a super-nerd feeding frenzy. How about "calculated risk" and the fact it's not in any of y'all's basements? The dangers expressed here are very real, I think we all know that, but so is getting out of bed in the morning. Good job Pete, looks like a fun concept and project.Unknownhttps://www.blogger.com/profile/04692904440989588684noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-57333077905756915512010-05-18T10:32:13.155-04:002010-05-18T10:32:13.155-04:00@Pete --
In case you're a software engineer, ...@Pete --<br /><br />In case you're a software engineer, you might want to check out the history of the Therac-25 radiation treatment machine. Here's a place to begin, with a teaser quote below.<br /><br />http://courses.cs.vt.edu/cs3604/lib/Therac_25/Therac_1.html<br /><br />>Reprinted with permission, IEEE Computer, Vol. 26, No. 7, July 1993, pp. 18-41.<br /><br />>Computers are increasingly being introduced into safety-critical systems and, as a consequence, have been involved in accidents. Some of the most widely cited software-related accidents in safety-critical systems involved a computerized radiation therapy machine called the Therac-25. Between June 1985 and January 1987, six known accidents involved massive overdoses by the Therac-25 -- with resultant deaths and serious injuries. They have been described as the worst series of radiation accidents in the 35-year history of medical accelerators.[1]Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-60845006113386343192010-05-18T10:13:12.325-04:002010-05-18T10:13:12.325-04:00@Pete --
>I'm having a pretty hard time un...@Pete --<br /><br />>I'm having a pretty hard time understanding your refusal to admit to the physical properties of water. What you call my "opinion" is actually scientifically based observations. <br /><br />Yes, it is. However I'm having an equally hard time understanding your refusal to admit to the existence of powers of ten. Very uncharacteristic behavior for an engineer.<br /><br />Smiling, but not fooling...Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-47334168999167335822010-05-18T10:09:28.943-04:002010-05-18T10:09:28.943-04:00@Mr -- right church, wrong pew. :-)
It truly is c...@Mr -- right church, wrong pew. :-)<br /><br />It truly is compressible, but volume change per increment of pressure is quite small. As pressure is increased to extremely high levels, nine (IIRC) different forms of ice can be produced -- check it out. I seem to recall that Ice IX has a melting point of around 450F but don't quote me on that.<br /><br />And when brake fluid boils, what you get is brake fluid vapor, the brake fluid equivalent of steam.Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-28924770401398937782010-05-18T10:04:28.073-04:002010-05-18T10:04:28.073-04:00@Pete --
> water is a highly compressible flui...@Pete --<br /><br />> water is a highly compressible fluid.<br /><br />Certainly it is. However speaking approximately an increase of ten bar (~150 psi) will reduce the volume of fifty liters of water by about 11.5 ml, every single one of which will come rampaging out when the tank fails. [/sarcasm]<br /><br />> This is why non-compressible fluids ie brake fluid has foil film under the cap - to keep humidity in the air out.<br /><br />Ermm...DOT 3 or DOT 4 brake fluid is extremely hygroscopic. It must be kept dry not because a small volume of water has any great physical effect but because it increases the vapor pressure i.e. lowers the boiling point of the brake fluid. Brake fluid works better when it's not boiling for exactly the same reason that I'm recommending hydrostatic rather than pneumostatic testing.<br /><br />> we engineers use a factor of safety of 1.5 which I am pretty close to.<br /><br />I'm curious what your engineering discipline is exactly?<br /><br />>Also, meh.<br /><br />Lad, in all seriousness you should go to sea. It will either teach you humility or kill you, whichever comes first. If you are a professional (licensed) engineer this might save you from killing a bunch of people later by.Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-49402291093771329262010-05-18T08:51:30.550-04:002010-05-18T08:51:30.550-04:00@mekon:
I'm having a pretty hard time underst...@mekon:<br /><br />I'm having a pretty hard time understanding your refusal to admit to the physical properties of water. What you call my "opinion" is actually scientifically based observations. <br /><br />I do not care to indulge your fantasies. You can read any book that I can. Or don't, I'm really not that worried what you do.Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-18593499323614943742010-05-18T08:26:35.326-04:002010-05-18T08:26:35.326-04:00@Pete
>Water IS compressible...
I've chec...@Pete<br /><br />>Water IS compressible...<br /><br />I've checked Google for that scientific fact and as far as I can see, it's going to exhibit negligible compression under the test procedure outlined by dbeierl. <br /><br />As far as I can tell, for practical purposes, Mr is right in saying that water is not compressible. It certainly seems very far from a 'highly compressible fluid'.<br /><br />I'm happy to be proven wrong, and if you can post up references that support your opinion, I'll be rather less worried for your safety.Mekonhttps://www.blogger.com/profile/12619491545055275303noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-61166190019511720642010-05-18T06:14:39.468-04:002010-05-18T06:14:39.468-04:00@Mr:
Water IS compressible however, I doubt I wou...@Mr:<br /><br />Water IS compressible however, I doubt I would be able to convince you of this scientific fact. I suggest googling it up and letting them convince you of this widely known physical property of h20 instead.Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-40177840315309290582010-05-18T06:02:14.835-04:002010-05-18T06:02:14.835-04:00Water is NOT compressable!!!
There is no water in ...Water is NOT compressable!!!<br />There is no water in brakefluid because it would start boiling from hot brakes (if you make a fullstop from let's say 50 mph your brakes will almost glow). And if it boils you have air in the system: bad idea!Unknownhttps://www.blogger.com/profile/15236369047678226404noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-74690301616496358902010-05-17T16:00:52.600-04:002010-05-17T16:00:52.600-04:00@dbeierl:
I get what you are saying but I don'...@dbeierl:<br /><br />I get what you are saying but I don't think the level of concern is warranted here. <br /><br />Two other notes: A: water is a highly compressible fluid. This is why non-compressible fluids ie brake fluid has foil film under the cap - to keep humidity in the air out.<br /><br />B: we engineers use a factor of safety of 1.5 which I am pretty close to.<br /><br />Also, meh.Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-34724192782070382752010-05-17T15:21:58.303-04:002010-05-17T15:21:58.303-04:00My father used to do hydrostatic testing of quarte...My father used to do hydrostatic testing of quarter-scale models for submarine parts.<br /><br />The point of using water to test with is that when the device begins to yield you simply stop adding water. Since the water doesn't have any significant energy stored up on compression, the part failure doesn't proceed to completion.<br /><br />Situation is entirely different with a compressive medium such as air (or in the case of submarines, the failure of the ocean to stop trying after the Thresher began to collapse). The device will violently explode or implode.<br /><br />I'd seriously suggest you re-think your testing strategy -- hydrostatic testing to I believe twice working pressure is the normal way. Pressure vessels are considerably more dangerous than car springs or garage-door springs, both energy-storage devices which have killed their share of people.<br /><br />I'm also leery of welding on a pressure vessel without at the very least first consulting the regulatory body that approved it originally. Fatigue resistance is one of the factors that may have changed, and a simple hydro test won't find that. In my youth a number of large airliners fell out of the sky because the fatigue-inducing character of the compression/decompression cycles wasn't sufficiently understood, and the aircraft that turned into a convertible in Maui a few years ago had the same problem -- because its flights were so short it racked up far more than the usual number of cycles. My sister rode on that a/c the previous day incidentally, though she wasn't in first class which was the area that lost its roof.Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-58175970795567633232010-05-17T14:55:18.591-04:002010-05-17T14:55:18.591-04:00No, water to see air bubbles escaping mainly, but ...No, water to see air bubbles escaping mainly, but you are right, the water will slow down any shrapnel that may arise. And hot water too to raise the temperature, thus the pressure just a bit too.Petehttps://www.blogger.com/profile/10432659350949374712noreply@blogger.comtag:blogger.com,1999:blog-1634572204034071649.post-46994705538393437362010-05-17T14:32:34.729-04:002010-05-17T14:32:34.729-04:00Water to retain the pieces if it blew, you mean?Water to retain the pieces if it blew, you mean?Unknownhttps://www.blogger.com/profile/11025719778395958202noreply@blogger.com