Are dynamos too noisy?

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Greg_Lewis
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Are dynamos too noisy?

Post by Greg_Lewis » Wed Apr 24, 2019 1:29 pm

I've got a set of castings I bought decades ago for a Pyle type E dynamo. I could build it as a dummy or a working dynamo. But to make it work will be a long and tricky project. I've heard that scale dynamos are so noisy that many owners don't use them. I don't really need it for power, but it would be fun to have one that works. But I don't want to spend my time making it work if I'll never use it because of noise. What is your experience with these things re. the noise factor? Thanks!
Greg Lewis, Prop.
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cbrew
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Re: Are dynamos too noisy?

Post by cbrew » Wed Apr 24, 2019 1:42 pm

I have a set of castings that i intend to build into an operational unit.
sayings its too loud is like saying the bark or the whistle is too loud. :D :) :shock:
If it is not live steam. its not worth it.

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Greg_Lewis
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Re: Are dynamos too noisy?

Post by Greg_Lewis » Wed Apr 24, 2019 2:08 pm

Well, there is stack talk and there is screeching. And to machine these castings will require some creative fixturing with Cerrobend because there is no way to hold them and get a reference point without such help. And these castings are no longer available and I'm clumsy! But it would still be nice to have it work. Decisions, decisions.
Greg Lewis, Prop.
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Marty_Knox
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Re: Are dynamos too noisy?

Post by Marty_Knox » Wed Apr 24, 2019 2:16 pm

There are firemen on full-size locomotives who complain about noisy turbos. In fact, I believe Pyle-National sold mufflers for the exhaust.

Pontiacguy1
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Re: Are dynamos too noisy?

Post by Pontiacguy1 » Wed Apr 24, 2019 2:52 pm

In my opinion, the only reason to make a working turbo generator is if you just want one on your locomotive and your mindset is such that it's just gotta work or you aren't going to be happy with it. There are a whole lot more convenient and easier ways to power your lights, which you've obviously already done. So I'd just make it a dummy, especially if you don't intend to use it as such. Make it a dummy, pipe it up, and you can actually have a wisp of steam coming out the exhaust for effect if you want to make it look more realistic. I heard of one person somewhere who just made the turbine side of it, running in bearings, not really driving anything, and would just turn it on so that it had the sound and the steam coming from the exhaust. I can't remember where I heard that. It's been a while.
I've been around several that were actually working generators. I didn't think the noise from them was too loud or annoying, at least not that I remember.

Rwilliams
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Re: Are dynamos too noisy?

Post by Rwilliams » Wed Apr 24, 2019 4:29 pm

If your exhaust is not that loud, the added noise of a working turbo can cancel out the stack noise real well. Worse is the saturated steam from the turbo will be right there in your face worse than the exhaust from the stack. If wearing glasses, you will soon be in a miniature traveling fog cloud. The steam consumption will go way up and the locomotive will need to be wiped down along with the operator ,on cool days it is worse. Best to watch the operation of a turbo on someone else's locomotive and speak to them before committing to such major efforts for not that much return on investment. There is a reason for modern electronic power sources in this case.

If you want the appearance of a working turbo, just pipe a bit of steam through a small valve from the cab and call it good.

A working turbo may look cool and have the sound, but the reward soon ends after that point in time.

Years ago the early low pressure saturated steam locomotives always seemed to have the exhaust of the turbo piped back and on top of the cab to keep the condensing steam from reducing their forward visibility.

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ccvstmr
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Re: Are dynamos too noisy?

Post by ccvstmr » Wed Apr 24, 2019 6:14 pm

Used to set up a G gauge RR in the family room for the holidays. Got an LGB box car with a sound module that would plug into the back of any number of LGB locos. Would simply turn the train on and let if run in circles for entertainment (watching the cat deal with the train was a real hoot). As the loco went around the railroad, you would hear...chuff, chuff, chuff, chuff, chuff. After a few minutes...the sound got to be more of an annoyance than anything else.

Why do I bring this up? Turbo generators are a nice "decoration". But if you're sitting in the engineers seat behind a turbo producing power for lighting...it's not the noise, it's the constant whining of the turbine unit that won't take long to get on your nerves (and maybe other peoples).

On electric diesel locos...if the sound system includes an engine "throb" and the speed of the loco never changes, that can be an irritation as well.

Have a sound system in my stock car. Plays CD's...including a CD of animal sounds...or other types of "rail road or period music". It's fine for awhile. But after some amount of time, even that gets annoying when playing the same track over and over (and I get many requests to play the "cow track"). Just sayin'...

Carl B.
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Greg_Lewis
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Re: Are dynamos too noisy?

Post by Greg_Lewis » Wed Apr 24, 2019 7:22 pm

Thanks, everyone, for your thoughts. Yeah, Pontiacguy, Carl and Robert. I think you are right. (I also unplugged the sound on the Christmas tree LGB set.) I don't even like the soft blowing of the swamp cooler on my shop.
Greg Lewis, Prop.
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Dan_M
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Re: Are dynamos too noisy?

Post by Dan_M » Wed Apr 24, 2019 7:46 pm

I have 3 working turbos on my Daylight. They are VERY noisy. Just running one will drive you nuts with the high pitched whining.

Dan

RET
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Re: Are dynamos too noisy?

Post by RET » Wed Apr 24, 2019 8:11 pm

Hi,

The topic of working turbogenerators keeps on coming up all the time on this website in various forms. There are two main threads for this subject, the first one is "Steam turbine generator" and the second is "Turbo generators." I have contributed to both of them. Most of the questions anyone may presently have will be answered in those threads.

Bill Huxhold and I sort of collaborated when he was building his units in the three different sizes (1/16th, 1/12th and 1/8th), so I know a fair bit about the way he built his. As an aside, his generators worked very well, and were quite efficient.

As far as "credentials" go, I am a retired mechanical engineer as is Wolfgang Habicher (civil, I believe) so we can claim to know a little bit about what we are talking about, but on the other hand, nobody knows everything, right?

As you can see in these threads, I find there is a marked reluctance by people to accept the fact that an impulse type turbine is probably the best type to use and that the turbine efficiency depends on how big an angle you can turn the discharge jet through with the turbine blades. Yes, you can use gear teeth, turbine buckets with a slight curvature, and many other styles and they will "sort of" work, but the efficiency just won't be there.

Simple physics says that momentum is mass times velocity and velocity is speed times direction. When you put it all together, it becomes momentum equals mass times speed times direction (Momentum=M*S*D), so that means that you don't have to kill the speed, but just change the direction. Simple, right?

Thus if you keep the speed but use the individual turbine buckets to turn the jet through 90 degrees, it is equivalent to stopping the jet completely (like letting it go "splat" against a gear tooth). Now if you can use your bucket to turn that jet through another ninety degrees (or even somewhat less) you can extract even more energy from the jet (almost as much again). Furthermore, if you put a "lid" on top of the individual bucket so the jet cant dissipate up or down, it becomes even more efficient.

Remember, Murphy says that things will only do what you want them to when they can't do anything else! My experience says that this is true.

As far as noise goes, yes there will be a whine, but most of the time it won't be objectionable, at least partly because (depending on the number of turbine blades you have) the frequency will be higher than you can hear.

Also, yes you can build a working unit, but it isn't a ten minute job and it takes a fair bit of knowledge and skill to do it. I don't know of anyone who is going to build one although down the road Anthony might. A lot of this stuff is purely a labour of love and you certainly aren't going to get rich doing it.

Hope this answers some questions, although some of the logic may not be immediately apparent.

Richard Trounce.

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BigDumbDinosaur
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Re: Are dynamos too noisy?

Post by BigDumbDinosaur » Wed Apr 24, 2019 8:17 pm

ccvstmr wrote:
Wed Apr 24, 2019 6:14 pm
...and I get many requests to play the "cow track"...
And that ain't no bull!
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Greg_Lewis
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Re: Are dynamos too noisy?

Post by Greg_Lewis » Wed Apr 24, 2019 8:20 pm

Thanks, Richard. Making the turbine may be more than I care to do at this point. And the laminations for the field windings will be even more challenging. I'm going to go for a dummy unit but I will assemble it in such a way that if I live long enough and decide to make it work I can go back and do that.
Greg Lewis, Prop.
Eyeball Engineering — Home of non-interchangeable parts.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

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