Re: How small is too small?
Pete, Actually run time is more a function of fuel burn time. Still about 25 minutes. There's always water left in the boiler after a run. I've always figured that maybe two cylinders use the available steam more efficiently than one cylinder, in addition to providing a smoother power output. Steve [EMAIL PROTECTED] wrote: Very neat Steve! Double the power and half the run time? PeteH
Re: How small is too small?
Pete, Here's a link to my "pair" of oscillators courtesy of Mr. Mike Martin's photography. The engine was made from Midwest parts on a homemade frame. The cylinders are 180 degrees opposed. http://www.panyo.com/nss2003/images/016.jpg The wicks and burners poke through the deck into the firebox. The fuel supply is in a reservoir below the deck and below the wicks, sort of like a chemistry set alcohol lamp but with two burners. The deck is 1/4" plywood with a sheet of aluminum between it and the firebox. Together the plywood and aluminum serve as a heat shield. Steve [EMAIL PROTECTED] wrote: Ahh, yes - good idea this reverse engineering of the boilers. Makes me wonder - how well do the Aster/Accucraft/etc loco's fit in with Mr Harris' outlines? Will be interesting to see. I would imagine he doesn't discuss sterno because it is such a poor fuel source! My Baggers never runs the same was twice! I think I will try Henner's ring burner when she comes apart for a proper boiler (assuming Mr. Harris agrees!). Did you use the burner design from the SiTG articles? Did you say a "pair" of oscillators Thanks for the info Steve :-) Kindest Regards, PeteH
Re: How small is too small?
Ahh, yes - good idea this reverse engineering of the boilers. Makes me wonder - how well do the Aster/Accucraft/etc loco's fit in with Mr Harris' outlines? Will be interesting to see. I would imagine he doesn't discuss sterno because it is such a poor fuel source! My Baggers never runs the same was twice! I think I will try Henner's ring burner when she comes apart for a proper boiler (assuming Mr. Harris agrees!). Did you use the burner design from the SiTG articles? Did you say a "pair" of oscillators Thanks for the info Steve :-) Kindest Regards, PeteH - Original Message - From: "Steve Shyvers" <[EMAIL PROTECTED]> > Pete, > > It sounds like you have some decent examples of loco boilers at hand. > When your Harris book arrives I recommend reverse engineering all three > boiler designs using Harris' methodology that I briefly outlined in my > previous post. > > Harris doesn't discuss Sterno, as used in the Basic (or BAGRS) Project > engine, but my Project has two 1/4" alcohol wicks and steams well enough > to power a pair of Midwest oscillating cylinders. > > Steve
Re: How small is too small?
Pete, It sounds like you have some decent examples of loco boilers at hand. When your Harris book arrives I recommend reverse engineering all three boiler designs using Harris' methodology that I briefly outlined in my previous post. Harris doesn't discuss Sterno, as used in the Basic (or BAGRS) Project engine, but my Project has two 1/4" alcohol wicks and steams well enough to power a pair of Midwest oscillating cylinders. Steve [EMAIL PROTECTED] wrote: Current loco inventory consists of a Basic project engine, an Aster Mikado and a 'under construction' G1MRA "Project". Yup, I'm a 'steam' newbie, but don't worry - I like to fiddle! :-) But point taken on the running characteristics of miniscule boilered models. I suppose I may just have to get a Lion, but strictly for research mind you. I ordered the Harris book although I didn't see it on the SS website? Thanks for pointing this out to me, I wasn't aware this information was 'readily' available. It should prove invaluable. Kindest Regards, PeteH
RE: How small is too small?
Speaking of miniscule boilers, have you seen the 'HO' scale live steam locomotive? I had a chance to chat with the fellow (from Cincinnati, Ohio) who built one. He uses a simple flue less boiler, and a butane burner in the tender. Just stirring the pot! Terry -Original Message- From: [EMAIL PROTECTED] Sent: Monday, August 02, 2004 9:27 PM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: How small is too small? Current loco inventory consists of a Basic project engine, an Aster Mikado and a 'under construction' G1MRA "Project". Yup, I'm a 'steam' newbie, but don't worry - I like to fiddle! :-) But point taken on the running characteristics of miniscule boilered models. I suppose I may just have to get a Lion, but strictly for research mind you. I ordered the Harris book although I didn't see it on the SS website? Thanks for pointing this out to me, I wasn't aware this information was 'readily' available. It should prove invaluable. Kindest Regards, PeteH - Original Message - From: "Steve Shyvers" <[EMAIL PROTECTED]> > Pete, > > What locos are you steaming now? It would be wise to get some experience > running a small loco of more typical design for gauge-1, like a Mamod, > Jane, or Ruby. These will provide lessons about small loco steam > generation, size of fires, and what the controls will and will not do. > The DeWitt Clinton in gauge-1 sounds like it might be on the far edge of > the small steamer design envelope, and might prove very fiddly and > frustrating to debug. > > On the other hand, having said all that, I recommend that you get a copy > of K.N.Harris' Model Boilers and Boilermaking. (Sulphur Springs lists > it in their catalog.) Harris will tell you where to start when > designing a boiler, including info on how to size the boiler tubes. > > Harris starts the design process by calculating the required steam > production rate (volume of steam needed per unit time) based on the > cylinder volume, driver diameter, and planned speed. Then he determines > the needed evaporative surface area from the required steam production > rate, steam pressure, firing method (fuel, BTU) and boiler > configuration. From there the firebox size, tube size, and number of > tubes can be determined. It's a rigorous process but not more difficult > than high school chemistry calculations. > > I wish that I had studied Harris before I configured my first > boiler/engine combination. Based on what I know now, thanks to Harris' > book, that effort fell far short of qualifying as a "design" process. I > did learn a lot, but only after I had Harris' book in hand, stepped > through the boiler design calculations, and saw where my empirical > assumptions were mainly wishful thinking. > > Steve > > "This e-mail is intended for the sole use of the intended recipient and may contain privileged, sensitive, or protected health information. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying, distribution, or action taken in reliance on the contents of this communication is prohibited. If you have received this e-mail in error, please notify the sender via telephone or return e-mail and immediately delete this e-mail."
Re: How small is too small?
You are correct Bob - I like! Thank-You very much :-) Kindest Regards, PeteH - Original Message - From: <[EMAIL PROTECTED]> > Pete, > You might be interested in this page. It has a pretty consice article on how > to build Idris, a De Winton model. > http://www.davewatkins.pwp.blueyonder.co.uk/steam.htm > Bob Starr >
Re: How small is too small?
Pete, You might be interested in this page. It has a pretty consice article on how to build Idris, a De Winton model. http://www.davewatkins.pwp.blueyonder.co.uk/steam.htm Bob Starr
Re: How small is too small?
Current loco inventory consists of a Basic project engine, an Aster Mikado and a 'under construction' G1MRA "Project". Yup, I'm a 'steam' newbie, but don't worry - I like to fiddle! :-) But point taken on the running characteristics of miniscule boilered models. I suppose I may just have to get a Lion, but strictly for research mind you. I ordered the Harris book although I didn't see it on the SS website? Thanks for pointing this out to me, I wasn't aware this information was 'readily' available. It should prove invaluable. Kindest Regards, PeteH - Original Message - From: "Steve Shyvers" <[EMAIL PROTECTED]> > Pete, > > What locos are you steaming now? It would be wise to get some experience > running a small loco of more typical design for gauge-1, like a Mamod, > Jane, or Ruby. These will provide lessons about small loco steam > generation, size of fires, and what the controls will and will not do. > The DeWitt Clinton in gauge-1 sounds like it might be on the far edge of > the small steamer design envelope, and might prove very fiddly and > frustrating to debug. > > On the other hand, having said all that, I recommend that you get a copy > of K.N.Harris' Model Boilers and Boilermaking. (Sulphur Springs lists > it in their catalog.) Harris will tell you where to start when > designing a boiler, including info on how to size the boiler tubes. > > Harris starts the design process by calculating the required steam > production rate (volume of steam needed per unit time) based on the > cylinder volume, driver diameter, and planned speed. Then he determines > the needed evaporative surface area from the required steam production > rate, steam pressure, firing method (fuel, BTU) and boiler > configuration. From there the firebox size, tube size, and number of > tubes can be determined. It's a rigorous process but not more difficult > than high school chemistry calculations. > > I wish that I had studied Harris before I configured my first > boiler/engine combination. Based on what I know now, thanks to Harris' > book, that effort fell far short of qualifying as a "design" process. I > did learn a lot, but only after I had Harris' book in hand, stepped > through the boiler design calculations, and saw where my empirical > assumptions were mainly wishful thinking. > > Steve > >
Re: How small is too small?
Pete, What locos are you steaming now? It would be wise to get some experience running a small loco of more typical design for gauge-1, like a Mamod, Jane, or Ruby. These will provide lessons about small loco steam generation, size of fires, and what the controls will and will not do. The DeWitt Clinton in gauge-1 sounds like it might be on the far edge of the small steamer design envelope, and might prove very fiddly and frustrating to debug. On the other hand, having said all that, I recommend that you get a copy of K.N.Harris' Model Boilers and Boilermaking. (Sulphur Springs lists it in their catalog.) Harris will tell you where to start when designing a boiler, including info on how to size the boiler tubes. Harris starts the design process by calculating the required steam production rate (volume of steam needed per unit time) based on the cylinder volume, driver diameter, and planned speed. Then he determines the needed evaporative surface area from the required steam production rate, steam pressure, firing method (fuel, BTU) and boiler configuration. From there the firebox size, tube size, and number of tubes can be determined. It's a rigorous process but not more difficult than high school chemistry calculations. I wish that I had studied Harris before I configured my first boiler/engine combination. Based on what I know now, thanks to Harris' book, that effort fell far short of qualifying as a "design" process. I did learn a lot, but only after I had Harris' book in hand, stepped through the boiler design calculations, and saw where my empirical assumptions were mainly wishful thinking. Steve [EMAIL PROTECTED] wrote: The firetubes are 'approx' 3" long. I was thinking of useing curved smoketubes like Aster used in the Mikado's. Firebox looks like it may be around the 1" x 3/4" size. Good idea, I shall look at the lion - I guess I'll have to buy one :-) I admittedly am rather a newbie to this, is there not a point where to small a tube will become ineffectual as far as carrying flue gases? Is there a practical limit? While more tubes may be understandably better able to produce steam - how does one determine what is needed/required? Kindest Regards, PeteH
Ring Burner Re: How small is too small?
Would a ring shaped burner work on the Basic Project Engine also? If so, could you send me a copy of the burner also? Thank You Michael Florida USA Iron Naut - Original Message - From: "Henner Meinhold" <[EMAIL PROTECTED]> To: "Multiple recipients of sslivesteam" <[EMAIL PROTECTED]> Sent: Sunday, August 01, 2004 12:51 PM Subject: Re: How small is too small? > Pete, > for vertical boilers a ring shaped burner is quite efficient. I can send you > drawings/photos of my A-Climax burner. > Regards > Henner > - Original Message - > From: "PeteH" <[EMAIL PROTECTED]> > > How would one size the meth burner for such a small boiler, would two 1/4" > > dia. wick tubes be a fair match for two 1/4" dia. burner tubes? >
Re: How small is too small?
The firetubes are 'approx' 3" long. I was thinking of useing curved smoketubes like Aster used in the Mikado's. Firebox looks like it may be around the 1" x 3/4" size. Good idea, I shall look at the lion - I guess I'll have to buy one :-) I admittedly am rather a newbie to this, is there not a point where to small a tube will become ineffectual as far as carrying flue gases? Is there a practical limit? While more tubes may be understandably better able to produce steam - how does one determine what is needed/required? Kindest Regards, PeteH > Pete, > > How long will the tubes be, and what are the dimensions of the firebox? > Intriguing project. > > My gut feeling is that the boiler will need a strong draft in order for > the 1/4" boiler tubes to handle two 1/4" wicks. You might want to peek > at an Aster Lion and compare wick size, tube dia., and boiler dia. > proportions. > > You probably will need generously-sized wicks because the heat losses > will be large with such a small boiler and small cylinders. Increasing > the number of tubes will increase the heated surface area, which will > improve efficiency. Have you considered trying 5 tubes of 3/16" dia? > Simplified calculations show about 80% more heated surface and 40% more > flue area compared to 2 tubes of 1/4" diameter. > > Steve > >
Re: How small is too small?
That would be great, Thank-You Henner! PeteH - Original Message - From: "Henner Meinhold" <[EMAIL PROTECTED]> To: "Multiple recipients of sslivesteam" <[EMAIL PROTECTED]> Sent: Sunday, August 01, 2004 11:51 AM Subject: Re: How small is too small? > Pete, > for vertical boilers a ring shaped burner is quite efficient. I can send you > drawings/photos of my A-Climax burner. > Regards > Henner > - Original Message - > From: "PeteH" <[EMAIL PROTECTED]> > > How would one size the meth burner for such a small boiler, would two 1/4" > > dia. wick tubes be a fair match for two 1/4" dia. burner tubes? > >
Re: How small is too small?
Pete, How long will the tubes be, and what are the dimensions of the firebox? Intriguing project. My gut feeling is that the boiler will need a strong draft in order for the 1/4" boiler tubes to handle two 1/4" wicks. You might want to peek at an Aster Lion and compare wick size, tube dia., and boiler dia. proportions. You probably will need generously-sized wicks because the heat losses will be large with such a small boiler and small cylinders. Increasing the number of tubes will increase the heated surface area, which will improve efficiency. Have you considered trying 5 tubes of 3/16" dia? Simplified calculations show about 80% more heated surface and 40% more flue area compared to 2 tubes of 1/4" diameter. Steve [EMAIL PROTECTED] wrote: While looking at the Dewitt Clinton as a candidate for a GA1 model with what scales out to approximatly a .875 (7/8") outside diameter boiler - the question is how small is too small ? I have roughly laid out the boiler with two 1/4" o.d. smoke tubes, there is room for perhaps three tubes but the water volume in the boiler is so small I think it better to keep the smoke tubes in the lower 1/3 of the boiler to get longer run times. One has been built (not by me), the pistons were .25 Dia. It only ran 4 minutes before water had to be added. How would one size the meth burner for such a small boiler, would two 1/4" dia. wick tubes be a fair match for two 1/4" dia. burner tubes? Kindest Regards, Pete Harjung
Re: How small is too small?
Pete, for vertical boilers a ring shaped burner is quite efficient. I can send you drawings/photos of my A-Climax burner. Regards Henner - Original Message - From: "PeteH" <[EMAIL PROTECTED]> > How would one size the meth burner for such a small boiler, would two 1/4" > dia. wick tubes be a fair match for two 1/4" dia. burner tubes?
