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Member postings for Jens Eirik Skogstad

Here is a list of all the postings Jens Eirik Skogstad has made in our forums. Click on a thread name to jump to the thread.

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Thread: How tight piston rings?
14/07/2011 06:09:57
Better in the supply pipe, but close to the steam chest.
13/07/2011 06:49:55
You can take running-in the steam engine with air, but you must stop steam engine often to lubricate the cylinder. The solution is the fog oil lubricator for air pressure tools.
 
Better to run in the steam engine with steam because you get all parts expanded by hot steam "to right size" + enough oil in steam.
 
Pors to retain the oil in cylinder wall is good since it is used cast iron as cylinder material. Other material such as bronze, brass, aluminium, best to have cross hatched honed surface.
11/07/2011 21:01:38
The pressure will press the piston ring against cylinder wall under work and keep tight against leakage in cylinder. The machined surface is not perfect worked by tools, then the steam engine/internal combustion engines need running-in to make fit perfect between piston ring and cylinder. But the cylinder surface need a lot of "oil in pockets", also the cylinder need cross hatchet cylinder honing on the surface. After running-in is done, there is still visible cross hatched tool marks by honing tool. It means lubricating the piston rings are good and will last long time so long the oil is available by "oil in pockets" in cylinder surface..
 
I has a TVR1A twin steam engine with O-ring as piston ring, it took me about 8 hour running-in to make perfect fit between O-ring and cylinder. It need a lot of oil under running-in. Now the steam engine is running fine with oil in steam by displacement lubricator. Without oil, the O-ring has enormous friction against cylinder. Piston ring is better than O-ring and need less oil, the real big steam engine need up to 2-3 drops oil per minute with mechanical lubricator under normal use (source: Book for mechanics by Peder Lobben, printed 1935). You need the displacement lubricator with valve to control the oil consumpion and keep steam engine well lubricated without spend too much oil.
10/07/2011 03:53:42
Springy??? If the engine has good compression and has good torque under starting since it is a steam engine, nothing wrong with the piston ring. It will take a time to get piston ring seated to cylinder under running-in period. Too tight ring gap can give more friction between pistonring and cylinder if the piston ring is expanded by heat of working temperature, also if you see the steam engine will loss revolution when the steam engine is in working temperature (let us say the "cold" steam engine is running fast and will reduce revolution when the steam engine is in working temperature caused by expanded piston rings due too little ring gap.).. Read this article about piston rings: http://www.btinternet.com/~sylvestris/rings/rings.htm
Thread: Boiler Leaks
26/06/2011 15:31:51
Inn old days the leaking boiler was cured with horse dung
Thread: Steam turbine, which of the design is effective??
02/06/2011 14:29:16


Posted by Ian S C on 02/06/2011 13:41:50:
Jens, you could drive a generator from the shaft, and load that to give the electrical power out put, ie., amps and volts. Some where I saw a test rig for a hot air engine using this system, and the generator was mounted so that the body of it was able to rotate, this was to enable the torque to measured. the little generator will be only about 50% efficient, but not as messy as propellers in water. Ian S C

Ian and folks there, how can i calculate the effect by generator and volt/amper if the rpm is known?

 

Edited By Jens Eirik Skogstad on 02/06/2011 14:42:48

02/06/2011 05:43:03
Hi folks!
 
The turbine is near complete and there is propeller shaft added. It is some parts to make ready to the turbine and add the propeller. I has tested the turbine with reduction gear, there is really good torque, difficult to stop with the fingers at the propeller shaft while the turbine is running, but it is a question about start torque from zero revolution to working revolution. The reduction gear house has oil inside to keep the gear lubricated. I will rig the test stand to test the turbine with boiler connected to the turbine and the propeller in watertank.
 
I early post i wrote: I am planning to test the horsepower with miscellaneoud air screws and tachometer + the program "Thrust hp", then i can learn out how much effective is the rpm range and steam pressure.
 
I will drop this test since there is enormous torque in the turbine to test a lot of propeller in watertank.
 


Thread: Ultrasonic Cleaners - Experiences? Any Good?
31/05/2011 20:01:41
I has the Aoyue ultrasonic cleaner, 30/50 watt effect. The cheap ultrasonic cleaner works very well. I used the warm water and Allosil cleaning fluid with high pH percent.
 
See this movie i own the Aoyue ultrasonic cleaner: http://www.youtube.com/watch?v=wOlcxZrdCTQ
Thread: Using Micrometer/Hi-Spot blue
25/05/2011 21:39:36
Hi, see these nice scraping method..
 
 
 

http://www.youtube.com/watch?v=esAqz6bCVyQ&feature=related

Edited By Jens Eirik Skogstad on 25/05/2011 21:45:11

Thread: boiler size
12/05/2011 22:32:00
You need the book about "Model boilers & Boilermaking" by K. N. Harris. There are a lot of information how to calculate and make boiler.

Edited By Jens Eirik Skogstad on 12/05/2011 22:32:33

Edited By Jens Eirik Skogstad on 12/05/2011 22:35:05

Thread: Steam turbine, which of the design is effective??
09/05/2011 23:01:34
Hi, i has maked the reduction gear to steam turbine, the gear ratio is 10.2:1. But not tested before the sear set is completed and ready to run. I am planning to test the horsepower with miscellaneoud air screws and tachometer + the program "Thrust hp", then i can learn out how much effective is the rpm range and steam pressure.

05/05/2011 22:51:23

Edited By Jens Eirik Skogstad on 05/05/2011 22:54:22

05/05/2011 22:37:51
Today i tested with steam with good results No problem with ball bearing with diesel oil, no mixed with water. The turbine ran above 35000 rpm with good torque. When i removed the heat of the boiler, the steam turbine was still running up to 2 minutes before the pressure was dropped of.. there was enough torque.
 
I am uploading the movie of my turbine in Youtube.. ready to see later..
 
 
I added the ball bearing 4mm x 9mm x 4mm instead bronze bearing. The turbine wheel in brass, 5/16" thick and the wheel is near close to the turbine house, about 0,5 mm clearance. The vanes is milled with 2 mm saw cut wheel. The shaft was silverbrazed to turbine wheel before complete machining the whole turbine wheel. There is no out of balance.
 
 


 
 

Edited By Jens Eirik Skogstad on 05/05/2011 23:06:11

04/05/2011 19:47:05
Hi folks!
 
I has maked the steam turbine after the drawning of Elmer Verburg steamturbine with ball bearing.
 
Then i took the test with difference oils in the bearings.
 
Here are the tests of oils and measured revolutions per minute:
Work pressure= Mobil ESP 5W-30 / Air tool oil /  Diesel oil (fuel for diesel engine as lubricant)
 
1 bar= 4700 / 13230 / 17600
1.5 bar= 6200 / 17900 / 25700
2 bar= 11400 / 21660 / 31500
2.5 bar= 15500/26340 / 36700
3 bar= 18600 / 28800 / 41800
 
As i can see the ball bearing get less friction with diesel oil as lucricant, it is sensitive for jet stream from nozzle. With high revolution above 15000, i can feel there are enough torque when trying to stop the turbine shaft.
 
I can think: With less friction means less waste of the steam and fuel for heating the boiler.
 
What is your meaning about the oil/rpm to a "fixed" working pressure?
 

Edited By Jens Eirik Skogstad on 04/05/2011 19:50:30

Edited By Jens Eirik Skogstad on 04/05/2011 19:57:56

01/05/2011 00:05:34
Thanks for the answer from you..
 
I searched the info about the model steam turbine ,and i found the book in PDF file. It is a book "Model steam turbines" by H. H. Harrison. I downloaded the book from Library of the university of California. The book is well written about the model steam turbine and how to calculate and make the steam turbine.
 
 
 
26/04/2011 22:56:00
Hi, also not simple to get enough power out of the steam turbine to run the model boat?
 
The vanes must be curved to make "jet stream" in other side of the turbine wheel?
 
I am planning to make the turbine wheel at 1-1/4" diametre with 25-30 vanes.. but not sure.. The ball bearings are at 4 mm d x 9 mm D x 4 mm W.
 
I saw at the Karstein turbine wheel, the vanes are mounted at side instead top of the turbine wheel, how are the effect compared to a turbine wheel with vanes mounted in top of the turbine wheel.
 
Better to machine the vanes in the turbine wheel (with milling machine and rotary table) or mount the loose vanes on the turbine wheel and solder the parts of turbine wheel togheter?
23/04/2011 09:39:11
Dear all folks, i am planning to make own steam turbine with reduction gear, all will be ball beared. Which of the turbine wheel is effective when we are talking about the same turbine wheel diameter with difference construction and use same steam pressure: Reaction-, pulse- or Tesla turbine?
 
I saw the Jensen and Wilesco steam turbine has difference construction from other such as Saito steam turbine and Proteus turbine. Will theJensen- and Wilesco turbine be useful for modelboat?
 
Come with the advice from you about steam turbine
Thread: Cutting speed theory
23/04/2011 09:28:22
With fine/small cut of material: select maximum cutting speed fot selected material.
 
When you want short time to turn from large diameter to smaller diameter with deep cutting in the selected material, select lower cutting speed to prevent heat by friction/compression by material. The lathe tool will be 45 degree angle left side to prevent the material is pushing away from lathe tool.
22/04/2011 06:16:29
Posted by Norman Willcox on 21/04/2011 17:14:43:
Hello Ramon, Clive, Sam,Jens Eirik and Ian,
Thank you so much for all the information and advice.
My son and I understand a lot more than we did. We shall be a lot better in selecting speed and rate.
Thank you,
Norman
 
 
Norman Willcox...
I will recomment the book "The Amateur’s Lathe" by L.H. Sparey, ISBN: 978-085242-288-5 .
 
 
You will learn out the book is best for the newbeginners and a lot of advice how to use the lathe, more than you will find in the instruction book who came with the lathe.
21/04/2011 07:20:51
Posted by Norman Willcox on 20/04/2011 22:52:48:
Hi Ramon,
 
Aluminium is known as having difficulties with cutting - stuff builds up on the tool etc.
 
Norman
 
Use kerosene or 5-56 as lubricant between aluminium and tool, it will give beautiful surface.
 
Not only cutting speed related to difference material, also the angle of rake on the tool is important too, to example 40 degree rake for aluminium, 0 degree for brass, cast iron.. See this: http://www.mfg.mtu.edu/cyberman/machining/trad/turning/turn.html#turn_cutter
 
Right cutting speed wil give the tool a long time to use between regrinding the tool/replace tool tipswith a new. Also too high cutting speed = short life time for the tool.
Keep the tool sharp and have the coolant fluid available then the tool will last longer..
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