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hot Air Beam Engine with cooling and generator

Posted: Thu Dec 15, 2016 3:16 am
by Trevor
This is my first attempt at making a Beam Engine. This engine will be using the Watt linkage for the displacer.
The engine is based on a displacer of 74mm and a stroke of 38mm. The piston is 38mm and will have a stroke of 64mm being a ratio of approx. 2.5 to 1.
The water pump is driven by an air operated diaphragm from the displacer chamber, which has a diaphragm of 25mm and uses about 4cc of air which is calibrated as part of the piston volume
Here is a few pics of how I am going with so far. Trevor

Re: hot Air Beam Engine with cooling and generator

Posted: Fri Dec 16, 2016 5:12 am
by Ian S C
Trevor, what will the motor be heated with?
Ian S C

Re: hot Air Beam Engine with cooling and generator

Posted: Sat Dec 17, 2016 4:38 am
by Trevor
I was going to go with gas Ian, but have changed my mind and now going with Meths burner.
Here is the latest pic of the fire box. I used investment powder to make the fire wall to retain the heat so it will not radiate outwards or downwards.
Trev

Re: hot Air Beam Engine with cooling and generator

Posted: Sat Dec 17, 2016 4:42 am
by Trevor
I have used investment powder to make the fire wall - All I need to do now is place the chimney to direct the heat away from the water Jacket.
Trev

Re: hot Air Beam Engine with cooling and generator

Posted: Sun Dec 18, 2016 2:52 am
by Ian S C
I presume this investment powder, is something like fire clay, and is heat proof for lining a furnace, or kiln, it looks handy stuff. Make sure the meths burner has a good air inlet as well as a chimney. Here meths is about $NZ7 for 1L, one reason I use gas for most of my motors.
Ian S C

Re: hot Air Beam Engine with cooling and generator

Posted: Sun Dec 18, 2016 4:12 am
by Trevor
Yep! The investment powder is for casting metal objects and will take around 1000 deg C. This will be the first time I have used it for this purpose. I don't know if it will work yet - It as we would say, Trial and Error Ian.
I buy the meths for around $6.00 for 5 litres here and you are correct - Expensive compared to gas - It just looks better using meths.

Another problem I had trialing the Beam apparatus (Watts Linkage). I have a 36 to 38mm length stroke for the displacer and used 35mm linkages for all the parallel bars (all equal length) but alas! It did not work. The high and low strokes caused tightness in the shaft. I gave up in the end and cut it all off and just use a single shaft for the displacer. Over the 4omm distance the movement off centre was only 1.5 mm - Not enough to worry about. I will send photo tomorrow for you. The length of the span is nearly 300mm so the are arc is large. Trevor

Re: hot Air Beam Engine with cooling and generator

Posted: Mon Dec 19, 2016 2:10 am
by Trevor
Another pic of what I am doing. You notice the idea of using a Watt linkage failed on me, so I have reverted to just using a long displacer rod.
I managed to get the pulley fitted into the lathe by grinding away all the grove section and then only just fitted. At least it is now finished. The bearing block will be set into place and the cranks made. It is going to be a challenge as I will be using a double crank on the same axis. It will look wired but it will work. This is due to two different crank lengths.
Trev

Re: hot Air Beam Engine with cooling and generator

Posted: Tue Dec 20, 2016 4:11 am
by Ian S C
Here's my beam engine, the bore is 3/8", and the stroke is 1/2", the hot cap is the steel case of an AA size NiCad battery.
Ian S C
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Re: hot Air Beam Engine with cooling and generator

Posted: Wed Dec 21, 2016 1:43 am
by Trevor
Nice one Ian. Lovely little engine and love your lathe work. I am afraid am not very good with a lathe, but learning fast. Your thread and Thanh's thread helped me with the parting off work. I can now say I have accomplished it - You were right about the slow speed...Majic.

I have just run up my engine for the first time test. I must admit I was mightily impressed with its performance and couldn't stop the shaft from turning with my fingers - so here's hope that the little generator will work now.
The water pump was excellent in its performance as well and made no difference to the operation of the engine.

Yahoo! Ian - couple of photos to show how it is at present with only a small flame operating it.
Trevor

Re: hot Air Beam Engine with cooling and generator

Posted: Wed Dec 21, 2016 1:53 am
by thanh-cuibap
Ian S C wrote:Here's my beam engine, the bore is 3/8", and the stroke is 1/2", the hot cap is the steel case of an AA size NiCad battery.
Ian S C
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very nice !! profession ..Ian !!!

Re: hot Air Beam Engine with cooling and generator

Posted: Wed Dec 21, 2016 1:56 am
by thanh-cuibap
Trevor ...i want to see video , both of your engines !!

Re: hot Air Beam Engine with cooling and generator

Posted: Wed Dec 21, 2016 2:12 am
by Trevor
HI Thanh - Er! Don't know how to set up video on this forum or putting on Utube as yet. A few other friends of mine have asked the same question, however I will try over the Christmas break - Just for you
Trevor

Re: hot Air Beam Engine with cooling and generator

Posted: Wed Dec 21, 2016 2:31 am
by Ian S C
I don't do video, I'm on dial up, and life is too short, well the computer shuts down before it completes the job.
The wee motor is made from stuff around the workshop, it's a great runner, and with a tiny flame will run up to 3000rpm, I'm sure that I could make a generator that would light at least one red LED for it.
Congrats on the motor running with the power that it does.
Ian S C

Re: hot Air Beam Engine with cooling and generator

Posted: Wed Dec 21, 2016 3:21 am
by Trevor
That's a good speed on that Ian. Have no idea how fast mine was going though as it started to shake all over the place (got to balance it somehow) Thanks Ian - Still got to do the hot box yet. Just got back from the shed after putting in the 3/4"holes (X2) for the exhaust - opposite each other and also putting on a lower lid to prevent heat loss downward. Dress the model up and paint.
You will get to see the finished product then Thanh.
Trevor

Re: hot Air Beam Engine with cooling and generator

Posted: Wed Dec 21, 2016 4:15 am
by thanh-cuibap
my stirling ..
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