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Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Sun Jan 02, 2022 6:35 pm
by dampfspieler
Hi,
the crankshaft was built from six parts and silver soldered. I heated the parts with my large burner to just below the working temperature of the solder and then soldered them with the GREGGERSEN soldering torch.
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It is critical that all parts are at the same temperature during the soldering process to avoid warping. After the parts were soldered, I let them cool down for a day.
As a result, the shaft then ran perfectly round.
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Dietrich
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Sun Jan 02, 2022 7:05 pm
by dampfspieler
Hi,
the base plates for the machine and the cylinder block were drilled in order to be able to mount the parts on a trial basis.
The crankshaft was turned to the final external dimensions and cleaned.
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The slide stone was again designed as clamp and can be easily locked with an M4 screw.
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Dietrich
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Mon Jan 03, 2022 8:07 pm
by PeteThePen1
A Happy New Year to Steamboaters everywhere!
Excellent progress Dietrich.
I was interested to see how you have dealt with the valves. I have, as a learning exercise with Alibre, started to draw the twin engine designed by Rudy. The sheet with the vales shows them so small I have not been able to work out what he was proposing. However, having seen this it must be very similar. I am not as far as valves yet as I have to learn how to install a plane that will allow me to do the diagonal drilling for the steam ports. Progress has been held up as I got diverted into drawing a cloakroom basin and cabinet that might fit in our house. All I wanted to know was how much reach the tap would need into the basin, but it seemed a pity to not draw the whole thing.
Pete
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Fri Jan 07, 2022 2:21 am
by dampfspieler
Hi,
some more pictures of the slide stone, so it's easy to understand how it works. The biggest advantage is that the slide can be adjusted very precisely.
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Dietrich
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Fri Jan 07, 2022 7:43 am
by fredrosse
Nice work you have made. If the valve rod is made with screw threads different pitch on each end, then the differential movement will allow adjustment similar to a micrometer.
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Mon Jan 10, 2022 8:22 pm
by dampfspieler
Hi Fred,
... with screw threads different pitch on each end,
that is another possibility. I have had good experiences with the variant shown, so I made it a reality.
The eccentric bodies were made from gray cast iron. The finished were blacked with KLEVER quick browning. Thin section ball bearings sit on them. Two setscrews with brass inlays held the eccentric in place at the crankshaft.
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Dietrich
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Mon Jan 10, 2022 8:32 pm
by dampfspieler
Hi,
the set screws are arranged at an angle of 120 °. The brass inlays protects the crankshaft from damage.
- Twin3238_216kl.jpg (52.56 KiB) Viewed 15147 times
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Dietrich
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Wed Jan 19, 2022 3:22 am
by barts
Otter's old engine used a thin-line ball bearing on the eccentric - it was very smooth and easy to turn over, even w/ some steam chest pressure.
That engine lasted many years, and the bearing still feels smooth. A squirt of oil now and then took care of lubrication.
- Bart
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Sat Jan 22, 2022 7:57 pm
by dampfspieler
Hi Bart,
was your bearing an open or an closed type?
I will use closed ball bearings on all eccentrics of my engine. They have a life time lubrication.
- The slide valve eccentric bearings
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- The pump eccentric bearings
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Dietrich
Re: TWIN 32 x 38 mm - steam engine for small boats or canoes
Posted: Sat Jan 22, 2022 8:11 pm
by dampfspieler
Hi,
yesterday i have got some laser cut parts. Two for a drill jig and four for eccentric rods. The drill jig parts were riveted together an then drilled the cylinder covers and the cylinder base plate.
- Cylinder cover drill jig avers
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- Cylinder cover drill jig revers
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- The parts for the eccentric rods
- Twin3238_241kl.jpg (55.44 KiB) Viewed 14880 times
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Dietrich