Page 3 of 8

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.

Twin3238_132kl.jpg
Twin3238_132kl.jpg (72.98 KiB) Viewed 15262 times
Twin3238_135kl.jpg
Twin3238_135kl.jpg (70.04 KiB) Viewed 15262 times
Twin3238_138kl.jpg
Twin3238_138kl.jpg (63.88 KiB) Viewed 15262 times

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.


--
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.

Twin3238_170kl.jpg
Twin3238_170kl.jpg (42.4 KiB) Viewed 15261 times

The slide stone was again designed as clamp and can be easily locked with an M4 screw.

Twin3238_187Akl.jpg
Twin3238_187Akl.jpg (82.17 KiB) Viewed 15261 times

--
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.

Twin3238_198kl.jpg
Twin3238_198kl.jpg (42.08 KiB) Viewed 15143 times
Twin3238_200kl.jpg
Twin3238_200kl.jpg (53.58 KiB) Viewed 15143 times
Twin3238_201kl.jpg
Twin3238_201kl.jpg (51.02 KiB) Viewed 15143 times

--
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.

Twin3238_214kl.jpg
Twin3238_214kl.jpg (58.04 KiB) Viewed 15045 times
Twin3238_219kl.jpg
Twin3238_219kl.jpg (62.78 KiB) Viewed 15045 times
Twin3238_221kl.jpg
Twin3238_221kl.jpg (55.74 KiB) Viewed 15045 times

--
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
Twin3238_216kl.jpg (52.56 KiB) Viewed 15044 times

--
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.

Twin3238_177kl.jpg
The slide valve eccentric bearings
Twin3238_177kl.jpg (60.59 KiB) Viewed 14778 times
Twin3238_175kl.jpg
The pump eccentric bearings
Twin3238_175kl.jpg (48.67 KiB) Viewed 14778 times

--
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.

VorR03_002kl.jpg
Cylinder cover drill jig avers
VorR03_002kl.jpg (52.93 KiB) Viewed 14777 times
VorR03_003kl.jpg
Cylinder cover drill jig revers
VorR03_003kl.jpg (61.4 KiB) Viewed 14777 times
Twin3238_241kl.jpg
The parts for the eccentric rods
Twin3238_241kl.jpg (55.44 KiB) Viewed 14777 times

--
Dietrich