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#Post#: 59750--------------------------------------------------
Second test in water for a Stuart Turner Henley steam launch.
By: Tony Bird Date: January 18, 2024, 3:57 am
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Hi,
There has been a second steam test on water of the Stuart Turner
Henley steam launch. One problem it doesn’t have is lack of
power! Lowering the boiler 5mm and fitting a lighter funnel
hasn’t done a lot to improve the stability of the model. The
next attempt to improve the stability will be a lighter fore
deck (the new one made would be heavier than the original), a
location system for the burner under the boiler and some
ballast. It is felt that the large steam loss is due to the
boiler making more steam than the engine can handle, the engines
port faces not yet completely bedded in isn’t contributing a
great deal to the steam loss. It had been suggested that a
regulator might be fitted but I thought that the model never
having had one and it was free running this wouldn’t be
necessary; a rethink might be in order? Before considering a
regulator, reducing the size of the burner will be tried. The
running times of the three steam tests in water have been
remarkably similar, from cold the engine running time between
the engine starting and stopping has been a little over 10
minutes. The boiler capacity is 225ml of which 50ml was removed
for a steam space and when the engine finished working there was
about 50ml of water left in the boiler, so water used 125ml.
Further work will be delayed as like our namesakes we fly south
for part of the winter.
Take care Tony.
(HTM) https://youtu.be/5DVZBIjyOQU
#Post#: 59757--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Stoker Date: January 18, 2024, 1:54 pm
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Question: is it truly a stability issue due to the CG being too
high, or could it be just that the CG is slightly off the
centerline to starboard?
On another note, I'm guessing you'll be installing a larger
diameter exhaust line next to eliminate the back pressure you
seem to be experiencing. Perhaps also tightening the cylinder
pivot a bit as well, to allow for higher pressure operation?
#Post#: 59759--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: txlabman Date: January 18, 2024, 4:30 pm
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Good luck Tony.
This has been a great project to follow.
Thank you.
Charlie
#Post#: 59765--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Tony Bird Date: January 19, 2024, 3:40 am
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Hi Daniel,
Question: is it truly a stability issue due to the CG being too
high, or could it be just that the CG is slightly off the centre
line to starboard?
I think a bit of both. The boiler has two water tubes under it
so making it about 12mm (1/2") higher than it might be, the hull
has a beam of 105mm (4.1/4") and the boiler casing with the
boiler is the same height, and when the boiler has water in it,
it is quite a weight.
Yes, the centre line of the CG is off, mostly due to the burner
having no fixed position under the boiler, this now has been
fixed.
On another note, I'm guessing you'll be installing a larger
diameter exhaust line next to eliminate the back pressure you
seem to be experiencing.
Yes, a short, larger diameter stub exhaust pointing over the
side has been fitted. There aren't many photographs of a Henley
available but several show the exhaust going straight from the
engine to the side. There isn't a lot of space between the
boiler and its casing for an exhaust pipe of any diameter, the
pipe also has to be fairly long and has several tight curves in
it.
Perhaps also tightening the cylinder pivot a bit as well, to
allow for higher pressure operation?
The spring is set to its optimum; regarding pressure against
friction, I have had similar problems before. Too much steam and
engine at terminal velocity, fitting a regulator would fix it,
but why take the easy way, but I might end up fitting one.
Henley's weren't fitted with regulators. My thoughts at the
moment is to partially cover the burner to reduce the heat
and/or fitting a smaller diameter steam pipe to the engine. With
the burner fixed and ballast to keep the hull vertical fitted
another steam test could be made, but with the temperature down
to -5C there will be serious ice in the test take and the
domestic authorities are not keen on steam in the bathroom
unless it comes from bath or shower; thought, I might think of
taking a long shower?
Take care Tony.
#Post#: 59766--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Raphael HAVRANEK Date: January 19, 2024, 8:35 am
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Bonjour Tony,
Other question, would your steam machine need an oil lubricator
as I don't see anyone ?
I know that wet team is self-lubricating but perhaps would that
help a little for steam sealing ?
Concern, you should have to install an oil separator to the
exhaust to prevent oil going on the water...
Other possiility, add a sheet of Teflon on the cylinder faces
lik this one :
(HTM) https://youtu.be/W293GPcmIDw
#Post#: 59774--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Tony Bird Date: January 20, 2024, 3:32 am
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Hi Raphael,
Other question, would your steam machine need an oil lubricator
as I don't see anyone?
The Stuart Turner Henley weren't fitted with either regulators
or lubricators, and at least for the start I am not going to fit
them. But who knows later maybe.
I know that wet team is self-lubricating but perhaps would that
help a little for steam sealing?
Yes, I think using steam oil might improve the sealing at the
engine port face.
Concern, you should have to install an oil separator to the
exhaust to prevent oil going on the water...
Again yes, but given the lack of room between the boiler and
engine, along with having to be able to remove the burner
fitting a oil separator and its reservoir isn't really
practical.
Other possibility, add a sheet of Teflon on the cylinder faces
like this.
I haven't heard of using Teflon for port faces, how is it held
in place and does it wear well, alas I have no French so didn't
understand the cometary. I have used PTFE instead of 'O-rings'
which works quite well
After yesterdays -5C temperature it is a balmy +3C today, so if
I manage to finish the modification on the Henley perhaps
another steam test will take place.
Take care Tony.
#Post#: 59779--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Raphael HAVRANEK Date: January 20, 2024, 1:26 pm
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Bonjour Tony,
Sorry for my French langage and thank you for Google traduction
help ;)
I hope this other video will help you to see how we use Teflon
(PTFE) sheets for oscillating pistons:
(HTM) https://youtu.be/p_YGayTPkjE
I have seen again you video, these cylinders leaks seem
definetely your main issue.
About lubricating, with Teflon, no more needed because you are
right, your hull is quite narrow!
I can't wait to see this steam arrow on a pond (mine is
currently also frozen).
#Post#: 59788--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Tony Bird Date: January 21, 2024, 3:13 am
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Hi Raphael,
Thank you for posting your video, it is very interesting, alas
the port faces of the ST engine are very small and are totally
covered by the port face of the cylinder, so there is nowhere to
use screws to hold the PTFE.
The temperature here has risen to 10C today, yesterday it was
5C, the ice in my test box was 12/15mm thick and had to be
broken up and replaced with warm water for me to test the
modification's made to the Henley. These modifications
consisting of a brass weight screwed to one of the longerons of
the hull to improve the hull's stability, it now sits vertically
in the water but is still a little tender being slow to recover
when displaced. A new fore deck was made from tin plate to
replace the thicker aluminium one made, I should have thought
there wasn't much weight difference as aluminium is about a
third of the weight of steel, if thinner aluminium becomes
available I will make another deck. A lighter funnel has been
made and fitted. The burner now sits on a carrier which holds it
in one place centrally under the boiler. The burner is now
covered for a third of its length to reduce its heat output.
What difference did these modifications make? Well the engine
maintained what seemed about the same speed for ten minutes
before the flames died back, I had though it might have run
longer because of the shorter length of the flame. The engine
leaked considerably less steam. Using less steam was reflected
in the fact that when the boiler drained they was 25ml more
water removed, so some progress?
Alas my camera ran out of battery before I could take all the
photographs I wanted which might be a relief to some. I think
an open water test next when it can be arranged. I live very
close to a large lake which isn't very suitable for model boats
which aren't radio controlled, but maybe a length of string tied
to the rudder post?
Take care Tony.
#Post#: 59789--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Tony Bird Date: January 21, 2024, 3:30 am
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Hello again,
Might be found interesting; my local lake enjoying better
weather where I might check the Henley out.
(HTM) https://youtu.be/rf8_z0GZAPE?si=uF2MwDIapU8EBmZC
The video is too long but the yacht does get attacked by a fish
and radio control is lost, like my camera I hadn't checked the
batteries!
Take care Tony.
#Post#: 59790--------------------------------------------------
Re: Second test in water for a Stuart Turner Henley steam launch
.
By: Raphael HAVRANEK Date: January 21, 2024, 8:13 am
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Bonjour,
"My" lake today ;)[attachimg=4][attach=1][attach=2][attach=3]
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