<div dir="ltr"><font color="#000000" face="Times New Roman" size="3">
</font><p style="margin:0in 0in 10pt"><b><span style="color:black;font-family:"Arial","sans-serif""><font size="3">Why
did you decide to remove the VBT? Was it problems with the VBT system,
need for the space, or...?</font></span></b></p><font color="#000000" face="Times New Roman" size="3">
</font><p style="margin:0in 0in 10pt"><b><span style="color:black;font-family:"Arial","sans-serif""><font size="3">To
use a VBT or not, that is question.<span> </span>In
my case, I had a hard VBT, with a volume of approximately 1.1 cu ft.<span> </span>Because of the size it could only generate
about 70 lbs of differential displacement.<span>
</span>As such I still had to add and subtract ballast to accommodate a difference
in pilot weights. I found that that my VBT had a hysteresis while operating and
it was sluggish in establishing neutral buoyancy.<span> </span>If I got the boat neutral near the surface,
then if I used the VBT at depth, there was a sudden inrush of water that would
have to be blown out to get back to neutral buoyancy at depth. Adding air at depth
uses a lot air and my air capacity is limited.<span> </span><span> </span>I used electrically activated ball valves on
the vent and flood ports of the VBT.<span> </span>It
would take about two seconds for these valves to fully open or close.<span> </span>While the VBT system worked, all of these
factors caused the VBT to be less responsive than I would have liked.<span> </span>Last weekend was the first time to dive my
boat without the VBT and just relying on adjusting ballast prior to diving to
get neutral and then using the vertical thrusters for descending, ascending and
depth control.<span> </span>I found with two MK 101s,
I had much better depth control and the system was more responsive (until the last dive in which they failed).<span> </span>Two other reasons I switched are that I used
much less air and it gives much needed storage room behind the pilot.<span> </span>It also simplified diving in that to ascend
all I do now is flood the MBT, trim the boat longitudinally with a trim system
that moves a 100 lb weight forward or aft hydraulically and then use the
vertical thrusters.<span> </span>To ascend, it is
even easier, as now, all I have to do is use the vertical thrusters. VBTs need
to be located at the CG/CB of the boat.<span>
</span>For a small boat like mine, this is an awkward location blocking access
aft of the VBT.<span> </span>Yes you can split the
VBT in two but this doubles the values, tanks and plumbing. </font></span></b></p><font color="#000000" face="Times New Roman" size="3">
</font><div style="margin:0in 0in 10pt"><b><span style="color:black;font-family:"Arial","sans-serif""><font size="3"><span>
Having said all that, fish have swim bladders so we know nature likes the VBT concept. Maybe I just need a better design for the VBT system.</span></font></span></b></div><div style="margin:0in 0in 10pt"><span style="color:black;font-family:"Arial","sans-serif""><font size="3"><span style="color:black;font-family:"Arial","sans-serif""><font size="3"><strong>I have always looked at my boat as a test bed. I change things all the time. I have never taken the boat out configured the same way. I will run this way for a while and see if I continue to like it as much as I do now. If not, I will try something different.</strong></font></span></font></span></div><font color="#000000" face="Times New Roman" size="3">
</font><p style="margin:0in 0in 10pt"><b><span style="color:black;font-family:"Arial","sans-serif""><font size="3">Long
answer to a short question.</font></span></b></p><font color="#000000" face="Times New Roman" size="3">
</font><p style="margin:0in 0in 10pt"><b><span style="color:black;font-family:"Arial","sans-serif""><font size="3">Cliff</font></span></b></p><font color="#000000" face="Times New Roman" size="3">
</font></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Sep 4, 2015 at 10:00 PM, via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><u></u>
<div style="color:rgb(0,0,0);font-family:Arial;font-size:10pt"><font color="#000000" face="Arial" size="2">
<div><font size="3">Cliff,</font></div>
<div><font size="3">Why did you decide to remove the VBT? Was it problems
with the VBT system, need for the space, or...?</font></div>
<div><font size="3">Thanks,</font></div>
<div><font size="3">Jim</font></div>
<div> </div>
<div>
<div>In a message dated 9/2/2015 7:22:37 A.M. Central Daylight Time,
<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a> writes:</div>
<blockquote style="padding-left:5px;margin-left:5px;border-left-color:blue;border-left-width:2px;border-left-style:solid"><font color="#000000" face="Arial" size="2" style="background-color:transparent">
<div style="color:rgb(0,0,0);font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12px;background-color:rgb(255,255,255)">
<div><span>Alec, </span></div>
<div><span>Agreed, I carry a bypass cable to power up
my motor in case the controller quits. Bypass switch is a
must!</span></div>
<div><span>Hank</span></div><br>
<div><br><br></div>
<div style="display:block">
<div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12px">
<div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:16px">
<div dir="ltr"><font face="Arial" size="2">On Wednesday, September 2, 2015 6:04 AM,
Cliff Redus via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>>
wrote:<br></font></div><br><br>
<div>
<div>
<div>Yes, same battery.<br clear="none"><br clear="none">On Tuesday, September 1,
2015, Alan James via Personal_Submersibles <<a title="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect">personal_submersibles@psubs.org</a>>
wrote:<br clear="none">
<div>
<blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">
<div>
<div style="color:rgb(0,0,0);font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:16px;background-color:rgb(255,255,255)">
<div><span>That's real weird Cliff, especially the fact that 2 separate
units</span></div>
<div dir="ltr"><span>are playing up. The only common denominator is the
batteries I suppose.</span></div>
<div dir="ltr"><span>Are they both drawing from the same
batteries?</span></div>
<div dir="ltr"><span>Alan</span></div><br clear="none">
<div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:16px">
<div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:16px">
<div dir="ltr">
<hr size="1">
<font face="Arial" size="2"><b><span style="font-weight:bold">From:</span></b>
Cliff Redus via Personal_Submersibles <<a title="http://" rel="nofollow" shape="rect">personal_submersibles@psubs.org</a>><br clear="none"><b><span style="font-weight:bold">To:</span></b> Personal
Submersibles General Discussion <<a title="http://" rel="nofollow" shape="rect">personal_submersibles@psubs.org</a>> <br clear="none"><b><span style="font-weight:bold">Sent:</span></b> Wednesday, September 2, 2015 2:21
PM<br clear="none"><b><span style="font-weight:bold">Subject:</span></b> Re:
[PSUBS-MAILIST] R300 Dive report - Canyon Lake, Tx<br clear="none"></font></div>
<div><br clear="none">
<div>
<div>
<div dir="ltr">
<div>They shut down at about 3 PM on Sunday. I disassembled them
today expecting them to be filled with water but they were dry. I
reassembled today. I charged the batteries up last night so they were
full charged this morning. When I powered the thrusters up
today, the were at ambient temperature and the controllers had been sitting
all night so they were cool. The thrusters started up misbehaving like
they did when they shut down, i.e., would not spin up. After playing
with them for about 10 minutes they both came back to life a few minutes
apart. They have been running fine ever since. </div>
<div><br clear="none"></div>
<div>Cliff</div>
<div><br clear="none"></div>
<div><br clear="none"></div></div>
<div><br clear="none">
<div>On Tue, Sep 1, 2015 at 9:00 PM, hank pronk via Personal_Submersibles
<span dir="ltr"><<a title="http://" rel="nofollow" shape="rect">personal_submersibles@psubs.org</a>></span> wrote:<br clear="none">
<blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">
<div><br clear="none"><br clear="none"></div>
<div>
<div>
<div style="color:rgb(0,0,0);font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12px;background-color:rgb(255,255,255)">
<div><span>Cliff, How much time lapsed before they fixed themselves?
maybe they needed encouragement to restart because they were just on
cusp of being cooled enough.</span></div>
<div><span>Hank</span></div><br clear="none">
<div><br clear="none"><br clear="none"></div>
<div style="display:block">
<div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12px">
<div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:16px">
<div dir="ltr"><font face="Arial" size="2">On Tuesday, September 1, 2015 7:39
PM, Private via Personal_Submersibles <<a title="http://" rel="nofollow" shape="rect">personal_submersibles@psubs.org</a>> wrote:<br clear="none"></font></div><br clear="none"><br clear="none">
<div>
<div>
<div>
<div>Wonderful detailed report Cliff! My theory is a thermal shutdown of
the controllers as Hank suggested. Although I have no documentation on
their speed controllers, the fact it fixed itself suggests that. But then
on the other hand why did it take all that switching on and off to
reset?</div>
<div><br clear="none"></div>
<div>This reinforces my intention to put a speed controller override into
the new boat.</div>
<div><br clear="none"></div>
<div>Best,</div>
<div><br clear="none"></div>
<div>Alec<br clear="none"><br clear="none">
<div><br clear="none"></div></div>
<div>
<div><br clear="none">On Sep 1, 2015, at 5:40 PM, Cliff Redus via
Personal_Submersibles <<a title="http://" rel="nofollow" shape="rect">personal_submersibles@psubs.org</a>> wrote:<br clear="none"><br clear="none"></div>
<blockquote type="cite">
<div>
<div dir="ltr"><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">I took the
R300 out this weekend.<span> </span>This was the first time to
have it back in water since the 2013 Psub convention in
Islamorada.<span> </span>The objective of the dive was to evaluate
some fairly significant modifications.</font></span></div>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span><br clear="none"></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">To improve
low speed maneuverability and reduce noise, I junked the jet pump and
ailerons and went to four fixed MK 101 thrusters. I also junked the VBT
and just add ballast to get neutral. Also I added a Garmin AIRMAR DST800
Smart Sensor to measure altitude, speed and water
temperature.<span> </span>It worked great.<span>
</span>Installed a new LED 5k light, upgraded to a new HMI, and changed
the foot and joystick controls. <span> </span>I also rewired the
main battery bank for 36VDC rather than 120VDC and installed four MK 101
motor controllers.<span> </span>I modified the aft horizontal
MK-101s by adding Kort nozzles and used air to pressure
compensate.<span> </span>I used the same pressure reducing
regulator Hugh Fulton posted about awhile back that he is using on the
QSub.<span> </span><span> </span>The changes decreased
the weight of boat by 200 lbs while the displacement remained the same.
<span> </span></font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span> </div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">My son, wife,
a diving friend and I took the boat to Canyon Lake in Texas this
Sunday.<span> </span>Visibility was less than 5 ft so could not
see much.<span> </span>My main interest at this point was just to
get into water.<span> </span>After launching the boat, I did some
testing to get the base line ballast both mid-ship and in the stern
correct so that I could get neutral and trim after flooding the
MBT.<span> </span>After establishing the fixed ballast, I took the
boat out to test how the horizontal thrusters work for surface
maneuvering. <span> </span>I was very happy with way the
horizontal thrusters performed. Surface maneuverability was excellent
and these motors are supper quite.<span> </span>I did find that
you could cavitate the props on the surface if you hit it with too much
power. As before the changes, when you get up to about 4 knots, the bow
wave obscures the pilots vision. <span> </span>Breaking is
much improved and it is now possible to rotate on the surface or in the
water column.</font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span> </div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">I then took
the boat out for the first submerged maneuvering.<span> </span>The
vertical thrusters were very effective for depth control, pitch and roll
control. <span> </span>I found that it was much easier to get to
specific depth and hold this depth using the vertical thrusters than the
old way I did it with the VBT.<span> </span>They worked
great.<span> </span>While removing the VBT simplified dive
operations, it did result in loss of freeboard of about 1
inch.<span> </span>This is a downside of removing the VBT as the
freeboard was already quite low.<span> </span>I just have to be
careful when opening the hatch.<span> </span>I opened and closed
that hatch throughout the day and only took splash one time when a boat
came by I did not see.</font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span> </div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">The new
Garmin AIRMAR DST800 Smart Sensor worked great. With visibility less
than 5 ft, being able to know the altitude was very helpful on dives. As
usual, it got darker as you descend but knowing when the bottom was
coming up was nice.<span> </span></font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span> </div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">On the
negative side, during the last dive of the day, the vertical thrusters
failed while my son was on bottom in about 27 ft of water.<span>
</span>He had to surface using the MBT. Why these thrusters failed is a
mystery. <span> </span>It was at the end of the day and I had
pushed the batteries pretty hard all day along but we still had plenty
of battery voltage.<span> </span>My sons second attempt to
surface was to put some air in the forward MBT to lift the nose and then
use the aft horizontal thrusters to power to the surface.<span>
</span>This failed as aft horizontal thrusters were not
responsive.<span> </span>After surfacing with the MBT, we
discovered that tree limb about 1.5” diameter had lodged in the
starboard horizontal thruster between the prop and the Kort
nozzle.<span> </span>This explains why we lost horizontal thrust
but not vertical.<span> </span>After getting the boat back on the
trailer, I tested the vertical thrusters.<span> </span>They would
barely turn even when giving them full power.<span> </span>My
first guess was that the air pressure compensation system failed and the
thrusters were full of water.<span> </span>When I got the boat
back to my workshop, I disassembled both vertical thrusters and
discovered they were dry. After recharging the boat, I tried the
vertical thrusters again and got the same slow speed
operation.<span> </span>After turning them off and on for about
five minutes, the starboard vertical thruster stared working
correctly.<span> </span>I kept switching the port vertical
thruster off and on and all of a sudden, it began working
correctly.<span> </span>When I had the motors apart, I put a
multimeter on the wires going to the brushes and found it showing
35VDC.<span> </span>At this point the control signal to these
motors was 2.5V so voltage to the motors should have been
zero.<span> </span>My guess is that the MK motor controller
is acting up.<span> </span>But it is strange that both the
vertical controllers would fail.<span> </span>Also, if it
were bad motor controllers, then why did they both start working
again.<span> </span>This is still a head stumper for
me.</font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"> </font></span><span><font color="#000000"> </font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">Also towards
the end of the day, the OTS underwater communication stared acting
up.<span> </span>Base and standby diver using an OTS Guardian full
face mask could hear underwater transmissions from me but I could not
receive either from the diver or from the base.<span> </span>The
underwater commns had been working great for the previous 7
hours.<span> </span><span> </span>I was also having trouble
about this time with the VHF radio that Alec gave me.<span>
</span>Again I could not receive.<span> </span>When I get a chance
I am going to see if the connection to the antenna got
disconnected.</font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span> </div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">One of the
nice new features of the new HMI besides being larger and having a
higher resolution, was it has built in data logging.<span>
</span>So after the dive it was very nice to be able to download into
Excel about 50 variables logged at a one minute interval. I was able to
plot these and get a detailed picture of how all the ship systems were
working during the day.</font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span> </div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">If anyone has
any thoughts on why the vertical MK 101 thruster motors failed, or have
had any negative experience with the MK101 motor controllers, I would
love to hear them.<span> </span>When they are working, they are
great.</font></span></div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000"></font></span> </div><font color="#000000" face="Times New Roman" size="3"></font>
<div style="margin:0in 0in 0pt"><span><font color="#000000">All in all, I
was very happy with the changes but have a few kinks to work out before
I take her out again.<span> Now if I could just find some clear
water to dive in, I would be a happy camper!</span></font></span></div>
<div style="margin:0in 0in 0pt"><span><font color="#000000"><span></span></font></span><br clear="none"></div>
<div style="margin:0in 0in 0pt"><span><font color="#000000"><span>Cliff</span></font></span></div><font color="#000000" face="Times New Roman" size="3"></font></div></div></blockquote></div>
<blockquote type="cite">
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