[PSUBS-MAILIST] R300 Dive report - Canyon Lake, Tx

Fri Sep 4 23:00:15 EDT 2015

Cliff,
Why did you decide to remove the VBT?  Was it problems  with the VBT 
system, need for the space, or...?
Thanks,
Jim

In a message dated 9/2/2015 7:22:37 A.M. Central Daylight Time,  
personal_submersibles at psubs.org writes:

Alec, 
Agreed, I carry a bypass cable to power up  my motor in case the controller 
quits.  Bypass switch is a  must!
Hank

On Wednesday, September 2, 2015 6:04 AM,  Cliff Redus via 
Personal_Submersibles <personal_submersibles at psubs.org>  wrote:

Yes, same battery.

On Tuesday, September 1,  2015, Alan James via Personal_Submersibles 
<_personal_submersibles at psubs.org_ (mailto:personal_submersibles at psubs.org) >  
wrote:

That's real weird Cliff, especially the fact that 2 separate  units
are playing up. The only common denominator is the  batteries I suppose.
Are they both drawing from the same  batteries?
Alan

____________________________________
 From:  Cliff Redus via Personal_Submersibles 
<_personal_submersibles at psubs.org_ () >
To: Personal  Submersibles General Discussion 
<_personal_submersibles at psubs.org_ () > 
Sent: Wednesday, September 2, 2015 2:21  PM
Subject: Re:  [PSUBS-MAILIST] R300 Dive report - Canyon Lake, Tx

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. 

Cliff

On Tue, Sep 1, 2015 at 9:00 PM, hank pronk via Personal_Submersibles  
<_personal_submersibles at psubs.org_ () > wrote:

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.
Hank

On Tuesday, September 1, 2015 7:39  PM, Private via Personal_Submersibles 
<_personal_submersibles at psubs.org_ () > wrote:

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?

This reinforces my intention to put a speed controller override into  the 
new boat.

Best,

Alec

On Sep 1, 2015, at 5:40 PM, Cliff Redus via  Personal_Submersibles 
<_personal_submersibles at psubs.org_ () > wrote:

I took the  R300 out this weekend.  This was the first time to  have it 
back in water since the 2013 Psub convention in  Islamorada.  The objective of 
the dive was to evaluate  some fairly significant modifications.

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.  It 
worked great.   Installed a new LED 5k light, upgraded to a new HMI, and changed  
the foot and joystick controls.  I also rewired the  main battery bank for 
36VDC rather than 120VDC and installed four MK 101  motor controllers.  I 
modified the aft horizontal  MK-101s by adding Kort nozzles and used air to 
pressure  compensate.  I used the same pressure reducing  regulator Hugh 
Fulton posted about awhile back that he is using on the  QSub.    The changes 
decreased  the weight of boat by 200 lbs while the displacement remained the 
same.  

My son, wife,  a diving friend and I took the boat to Canyon Lake in Texas 
this  Sunday.  Visibility was less than 5 ft so could not  see much.  My 
main interest at this point was just to  get into water.  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.  After establishing the fixed ballast, I took the  boat out to test how 
the horizontal thrusters work for surface  maneuvering.   I was very happy 
with way the  horizontal thrusters performed. Surface maneuverability was 
excellent  and these motors are supper quite.  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.   Breaking is  much improved and it is now possible to rotate on 
the surface or in the  water column.

I then took  the boat out for the first submerged maneuvering.  The  
vertical thrusters were very effective for depth control, pitch and roll  control. 
 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.  
They worked  great.  While removing the VBT simplified dive  operations, it 
did result in loss of freeboard of about 1  inch.  This is a downside of 
removing the VBT as the  freeboard was already quite low.  I just have to be  
careful when opening the hatch.  I opened and closed  that hatch throughout 
the day and only took splash one time when a boat  came by I did not see.

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.  

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.   He had to 
surface using the MBT. Why these thrusters failed is a  mystery.  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.   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.   This failed as aft 
horizontal thrusters were not  responsive.  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.  This explains 
why we lost horizontal thrust  but not vertical.  After getting the boat back 
on the  trailer, I tested the vertical thrusters.  They would  barely turn 
even when giving them full power.  My  first guess was that the air pressure 
compensation system failed and the  thrusters were full of water.  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.  After turning them 
off and on for about  five minutes, the starboard vertical thruster stared 
working  correctly.  I kept switching the port vertical  thruster off and on 
and all of a sudden, it began working  correctly.  When I had the motors 
apart, I put a  multimeter on the wires going to the brushes and found it 
showing  35VDC.  At this point the control signal to these  motors was 2.5V so 
voltage to the motors should have been  zero.   My guess is that the MK motor 
controller  is acting up.  But it is strange that both the  vertical 
controllers would fail.  Also, if it  were  bad motor controllers, then why did 
they both start working  again.  This is still a head stumper for  me.

Also towards  the end of the day, the OTS underwater communication stared 
acting  up.  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.  The  underwater commns had been working great 
for the previous 7  hours.   I was also having trouble  about this time 
with the VHF radio that Alec gave me.   Again I could not receive.  When I get 
a chance  I am going to see if the connection to the antenna got  
disconnected.

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.   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.

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.  When they are working, they are  great.

All in all, I  was very happy with the changes but have a few kinks to work 
out before  I take her out again.  Now if I could just find some clear  
water to dive in, I would be a happy camper!

Cliff

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