You probably reached this "Blog1" page from that called
GPS Guided Trans-Atlantic Robot Boat,
or the
Design of Snoopy Sloop page
.
If not, click on a link to know more.
Each "blog" page describes detailed work preparing for the next Atlantic Attempt.
i.e. covering a period in the region of a year: less if more than one attempt is made.
The Blog pages were started after the first 2012 Attempt, where Snoopy's boat was lost. All later attempts were
with the same boat, sometimes after major repairs. The blogs provide online "Engineering Notebooks",
providing a day-by-day account of repairs, changes, and testing: mostly testing.
These blog pages are mostly about numerous repairs to the boat, results from "BRAY LAKE TEsts", or 24/7 reliability testing on Bray Lake.
i.s. Snoopy sailing back and forth over a 24/7 waypoint in "Snoopy Corner". This is typically for several weeks,
in all weather, including gale force winds.
Sometimes, a few things happened which resulted in amusing pictures or stories,
such as countering human-intervention, or testing the wheels for Snoopy's trolly.
Click on the pictures either side for larger versions, or visit earlier blogs above.
BlogX, the "blog of experiments", shows ideas and products, some of which may appear
in future boats.
This is a record of repairs and changes made to the new boat, during many weeks of testing on Bray Lake in 2013, until October 2013.
Wednesday 13th February: First sail: keel bulb needed more lead (from 2.2kg to normal marblehead 3.7kg). Total 12.3kg.
Friday 15th February: completed Bray Lake Test. Started 24/7 tests, left in Snoopy Corner of Bray Lake.
18th Feb: Monday's "minor repairs" included fixing the FM Transmitter (FM Tx) which now works, if you are within about 100 yards, and tune an FM radio into about 97MHz. You may just hear the computer speaking things like "at waypoint", "125 degrees", "right 45", etc. Also the rudder servo creaking, and waves splashing on the boat :-) A switch cover, based on the top of a lemonade bottle, now protects the on/off switch. This is now documented on the design page. The eye on the deck, where the main sail is tied, was strengthened.
20th Feb: Wednesday's repairs were: re-tieing the string that had come loose, from mainsail to deck;
strengthening the join between rudder and it's shaft by drilling and lacing with string, before coating in fastglass resin;
glueing the on/off switch cover back on.
Sunday 24th February: Snoopy started to wander overnight, then ended up on the south bank - probably due to main 5v power having dropped to below 4v. Met site showed wind greater than 6mph all night. FM Transmitter was removed and Snoopy was re-launched at 10am Sunday, in hope that sun appears later, to charge his 5v battery. The FM Transmitter was removed, in case it had contributed to power loss - although that seems unlikely: tests at home confirmed little extra power is drawn by it. The 5v 10AH supply had been fully charged before testing started on 13 Feb. Typical average power drawn is 70 or 80mA. i.e. from 10AH that's 125 hours or 5 days. Last day of some sunshine was 7 days ago. Expected to remain dull :-(
Monday 25th February: Battery Booster added at 1115am based on 2000mAH 5v pack, a diode, and 1 ohm of resistors in series.
Main 5v had been 2.19v and rose to over 4.54v within 5 minutes. Boat re-launched onto 24/7 at 1125am.
After delivering it's 2AH of power, the diode prevents this booster battery taking power. This is a better
way of investigating the solar power than re-charging the main 10AH battery. Here's hoping for sunshine ! :-)
GLUE TEST STARTED: Three "glues" that have coped well in the past year of 24/7 tests on Bray Lake are: Wickes Silicon Sealant,
Fast Glass Resin, and Duck Tape :-) The silicon sealant seems to have stuck well to pretty well everything - but not to the
recent plastic lunchbox. e.g. where the lemonade bottle top protects the on/off switch. I've started a test, with bits of
lemonade bottle, glued to the same type of box, with every type of glue I can easily find: Those above, plus UHU, Evostick
Serious Glue, Araldite, Wickes Solvent Cement, ZAP super glue, Extreme Power Glue, Heat Gun glue, etc, etc. Yes - I know some will not give good results ! :-)
RESULTS OF GLUE TEST: Only the hot glue worked at all. All the rest came off the polypropylene ADDIS Clip & Close box straight away.
Wednesday 27 Feb: Snoopy brought home to diagnose why autopilot did not work,
after connecting a new booster battery. Problem quickly diagnosed as faulty
contact on standard Futaba servo connector. Any connector is now the weak link.
Solution was to bi-pass connector with a direct, soldered, connection.
While at home, the main 5v 10AH battery was re-charged (4A for 2.5 hours),
and heat-glue used to glue the lemonade bottle top over the on/off switch.
The SPOT timer was also reset to "press" [ON] at 29 minutes past the hour.
Last night, Snoopy had started to wander, all over the lake. This could
have been partly due to the servo connection, but was more probably due
to the expected loss of power. At 1030am the main power (with solar panels)
was flat at 3.1v, and the flat booster was 0v. This 2AH booster had kept the
boat working for about 37 hours, instead of the calculated 25 hours (80mA, 2AH).
The extra 12 hours may have been a contribution from the solar panels in dull conditions.
Re-launch onto 24/7 was at 2pm - and the sun came out :-)
At 3:31pm on Thursday 28th February, the SPOT system gave an unexplained
bad position,
near an Equestrian Centre,
about 0.7 miles / 1.1 km south of where Snoopy was. Accuracy is normally nearer 5 metres.
This is what was put on our front page...
Horse snatches boat ! The SPOT tracker 3:31pm position report shows Snoopy,
on the other side of the main Windsor Road, in a field near the Equestrian Centre.
We are unreliably informed that a horse was seen swimming out into the lake,
ridden by someone wearing a wetsuit. After coming ashore, with the boat,
they galloped off, away from Bray Lake Watersports. The next position report,
at 4:30pm, shows Snoopy back on the lake. It seems
they rode quickly back and returned Snoopy to his 24/7 tests.
Don't believe me ? Click on the
SPOT map or
the horse.
Of course - it could have been a rare error in the GPS position report :-)
Sunday 3rd March: Snoopy got stuck in ice, from 1030pm until 1130am, after
the lake froze over. He then freed himself, without help, after the wind came back up. The SPOT tracking showed Snoopy straying
from the 24/7 position to where he got stuck by 1030pm Saturday. He was still
there until late Sunday morning. The ice had been broken by then,
by Bray Lake staff having sped around the lake in their RIB. The static position
shows GPS tracking errors to be typically 5 metres, occasionally up to 25 metres.
Tuesday 5th March: Snoopy got stuck in ice again, 4am - 11am, after
the lake froze. Snoopy freed himself, without help, when the ice melted,
despite very little wind.
Temporary ice like this helps: it starts to form near the shore,
and prevents Snoopy drifting closer and being tangled in trees.
Wednesday 6th March: Snoopy pushed out at 10:15am after wandering in light wind then snagging a tree on west bank.
Thursday 7th March: Snoopy pushed out at 10am from north bank, in still conditions, after wandering
in night and arriving near west bank at about midnight. Power systems checked and all OK:
Autopilot: 5.09v, SPOT: 3.76v, Light 2.56v.
Monday 11th March: NE Wind very strong, at 20 gusting to 35mph. Snoopy pushed out from west bank at 915am and 10am.
Just keeping 24/7 station, leaning by 45 to 60 degrees when making turns.
Tuesday 12th March: Pushed out after rescue and power check, covered in ice. Main power low at 4.36v but may survive the night
because it was sunny. Main 4.36v, SPOT 3.89v, Lamp 2.66v. The ice makes sails stiff, but seems to function OK. A branch, from tree on shore, was in gap between keel and rudder,
and may have contributed to power loss due to a stalled rudder servo. Click on the picture to see Snoopy covered in ice !
Thursday 14th March 8pm: Snoopy started to wander, when the wind dropped, at 935pm Wednesday. He then wandered east, to the other end of the lake, and got close to the east bank by 0235am. However, ice near the edge, stopped him getting closer, with risk of getting stuck. He broke free, when the wind picked up, and parked near the clubhouse after 1036am. He was re-launched from Snoopy Corner at 230pm after checking batteries: Main 5v power was low at 4.69v, despite several days of sunshine. SPOT OK at 3.78v and Lamp at 2.76v. Drifted to north bank after 530pm.
Friday 15th March: Snoopy spent Thursday night near north bank, after drifting there before 636pm. Without help(?),
he started to drift out before 0737am this morning, and was near his 24/7 waypoint by 0836am.
630pm Saturday 16th March: Snoopy hit west bank after midnight, where he spent the night, snagged in a tree. Sailed back out before 0937 without assistance. Strong winds were from south at 20 gusting to 35 mph. Snoopy was still on 24/7 duty at 2pm, and was joined by his twin brother, sailing the windmill boat. This little boat was collected after his battery went flat, but before the gate was shut for the night.
Sunday 17th March: Snoopy wandered to north bank, when wind dropped, before 0437am,
but, without help, sailed out again before 0638.
Wandered south when wind dropped at about 3pm, but then returned to 24/7 position.
Monday 18th March: Snoopy wandered when the wind dropped, after 2am, but returned about 6am.
Tuesday 19th March: Snoopy has wandered up to 200 metres from his 24/7 position
when the wind dropped to below 1 or 2 mph. Last push-out was on 14th March.
Thursday 21st March: Snoopy still holding his 24/7 position well.
Last push-out was on 14th March. Last repairs were on 27th February:
re-charging main battery and fixing a bad connector.... etc.
Thursday 21st March, 1pm: This Saturday 23rd March looks good for the attempt, being dry,
and with wind expected to be from the east for the best part of a week. Robin brought Snoopy home this morning,
from Bray Lake, to check him out, top-up his 5v battery, and prepare him for the launch.
The SPOT map link above will show his movement from Bray Lake, to Sunninghill,
then - on Saturday morning - his trip down to Barton-on-Sea near Bournmouth, for launch late morning.
More detail on tests done at home: everything was working, and no significant repairs or changes are needed.
The boat could be launched "as is" but minor changes below are being done - very carefully ! :-)
Main 5v power was low, at about 5v in shade and 5.37v in weak sun - but it has been high enough
to keep the autopilot running all night. This 10AH NiMH battery was re-charged at 5A (for over 30 minutes
before charger auto-switched to trickle charge). SPOT power was good at 3.87v and
the solar lamp at 2.65v.
There was less than an egg cup full of water in the lunchbox - possibly due
to some having crept up the rudder post. Has been re-greased, top and bottom.
Will add duck tape around lid, in case the seal was source of leak.
The main sail had a slight fold near the bottom, where it meets the mast, and was tightened at the top.
The rear stay was also tightened.
The SPOT Timer was reset at 60 secs before 1330, so that position reports should now be given
closer to 30 minutes past each hour (when the boat has a good view of the sky and satellites).
A manual transmission was also initiated at the same time.
Low temperatures of near freezing, meant that the timer lost about 11 minutes in 22 days,
since the picaxe based timer is temperature-dependent. i.e. the reporting has run slow
by about 30 seconds each day. However, in the higher temperatures expected over the sea,
of 10C/50F or more,
the timer is expected to remain more accurate. This was the temperature at which the timer software was adjusted.
Friday 22nd March: the picture on the right shows the open lunchbox, with extra grease around
the top of the rudder post, and a few blobs of heat glue to keep all the items in place,
including the GPS logger and SPOT tracker.
Click on the picture for a bigger version.
During over four weeks of 24/7 testing,
the lid had simply been clipped into place, relying on the waterproof seal.
However, before clipping the lid back on, the seal was smeared with clear silicon sealant.
PVC tape was then stretched around the top of the box, over the clips.
This was then followed by a strip of white duck tape. Finally, this was smeared
with more silicon sealant. This should stop any water that gets into the box getting out again :-)
Tuesday 26th March (after Snoopy's failed attempt on 23rd March) :
On our
front page we said:
"The damage sustained to Snoopy's new boat was minor, and, with hind sight now,
we could have re-launched him then. However, it was wise to bring him home,
to be absolutely sure. We will use the opportunity to tighten up the jib, that had loosened a bit;
to tighten up the lever by which the servo turns the rudder;
and to stick a bit of plastic trim back onto the navigation light.
We may even have time to put a lick of paint onto the rudder and the bottom of the keel,
which had remained unpainted since being mended weeks ago ! "
We've done all this, although the main 5v battery is still being tested *. There is now white paint
on the very bottom of the keel, and on the rudder repair - to which a bit more fast-glass was added.
The most significant change is the finger from a rubber glove, now attempting to completely
seal the top of the rudder post - in case any water had got in there in the past.
Elastic bands and then heat glue fixes the ends. The rudder post was re-greased and there is no friction at all.
* It looks as if one cell, in the 4-cell Main 5v pack, has failed during the weeks of 24/7 testing. Click on the right hand picture to see the discharge graph in more detail. The battery still functions, but will do much better if we replace the faulty cell. I have a spare cell, but have ordered four more, so we can replace the whole battery. We will know for sure when the pack is dug out of the bottom of the hull !
Wednesday 27th March: The boat was put outside at 0715, to gather a little light from the brighter sky we have today,
and charge up the SPOT and Lamp batteries that are being monitored. After over two days indoors, they had dropped
to 3.61v (OK) and 1.54v (Low) by 0715 this morning, but by 1030am had risen to 3.69v (OK) & 2.62v (OK).
The main battery, disconnected from it's solar panels, had dropped to 4.04v over night, confirming just one cell is dead.
I will soon be carefully removing at least one solar panel assemby and digging out the 5v battery to replace or repair.
1pm Wednesday: The whole process, of digging out the faulty battery, took less than an hour, and confirmed that only one cell was completely dead - just 0.004v,
when the other three were nearer 1.3v, above the nominal 1.2v. I took lots of pictures, for my records, but here is the last:
click on it to see it full size.
You can see some of the tools used : such as the meter, and those on the floor. But you may not see the most important ones: one of June's
kitchen knives, used to cut the silicon sealant holding the solar panel to the deck; also the kitchen "baster" (glass tube with rubber
squeezy thing on end, used to squirt hot fat over meat in the oven) - used to suck maybe an egg cup full of water from bottom of hull.
You can see the pint beer glass for the water. Maybe the most important tool: a pin from her sewing box (rarely used by her in over 40 years),
used to probe into the battery, through it's sealant covering.
There are two ancient sayings: 1) "the bad workman blames his tools." and 2) "use the right tool for the job". I prefer the latter ! :-)
You can see the spare cell, still holding 1.27v from when it was purchased. I'll update this page after I've replaced the dead cell.
3pm Wednesday: the battery is now fixed, back in the boat, on charge, and foam has been squirted in, to expand and set overnight.
I took lots of pictures again, at every stage, and this was the last. If you click on it to see it better, you may see the foam stain
on my shirt, from a similar operation years ago. Why throw away a good shirt ? When using this squirty foam for the second time,
unblock the nozzle BEFORE you press the trigger. I forgot this again, and foam shot all over the place. It's very sticky. This picture
was taken after I'd cleared up the mess. After using a huge soldering iron to swap the bad cell for a good one, I saw the voltage was
already 5.24v - nicely above the nominal 4.8v. This time I used heat-glue, instead of silicon sealant, to fix the four cells together,
and to protect any soldered contacts from water and erosion. A sandwich bag, raided from a kitchen cupboard, was used as another
layer of protection, sealed with knicker elastic and then duck tape.
The mended battery is now in the bottom of the boat again, wired into the system, and on charge to top it up completely. I considered replacing the
battery completely, using the new cells ordered yesterday. However, after inspecting these more closely, I decided I'd rather
have an extra one or two days of testing.
I see the expanding foam is now well above the deck, and should be ready tomorrow morning. I'll then cut it flush, smear the deck with
silicon sealant, and use this to stick back down the solar panel assembly. The boat should be ready the next day.
5pm Wednesday. Autopilot switched on to test main 5v battery without solar power (panels covered). See start of blog, above,
at Sunday 24th February: maybe this cell was bad near the start ? 5.43v at 5pm, when switched on.
Thursday 28th March: The mended 5v 10AH battery looks good: more later. By an amazing coincidence,
which has been a stroke of luck, the same fault, of a cell going short-circuit, seems to have
happened to one of the pack of four Extreme cells that were delivered by Royal Mail this morning.
The parcel was hot to touch, and at first I thought it was where the parcel was kept by Mr Postman.
But, when I opened the two blister packs, I found three cells perfect, at 1.26v, and one,
still very hot to touch, with no voltage at all. The heat has damaged it's plastic sleeve.
Maybe this is the explanation for that cell failing in the boat ? Spontaneous failure
due to a rogue cell slipping through the "quality control" in China ? I'm still very happy with
the UK supplier, and will try and contact him to learn more (see later). e.g. place of manufacture.
I was begining to think our failed cell might have been the result of soldering,
rather than welding the cells together. Maybe we will add a small welded pack,
in parallel with the main 10A pack, now deep in the hull. i.e. like our main 5v power on the
boat that sailed in November. Having said all that, it was good to see that our autopilot
can continue to function, including through the night, when one of it's four cells has failed.
If more failed, it would only steer the boat during the day, powered by the solar panels.
The mended 5v battery, now buried below foam in the hull, performed well over night,
only dropping to 5.1v by 0915, while powering the Autopilot without solar power.
5pm: The solar panel was been put back on, by 11am, using silicon sealant (after screws & hot glue).
The boat was put outside at 1420, with the autopilot running, and main 5v power at 5.06v. The
solar panels soon charged the 5v battery to 5.14v under a dull sky, and with weak sun, by 1635 was 5.15v.
The SPOT was 3.69v (OK) and Lamp 2.58v (OK). The SPOT timer was reset at 1639 to report at 40 minutes past the hour,
in anticipation of a 1240pm launch Saturday.
7pm: I've now spoken to the UK supplier of the "Extreme" brand of 11,000mAH cell, and he confirmed
these cells are shipped to him from Shenzhen, China, after adding his labels.
I've ordered yet another four cells, for longer term testing, to see if this
product can be relied upon in the future, after rejecting faulty ones.
Interestingly, the supplier of this "Extreme" brand of battery is in Plymouth, UK
- but they do not have a replica of The Mayflower moored nearby :-)
TESTS AND REPAIRS AFTER SNOOPY'S "TUMBLE TEST" AT BARTON-ON-SEA ON SATURDAY 30th MARCH
Sunday 31st March: Perhaps "tumble test" is a good term for what Snoopy has been subjected to
on the two recent attempts to get beyond the breaking surf due to high waves.
Watch the video by clicking on this small picture if you have any doubts. The most significant strain will be
on the rudder servo, when the boat is being pushed backwards through the pebbles,
with the rudder acting as a plough. All the water seals will also be "challenged".
A good egg cup full of water had made it's way into the lunchbox (via the lid?),
but all parts should be protected, within the box.
Voltage tests are all good : Main Autopilot 5v (switched off): 5.28v (OK); SPOT 3.68v (OK); Lamp 2.47v (OK).
Solar Navigation Lamp was flickering when dark last night: water may have reached the electronics.
Rudder Servo: gears were stripped this time, because when switched on you hear the motor spin.
the old servo was taken out and a new one prepared: four screws tightened and coated with
clear silicon sealant. Note that the servo wires must be soldered, so not as to rely on the standard futaba
plug and socket.
SPOT tracker: this stopped automatic reports after Boscombe at 3:41 pm. i.e. well after the "tumble test".
Maybe some water got into the extra box protecting the picaxe based spot timer, but took time to do it's evil work ?
The SPOT Timer was reset, by unplugging then plugging it it's power, at 503pm, and that restarted it.
The SPOT Timer box was opened and no moisture seen inside. Reliability of the Futaba plug and socket ?
The Autopilot picaxe computer still works when switched on.
The I-GotU GPS logger is still working (blue light flashes) and has not been switched off.
Tuesday 2nd April: The PCB inside the solar lamp was swapped for that from a new one (Homebase £7).
It was varnished before reassembling the whole lamp unit, using silicon sealant as glue.
This was after discovering corrosion was causing the solar lamp to be unreliable. e.g. tracks shorted by residue.
This corrosion was due to moisture, from weeks of testing on Bray Lake - not only sea tests.
The SPOT messenger and picaxe based timer were OK, but it seems moisture had corroded the futaba servo connectors.
This is what had stopped the SPOT position reports.
The solution was a combination of direct wiring and duplicated connectors.
Direct wiring to SPOT 3.6v power is via a normally closed push button switch, instead
of Futaba connectors, used when resetting the timer.
The picaxe spot timer box was filled with candle wax. Click on these two little pictures, to see bigger versions.
Monday 8th April: ANOTHER MAIN BATTERY EXTREME CELL SPONTANEOUS FAILURE: The boat has been sat indoors for days,
with SPOT tracker running but autopilot switched off. There have been regular voltage checks on the three power
systems: Main Autopilot 5v supply, typically 5.3v; SPOT tracker, typically 3.7v; Lamp, typically 2.6v.
This morning the main 5v supply was only 4.15v, and when switched on, dropped to about 3.7v. This is almost
certainly due to yet another Extreme cell having spontaneously failed - the third case - see Thursday 28th March above.
It is clear that we cannot rely on this battery product, since a similar failure in the SPOT tracker power
would be even more disasterous than in the autopilot. It would not be wise to simply rely on alternative brands of
these 10,000mAH cells, since they probably all originate from the same sources in China. The most significant
pointer to reliability (or lack of it) is the fact that you cannot find these battery products in the shops.
I'm told that the main manufacturers of NiMH cells attempted to produce high capacity cells, but they did
not survive in the marketplace, because the higher capacity needed thinner internal membranes,
which resulted in reduced reliability. i.e. they were prone to internal short-circuit failure.
Conclusion ? To rebuild the Main 5v and SPOT 3.6v NiMH power units by use of duplicated, lower capacity cells
or welded packs, as has been done with earlier boats. Lesson learned ? Robin should follow his own rules,
and use mass-market, well-tested, products - rather than be tempted by what looks like a better product on paper ! :-)
Tuesday 9th April: The faulty Extreme 5v battery was removed: a second cell HAD gone short-circuit. The principle of duplication, with different types and brand of batteries on two sides was used: For main 5v power, one side is 4 x Dyna-fun 3300mA, and other side is 4 x GP 3700mAH (duplicated in parallel), so total capacity is 10,070mAH. Wires are fed out from both sides, and the batteries - in plastic sandwich bags - covered in squirty foam. For the SPOT 3.6v supply, the existing (untrusted) 3 x Extreme 10,000mAH were left deep in hull, but duplication is provided by 3 x Panasonic 2400mAH AA cells inside the lunchbox. The duplicated batteries will be wired inside the lunchbox to split solar panels, and diodes used to bring the duplicate power sources together. i.e. a failure on one side, including a short-circuit cell, should allow full voltage to be maintained.
Wednesday 10th April: wiring completed inside lunchbox, including diodes (triplicated with different products) on both sides of duplicated
batteries for SPOT and Main 5v power. i.e. 12 diodes in total. LHS main solar panel fixed back down with screws and silicon sealant.
Thursday 11th April: The problem in using diodes to isolate the duplicated batteries, is the forward voltage drop of typically 0.7v.
The practical result of this is that the Autopilot would only get 4.1v when the battery charge drops to 4.8v. A fully charged battery,
at maybe 5.2v, would only provide 4.5v. The same applies to the SPOT power: 3.7v reduced to 3.0v. After testing a mixed pack of 100 diodes,
most measured typically 0.69v, some power diodes gave 0.56v, but one - the Philips BYV20_45 only dropped 0.27v - giving an increase in 0.4v.
i.e. if we used this product, the main supply would fully charge to nearer 4.9v (if 5.2v on battery) and 4.5v (4.8v). The SPOT supply
would be 3.7v reduced to 3.4v, instead of 3.0v. Specifications for the BYV20_45 only claim 0.5v, but this is probably cautious, at a much
higher current than the < 100mA drawn by the autopilot. The two samples tested, were from different bags, and gave the same low forward voltage.
Maplins only stock this product in the mixed bag, but some will be ordered elsewhere, if a source can be found.
Meanwhile, 24/7 testing continues, using the 0.7v diodes already fitted.
Friday 12th April: Two Philips diodes were soldered into the main 5v supply, raising it from 4.38v to 4.78v. Thanks to Nuno for
finding these
Vishay TMiniP2-F2-B Diodes from RS.
I've ordered 10 at less than 10 GBP to confirm they provide an even lower voltage drop. Meanwhile 24/7 testing continues at home.
Monday 15th April: the Vishay diodes arrived and were smaller than expected. However, after careful soldering with a small iron,
the diode still worked, and I can confirm the forward voltage drop is only 0.18v. i.e. a gain of 0.5v. 24/7 testing
continues with the Philips product, despite it dropping 0.1v more.
Friday 18th April: two 5v batteries connected in parallel to simplify monitoring. Off to Sicily for 2 weeks holiday :-)
Sunday 19th May: SPOT tracker and Autopilot have run OK, although main 5v power seems low: often below 4v and only just enough to keep autopilot running. The deliberate short between duplicated 5v batteries was removed and the two sides of the duplicated system will be monitored. Currently 4.82v and 5.24v resulting in 4.99v after diodes.
Sunday 26th May: Still under 24/7 test in garden. SPOT OK at 3.19v with position reports reliable, every hour,
but 15 minute delays typical due to fact that there are now leaves on the trees, screening the signals.
Solar lamp had stopped working: traced to broken connection, probably due to corrosion; soldered and re-assembled.
Duplicated 5v supply: Autopilot still running 24/7 but with main 5v power dropping to typically 3.65v by morning.
Traced to probable fault with one battery (s/c cell?) but not "Extreme" brand - no longer used in main supply.
It's clear that half the system - just 4 solar panels - are JUST enough to keep the autopilot running in summer.
A small 2000mAH pack was added inside the lunchbox, and soldered in to replace the failed pack deep inside the hull.
Boat put back into the garden to continue it's 24/7 testing.
Friday 31st May: original lamp was still intermitant, so built a complete replacement, from the usual parts including those from the £7 Homebase "bright solar light", better 2000mAH AA NiMH cells, plastic beer glass, and 130mmx130mm solar panel. Minor changes in construction included use of heat glue before clear silicon sealant. The old lamp, now removed, was then repaired - corroded diode replaced - and put on test, in case it is used as a "spare" in future.
Wednesday 6th June: One of the (duplicated) SPOT 3.6v NiMH batteries needs replacing: the one "Extreme" pack still used (see earlier notes on this product). This failure probably happened weeks ago, and I was pleased to see that the SPOT system had continued to work. I then saw that the transmissions were often every 1.25 hour, instead of every hour - not due to "leaves on the trees" - but the result of this failure. The SPOT Messenger succeeded - with only 3v or less - to get it's position report out, switching on for the usual 15 minutes (and increasing current drawn from about 1mA to nearer 80mA). This increased current drain, pulled the (weakening) battery voltage down, below that at which the picaxe timer would work. When SPOT stopped it's 15 minute transmission, the voltage would rise enough for the PICAXE to work, and an hour later, it started another transmission. The result: as intended, weakening SPOT power results in slower position reporting - telling us what happened and reducing SPOT power consumption. New SPOT battery, made from three "AA Energizer ACCU POWER PLUS 3x" (not 6x) 2000mAH NiMH cells soldered inside lunchbox, and wire from bad "Extreme" pack snipped. Supply (after diodes) rose to 3.5v and regular SPOT transmissions resumed at about 29 minutes past each hour.
Friday 14th June: Snoopy was pining for Bray Lake, so he was given a test sail, around the usual "Bray Lake Test" waypoints, in a southerly wind of about 15 to 20mph. As expected, he took ages (45 mins?) to reach the first waypoint, almost directly upwind, but then returned much faster, within maybe 15 minutes, and within a metre of his base. He was then put on 24/7 test, in "Snoopy Corner". The plastic pipe "T-piece", used as an alternative to a "kicking strap" (to hold the main sail boom down), seemed a "good idea at the time", when the boat was built in January. However, this had stiffened up, and it was decided to simply unplug the main boom, and rely on the string. i.e. the boom is allowed to be pulled up by wind on the sail.
Thursday 20th June: The SPOT tracker stopped reporting after 837pm 19th June.
A note was added to front page: "* SPOT map updates expected to resume again soon, after SPOT Support Desk complete an account change."
The problem is thought to be Robin giving the wrong ESN to the SPOT Support desk, to swap air time,
from the SPOT tracker lost at sea in boat 8, to a "new" spare. It's thought they swapped with that in boat 9.
The Support Desk normally take a few days to respond, but it is hoped this will be fixed soon.
In total, Robin has purchased four SPOT Messengers, identified by their ESN:
1. ESN 0-7485929 - the first; from Steve; 17th April 2012. Eventually failed with a red flashing light.
2. ESN 0-7384707 - from Pete; 19th May 2012; put into boat 8; Lost at sea in November 2012.
3. ESN 0-7379137 - from Simon; 1st August 2012; put into boat 9 in January 2013.
4. ESN 0-7368026 - from Paul; 14th April 2013; spare; swap air time with 2 ?
Saturday 22nd June: Snoopy brought back home after collecting him from Bray Lake. We went over to check him,
since we are still waiting for the tracker to be put right. Snoopy had come to the bank, just a few hours
earlier - according to a fisherman. The reason was his sails being loose: the mainsail boom had come away,
and also, the string which tied the jib to the deck had broken (see picture on right). This was obviously due to wear, after
several months of continuous sailing on 24/7, including more than average "fluttering" due to making
way upwind to the 24/7 waypoint. It's about time his rig was given an "overhaul" !
Thursday 27th June: The SPOT Service Desk corrected the problem, after the expected week's delay, and last night tracking resumed. The tracker on the boat now works again, and we have a spare SPOT tracker - for next year's boat ? :-) The rig was rebuilt, removing all the old string, replacing it with new, and also three quick links where the strings meet the deck. See picture left for the link for the jib. I used the "SECURIT 3mm Quick Link Ref S5679" from a local hardware store. This is zinc plated (galvanised) steel, and should be plenty thick enough for a few months wear and tear. It was smeared with silicon sealant, to reduce the ammount of movement and consequent "rubbing".
Sunday 30th June: Snoopy holding his 24/7 position well, but timing of SPOT transmissions show that voltage is running low: e.g. 0445, 0545, 0700, 0800, 0901, 1000. i.e. slipped 15 minutes at 0645. It is sunny today, so will be interesting to see if we get same problem in early hours of tomorrow, or if the SPOT batteries have re-charged sufficiently.
Monday 1st July: SPOT voltage continued to run low - indicated by times of: 2100, 2200, 2301, 0016,
0130, 0245, 0400, 0515, 0631, 0739, 0839, 0939, etc. Snoopy brought home from Bray Lake to be checked:
both sides of duplicated SPOT power OK, but low, at 3.77v & 3.54v giving 3.29v after diodes.
Main 5v power good at 5.63v and solar lamp good at 2.82v. Seems that the existing two small solar cells
are barely enough to keep SPOT working for months. An extra power source was added to take most
of the 20mA from the main 5v supply as a "trickle" from a diode (two in parallel) in series
with 65 ohm resistor (three 220 ohm in parallel). 18.5mA was seen from this source.
An extra quick link was inserted, to allow the main sail boom to be let out to nearer 40 degrees from centre.
Snoopy was returned to Bray Lake and completed "the Bray Lake test" in about 1.3 hours - the first hour being
the upwind part to waypoint B. Snoopy was then put back on 24/7 test.
Friday 5th July: Snoopy wandered to bank by 0242am, when the wind dropped below 1mph, but by 0943 he had freed himself, and was back towards his 24/7 waypoint. However, in very slack "wind", Snoopy drifted in to the west bank by 1143. Robin managed to reach him with a long pole, and pushed him out at 1330. He eventually reached the 24/7 waypoint by 1440, but is expected to wander when it becomes even calmer tonight.
Sunday 7th July: drifted in to south bank by 0345 when wind dropped to about 1mph. Put back onto 24/7 test at about 1345 after checking out and fixing rudder servo linkage: had probably come off during the first rescue. Voltages were all good at Main: 5.29v; SPOT: 3.65v; Lamp: 2.52v. Boat 6 also visited Bray Lake and had a test sail in the calm conditions. 6pm update: Snoopy hit the island again, before 4:47pm. Looks like he will need to come home for a more thorough check-out ! See below for the picture of Snoopy among many friends on Bray Lake.
Monday 8th July: Lots of wandering, ending up on the island, and in wind of above 5mph, was traced
to the rudder-servo linkage having come off again. The boat was brought home and the linkage replaced
by a simpler double Z link seen here in the picture. It was easy to remove the "rumples" in the main sail,
simply by adding a small (split) plastic tube spacer, above the main mast-boom pivot.
Snoopy did the Bray Lake Test in less than an hour, and was then put back on 24/7 test.
Last night, when the boat was beached on the island, we got a "rogue" SPOT position
on the bank near the club house. i.e. very much like the "horse incident" back in February :-)
I saw that Snoopy had drifted to the south bank
soon after 5pm, and went over to Bray Lake to check him out. The wind had been steady at about 9mph
from the North-East, and this was unexpected. After Alex rescued him there was a BIG surprise:
the lunch box, well above the waterline, was practically full of water, within an inch of the lid.
This is why much of the electronics - particularly the rudder servo, were not working.
It would have been a major mystery - if it were not for Snoopy. He is normally stood
proudly at the front. But NOW he was broken off and INSIDE the lunchbox.
Many Thanks whoever put him there - he can easily be glued back together
- and it does rule out "natural causes" :-)
I have spares for most bits
that fail to work after being dried out, but it would be good to know
what happened. Maybe an accident ? Kids in canoes are often seen playing with Snoopy.
Don't worry, nobody will "get into trouble", but it will help us a lot to know what happened,
and do what we can to avoid it happening again.
The only part that was lost is the I-GotU and it's cable: see "REWARD" below ;-)
The I-GotU was not expensive when purchased, and has almost no value second-hand, without
original packaging, software, etc. BUT the GPS data in it, has great value to Robin. It has been
recording many months of Snoopy's 24/7 testing since February 2013.
Friday 12th July: The bad news is that Maplins are out of stock of that I-GotU GPS logger,
needed to comply with the Microtransat Rules. I've asked for the rules to be relaxed,
but this seems unlikely this year. I've spoken to the manufacturer in China,
but it could take time to get a new one. It would certainly take many weeks,
or more, to find and test an alternative. None of this was known yesterday,
and it makes it more important to contact the guys who took the I-GotU
out of it's box. The good news is that someone saw it happen, but the bad news
is that these two guys may be too embarassed to contact us, and may
already have thrown the tracker away. Don't be shy - I've done far worse things in my life :-)
Read the
I-Gotu Letter that I hand delivered to "C" at the correct address,
and we chatted on the doorstep. Names will only be added later if they want me to.
My letter was addressed to "S", who hired the boat, and went out with "D" from
1310 to 1410, when the incident happened. Later, between 1645 and 1745,
"S" went out again with "C". Robin looks forward to buying "S and D" a beer soon !
More information will be added, making sure everyone is happy about it :-)
Robin also has a useful extra item of "support equipment": a 10 metre long telescopic pole,
from
KitesUK.com
which is a much more effective and convenient tool to push Snoopy out, when he comes to
the shore at Bray Lake. Maybe we could even use it for sea launches ? :-)
Thursday 18th July: Click on lunchbox in new picture above right to see better new "We can see you ! :-)" sign, added today.
Monday 2nd September: Batteries re-charged again. It seems that, in my shady back garden, in a sunny August, the 5v power will run for
almost 1 week, before the power drops too low for the Autopilot. Last test was 6.7 days, with the autopilot stopping after 0400.
The system usually recovers by about 9am. The SPOT tracker sub system always has plenty of power, and reports reliably every hour.
Saturday 21st September: Snoopy on boat 9 still waiting at home for weather window. Meanwhile, see
Compass-Steering experiments for possible use in the next boat ? :-)
ATLANTIC ATTEMPT ON FRIDAY 11 OCTOBER 2013: Full details on the page:
October 2013 Atlantic Attempt. Snoopy was rescued and is back home in Sunninghill.
Thursday 17th October: this blog page will be updated with the details of tests, repairs, and design changes,
to give Snoopy a better chance of success on his next attempt, expected before Christmas. An important part of this
process will be repeated tests on Bray Lake, to try and uncover steering problems, including in strong wind.
Then testing of changes, such as adjustment of the sails and/or software steering logic. Then 24/7 testing to
give confidence in reliability.
© 1991-2014 Robin Lovelock. Please credit www.gpss.co.uk if you use material from any of these pages. Thankyou.
Tuesday 9th July: INCIDENT ON BRAY LAKE
Were you there that day ? Please read on ...
Robin is happy to pay a reward to anyone who manages to find that missing I-GotU,
that may have floated to the shore - but it must be that same I-GotU unit, with the data inside it.
If done soon, Robin will not need to buy a new one - but it is the GPS data he is interested in.
You can either hand the I-GotU in to the Bray Lake Clubhouse, or contact Robin direct in any way you like,
including his home on 01344 620775, mobile 07736 353 404, or email on Robin's
contact page. Don't worry if you took the I-GotU out of Snoopy's
lunchbox, and that's how water got in:
Robin may give a bigger reward to you ;-)
Wednesday 10th July: After drying out at home, all of Snoopy's electronics seem to be working perfectly,
but we will keep him here, in case modifications are needed.
Thursday 11th July: Snoopy is at home being tested, and almost ready to resume 24/7 tests on Bray Lake.
The unplanned "incident" had several unexpected benifits. e.g. the electronics were given a
"total water immersion" test lasting several hours - and survived. Candle wax was poured into
the picaxe container, like that in the SPOT timer, at the bottom, which continued to work well.
Our less widely known "support system" also proved it's worth, and I'm looking forward
to chatting to the guys who "found" the I-GotU soon, as we did to the schoolboys last year,
who took Snoopy's boat home. These lads were given a handsome reward, but not for
finding the boat - it was for their advice on things like the "I am tracked" sign ;-)
Then, later in the year, that same boat was snatched at sea.
Robin's open letter to "Mr Snoopy-Snatcher"
was written before we found out "who dun it", but I'm sure you can guess
- see that picture of the Royal Marines LCU ship on the horizon ;-)
Tuesday 16th July: Snoopy is being 24/7 re-tested at home and one of Robin's (many) CCTV cameras
are proving more valuable for this than expected. e.g. in the hours when it is dark, the SPOT
flashing lights can be seen, including the long flash with the [OK] button is "pressed"
to begin a transmission sequence. i.e. we can watch any drift of the spot timer. More important
is the pattern of rudder movement, every few seconds. e.g. any autopilot problems
due to main solar power falling low in the hours before dawn.
Sunday 28th July: CCTV shows autopilot lost it's normal 7sec cycle to 1sec at 1849 then stopped at 2130. Restarted at 0930. Power OK 5v.
Monday 29th July: 7sec cycle lost at 0050. Only 3.12v at 0715. Ok at 0800 4.55v. Was cloudy. Solar power marginal in shady garden ?
Tuesday 30th: 7sec lost@0445 (sun helped). 3.2v@0715 & 0930. Cloudy. OK again at 1110. 3.8v@1130. 4.69v@6pm. Lost@1940. 3.4v@8pm.
Wednesday 7th August: tests seem to confirm solar power is marginal in the (shaded) back garden. Depends upon how much sun the
previous day, but Autopilot stops at night, anywhere between dusk and dawn, but usually starts early morning, between 8am and 10am.
By dawn, 5v power - needed by GPS, Picaxe and servo - has often dropped to 3.5v or even 2.2v. Both batteries recharged and
a battery test started at 1115am, with solar panels covered. If Autopilot takes average of 50mA, the system should run for 3 days +.
Friday 9th August: Stopped at midnight, after only 37 hours. i.e. Capacity less than half 4000mAH ? Only 2.5v @0700 but had restarted
in weak sun (towel taken off) by 0920. 4.74v. Taken indoors, swapped pack inside lunchbox for new "2600" r/c pack. Re-charged pack inside hull.
Started another test, with solar panels covered, at 1140.
Tuesday 13th August: soldered replacement battery into lunchbox, after snipping wires to degraded battery deep inside hull. New battery based
on 4xAA Maplin 2000mAH NiMHd cells. Old battery had degraded to below 800mAH, based on tests with solar panels covered. Test restarted at 10am.
Friday 6th September: SERVO FAILURE ? ! The servo used to control the rudder was replaced. This is an Acoms AS-17 servo, used in all the
boats for years. So far, all failures were after water ingress. Water seldom gets into the lunchbox, but before installing a servo, the four
screws are tightened, the case is smeared with silicon sealant, and the shaft at the top smeared with grease. The symptoms were the servo
moving too far anti-clockwise (left) and travelling to twice it's normal "full left" position. CCTV showed this starting to happen after 6pm
on Thursday, and adopting the "super-full left" position by 630pm. Robin noticed this by 730pm, and repeated restarts of the autopilot
did not clear the condition. The autopilot was turned off and checked today. At first it worked correctly when restarted,
but after an hour, the problem started to appear intermittently. Suspected fault: wear of the internal servo potentiometer. This particular
servo has been operating almost continuously for over 6 months. That's over 4,000 hours, or about 2 million servo operations - the
servo moves the rudder every 7 seconds. The servo was replaced, and the boat put on 24/7 test in garden by 1130am.
The boat is ready, but it's wise to continue 24/7 testing while waiting for the "weather window".
See the
Blog2 Page for progress after October 2013.
Snoopy's Bray Lake Test ... sail 530 metres automatically, through 5 waypoints ...
