modifying your HH primary

paulraymaekers · 3rd July 2006, 18:42

hello all,

I know I should not do it, but if no-one can help, I have to start myself!

related to the problems with the pressure sensor, not surfacing at the end of the dive, I modified my primary.

after the dive on saturday, salt water, very deep!! (16m:-) my unit that just recieved a new lens and pressure-sensor, did not surface (stayed at 3m)
5 minutes rincing with fresh water and 'sucking' and 'blowing' on the little hole, it surfaced and went to sleep..
second dive that day: exactly the same!

at the factory, I openend the HH, took out the pressere sensor and looked under microscope: in the silicon oil there was a drop of water 'embedded', and in that drop were little grains of sand!, this sand must have come trough the little hole..

changements:

1 I made the hole in the lens bigger
2 I placed a black rubber disc inside between lens and SS tube of the sensor, but so that it can move around a bit (this is to take away light from the sensor)
3 I drilled a 3.5mm hole in the coverplate, and smoothened the edges
4 I filled everything with silicon oil
5 when fitting lens and coverplate, I placed a small silicon membrane (thickness 0.3mm diameter 8mm) between lens and cover plate

when thightening (??) the cover-plate, I see the membrane become a bit 'spherical' as I press out the oil that was under membrene

starting the unit, I got 1005 mbar, looks ok

so what do I have now: a pressure chamber that transduces the pressure from outside to the sensor, but never any dirt can come in contact with the sensor, no dirt between coverplate and lens, no light on the sensor...

thursday testdiving the unit.... lets hope is works, but I have faith :-)
(can't be worse then last saturday)

regards
paul

PCDiver · 3rd July 2006, 23:05

Quote: (Originally Posted by paulraymaekers)

hello all,

I know I should not do it, but if no-one can help, I have to start myself!

related to the problems with the pressure sensor, not surfacing at the end of the dive, I modified my primary.

after the dive on saturday, salt water, very deep!! (16m:-) my unit that just recieved a new lens and pressure-sensor, did not surface (stayed at 3m)
5 minutes rincing with fresh water and 'sucking' and 'blowing' on the little hole, it surfaced and went to sleep..
second dive that day: exactly the same!

at the factory, I openend the HH, took out the pressere sensor and looked under microscope: in the silicon oil there was a drop of water 'embedded', and in that drop were little grains of sand!, this sand must have come trough the little hole..

changements:

1 I made the hole in the lens bigger
2 I placed a black rubber disc inside between lens and SS tube of the sensor, but so that it can move around a bit (this is to take away light from the sensor)
3 I drilled a 3.5mm hole in the coverplate, and smoothened the edges
4 I filled everything with silicon oil
5 when fitting lens and coverplate, I placed a small silicon membrane (thickness 0.3mm diameter 8mm) between lens and cover plate

when thightening (??) the cover-plate, I see the membrane become a bit 'spherical' as I press out the oil that was under membrene

starting the unit, I got 1005 mbar, looks ok

so what do I have now: a pressure chamber that transduces the pressure from outside to the sensor, but never any dirt can come in contact with the sensor, no dirt between coverplate and lens, no light on the sensor...

thursday testdiving the unit.... lets hope is works, but I have faith :-)
(can't be worse then last saturday)

regards
paul

nice idea Paul. Let us know how it goes.

BTW. Was the hole in the plastic bezel filled with silicone? When I replaced the depth sensor I filled the hole with some silicone. It was completely filled because it squirted out from the other side. That should prevent sand from getting through until the silicone is dissolved by the sea water.

Peter

paulraymaekers · 4th July 2006, 06:57

Quote: (Originally Posted by PCDiver)

nice idea Paul. Let us know how it goes.

BTW. Was the hole in the plastic bezel filled with silicone? When I replaced the depth sensor I filled the hole with some silicone. It was completely filled because it squirted out from the other side. That should prevent sand from getting through until the silicone is dissolved by the sea water.

Peter

peter, after filling the hole with silicone, how do you know there was no gas locked up between sensor and lens, was the O-ring in its 'most down' position??

during the first dive, any gas locked up will be compressed, and water will be pressed trough the little hole inside the chamber
also: the o-ring has quite some space: by pressurising the unit, the O-ring is pressed in its deepest position: this also makes water enter the small cavity

regards
paul

Drmike · 4th July 2006, 08:04

Quote: (Originally Posted by paulraymaekers)

peter, after filling the hole with silicone, how do you know there was no gas locked up between sensor and lens, was the O-ring in its 'most down' position??

He will know if the unit gives him the wrong deco and he dies or ends up peeing in a bag for the rest of his life. Is Silicon as compressible as water?

I would have thought this kind of mod should be done by, or at the very least approved by the factory -as it could have serious consequeces.

Tweak -tweak!....thud!

PCDiver · 4th July 2006, 08:39

Quote: (Originally Posted by Drmike)

He will know if the unit gives him the wrong deco and he dies or ends up peeing in a bag for the rest of his life. Is Silicon as compressible as water?

I would have thought this kind of mod should be done by, or at the very least approved by the factory -as it could have serious consequeces.

Tweak -tweak!....thud!

It was done per instructions from Kevin and Doug. I don't rely on the HH only, I use a VR3 as primary deco computer. So far, both the HH primary (if it works) and the HH secondary track depth identical to my VR3.
But I also have a Vision upgrade on order.

PCDiver · 4th July 2006, 08:43

Quote: (Originally Posted by paulraymaekers)

peter, after filling the hole with silicone, how do you know there was no gas locked up between sensor and lens, was the O-ring in its 'most down' position??

I removed the sensor (careful they get damaged easily) and filled the hole with silicone (provided by Juergensen Marine). Then I pushed the sensor in. The surplus silicone squirted out through the narrow end. It was done by the factory on my HH, but I had to replace the sensor since it was malfunctioning.

Drmike · 4th July 2006, 08:47

Quote: (Originally Posted by PCDiver)

It was done per instructions from Kevin and Doug. I don't rely on the HH only, I use a VR3 as primary deco computer. So far, both the HH primary (if it works) and the HH secondary track depth identical to my VR3.

But-but I thought the VR3 was as unreliable as the HH?

PCDiver · 4th July 2006, 09:00

Quote: (Originally Posted by Drmike)

But-but I thought the VR3 was as unreliable as the HH?

My brand new, 2 weeks old VR3, was very reliable - after it was repaired because of a full flooding on dive 5

.

What happened was that the port connector leaked. I had never used the port connector so it was probably not properly tightened down at the factory.

But I really like my VR3 now.

Only the OC bailout sucks.

Peter

paulraymaekers · 4th July 2006, 09:47

well, after my last trip, I've learned!!

left arm: HH primary AND cochran 20

right arm: VR3, and the most reliable unit: the scubapro bottomtimer!

(only missing a HS somewhere....)

regards
paul

J. V. · 11th July 2006, 11:08

Quote:

(only missing a HS somewhere....)

In Florida, since some weeks!

3rd July 2006, 18:42	#1 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,637	modifying your HH primary hello all, I know I should not do it, but if no-one can help, I have to start myself! related to the problems with the pressure sensor, not surfacing at the end of the dive, I modified my primary. after the dive on saturday, salt water, very deep!! (16m:-) my unit that just recieved a new lens and pressure-sensor, did not surface (stayed at 3m) 5 minutes rincing with fresh water and 'sucking' and 'blowing' on the little hole, it surfaced and went to sleep.. second dive that day: exactly the same! at the factory, I openend the HH, took out the pressere sensor and looked under microscope: in the silicon oil there was a drop of water 'embedded', and in that drop were little grains of sand!, this sand must have come trough the little hole.. changements: 1 I made the hole in the lens bigger 2 I placed a black rubber disc inside between lens and SS tube of the sensor, but so that it can move around a bit (this is to take away light from the sensor) 3 I drilled a 3.5mm hole in the coverplate, and smoothened the edges 4 I filled everything with silicon oil 5 when fitting lens and coverplate, I placed a small silicon membrane (thickness 0.3mm diameter 8mm) between lens and cover plate when thightening (??) the cover-plate, I see the membrane become a bit 'spherical' as I press out the oil that was under membrene starting the unit, I got 1005 mbar, looks ok so what do I have now: a pressure chamber that transduces the pressure from outside to the sensor, but never any dirt can come in contact with the sensor, no dirt between coverplate and lens, no light on the sensor... thursday testdiving the unit.... lets hope is works, but I have faith :-) (can't be worse then last saturday) regards paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
(Online)

3rd July 2006, 23:05	#2 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	Re: modifying your HH primary Quote: (Originally Posted by paulraymaekers) hello all, I know I should not do it, but if no-one can help, I have to start myself! related to the problems with the pressure sensor, not surfacing at the end of the dive, I modified my primary. after the dive on saturday, salt water, very deep!! (16m:-) my unit that just recieved a new lens and pressure-sensor, did not surface (stayed at 3m) 5 minutes rincing with fresh water and 'sucking' and 'blowing' on the little hole, it surfaced and went to sleep.. second dive that day: exactly the same! at the factory, I openend the HH, took out the pressere sensor and looked under microscope: in the silicon oil there was a drop of water 'embedded', and in that drop were little grains of sand!, this sand must have come trough the little hole.. changements: 1 I made the hole in the lens bigger 2 I placed a black rubber disc inside between lens and SS tube of the sensor, but so that it can move around a bit (this is to take away light from the sensor) 3 I drilled a 3.5mm hole in the coverplate, and smoothened the edges 4 I filled everything with silicon oil 5 when fitting lens and coverplate, I placed a small silicon membrane (thickness 0.3mm diameter 8mm) between lens and cover plate when thightening (??) the cover-plate, I see the membrane become a bit 'spherical' as I press out the oil that was under membrene starting the unit, I got 1005 mbar, looks ok so what do I have now: a pressure chamber that transduces the pressure from outside to the sensor, but never any dirt can come in contact with the sensor, no dirt between coverplate and lens, no light on the sensor... thursday testdiving the unit.... lets hope is works, but I have faith :-) (can't be worse then last saturday) regards paul nice idea Paul. Let us know how it goes. BTW. Was the hole in the plastic bezel filled with silicone? When I replaced the depth sensor I filled the hole with some silicone. It was completely filled because it squirted out from the other side. That should prevent sand from getting through until the silicone is dissolved by the sea water. Peter
(Online)

4th July 2006, 06:57	#3 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,637	Re: modifying your HH primary Quote: (Originally Posted by PCDiver) nice idea Paul. Let us know how it goes. BTW. Was the hole in the plastic bezel filled with silicone? When I replaced the depth sensor I filled the hole with some silicone. It was completely filled because it squirted out from the other side. That should prevent sand from getting through until the silicone is dissolved by the sea water. Peter peter, after filling the hole with silicone, how do you know there was no gas locked up between sensor and lens, was the O-ring in its 'most down' position?? during the first dive, any gas locked up will be compressed, and water will be pressed trough the little hole inside the chamber also: the o-ring has quite some space: by pressurising the unit, the O-ring is pressed in its deepest position: this also makes water enter the small cavity regards paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
(Online)

4th July 2006, 08:04	#4 (permalink)
Drmike RBW Member Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,378	Re: modifying your HH primary Quote: (Originally Posted by paulraymaekers) peter, after filling the hole with silicone, how do you know there was no gas locked up between sensor and lens, was the O-ring in its 'most down' position?? He will know if the unit gives him the wrong deco and he dies or ends up peeing in a bag for the rest of his life. Is Silicon as compressible as water? I would have thought this kind of mod should be done by, or at the very least approved by the factory -as it could have serious consequeces. Tweak -tweak!....thud! __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

4th July 2006, 08:39	#5 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	Re: modifying your HH primary Quote: (Originally Posted by Drmike) He will know if the unit gives him the wrong deco and he dies or ends up peeing in a bag for the rest of his life. Is Silicon as compressible as water? I would have thought this kind of mod should be done by, or at the very least approved by the factory -as it could have serious consequeces. Tweak -tweak!....thud! It was done per instructions from Kevin and Doug. I don't rely on the HH only, I use a VR3 as primary deco computer. So far, both the HH primary (if it works) and the HH secondary track depth identical to my VR3. But I also have a Vision upgrade on order.
(Online)

4th July 2006, 08:43	#6 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	Re: modifying your HH primary Quote: (Originally Posted by paulraymaekers) peter, after filling the hole with silicone, how do you know there was no gas locked up between sensor and lens, was the O-ring in its 'most down' position?? I removed the sensor (careful they get damaged easily) and filled the hole with silicone (provided by Juergensen Marine). Then I pushed the sensor in. The surplus silicone squirted out through the narrow end. It was done by the factory on my HH, but I had to replace the sensor since it was malfunctioning.
(Online)

4th July 2006, 08:47	#7 (permalink)
Drmike RBW Member Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,378	Re: modifying your HH primary Quote: (Originally Posted by PCDiver) It was done per instructions from Kevin and Doug. I don't rely on the HH only, I use a VR3 as primary deco computer. So far, both the HH primary (if it works) and the HH secondary track depth identical to my VR3. But-but I thought the VR3 was as unreliable as the HH? __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

4th July 2006, 09:00	#8 (permalink)
PCDiver Submerge Productions Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Belgium Posts: 1,003	Re: modifying your HH primary Quote: (Originally Posted by Drmike) But-but I thought the VR3 was as unreliable as the HH? My brand new, 2 weeks old VR3, was very reliable - after it was repaired because of a full flooding on dive 5 . What happened was that the port connector leaked. I had never used the port connector so it was probably not properly tightened down at the factory. But I really like my VR3 now. Only the OC bailout sucks. Peter
(Online)

4th July 2006, 09:47	#9 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,637	Re: modifying your HH primary well, after my last trip, I've learned!! left arm: HH primary AND cochran 20 right arm: VR3, and the most reliable unit: the scubapro bottomtimer! (only missing a HS somewhere....) regards paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
(Online)

11th July 2006, 11:08	#10 (permalink)
J. V. RBW Member Current Rebreather/s: rEvo Other Rebreather/s: Not Bought Yet rEvo Join Date: Mar 2006 Location: Lot & Savoie Posts: 249	Re: modifying your HH primary Quote: (only missing a HS somewhere....) In Florida, since some weeks! __________________ -------------------- Jacques NPSFQQA-EDS IT # 007 (remué non agité)
(Offline)

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