Spheres

***caveseeker7*** · 14th November 2007, 14:14

Before (and maybe since) the MK15 the flasks were made of steel.
Doesn't Jason have them in his? I've seen two or three CCR1000/MK15 divers using them.

AUS$ 1000, right now around US$ 900 or €600 ... not a bargain, but may well be worth it anyway.
Not that many of them to go around ...

cool_hardware52 · 14th November 2007, 14:20

I would consider forming 1/2's rather than machining from solid, better grain flow.

No welded pressure vessel is or will be approved for DOT AFAIK.

Tobin

DZLHED · 14th November 2007, 14:24

I've been pursuing the same train of thought. I've got a nuke certified welder that says no problem on making a few. I can specify any neck thread. I was looking at the valves on the Mk 6p at DEMA. 316 stainless and same dimensions as the Inconels. We are working with various suppliers trying to cost them out. Trying for around 600 usd each. As for the DOT approval... They are welded. It will never happen. Most dive shops in the US won't touch tanks that aren't Dot approved though there really is no reason they can't. I suggest developing a really good relationship with someone who has a compressor.

SteveL · 14th November 2007, 18:45

Quote: (Originally Posted by Steve)

I'm not really following you on the expansion issues. Sure the wall thickness would need to be a shade thicker than standard but it shouldn't be a biggie and if they were made from less expensive steel, made so the valves screwed in rather than were welded and painted you may well stand to save a fortune in production costs. If my rough order of magnitude costs are anything to go by you could toss them away every couple of years.
Thoughts?

yeah the guys suggested that - I remember koputai repainting old mk15 steel spheres some time ago and I think he found that over time the enamel coating cracked off - im just assuming expansion contraction from both temperature and pressure - maybe Im wrong - certainly no metalurgist

S

SteveL · 14th November 2007, 19:01

i dont think DOT is the main objective. Most of us with these type of units probably have ways and ways of filling odd shape cylinders by now.

We just need an alturnative sphere that is in the realm of obtainable.

Yes cold hard light of day has arrived (with a sore head urgh - airline lounge coffee isnt fixing it either!)

Still, I dont believe it will be a big machining issure. I will ask them about steel. We use very high grades like 4140 and 4145 and also stainless or monel, - getting a chunk big enough should be OK -

The wiz bang mills can certainly do the milling into that shape. As to bettder grain flow - yes that seems logical - I will get the guys to look at it.

If we dont try we will never know!! heck I Need another little project before christmas anyway

- will revert soon......

Steve

cool_hardware52 · 14th November 2007, 19:13

Quote: (Originally Posted by SteveL)

The wiz bang mills can certainly do the milling into that shape. As to bettder grain flow - yes that seems logical - I will get the guys to look at it.

I'd look at 4130. Good mix of weldability, yield and ductility if properly Heat Treated.

Us the CNC gear to make the forming tools. Blank out the sheet stock, AWJ or laser.

Anneal the blanks

Put forms tools in a suitably large press, push real hard on the blanks

Trim the blanks

Turn a few "necks"

Weld everything together and HT.

Galvanize or maybe electroless nickel plate (bake after)

Hydro

We should have some next weeK

Tobin

SimonK · 14th November 2007, 19:32

At work we make titanium pressure vessels from machined and welded parts, the design is controlled by American boiler specs of some description, can dig them out if anyone is interested.

Simon

chunter · 14th November 2007, 19:49

Quote: (Originally Posted by SimonK)

At work we make titanium pressure vessels from machined and welded parts, the design is controlled by American boiler specs of some description, can dig them out if anyone is interested.

Simon

Not sure I'd want to use titanium for oxygen. Sparky sparky.

streamway_explorer · 15th November 2007, 08:33

Quote: (Originally Posted by SteveL)

i dont think DOT is the main objective. Most of us with these type of units probably have ways and ways of filling odd shape cylinders by now.

We just need an alturnative sphere that is in the realm of obtainable.

Yes cold hard light of day has arrived (with a sore head urgh - airline lounge coffee isnt fixing it either!)

Still, I dont believe it will be a big machining issure. I will ask them about steel. We use very high grades like 4140 and 4145 and also stainless or monel, - getting a chunk big enough should be OK -

The wiz bang mills can certainly do the milling into that shape. As to bettder grain flow - yes that seems logical - I will get the guys to look at it.

If we dont try we will never know!! heck I Need another little project before christmas anyway

- will revert soon......

Steve

Has anyone ever asked a tank company like faber or a smaller company if they would make them?.of course they need an order of a 10,000 I'm sure. which would kill the idea due to lack of people wanting to buy that many.

My unit has a O2 off board as well. just in case I can't fill my sphere's for some reason at lease I can get my stardard 3lt tanks filled so I can go diving.

Jimmer · 15th November 2007, 12:17

I gotta agree with Tobin on this one, form the halves if possible. That way the grain structure is maintained, and POSSIBLY enhanced due to the forging. Anneal and heat treat accordingly. 4130 or 4340 would both be good options for material. I'd be very interested to see a set of these after production is complete. Makes me wish my shop here had the machines to make these, all we have is a laser, and a shit load of manual and robotic MIG welders.

14th November 2007, 14:14	#31 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,284	Re: Spheres Before (and maybe since) the MK15 the flasks were made of steel. Doesn't Jason have them in his? I've seen two or three CCR1000/MK15 divers using them. AUS$ 1000, right now around US$ 900 or €600 ... not a bargain, but may well be worth it anyway. Not that many of them to go around ... __________________ Cheers Stefan Be Water, My Friend - Bruce Lee Sponsor Lou in Race For Life!
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14th November 2007, 14:20	#32 (permalink)
cool_hardware52 RebreatherWorld Sponsor Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Mar 2005 Location: SoCal USA Posts: 358	Re: Spheres I would consider forming 1/2's rather than machining from solid, better grain flow. No welded pressure vessel is or will be approved for DOT AFAIK. Tobin __________________ www.deepseasupply.com
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14th November 2007, 14:24	#33 (permalink)
DZLHED Swimmin' upstream Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Join Date: Jun 2005 Location: Maui County, Hawaii Posts: 101	Re: Spheres I've been pursuing the same train of thought. I've got a nuke certified welder that says no problem on making a few. I can specify any neck thread. I was looking at the valves on the Mk 6p at DEMA. 316 stainless and same dimensions as the Inconels. We are working with various suppliers trying to cost them out. Trying for around 600 usd each. As for the DOT approval... They are welded. It will never happen. Most dive shops in the US won't touch tanks that aren't Dot approved though there really is no reason they can't. I suggest developing a really good relationship with someone who has a compressor. __________________ Aloha, Dieselhead To err is Human... to ccr, Divine. www.NorthShoreExplorers.com
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14th November 2007, 18:45	#34 (permalink)
SteveL Custom Title Allowed! Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Join Date: Nov 2005 Location: Sydney Australia Posts: 221	Re: Spheres Quote: (Originally Posted by Steve) I'm not really following you on the expansion issues. Sure the wall thickness would need to be a shade thicker than standard but it shouldn't be a biggie and if they were made from less expensive steel, made so the valves screwed in rather than were welded and painted you may well stand to save a fortune in production costs. If my rough order of magnitude costs are anything to go by you could toss them away every couple of years. Thoughts? yeah the guys suggested that - I remember koputai repainting old mk15 steel spheres some time ago and I think he found that over time the enamel coating cracked off - im just assuming expansion contraction from both temperature and pressure - maybe Im wrong - certainly no metalurgist S
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14th November 2007, 19:01	#35 (permalink)
SteveL Custom Title Allowed! Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Join Date: Nov 2005 Location: Sydney Australia Posts: 221	Re: Spheres i dont think DOT is the main objective. Most of us with these type of units probably have ways and ways of filling odd shape cylinders by now. We just need an alturnative sphere that is in the realm of obtainable. Yes cold hard light of day has arrived (with a sore head urgh - airline lounge coffee isnt fixing it either!) Still, I dont believe it will be a big machining issure. I will ask them about steel. We use very high grades like 4140 and 4145 and also stainless or monel, - getting a chunk big enough should be OK - The wiz bang mills can certainly do the milling into that shape. As to bettder grain flow - yes that seems logical - I will get the guys to look at it. If we dont try we will never know!! heck I Need another little project before christmas anyway - will revert soon...... Steve
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14th November 2007, 19:13	#36 (permalink)
cool_hardware52 RebreatherWorld Sponsor Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Mar 2005 Location: SoCal USA Posts: 358	Re: Spheres Quote: (Originally Posted by SteveL) The wiz bang mills can certainly do the milling into that shape. As to bettder grain flow - yes that seems logical - I will get the guys to look at it. I'd look at 4130. Good mix of weldability, yield and ductility if properly Heat Treated. Us the CNC gear to make the forming tools. Blank out the sheet stock, AWJ or laser. Anneal the blanks Put forms tools in a suitably large press, push real hard on the blanks Trim the blanks Turn a few "necks" Weld everything together and HT. Galvanize or maybe electroless nickel plate (bake after) Hydro We should have some next weeK Tobin __________________ www.deepseasupply.com
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14th November 2007, 19:32	#37 (permalink)
SimonK Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Oct 2005 Location: Cumbria UK Posts: 231	Re: Spheres At work we make titanium pressure vessels from machined and welded parts, the design is controlled by American boiler specs of some description, can dig them out if anyone is interested. Simon
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14th November 2007, 19:49	#38 (permalink)
chunter I like diving Current Rebreather/s: Sport Kiss MK 15.X Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Classic Kiss Join Date: Jul 2006 Location: Honolulu Posts: 452	Re: Spheres Quote: (Originally Posted by SimonK) At work we make titanium pressure vessels from machined and welded parts, the design is controlled by American boiler specs of some description, can dig them out if anyone is interested. Simon Not sure I'd want to use titanium for oxygen. Sparky sparky. __________________ "Foolish consistency is the hobgoblin of little minds." - Emerson "Hobgoblin is a cool word." - Charlie
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15th November 2007, 08:33	#39 (permalink)
streamway_explorer New Member Current Rebreather/s: MK 15.X Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Home Build Join Date: Aug 2007 Location: Australia Posts: 41	Re: Spheres Quote: (Originally Posted by SteveL) i dont think DOT is the main objective. Most of us with these type of units probably have ways and ways of filling odd shape cylinders by now. We just need an alturnative sphere that is in the realm of obtainable. Yes cold hard light of day has arrived (with a sore head urgh - airline lounge coffee isnt fixing it either!) Still, I dont believe it will be a big machining issure. I will ask them about steel. We use very high grades like 4140 and 4145 and also stainless or monel, - getting a chunk big enough should be OK - The wiz bang mills can certainly do the milling into that shape. As to bettder grain flow - yes that seems logical - I will get the guys to look at it. If we dont try we will never know!! heck I Need another little project before christmas anyway - will revert soon...... Steve Has anyone ever asked a tank company like faber or a smaller company if they would make them?.of course they need an order of a 10,000 I'm sure. which would kill the idea due to lack of people wanting to buy that many. My unit has a O2 off board as well. just in case I can't fill my sphere's for some reason at lease I can get my stardard 3lt tanks filled so I can go diving. __________________ Michael Collins www.trimixdivers.com
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15th November 2007, 12:17	#40 (permalink)
Jimmer New Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Dec 2006 Location: Ontario, Canada Posts: 58	Re: Spheres I gotta agree with Tobin on this one, form the halves if possible. That way the grain structure is maintained, and POSSIBLY enhanced due to the forging. Anneal and heat treat accordingly. 4130 or 4340 would both be good options for material. I'd be very interested to see a set of these after production is complete. Makes me wish my shop here had the machines to make these, all we have is a laser, and a shit load of manual and robotic MIG welders.
(Offline)

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