Adjusting Equipment Buoyancy

I've been thinking for ages about trying to get my system slightly more neutral for macro. With the 2x Retras I have just bought I reckon it's about 600gms negatively buoyant. That is with 2x 5" arms and 2x 8" arms fitted with a total of 8x Jumbo Stix floats which give about 1400 gms of positive buoyancy. 

I'm wondering about switching it from 2x 5" and 2x 8" arms to 4x 8" which would allow me to add 2x Stix Jumbos - an extra 360gms of buoyancy. Not ideal though.  A bit more would be better but I'm not sure where I can put additional Stix. I don't want to use a collar.

Hmmmm 

Triple clamps on the handles and a float arm across the top? Can be a good place for a dive computer as well.

46 minutes ago, Barmaglot said:

Triple clamps on the handles and a float arm across the top? Can be a good place for a dive computer as well.

Yeah maybe.... not a bad idea

Sorry folks, I've hijacked this post a bit. Back to Retras!
 

On 4/7/2020 at 4:47 PM, TimG said:

I'm wondering about switching it from 2x 5" and 2x 8" arms to 4x 8" which would allow me to add 2x Stix Jumbos - an extra 360gms of buoyancy. Not ideal though.  A bit more would be better but I'm not sure where I can put additional Stix. I don't want to use a collar.

For macro? What about using a Stix Float Belt?

It would provide the additional buoyancy without changing the arms.

It impacts the housing balance, but I find in a positive way, as the macro port tends to be heavier that the body and the belt provide lift just where needed.

41 minutes ago, Algwyn said:

For macro? What about using a Stix Float Belt?

It would provide the additional buoyancy without changing the arms.

It impacts the housing balance, but I find in a positive way, as the macro port tends to be heavier that the body and the belt provide lift just where needed.

Yeah, I've thought of that but they just look so fiddly. Wouldn't it block a manual focus wheel? Or is it possible to position that in the gap?

I can see your point though on the balance aspect.

I'm using one, I've had no issue with it so far. It's not "fiddly", quite easy to install.

The segments enables you to fine tune the buoyancy if needed. If the velcro strap is too long, you may cut it to the right size.

The belt also support the port outside of water:

The belt may rotate underwater if the port body is smooth and you do not tighten the velcro strap. But once correctly set, it is holding for a whole trip. 

As an alternative, you could try the float ring from Flex-arm (other size) If the size does not fit your port, you can buy a rectangle of foam (Flexarm or Carbonarm), and cut it to your port size. But this would be less flexible and versatile than the belt.

Thanks for that. Certainly, worth some thought.  

I'm just not sure though that with any of those 3 systems (Stix, Flexarm or Carbonarm) I would be able to use manual focussing on my Subal housing - which I use quite a bit with macro. The system has a rotatable lever about 3 cms in diameter which extends out from the macro port. I can't see that any of these systems would work well with that.

I thought Barmaglot's idea might work well: of triple clamps with an arm between the two strobe arms. I thought if I bought an 8"  arm I could use 2.5 Jumbo Stix floats which would increase the buoyancy by 450 gms which would be good.

Alternatively I thought about just buying the Stix floats and weaving my housing handle though them - and see how that goes. They'd float upwards slightly in-water so I don't think would get in the way.

I always thought why no one, including my self, has never tried a baby lift bag that can have air added at depth.  Maybe someone has and it was a bad idea, but i do not think so.  I heard people using plastic bottles tied to their kit.

Yep, I've seen people, usually Japanese divers, using plastic bottles and little floaty things the housing hangs from. 

A lift bag would work in theory but there would be complications on ascent with having to dump air; and I'm sure the thing would get in the way.

I think that a lift bag flopping around above the camera would get in the way a lot, much more trouble than it's worth. If you want to fine-tune buoyancy while in the water, a number of companies sell adjustable-lift float arms that can be partially flooded to reduce their lift.

https://www.hugyfot.com/hugyfloat-compact/hugyfloat-adjustable.html

https://www.krakensports.ca/product/kr-fa01-float-arm/?v=e4b09f3f8402

https://www.weefine.com/product/wfa37-adjustable-float-arm-88mm-180mm/

You can also DIY a similar system, like this.

You could try some float arms I like the  INON ones Which could give 1300 gram of buoyancy from 2x Mega float arm M which are 8" long.  Then keep about 600gm worth of Stix on your regular arms.  Get two long clamps to join the float arm to your regular arm for more flexibility in positioning.  Here are the arms:  http://www.inon.jp/products/armsystem/arm.html

1 hour ago, ChrisRoss said:

You could try some float arms I like the  INON ones Which could give 1300 gram of buoyancy from 2x Mega float arm M which are 8" long.  Then keep about 600gm worth of Stix on your regular arms.  Get two long clamps to join the float arm to your regular arm for more flexibility in positioning.  Here are the arms:  http://www.inon.jp/products/armsystem/arm.html

Thanks Chris. I had a couple of those some years back - and sold them! LOL, I knew I shouldn't have kept them 

On 4/7/2020 at 5:53 PM, Barmaglot said:

Triple clamps on the handles and a float arm across the top? Can be a good place for a dive computer as well.

Triple clamps an float arm across the top looks good. How long and what diameter should the float arm have (NA-EM1II housing)? Is the float arm in the way, when one wants to attach a focus light on the cold-shoe, or on the other attachment point of the housing?

Wolfgang

I was going to set up my housing and try and figure it out. Something to do! Will report back

So, here's a ULCS 8" arm loaded with 2.5 pieces of Stix jumbo sized.

This seems to fit quite nicely and, in addition to providing a nice carrying handle, it would give about an extra 450gms of buoyancy for the cost of a pack of Stix (about €45) plus an extra 8" arm (say, €35) compared to using a float arm.

But, yes, it does block the focus light attaching point. Darn.

I think I'm going to try threading my current cord-woven carrying handle through some Stix first. If this proves too awkward, I may well get another 8" arm and, as Barmaglot suggested, a couple of triple clamps. 

What's the best way of cutting Stix? A hacksaw?

Of course I actually have to be able to go diving too..... 

On 4/10/2020 at 4:11 PM, TimG said:

I'm just not sure though that with any of those 3 systems (Stix, Flexarm or Carbonarm) I would be able to use manual focussing on my Subal housing - which I use quite a bit with macro. The system has a rotatable lever about 3 cms in diameter which extends out from the macro port. I can't see that any of these systems would work well with that.

Well, with the Stix float belt it should work. The float belt covers only 2/3 of the port circumference, so you may orient it to have the velcro on the side of you manual macro focusing knob. And you may end up not needing all the float segments of the belt.

2 hours ago, Algwyn said:

Well, with the Stix float belt it should work. The float belt covers only 2/3 of the port circumference, so you may orient it to have the velcro on the side of you manual macro focusing knob. And you may end up not needing all the float segments of the belt.

Thanks Algwyn

Can you actually remove floats from the belt?

Any chance you could take a photo of the area of the belt where there are no floats? This would give me a better idea of whether the Subal focussing knob (its quite big) would fit in the gap with the strap of the belt. 

The best way to cut foam floats is with a hot wire kit. The hobby type kits should be available around $30. 

3 hours ago, Captain Fathom said:

The best way to cut foam floats is with a hot wire kit. The hobby type kits should be available around $30. 

 

 

Oh right! Many thanks.

On 4/22/2020 at 3:17 AM, TimG said:

Can you actually remove floats from the belt?

The belt is  a velcro strap with several segments slid onto it.  You can move the segments around or add/remove them to fine tune buoyancy.  Here's a couple of photos, the first shows the belt on one of my old Subal Type 3 extension rings (approx 115mm in diameter).  You could make the gap larger by removing a segment or two.