PLBs Can Save Your Life

[Dan]

McMurdo FastFind 220 has dimension of 1.85" W x 1.34" D x 4.17". It will definitely fit to the old Sony camera case MPK-PHA.

 

[Dan]

I'd get rid of the threaded hole in the bottom. 1/8" (~3mm) is not very thick. I'd be concerned that it may be too thin for a pressure vessel in acrylic once you've cut threads in the surrounding material. Acrylic camera housings are injection moulded, they don't have stress risers like those that occur when you drill and tap holes into a facing structure like your design.

If nothing else, I'd pressure pot test the thing beyond your planned depth just to make sure.

Thanks! Erased it off the drawing.

 

[Celt]

My approach to PLB,s is very simple, I don’t use any. I have zero expectation of anyone coming to save me if things go south. To me not to be able to get back to my boat or ashore means certain death and it’s amazing how that attitude focuses the mind. All my diving is solo from shore or my boat, mostly from my boat.

 

[Jay]

My approach to PLB,s is very simple, I don’t use any. I have zero expectation of anyone coming to save me if things go south. To me not to be able to get back to my boat or ashore means certain death and it’s amazing how that attitude focuses the mind. All my diving is solo from shore or my boat, mostly from my boat.

You might have zero expectation but your local SAR, family, friends etc etc might have different ideas!! It's not all about you you know

 

[Celt]

You might have zero expectation but your local SAR, family, friends etc etc might have different ideas!! It's not all about you you know

It’s the exact opposite my family and friends will always know I’m at my boat.

 

[-JD-]

I'm also working on making my own acrylic canister with a local plastic machine shop. Here is a rough drawing for it.

View attachment 513464

The internal cavity would be about 2.5” ID & 3.25” H to fit the PLB1 with its floating pouch, as shown below. The case OD would be 3.0” & height = 4.5”
-snip-

One suggestion would to be mill out a step at the perimeter of the bottom piece to form a shoulder that the tube slips over. If done precisely, it would provide additional solven-weld area and adds a mechanical support in that area that would otherwise be reliant on the "glue" joint.

I'd get rid of the threaded hole in the bottom. 1/8" (~3mm) is not very thick. I'd be concerned that it may be too thin for a pressure vessel in acrylic once you've cut threads in the surrounding material. Acrylic camera housings are injection moulded, they don't have stress risers like those that occur when you drill and tap holes into a facing structure like your design.

If nothing else, I'd pressure pot test the thing beyond your planned depth just to make sure.

How about using Delrin for the cap material? (It would be less fracture prone with the milled blind-holes.)

<EDIT>
EPlastics also offers Acetal Tube in 70mm ID/90mmOD x 5ft - a bit bigger, but tougher ...
90mm OD X 70mm ID Natural Acetal Tube at ePlastics
90mm OD X 70mm ID Black Acetal Tube at ePlastics

</EDIT>


Also, if you extend the cap past the tube in each "corner" (clover-leaf) to create a tab area with a through-hole to mount your attachment and grasp for unscrewing.

Pull cord through or use a SS mini shackle:
https://www.amazon.com//dp/B071Y57Y8H

or a quick-link
https://www.amazon.com/dp/B072PXM38N

 

[Dan]

One suggestion would to be mill out a step at the perimeter of the bottom piece to form a shoulder that the tube slips over. If done precisely, it would provide additional solven-weld area and adds a mechanical support in that area that would otherwise be reliant on the "glue" joint.



How about using Delrin for the cap material? (It would be less fracture prone with the milled blind-holes.)


Also, if you extend the cap past the tube in each "corner" (clover-leaf) to create a tab area with a through-hole to mount your attachment and grasp for unscrewing.

Pull cord through or use a SS mini shackle:
https://www.amazon.com//dp/B071Y57Y8H
View attachment 513469

or a quick-link
https://www.amazon.com/dp/B072PXM38N
View attachment 513470

Thanks! Fine ideas, but I worry about the machining cost. I'll talk to the machinist about these options.

My first thought is it would be much easier to machine the bottom plate & lid from a 3.25" rod with a lathe than from a plate with CNC machine. A foot long 3.25" diameter acrylic rod from ePlastics.com, Shopping costs about $184. They might be able to make 5-6 of the bottom plate & lid out of that material.

 

[IncreaseMyT]

What if you come up and the boats gone Mac? That’s why I got one

 

[Celt]

What if you come up and the boats gone Mac? That’s why I got one

I clip my reel to the anchor or mooring rope

 

[JohnnyC]

It's cool dude, I totally get you. I don't wear my seatbelt because I've got antilock brakes and airbags.