Dirt Cheap BP/W Mk2

[James79]

As promised (threatened?) version 2 of the Death Wish Engineering BP/W!

This is shown with a Steel 72 and my 13 y.o.'s MK5 with U.S. Divers SEA 4 seconds (cut him some slack, he rebuilt them himself).
Notable improvements:
3d printed ABS hardware has been vapor polished (stronger and smoother finished part)

Grommets installed at bottom and top (either side of elbow) to allow water/air out of space between shell and bladder.

Slightly thicker (1/2 inch) cutting board (doesn't flex as much, but I cut it sloppy as hell)


More on next post.

 

[James79]

Regarding the comparisons...
The following Bill of Materials puts it at $187.80 if you bought everything just for this project, including commercial replacements for the 3d printed parts. However, the only pieces I bought for this project were cutting board, fabric, grommet kit, pond tubing, and kids swim-rings, putting my cost at approximately $55 with parts left over (excess tubing, fabric, grommets, and swim-rings) for 2 more sets. Access to a 3d printer cuts the costs on the BOM by $43 ($65 if you use a 3d printed buckle instead of the cobra buckle my kids insisted on). Compared to approximately $350-600 for commercially produced BPWs I call this a win (and I will be looking at larger swim-rings or alternate bladders in the future for a wing that will fit a standard back plate).

Bill of Materials:
Bladder flanges (2 ea) 3d printed or DiveGearExpress $9.00 ea
DGX Bladder Flange Assembly | Dive Gear Express®

Over Pressure/Dump Valve (1 ea) 3d printed or DGX $5.00
DGX BC Overpressure Relief and Dump Valve | Dive Gear Express®

Plain Elbow assembly (1 ea) DGX $10.00
Dive Rite Plain (Non-Exhaust) Elbow w/Nut | Dive Gear Express®

LP Inflator assembly (1 ea) DGX $16.95
45-degree Oral Power Inflator | Dive Gear Express®

1 Inch ID pond tubing (16 inches) Lowes $19.98 for 20 feet
https://www.lowes.com/pd/smartpond-Black-Pond-Tubing/1000843644

Cam Bands (2 ea) Piranha Dive MFG $17.99 ea
Plastic Adjustable Reinforced Cam Straps , Piranha Dive Shop |

11 x 14 cutting board (1 ea) Big Lots $5.50
Farberware Cutting Board, (11

D rings (4 ea) Belt sliders (2 ea) Harness T-Plates (2 ea) 3d printed or source independently approx$10.00

Cobra Buckle (1 ea) Strapworks $22.00
https://www.strapworks.com/ProductDetails.asp?ProductCode=MTH-SRB-COB-000

Webbing (10 ft.) Strapworks approx $1.00 ft (pick your webbing)

600d Polyester Canvas (1 yd.) Amazon $6.99
https://www.amazon.com/dp/B071WN2Y3D/ref=twister_B07LB85V9R?_encoding=UTF8&th=1

¼ inch Grommets (4 ea) Amazon $10.99 (kit)
https://www.amazon.com/Bememo-Gromm...crafts&sprefix=grommet,arts-crafts,159&sr=1-5

Upholstery thread (1 spool) Amazon $4.39
https://www.amazon.com/COATS-Strong...ts-crafts&sprefix=upho,arts-crafts,159&sr=1-5

Intex 24 inch swim ring (1 ea) Amazon $11.13 (3 pack)
https://www.amazon.com/Intex-Transp...nch+swim+ring&qid=1568153549&s=gateway&sr=8-1

 

[James79]

Lamp Shade Junior rocking the backplate... along with an SP MK5 that he paired with Aqualung SEA4 seconds (he did the rebuilds himself, under my eye) and an old school steel 72.

 

[MattAO]

I was curious how this has held up for you guys.

I want to try my hand at making one.

Probably 3D print a portion of the parts and I've got two old BC's lying around for some parts as well.

 

[James79]

He only has the one dive on it so far.... Boy Scouts has kept him busy. I've put a handful on the prototype, and so far all is good.

 

[MattAO]

Awesome. Sounds like it's a solid platform. Appreciate you taking the risk, prototyping, and sharing.

Time to get to work

 

[Diver below 83]

Very cool work

 

[James79]

Very cool work

Thanks!

 

[MattAO]

Just dove my bp/w based and inspired on James79 build. It dove great a few tweaks and it will be amazing.

Super huge thanks to James and his son for coming and diving with me today to try this thing out. And for all the emails and texts to sort it out and make it work.

Lessons learned from the dive
- thicker webbing
- triglides with teeth
- crotch strap
- Keep your wing tight to wide and it tacos

Thanks again man for the inspiration and ALL the help.

 

[Brian Huff]

My reactions throughout this thread (and the others)

Oh, that's funny, a BP/W from a cutting board

Um, holy crap, he took it in the water

Hmm, that's an option for light travel gear.