"Build Your Own Diving Lung", Revisited in 2018 -2022

[antique diver]

Great job!! Love the story and photos. Thanks.

Thank you Allan. I wish you could have been here with us!

[SurfLung]

What a great vintage diving day. Thanks Bill.

[Vancetp]

Great video! I love seeing that Bendix reg in action. You really accomplished something by revisiting that conversion so successfully!

I am still working on my own version, but it has been back-burnered so many times. I have some new twists to add, but I have a million other projects....

[antique diver]

Eben and Phil, If you get to Texas during last of May through September or mid-October you can dive here in just a swimsuit, and take a dive with the "LUNG".

I just spent most of the day with it on the workbench. Had to resurface the HP poppet, and while it was all opened up changed out the LP seat and removed an unnecessary internal fitting to increase air flow. I finally took the time to tinker with adjustments on that crazy brass bellows in the first stage, and was able to raise the IP to a level that makes a remarkable improvement in breathing. At least in my shop, and I will be going to water again next week to give it the real test. I'm sure my new Vintage buddy will be there too, and hoping Francie will give it a try.

[Vancetp]

Very cool. Pls post what you did to improve the IP and air flow! I'm still working on (staring at) my Bendix unit.

I'd love to come to Tx to dive that beast, but I've used up my plane fare allotment this year with a trip to KC that took me down into Kansas, up to north-mid Missouri; then West Virginia and around Maryland, Ohio, Pennsylvania, and Virginia; a trip to Glacier NP,; tickets to Hawaii in September, and NOLA in October. Retirement is keeping me busy!

Save me a place in line for a future trip. I'll bring some of my custom regs!

[antique diver]

Very cool. Pls post what you did to improve the IP and air flow! I'm still working on (staring at) my Bendix unit.

I'd love to come to Tx to dive that beast, but I've used up my plane fare allotment this year with a trip to KC that took me down into Kansas, up to north-mid Missouri; then West Virginia and around Maryland, Ohio, Pennsylvania, and Virginia; a trip to Glacier NP,; tickets to Hawaii in September, and NOLA in October. Retirement is keeping me busy!

Save me a place in line for a future trip. I'll bring some of my custom regs!

I think the slotted screw in upper center is supposed to adjust IP , but I can't get it to budge and afraid I may break something that just can't be found at Home Depot.

62.reg dry.JPG

I took the cover off for access to the pressure sensitive brass bellows that moves an L-shaped lever to open and close hp poppet. There is an threaded adjustable stem attached to that lever, and I experimented first turning it in a couple of turns. Worse. So back to original setting, then backed it out two turns. That made a noticeable improvement. It may have increased the IP, or just opened the poppet further, thus allowing more air volume to flow. I'm looking forward to diving it next week to see just how much it helps.

21. first stage bellows.JPG

The poppet also has an adjustment screw, so after refurbishing the sealing surface on it I backed that screw out a turn or maybe bit more. There are photos of those in earlier posts. Also removed a couple of internal parts that may have disturbed air flow, then put it back together. Breathes even better now, so I think I'm finally on the right track to improving the performance. If the weather holds I will know late next week.

[Vancetp]

Thanks for the update, Bill. Good photos.

That plug is staked, bigly.

I'm looking at mine, and it was staked more aggressively than I'd have done. If you drilled into the punch mark with a 1/16" or so bit, you might be able to break the crimp that is locking it in place. I wish I knew what the plug/adjuster mechanism looks like. It isn't a simple brass plug, and seems to be made up of at least a couple of parts.

Maybe we need a sacrificial unit to experiment on? That mought could be mine, I suppose. I'll do a bit of experimentin' and see if I can get the adjuster loose. I'll set it up in the mill and try to delicately cut that staking away.

I keep getting inspired to do something with my diluter, and then I get distracted. My next project step is to machine a long tube that extends from the second stage opening boss all the way into the intake horn. I'll get rid of the screen that's fixed in the opening of the horn, so the tube enters the horn a bit. I wonder if, if it was reduced at the end with an adjustable jet, it could achieve a bit of venturi?

That'd be something.

[antique diver]

Thanks for the update, Bill. Good photos.

That plug is staked, bigly.

I'm looking at mine, and it was staked more aggressively than I'd have done. If you drilled into the punch mark with a 1/16" or so bit, you might be able to break the crimp that is locking it in place. I wish I knew what the plug/adjuster mechanism looks like. It isn't a simple brass plug, and seems to be made up of at least a couple of parts.

Maybe we need a sacrificial unit to experiment on? That mought could be mine, I suppose. I'll do a bit of experimentin' and see if I can get the adjuster loose. I'll set it up in the mill and try to delicately cut that staking away.

I keep getting inspired to do something with my diluter, and then I get distracted. My next project step is to machine a long tube that extends from the second stage opening boss all the way into the intake horn. I'll get rid of the screen that's fixed in the opening of the horn, so the tube enters the horn a bit. I wonder if, if it was reduced at the end with an adjustable jet, it could achieve a bit of venturi?

That'd be something.

I drilled on that staked spot a bit in hopes of getting the threads to budge, but was concerned about what I could damage below that and never got it to give. There appears to be a rubber diaphragm showing through the slot and didn't want to damage that.

I agree with you about it a venturi boost... badly needed. The factory venturi system is just in the way and won't benefit use as a diving reg. I eliminated all that, and had thought about threading the second stage outlet ID for a tube of some type. If I get around to that I think I want to try it first with the full bore size extending to the horn, then maybe experiment with different sized orifices screwed into it, or leave it wide open if I find no benefit to increasing the air velocity there.

Keep me posted on your results. I'm leaving mine as it currently is for this week, as i first want to test the effect of the adjustments I made on the first stage lever height. Feels promising on the bench. Going diving Thursday with SeaWolf, new diver Monte and lot's of vintage goodies.

[antique diver]

I made a simple change in the diaphragm support plate that greatly reduced the breathing effort at higher demand levels. It took three years for me to come up with this idea, and 20 minutes to implement it. Please ignore the ugly diaphragm, but it works well now.

Hoping you can get the sound to work on this link to video.

https://i.imgur.com/3USTvbi.mp4

[Vancetp]

That's amazing. Great work!

I'm going to make some new levers for the diluter that might be more efficient for adjusting, etc. I'll keep in touch, and post progress.

[antique diver]

That's amazing. Great work!

I'm going to make some new levers for the diluter that might be more efficient for adjusting, etc. I'll keep in touch, and post progress.

Doesn't yours have the adjustment screw and locking nut back at the pivot point? That's about as easy as it gets for adjusting the lever height.

[SurfLung]

Eben and Phil, If you get to Texas during last of May through September or mid-October you can dive here in just a swimsuit, and take a dive with the "LUNG".

Thanks for the invite. That would be a heck of a neat thing and great personal opportunity. My son and his wife just moved to Corpus Christi so now I have an excuse to drive down to TX... And could actually make a side trip to visit you.

[antique diver]

Eben and Phil, If you get to Texas during last of May through September or mid-October you can dive here in just a swimsuit, and take a dive with the "LUNG".

Thanks for the invite. That would be a heck of a neat thing and great personal opportunity. My son and his wife just moved to Corpus Christi so now I have an excuse to drive down to TX... And could actually make a side trip to visit you.

Excellent! We would love to see you and Jill, and I'm sure we could spend hours and hours talking diving. We would drive the wives crazy.
Our place would be a good stopping point for a night or two on your drive to CC, which is 6 - 7 hours south. We could take in a day or two of diving at Wheeler Branch Reservoir in Glen Rose. At right time of year, and if winds cooperate, you could get in some Gulf rig diving at the coast.

Let's get a plan!
BT

[Vancetp]

That's amazing. Great work!

I'm going to make some new levers for the diluter that might be more efficient for adjusting, etc. I'll keep in touch, and post progress.

Doesn't yours have the adjustment screw and locking nut back at the pivot point? That's about as easy as it gets for adjusting the lever height.

Yes, it seems like it is the easiest method, but on my second diluter, I broke the pivot off the lever while trying to get the nut off. I think I'll try out various ways to repair it. Seems like an opportunity to raise the lever. A new diaphragm has to be fabricated, so it could be made higher in order to keep the castings from interfering with the diaphragm plate.

[antique diver]

That's amazing. Great work!

I'm going to make some new levers for the diluter that might be more efficient for adjusting, etc. I'll keep in touch, and post progress.

Doesn't yours have the adjustment screw and locking nut back at the pivot point? That's about as easy as it gets for adjusting the lever height.

Yes, it seems like it is the easiest method, but on my second diluter, I broke the pivot off the lever while trying to get the nut off. I think I'll try out various ways to repair it. Seems like an opportunity to raise the lever. A new diaphragm has to be fabricated, so it could be made higher in order to keep the castings from interfering with the diaphragm plate.

We may not be talking about the same adjustment screw. Back where the lever assembly hinges on the second stage there is a lever height adjustment. Sound like you were referring to the screw at the end where lever linkage attaches to diaphragm. I understand that is where you broke the linkage, I think. That shouldn't be too difficult to make a new piece. Might even use a slightly larger screw diameter and carefully split the end to slip over the lever bar?

About the taller diaphragm, that is exactly what I am doing today once I get a fresh tube of the "flowable" silicone from Autozone or the like. Made a mold modification yesterday to gain about 1/4" in diaphragm height. Also tried using spray Plasti-Dip on the nylon material, but that didn't work out. Too stiff, so going back to my old tried and true Silicone.