Vancetp
Master Diver
Posts: 191
Joined: Tue Oct 04, 2016 7:26 pm
First Name: Phillip
Location: Belmont CA

Titan II conversion to Double Hose

Fri Jun 28, 2019 8:01 pm

I've been making some Titan II to double hose conversions the past several months. These are based on the single hose Titan II and the FX reproduction cans available from Rob.

This is nothing new, and others have done these in various ways. The Titan II was made with the same first stage casting as the Trieste double hose reg. They simply blanked off an existing second stage drilling and hard seat. One of mine had a second stage body, seat carrier and soft seat and spring installed to seal the hole. Unfortunately, they didn't install a Trieste body, which would have made things much easier. The other two had a simple plastic plug.

So, one needs a substitute second stage in order to make this into a double hose. To complicate things, the Titan and Trieste are threaded differently than the US Divers bodies. The Voits have 24 tpi threads, and the USD regs have 27 tpi ( an odd choice, IMO). So you can't easily do what might seem at first to be the simplest answer: install an HPR.

The threads are similar but different enough to give pause to the intrepid modder who may consider just running one on in. I actually did this. It worked, and the threads were realigned enough to fit quite nicely. But, the machinist in me rebels at this kind of roughshod running over of things, and things don't really line up right. I have zero misgivings about the threads. They are solid and the realignment took place on the HPR body, not the first stage body. The second stage cannot blow out of the hole or some other type nonsense prediction of doom. But. the HPR was designed for a different regulator and the orientation is wrong for the lever and for the jets. The HPR does work, and its performance is adequate, but not what it could be.

So, I made new second stages and levers that fit the threaded hole, interface with the diaphragm correctly, and have jets aimed the right direction. They are not that difficult to make, and they work very well. In fact, my venturi is too strong without throttling it down with a DSV mouthpiece. One is made of brass, and two others are made of delrin. They work equally well.

ImageIMG_4473 by Vancetp, on Flickr

ImageIMG_4532 by Vancetp, on Flickr

ImageIMG_4531 by Vancetp, on Flickr

While I was at it I made a plug for the J valve hole that accepts an SPG

ImageIMG_4500 by Vancetp, on Flickr

User avatar
Herman
VDH Moderator
Posts: 1234
Joined: Thu Oct 25, 2007 1:45 pm
Location: Raleigh NC

Re: Titan II conversion to Double Hose

Sat Jun 29, 2019 6:41 am

Nice work. We went round and round about the threads on the USD. To make matters worse, 5/8-28 is a fairly common thread used on gun flash suppressors so at first look, that is what it appeared to be. It took some high magnification and lots of looking to figure out it was 27 and not 28, that's not a lot of difference over an inch span.
I am pretty sure the newer LP seat holders (HPR) will work for that holder, the screwdriver slot in them makes adjustment easier.
The lever looks good, how did you cut it? Rough on a band saw then Dremel/file it?
Herman

Vancetp
Master Diver
Posts: 191
Joined: Tue Oct 04, 2016 7:26 pm
First Name: Phillip
Location: Belmont CA

Re: Titan II conversion to Double Hose

Sat Jun 29, 2019 12:32 pm

Thanks, Herman.

Yes, the new HPR seat holders do work well in my second stages. The stock ones are just a bit short, making adjustments of the second stage body tricky.

The levers were made by rough cutting with a hacksaw, and drilling holes to remove material and giving access for a small file. They aren't hard to make but a bit labor intensive. I was going to add a teflon button ala the HPR, but it works fine with the tips bent. They are becoming more refined as I make more.

Vancetp
Master Diver
Posts: 191
Joined: Tue Oct 04, 2016 7:26 pm
First Name: Phillip
Location: Belmont CA

Re: Titan II conversion to Double Hose

Sun Jun 30, 2019 9:17 pm

As Herman and others may know, I am working on a Dacor 400 Balanced conversion to DH, but with a bit different approach than Herman's previous Derringer mod. I have done a bunch of stuff to begin except for the hard part, which is drilling the Dacor first stage body for the new second stage.

This in itself isn't that much of a problem. However, there are many ways to go with this, including my first prototype which used a modified single hose second stage body with an integrated hard seat. But, because the Dacor body has limited meat to drill into, I may have to abandon that idea. The next idea is to make a second stage body, something like my Titan body and to sink a hard seat into the Dacor casting . A third idea is to mod an HPR, and add the hard seat.

I don't feel the need to make everything myself, and I think it would be cool to mod this with an existing second stage like the HPR. The only real problem is air delivery to the intake horn. This might only necessitate plugging one of the existing HPR ports and resizing the plugged one and one other in order to get a big jet that is oriented toward the intake horn. Or it might require some kind of venturi tube. I'm thinking the redirected jet will work, since I've had success with this on my Titans.

Vancetp
Master Diver
Posts: 191
Joined: Tue Oct 04, 2016 7:26 pm
First Name: Phillip
Location: Belmont CA

Re: Titan II conversion to Double Hose

Tue Jul 02, 2019 8:42 pm

I have made significant progress on the 400 conversion. I will post when I get closer!

Vancetp
Master Diver
Posts: 191
Joined: Tue Oct 04, 2016 7:26 pm
First Name: Phillip
Location: Belmont CA

Re: Titan II conversion to Double Hose

Fri Aug 09, 2019 8:55 pm

I dove my conversion at Monterey. It worked ok, and delivered adequate air. I'd like a bit more venturi with the DSV. I was too light after losing 20+ lbs and couldn't get underwater easily. Then, I started getting wet breathing and aborted the dive. On the way back in, I dove down several times and the wet breathing went away. I think it was misuse of the DSV mouthpiece. I probably didn't get the mp closed properly and it allowed water in.

When I got home, I took the reg apart. The "stainless" steel i used to make the levers out of was *hit. The thing was rusty beyond belief! I got some new metal and I'm making new levers.

It's a process!

Vancetp
Master Diver
Posts: 191
Joined: Tue Oct 04, 2016 7:26 pm
First Name: Phillip
Location: Belmont CA

Re: Titan II conversion to Double Hose

Wed Aug 21, 2019 12:45 pm

The new lever installed, and a blank for my Dacor conversion:

ImageIMG_4734 by Vancetp, on Flickr

I used good stainless sheet this time, and the levers are stiffer and hopefully rust resistant.

The finished regulator and its Titan II second ready for pool testing:

ImageIMG_4747 by Vancetp, on Flickr

ImageIMG_4749 by Vancetp, on Flickr

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