Who is Herman?

[Green Frog]

I just rewatched the You Tube from Double Hose on how to service the Conshelf XIV, and noticed that one specialty tool Bryan used is not available from any source I’ve seen. It was a collar and plunger for reassembling the filter, springs etc and the circlip all in one push. He mentions that it is/was available at a reasonable price from “Herman” who made it. Can somebody tell me who Herman is and how to get in contact with him (email, website, etc)?
I was admittedly daunted by the prospect of doing this servicing, but after watching the video a couple of dozen times, it actually looks do-able if I can get this and one or two more tools (as well as a rebuild kit, of course).
So instead of “Where’s Waldo?” it’s become “Where’s Herman?”
As always, thanks for any and all help.

 

[rhwestfall]

Herman Mowrey, is here on SB ( @herman ), but to my knowledge is no longer making the custom tools he made and sold.

In the case of the one you mentioned, there was a recent post from a SB user that used some PVC and the yoke for the first stage. Very clever.

Herman also made a body holder, a combo bit driver/screwdriver for tuning the lever, and a whole bunch more helpful stuff.

A real treasure was the 109 lever bending tool.....

His old catalog is still on the VDH site for inspiration to make or commission others...

There are a few folks experimenting with tool manufacture, mostly printing stuff

 

[boat sju]

It seems like you could make the tool out of pvc rod if you have a drill press.

Huge Selection of PVC Type 1 Rod Cut-to-Size & In Stock

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I recently refurbished an AquaMaster and found I could use a drill guide and a wood dowel. (shaved the dowel end to a partial circle to accommodate the snap ring pliers)

https://www.homedepot.com/p/Milescraft-DrillBlock-Hand-Held-Drill-Guide-1312/204590191

 

[Skip Y]

You can do a work around without the tool. get a dowel at Home Depot. You want the circlip to be able to go over the dowel and give you room to squeeze the clip. Put the yoke on and the yoke screw in. The dowel will need to be cut a little longer than a dust cap. Put everything in the nozzle except the clip. The clip goes over the dowel and the two go where the dust cap normally goes. The yoke screw works as a press

 

[Green Frog]

OK, thanks for all the information and suggestions. I actually have a medium sized bench lathe, long disused, that I might be able to use to cobble together what I need, the collar out of aluminum and the punch from machinable nylon. If I don’t hear anything positive from Herman, that’s probably what I’ll do. What do you guys think of my choice of materials?

 

[happy-diver]

Yeah a piece of dowel and get on with your life, I use a socket extension or something

 

[Luis H]

@herman tool was excellent. Similar tools are available from a couple of sources below.

Before we had that type of tool we used to use the old dowel method. I started using the dowel method over 50 years ago. I did it long enough, but I will never do that again. It works, but there are better ways...

I have also used several insertion tools made by Herman (some custom made) and several other sources. They all work much better than the dowel method and a lot less risk of items springing across the room.

Herman even made me one of those tools that work in combination with the yoke and yoke screw to help insert all the components. It works great.


Now, after all these years I saw the video below, it uses a similar principle as the old dowel and snap ring tool (with no guiding/compression barrel), but it uses the yoke and yoke screw to control all the components while compressing the springs. It is so simple, that I am annoyed that I have never done it that way before. All it requires is a little plastic stand-off.

You have to guide the components going in, but the yoke and yoke screw is like having a third hand. And that is a very steady third hand that can precisely hold position (or move with precision, in or out) and it doesn't get tired. This is now my preferred method because I have a lot of control.

Another advantage is that this method also allows for a very control disassembly and assembly.

Take a look at the video below.


From Scuba Clinic:
Filter Bushing Tool for Aqualung
Filter Bushing Tool for Aqualung and Mares First Stage


From Scuba Service Tools:
Aqualung guide bushing for Conshelf series
https://www.scubaservicetools.com/product-page/guide-busing-for-conshelf-series





Here is a thread showing where this video came from:
Method for Disassembly and Assembly of a AL Conshelf Nozzle | Vintage Scuba Diving Community Forum
.

 

[boat sju]

@Luis H , So it's ok to push on the filter like that? The reason I used a 1/2" wood dowel was so I could make contact with the outer ring of the filter. That method in the video is slick.

boat

 

[Luis H]

@Luis H , So it's ok to push on the filter like that? The reason I used a 1/2" wood dowel was so I could make contact with the outer ring of the filter. That method in the video is slick.

boat

Yes, it is OK. Back in the 70's, when I worked at Divers Service Center we always used a 1/4" diameter dowel. With the old dowel method you had to use a small dowel so that you can use a snap ring tool to compress the snap ring and inserted. The snap ring has to be in position around the dowel.

This method, using the yoke is basically the same procedure, but you add a very controllable restrain that actually works better than having a third hand.

Now, one word of caution: the yoke screw can have a lot of mechanical advantage, so you need to make sure nothing is binding or out of position and do not force it. You have a lot of control and can go very slowly, but you can also produce a lot of force with the screw, so be gentle and careful.


I would recommend cleaning the yoke screw threads and maybe spraying some silicone spray lubricant on the threads to reduce friction. That way you will just use your fingertips to turn the knob and will be able to feel the resistance when it bottoms out in position.

This is not delicate or precise like a Swiss watch, so it is not a big concern. Just don't over do it, when cranking it down.



Added: The center of the filter (actually the entire filter) is supported by the balancing chamber (the little spring is mostly inconsequential). Therefore, if you apply way too much force with the screw, what is likely to get damage are the corners of the balancing chamber (the new square chambers), where they come in contact with the ledge on the side on the barrel.

The ledge on the inside of the barrel is there to support the balancing chamber and take the pressure thrust from the tank pressure on the back of the chamber. That is what makes the first stage valve balanced.

The pressure thrust (force) on the balancing chamber is not very high because it is a very small area. I will share some numbers in a while, when I have a chance.

So, assuming a tank pressure of 3500 psi pushing on the back of the balancing chamber:
The pressure force is only about 43 pound.
The diameter of the volcano orifice is about 0.125 inches,
The pressure area is only about 0.012 inch-square.

The torque on a yoke screw that would produce the same force of 43 pounds is:
For a 3/8" yoke screw, torque is about 3.2 inch*pounds
For a 1/2" yoke screw, torque is about 4.3 inch*pounds

So that is why I said that all you need it finger tips to turn the yoke screw.


If you don't have a decent hardware store near by you can get them from many sources on line.

Amazon has 25 for $8.52. I know, that is a life time supply or you can share them with friends. All you need if one... if you don't lose it.
"Small Parts 141604HFN Female Threaded Hex Standoff, 6/6 Nylon, 1/4" Hex Size, 1" Length, 4-40 Thread Size (Pack of 25)"

 

[Green Frog]

Looks like the “Ace Tool” by Richard Kanner makes the process as simple as possible, and I have two Ace Hardware stores within a ten mile radius! Thanks again to all who responded and especially to @Luis H (and of course, Richard Kanner!)