Author Topic: Pennsylvania A3 Switcher (Kozo)  (Read 327527 times)

Online crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #705 on: July 07, 2020, 05:23:53 PM »
Just did some searching for nitride, is it the silicone nitride balls you are using?

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #706 on: July 07, 2020, 09:40:52 PM »
Since Silicon Nitride is stronger than steel, how would it be better than using Stainless Steel?  Isn't the benefit of using the rubber balls that they will conform to the seat better if it is slightly out of round or has a little defect?  If you use something harder than steel, you lose that benefit, so maybe I should just stick with the Stainless balls I already have?

Is there other reasons that make the Silicon Nitride better?

Thanks,
Kim

Offline Liero

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #707 on: July 08, 2020, 02:59:44 PM »
Hi

The mentionded balls are made of silicon nitrile (not nitiride)  ==> they are soft "rubberlike".

Lukas

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #708 on: July 08, 2020, 08:38:59 PM »
Ah... makes sense.  I'll look that up now :)
Thanks Lukas!
Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #709 on: July 08, 2020, 08:41:20 PM »
Wrapping up the pump body, I cleaned and prepped the piece to silver solder the base in place.


After a good pickling and some clean up, here’s the completed Pump Body assembly.


As previously stated, a lot of steps and operations involved in making the pump body assembly.  Glad that ones done!  The next few parts should go more quickly!

Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #710 on: July 08, 2020, 08:45:14 PM »
Chapter 8.2 – Plunger

Next, I made the plunger for the hand pump.

The plunger was made from 3/8” 303 Stainless rod.
Here I’m tapering the front end of the ram:


And now I’m using a slitting saw to cut a 1/8” wide notch in the plunger.  I’d already drilled a hole to terminate the slot, and another 1/8” hole at 90o to secure the end of the pump handle.


Here’s the completed plunger:


This was a simple part!

Online crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #711 on: July 08, 2020, 08:45:40 PM »
Nice clean job, should be pumping water soon!

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #712 on: July 08, 2020, 08:47:33 PM »
Chapter 8.3 – O-Ring Retainer

The next small part to make for the pump was the O-Ring Retainer.  This piece slides into the wide end where the plunger goes to hold an o-ring in place.

It was made from a sort length of 5/8” bronze.  Though Kozo specifies phosphor bronze, I’m using 544 bearing bronze because it is obtainable, less expensive, and works easily.  Hopefully, the minor difference in composition between the two won’t make too much difference for my model that will see limited use.

The bronze rod comes slightly oversized.  So even though I was using 5/8” rod, I had to hold it in a 43/64” collet.

First I drilled the hole for the plunger:


Then I cut the profile, which is just an extra lip at the end of the retainer.  Then I cut off the part from the parent stock.


Here’s the pump family picture, showing the pump body, plunger and o-ring retainer.


And this is what they look like assembled.


These little pieces make me feel like I’m making great progress!  Two in one day!

Thanks for stopping by to take a look,
Kim

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #713 on: July 08, 2020, 08:48:18 PM »
Nice clean job, should be pumping water soon!
Thanks Chris!  :cheers:
Kim

Offline Dave Otto

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #714 on: July 09, 2020, 12:11:09 AM »
Nice work on the pump Kim!
Just curious, what holds the O-ring in place?

Dave

Online crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #715 on: July 09, 2020, 12:51:44 AM »
Nice work on the pump Kim!
Just curious, what holds the O-ring in place?

Dave
The bore for the plunger is wider out at the end for the inner edge of the o-ring, the outer end of the o-ring is pressed in by the o-ring retainer collar.

Offline Dave Otto

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #716 on: July 09, 2020, 12:57:11 AM »
What I should have said is what holds the O-ring retainer collar in place. :wallbang:

Dave

Online crueby

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #717 on: July 09, 2020, 12:59:49 AM »
What I should have said is what holds the O-ring retainer collar in place. :wallbang:

Dave
Ah - the little hole above the opening of the bore is for a set screw.   :cheers:

Offline Dave Otto

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #718 on: July 09, 2020, 01:07:12 AM »
 :ThumbsUp:

Offline Kim

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Re: Pennsylvania A3 Switcher (Kozo)
« Reply #719 on: July 09, 2020, 05:37:23 AM »
Yeah, what Chris said :)
Kim

 

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