Author Topic: Double acting Double cylinder Oscillator  (Read 9520 times)

Offline 10KPete

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Re: Double acting Double cylinder Oscillator
« Reply #165 on: June 13, 2018, 02:00:22 AM »
A thin bit of UHMW or teflon or such as a 'gasket' will solve the metal-to-metal issues...

Or even greased paper...

Pete
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Offline Jasonb

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Re: Double acting Double cylinder Oscillator
« Reply #166 on: June 13, 2018, 07:19:05 AM »
Why do you need to run it on 50psi if its just a display engine, 5psi should be more than enough. With this lower running pressure you also lower the force required to hold the cylinder against the port face by 90% so can run much lighter springs which will help to reduce the tightness and galling.

Also make a spring seat to go under the locknut or even machine the bottom of the locknut so the spring is centralised rather than being pushed off to one side as it is now. Being crooked will be putting uneven load onto the pivot again making things tighter than they should be.

Address the causes rather than try to fix the symptoms!

Offline NickG

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Re: Double acting Double cylinder Oscillator
« Reply #167 on: June 13, 2018, 07:38:26 AM »
I think youíll probably find that the spring pulling the faces together hardly contributes to the overall friction in the system. If properly lapped and oiled the friction is very low from that interface. I donít like aluminium as a material choice for cylinders, especially if itís a soft grade, but as you say the amount itís actually going to run it probably doesnít matter. Iím with Jason, 5psi should be sufficient here. Iíve made a couple of oscillators and rocking engine that will run on lung power, I try to reduce the stiffness by getting fits right during the machining phase.


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Offline Brian Rupnow

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Re: Double acting Double cylinder Oscillator
« Reply #168 on: June 13, 2018, 12:27:33 PM »
You misunderstood me guys. I hope to have it run on 5 or 10 psi. The 50 pound pressure I quoted was just a run in pressure to get it started and take out any tight spots.

Offline Brian Rupnow

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Re: Double acting Double cylinder Oscillator
« Reply #169 on: June 13, 2018, 03:58:01 PM »
So folks, here we have it. It runs just as well as I had hoped it would, and will self start with the crank throws at 90 degrees to each other. It runs on about 10 psi of air. This engine has the fewest parts of any engine I have ever built. If anyone would like to build this engine, I sell a complete set of plans for $25 Canadian funds. There are 23 drawings in the set, including general arrangements and bills of material. You can contact me at brupnow@rogers.com
« Last Edit: June 14, 2018, 12:01:32 AM by Brian Rupnow »

Offline 10KPete

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Re: Double acting Double cylinder Oscillator
« Reply #170 on: June 13, 2018, 04:06:28 PM »
 :pinkelephant: :pinkelephant:

That runs beautifully, Brian!! Congratulations on another successful engine.
 :cheers:

Pete
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SB 10K lathe, Benchmaster mill. And stuff.

Offline crueby

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Re: Double acting Double cylinder Oscillator
« Reply #171 on: June 13, 2018, 04:09:56 PM »
Wow - very nice for a first run! Already pretty slow for an oscillator, majestic at that size.
 :ThumbsUp:

Offline Brian Rupnow

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Re: Double acting Double cylinder Oscillator
« Reply #172 on: June 13, 2018, 04:52:14 PM »
After 3/4 of an hour running, 80% of the stiffness is gone. Any residual friction  is easily overcome by the power of the engine. I thought it would be like that, but I'm never sure until I've run a new engine for a while.

Offline NickG

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Re: Double acting Double cylinder Oscillator
« Reply #173 on: June 13, 2018, 05:04:27 PM »
Nice work Brian, sounds good too


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Offline b.lindsey

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Re: Double acting Double cylinder Oscillator
« Reply #174 on: June 13, 2018, 05:45:55 PM »
Well done Brian. A nice slow runner too. Looks and sounds great.

Bill

Offline zeeprogrammer

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Re: Double acting Double cylinder Oscillator
« Reply #175 on: June 13, 2018, 06:14:13 PM »
And here's your  :pinkelephant:.

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Offline Tennessee Whiskey

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Re: Double acting Double cylinder Oscillator
« Reply #176 on: June 13, 2018, 06:28:01 PM »
Great job Brian. It really has an ďindustrialĒ look. Think it would be just right what for hooking up to your cross cut saw

Cletus

Offline Brian Rupnow

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Re: Double acting Double cylinder Oscillator
« Reply #177 on: June 14, 2018, 01:18:46 AM »
Thank you for your kind words gentlemen. This engine has a fit of flair to the style, to me it looks a bit like 1950's version of what engines would be in the future. i.e. "The Jetsons". I didn't make any allowances for a power take-off on this engine because I was only interested in the engine itself. It is easy to see why this type of engine was so popular for small marine applications, there are really no "small or intricate" parts to it.

Offline Larry

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Re: Double acting Double cylinder Oscillator
« Reply #178 on: June 14, 2018, 03:21:25 AM »
Runs great - enjoyed your build log !

Offline Art K

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Re: Double acting Double cylinder Oscillator
« Reply #179 on: June 14, 2018, 03:21:52 AM »
Brian,
It runs great, Good job. I have to admit watching your video had me doing down the Jay Leno rabbit hole.
Art