Author Topic: Conversion of 4 Cycle Utility Engine to Steam  (Read 38367 times)

Offline vtsteam

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #100 on: March 28, 2013, 09:34:15 PM »
Thanks B85V!  Coming along slowly but surely.

I call the new one my experimenter's head. I can try different valve assemblies by bolting them to the new big flat boss. If one doesn't work out, I can just make another one without having to cast a whole new head, and bolt it in place. That's what I call planning for plan B!

I squared up a blob of roughly cast aluminum to fit the new valve space (shown lower right in the photo). I need to line bore it to take a long bronze rotary valve bushing. Well, half bore it. Basically cut a 1.050" D. semicircular channel along the top face. This would have been easy to do on my old Gingery lathe with the boring table and milling attachment I made and a fly cutter mounted between centers. One of those jobs where a horizontal mill would be ideal.

But now all I have access to is my Craftsman 12" x 42", and it doesn't have a boring table. I'm thinking about making up a new table for the Craftsman. Either that or, adapt the boring and milling rig from my Gingery to the larger lathe.

Anyway, here's the current state of affairs. I think this photo should be titled "Two heads are better than one."



I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline Brass_Machine

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #101 on: April 01, 2013, 11:01:00 PM »
I need to get in the truck and drive to VT and get some lessons in casting  :smart:

Quote
I'm thinking about making up a new table for the Craftsman.

I think that is the way to go.

1. Because you can
2. Because it would be exactly as you want
3. Because I want to see it done.

Eric
Science is fun.

We're all mad here. I'm mad. You're mad.

Offline vtsteam

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #102 on: April 02, 2013, 01:17:37 PM »
I need to get in the truck and drive to VT and get some lessons in casting  :smart:

Sure. But better make it after mud season, the fifth season of the year is upon us -- the thirty days surrounding the day taxes are due, when Vermont is covered with mud!

As for the table, I made a small temporary one, but want to cast a larger permanent version in iron after the weather warms and the land is dry.

For the permanent version, I want to make something similar to the Myford's Super 7 cross slide (preferably the long version) , but altered fit the Craftsman/Atlas lathe saddle's dovetail ways.

I very much like the British cross slide system. With a similar cross slide I could then also easily build lathe accessories to fit -- as described in UK books by Tubal Cain,  JA Radford, and others.

What I would need for that are some basic measurements of the Myford cross slide, and then I could draw up the Atlas version to suit.

Mainly I need the length and width of the table, the Tee groove size and locations, and the location and size of the pivot hole for the top slide. If anyon could help with those, I'd be greatly obliged!

As for the smaller temporary table, I was looking through my scrap bin for something over an inch thick to make into a table of about 4"x4" in size. All I found was a slab of 4" diameter round, about 1-1/2" thick that someone had given me. It was some kind of machining mistake, and had 4 tapped holes in it and some shoulders one side, and a big cone shaped depression in the center of the other side. Outside was still raw, and it was stamped 2021-T4, so good stuff!

I cleaned it up, cut off the shoulders to flatten the top, and bored out the depression on the bottom side to fit the circular dovetailed pedestal on the Craftsman cross slide. I haven't finished it yet -- I need to put in the locking screws and pins. Though small and round, it does look to have some advantages, since it is easily rotable. Some tommy bars, indexing marks and a pointer and it could be used as a rotary table, as well as a small boring table. I also just set my vertical slide from the Gingery lathe project on top of the table, and it seems to fit there as well. I'll need to drill and tap new holes for that.

Unfortunately there's not a lot of bearing, and the center post of the cross slide is not the best design for taking heavy loads, so I'll need to be careful. A much better solution will be the larger cast iron Myford style cross slide that I hope to build, since it will bear all the way across the saddle, instead of at one point on the dovetail pedestal.

Anyway here are some photos showing the construction of the Craftsman saddle, and the new small boring/rotary table and the vertical slide setup:

The small table cleaned up and bored. The Sears Craftsman/Atlas 12" cross slide has dovetail ways, and a dovetailed post for accepting the top slide.




The small table mounted in place. It still needs fixing screws and pins.



Trying my smaller lathe's vertical slide to see if it will fit.




I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #103 on: April 02, 2013, 10:02:07 PM »
Today I drilled and bored out the valve housing block to fit a piece of red brass pipe, which will serve as a valve liner. Should be easy to replace, and the exhaust will pass through axially, so I can route it via the threaded pipe to a condenser some day.

The steam entry will be perpendicular to the valve.

Today I also bored the pipe true and then lapped it with a lead lap.

After that I turned a valve out of a piece of hot rolled rod and made it a nice close fit to the liner. 

I milled a slot shaped port in the head and a matching port in the valve housing. Haven't milled ports in the liner yet, but hope to tomorrow



I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #104 on: April 08, 2013, 08:14:06 PM »


I've been working on the rotary valve and it's finally finished. The exhaust ports through the aft portion of the valve which is hollow. The steam section is solid and follows a channel connecting a steam port and a head port. It was tricky working out the sizes of the ports and channels to get the valve timing.

I milled the ports in the valve spindle with a somewhat iffy collet spinner -- tough getting it not to rotate while milling, but I took light cuts.

I do have a massive very old 10" dividing head, it weighs 125 lbs and I picked it up for $50 at an auction -- including an attached three jaw chuck and a tailstock. But it doesn't have division plates or an index arm. I hope to make the parts I need for it -- would have been nice to have for this job. Looking at it carefully I just found the maker's name -- it's Kempsmith. I'm going to guess from the lettering style that it is near turn of the century in age.

I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #105 on: April 28, 2013, 05:02:25 PM »
First run!  :ddb:

[embed=425,349]<iframe src="http://player.vimeo.com/video/65002574" width="425" height="349" frameborder="0" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe> <p><a href="">FirstRun4CyConv</a> from <a href="http://vimeo.com/user9419463">vtdiy.</a> on <a href="http://vimeo.com">Vimeo</a>.</p>[/embed]
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline awemawson

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #106 on: April 28, 2013, 05:23:27 PM »
Excellent news! Looks good, sounds good   :wave:
Andrew Mawson
East Sussex

Offline krv3000

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #107 on: April 28, 2013, 05:53:31 PM »
brill work  :thumbup:

Offline Stilldrillin

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #108 on: April 29, 2013, 02:15:38 AM »
WOW!!   :bugeye:

Great work VT!  :clap: :clap:

It really looks good, too........  :thumbup:

David D

David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline vtsteam

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Re: Conversion of 4 Cycle Utility Engine to Steam
« Reply #109 on: April 29, 2013, 01:04:25 PM »
Thanks awemawson, krv3000, and Stilldrillin!! :beer:

Well it's a start. I used the free Visual Analyzer program on the audio portion of the video, and it looks like the engine is turning a little under 700 RPM @ 100 PSI compressed air.

(Visual Analyzer:  http://www.sillanumsoft.org/prod01.htm )

 I'd like to start on making it a real steam engine, now. Lagging, release valve, pumps, oiling, boiler.

The compressed air isn't doing it any favors re. power output. The valve inlet timing has a fairly short cutoff intended for steam and that doesn't help any on compressed air. And I also would like to get closer to 200 lbs pressure.

Presently just for a ballpark estimate:

Pressure say 75 lb
Length of stroke 2.25" or .1875'
Area of piston 5.41 sq in
Number of power strokes 670/min

P x L x A x N = 50972
Power = 50972/33000 = 1.5 Hp



I love it when a Plan B comes together!
Steve
www.sredmond.com