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My Workshop / Re: Workshop adjustments
« Last post by Flyboy Jim on Today at 04:23:45 AM »
What a beautiful vise! :ThumbsUp: Might be a little big for my Sherline mill, but I'd love to have one to just set on my workbench and look at!
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Specific Engine Help / Re: DOM tubing cylinder sleeve
« Last post by Rustkolector on Today at 03:28:24 AM »
I have used DOM tubing for cylinder liners on a number of slow speed gas engine models with CI rings. In my opinion and experience it makes an excellent cylinder for model engine use with CI rings. Buy the closest ID and OD combination to your meet your needs. I suggest using the parent bore of the tubing and make a lap to check the bore for roundness. The bore must be round for rings to properly seal, and not all DOM tubing is perfectly round throughout. I found one piece of DOM tubing where the tube weld showed up as shadows when viewed against a light. A lap or Sunnen hone must be used to correct this problem. Cross hatch hone the final bore and then make the piston and rings to match the final bore. I think you will be happy with this choice.
Jeff
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Specific Engine Help / Re: DOM tubing cylinder sleeve
« Last post by derekwarner_decoy on Today at 02:24:09 AM »
This is a little more problematical than first mentioned

1/8" oversize in the bore represents a 1/16" [0.0625"] wall thickness finished size bush.....which in a quality Grey Iron is a delicate item & easily damaged by compression  :killcomputer:

You mention Perkins...is this a single or multi cylinder engine?...
What is the nominal cylinder bore size?
.....or what is the Model of the Perkins engine?
You mention that a cylinder is currently "bored" oversize......was this achieved in a lathe or mill?

Answers to the above will assist in understanding the best mechanical solution/fix & will dictate if a cylinder liner of smaller bore could be manufactured, inserted via a shrink fit & later bored to standard size

Derek

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Looks good Mike, I like that finish.

Have a great day,
Thomas
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My Workshop / Re: Workshop adjustments
« Last post by b.lindsey on Today at 01:32:13 AM »
It's beautiful Stuart!! You will notice quite a difference between it and the import I am sure.  Congrats on the new toy.

Bill
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I didn't get any time in the shop yesterday and precious little today due to an out of town meeting and visiting my MIL in the nursing home.  But I did get a bit of time today to progress a bit.  So here's what transpired.

I spent a fair bit of time trying to improve the finish on some of the parts.  My main conclusion is that I don't care much for a bunch of polishing and I'm not convinced that I like the way it looks.  What I liked the look of the best way finishing with Scotch Brite pads and a powered wheel.  I did figure out that you had to be VERY careful with the powered wheel as you can easily round edges.  I also used some 400 and 600 grind sandpaper laid on top of a discarded small surface plate that I got from a local shop that was getting rid of.  It's more than adequate for lapping flat surfaces though.  i spent a considerable amount time lapping (if you can call it that) the column faces, the cylinder face and the reversing valve, just in an attempt to get the best possible contact surface to avoid air leaks.  I also cleaned up the parts, degreased them and did secured the necessary bits together.

First is a pix of the crosshead guide after I applied Loctite 603 to serve as the lower piston guide.  The round insert is made from SAE 660 bronze so hopefully it will work well against the piston rod, which is made from drill rod.  An extremely exciting shot of Loctite curing!


Here's a pix of the assembled base, column, crankshaft and crankshaft bushing housing.  it all appears to fit and the flywheel seems to run true.


A closeup pix of how I sealed up the drilled passages.  I tapped each hole and then used 10-32x1/4" brass setscrews with a drop of Loctite 545 to seal them up.  I liked the look of this vs driving in plugs in each hole and sanding them flush.  You can also see the finish I got with the Scotch Brite.  As i said above, I actually prefer this finish.


And the cylinder and cylinder pivot components all assembled.  Everything fit and rotated freely and smoothly, at least by hand.  I also made a run for different springs and found some more suitable springs, at least that's my hope.  Tomorrow I'll need to cut one of the springs and reassemble. 


So tomorrow, the crosshead guide insert should be ready to go and I should get the spring situation more or less sorted out.  I hope to be able to get the assembly work finished and to apply some air to the engine to see if it runs!  I hopeful, but I always have a fear that I've overlooked something important. 

A co-worked and I used to always be amazed when we actually got things to work.  We were always pessimistic about our chances of success.   He's Scottish and I'm an old farm-boy so pessimism seemed to be our fundamental nature.  That same thought process has carried into retirement with me evidently!

In any case, enjoy!

Mike.
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Engines / Re: Machining a Cross Head
« Last post by b.lindsey on Today at 01:26:08 AM »
Quite an amazing albul of pictures, and you don't have to be on Facebook to see them fortunately.

Bill
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My Workshop / Re: Workshop adjustments
« Last post by crueby on Today at 01:15:06 AM »
Only thing better than new tools is top notch new tools!


 :cartwheel:
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Hints, Tips & Tricks / Re: How does this clutch work?
« Last post by Brian Rupnow on Today at 01:08:42 AM »
Bill--You could be right---but---Open the link in the very first post of this thread and see what they did. I probably have the reduced diameter of the expander cone too exaggerated. I'll take a closer look at that in the morning.
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Engines / Re: Machining a Cross Head
« Last post by propforward on Today at 12:53:14 AM »
Quote
Kory Anderson, age 35 decided 10 years ago that he would build this monster machine (70,000 pounds) himself from the drawings. After 4,000 hours of engineering and use of SolidWorks Kory began to make patterns for the 250 different castings necessary for this machine. He had these castings made in a foundry that he bought, machined the castings, and with the help of many good friends completed this machine a few weeks before the Andover, SD steam show.


 :NotWorthy:

THAT is impressive.
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