Elmer's Double Acting Reversing Wobbler

[Dreeves]

Looking good. Keep the pics coming.

Dave

[Don1966]

Looking great Phil and I like the way you cut the slot in the guide very intuit......

 
Don

[philjoe5]

I worked on the crankshaft bearing and here’s a short pictorial of what I did.  I didn’t have a piece of  bronze or brass in a size suitable to make this bearing but I have lots of Durabar cast iron and so decided to make this bearing with it.  This is a 2x scale model, BTW, and I suppose I should have stated that in the title.

I sawed, and milled a block to the overall dimensions and made it a bit thicker in the flange than the plans called for. 

Next, I drilled and reamed the crankshaft hole ½”.  Without removing the work from the vise I drilled the 4 mounting holes.  I realized that these clearance holes for a #8 screw would need to go 1.3” or more deep.  Hopefully, they will not wander.

Now I’m ready to turn the ends on the lathe using the four jaw chuck, but first I removed most of the stock on the mill to lessen the amount of interrupted turning required.

Now I’m ready for some lathe work.  This almost looks like a casting!

Here’s the setup on the lathe.  I used a ½” dowel in the bore to indicate from and a live center to improve rigidity.  Yes, that's a brazed carbide turning tool doing an interrupted cut in cast iron.  And no, I don't seem to have any problems with this cutting tool.  But I'm not turning at high rpm's.

I turned the side entering the column first to a diameter of 0.875”.  Here I’ve verified that this end will fit through the column.  Note that it stands proud of the column on the cylinder side by 1/16” according to the plans.

With both ends turned I did a test fit which was good.

Finally, with the fit confirmed I drilled the oil hole to finish the part.


Thanks for looking in

Cheers,
Phil

[crueby]

Nice work on the bearing, looking good!   

[b.lindsey]

More nice progress Phil. Great pictures as always too!!

Bill

[Thor]

 Nice work Phil, what you have done so far on the engine is looking good.

Thor

[philjoe5]

I worked on the pivot bearing and its associated nut.  I turned the pivot bearing in two steps past the flange although the plans described a straight run past the flange.  The reason being at this 2 x scale, the end of the bearing would be a ¾’ thread and a corresponding tap for the nut.  I didn’t have these, didn’t want to buy them, didn’t want to thread single point on the Logan, so I just made the thread for the nut 5/8” – 18 NF using a tap and die that I had.

After turning the diameters, I cut the 5/8” – 18 threads using an adjustable wrench to hold the hex die, and I manually rotated the chuck while maintaining pressure from the tailstock on the die.

Then I reamed the hole 3/8” for the pivot pin.

I cut off the work from the stock and faced the flange end to a thickness of 0.120”, this end is fitted into the 0.125” deep recess on the column.

I made the bearing retaining nut from some 1 1/8” brass stock.  Drilled and bored it out to about 7/8” to accommodate a spring.  I'm using the dial indicator to warn me when I'm close to the bottom of the blind hole.

Then I drilled a pilot hole and bored it to 0.578” to accommodate a 5/8” – 18 tap.  I tapped this on the Logan lathe by hand turning the chuck while following the thread with the tailstock.

Tthe bearing is shown installed in the column with a brass ring spacer that represents where the actual valve will go.  The valve has spacers on either side of it to act as bearings for the valve.

These are the parts for the bearing

The valve is the next part to be machined.  Thanks for looking in and thanks for the kind words Thor, Crueby, Don, Bill, Dave

Cheers,
Phil

[b.lindsey]

Its beginning to look like an engine Phil. All the parts are looking good as well. Still following along here ...may even have a go at this one at some point.

Bill

[Gas_mantle]

Looks good Phil.

It's gonna be a monster size version when it's done. 

[philjoe5]

Thanks Bill

Gas_mantle:  A friend of mine showed up at one of model shows with this double acting Oscillating cylinder engine.  It was in very good condition and ran well on air.  The wide pulley on it suggests it was actually used to drive some piece of equipment.  It has a generous oiler as well.



My friend didn't want to sell it and I thought it was a neat engine so I've been searching for plans for a double acting wobbler for over a year.  Marv put me onto Elmer's #36 so I decided to build it in my friend's scale which is about 2x Elmer's.  Now, of course, I can reverse mine when it's finished

Cheers,
Phil

[Tennessee Whiskey]

Phil, the build is coming along nicely.  Now,  when you finish the 2x,  you should do a 1/4 scale to present beside it   

Cletus

[philjoe5]

Cletus,
The smallest screw in the original plan is a 2-56, diameter of 0.086", so 1/4 scale is a screw with diameter = 0.021".  That's a screw that's off my tapping chart, outside of my eyesight range, a bit too fragile for my aging jitters   However, I appreciate your confidence in my ability to tackle the insane    Plus, if I built it 1/4x scale, my loving wife would probably think I tracked a sliver of scrap into the house and she'd chuck it in the trash.

Cheers,
Phil

[philjoe5]

This weeks project was making the valve.  Starting with some 2 ¼” steel alloy (1144) I turned a diameter to 2.000”.  Then I drilled to 5/8”, bored to about 0.73” and reamed it to 0.750”.  I cut off the work on the bandsaw.




Then I placed the valve in the 3 jaw using this technique that ensures it won’t end up lopsided in the jaws. 

Faced the valve to a thickness of 0.375”.

Next operation required the rotary table and after making a fixture to hold the work in the MT2 collet of the rotab, slotting commenced.

After a few mishaps (read “broken”) using an extra long 3/16” end mill to clear the hex bolt head, I switched to a double ended end mill held in an ER-32 collet and finished the job.


I’m stopping work on the valve at this point because I want to design some kind of reversing lever.

Now, it occurs to me that I can test the valve operation by injecting some compressed air into the column and rotating the valve by hand.  The black ink mark on the valve shows the location of one of the slots. 

Well all seems to be in order with air coming out of the face from the proper ports so I guess I drilled and plugged the right ones in the column.

Thanks for checking in.  I’m motivated to finish this engine for the Cabin Fever Expo – I’ll get one balloon for my Opposed Piston Steam Engine (Elmer’s #30), and I’m going for a second one for this build.

Cheers,
Phil

[Don1966]

Looking good Phil and still with you......


Don
 

[Tennessee Whiskey]

Boy don't you just hate it when your tool breaks over when you try and stick it out too far  . I really like the "pin alignment ". Since I bought some pin gauges,  I've used that method to get several parts indicated in " close enuf " . You keep on,  I'm going for a  and  and I'll be back.

Cletus