Elmer's Double Acting Reversing Wobbler

[Dreeves]

It will look like a birthday party at our table. 😂 I have 6 elmers stan has a few you have a few Scott has one

Dave

[b.lindsey]

If I make it to CF, I can add six more to the total Dave.

Bill

[b.lindsey]

Oh...nice progress Phil 

Bill

[philjoe5]

Thanks for the comments guys.  It will be good to see everyone at the Cabin Fever show.

Work continues and seriously guys, your encouragement motivates me

Cheers,
Phil

[philjoe5]

I have been working on the cylinder.  This part threw me a slight curve in that it has a rectangular component and an arced segment.  So I wondered if I should start with a round or rectangular piece of stock.  It was a 50/50 proposition but I chose the wrong direction initially.

I happen to have some round stock in the 3” range and started with that.  I turned it to a diameter that the arced segments called for.  Unfortunately, that led to rectangular sides that did not meet at sharp corners
.


This prevents the crosshead guide from mating properly.  And I couldn’t mill the sides any further without cutting into the air passages.


I cut my losses and restarted with  rectangular stock.  This time I approached the job with the following strategy.  The face that mates with the column needs to be perpendicular with the bore.  So I milled the stock accordingly, then bored the cylinder and drilled and tapped the crosshead guide holes.




Unfortunately, boring on the mill/drill has never produced good results with my equipment.  The result was a bore with a 0.002” taper – unacceptable. 


So, I clamped the workpiece in the 4 jaw, and indicating off of the bore on the small end, I bored the cylinder out on the lathe to 1.263”.


At his point I came to the realization that the rectangular piece is best machined by:
Milling to correct overall dimensions
Boring the cylinder
Drilling/tapping the cylinder head and crosshead mounting holes
Drilling/tapping the cylinder mounting holes and air ports
Everything else is cosmetic.

Here’s a family shot with the cylinder attached and a temporary nut holding the pivot pin to secure the cylinder against the column face

At this stage I decided to check air flow in both valve positions and everything seems to be working OK, with air entering the cylinder ports as expected.


Thanks for looking in

Cheers,
Phil

[Thor]

 The cylinder looks great Phil, when I made my version I didn't bother with the arced segment, just milled the cylinder as a block.

Thor

[philjoe5]

Thor,
After the initial tragedy starting with round stock I was tempted to just make a block, but decided to put the arcs in there to dress it up a bit.

Cheers,
Phil

[philjoe5]

The flywheel assembly consists of a crankshaft, crank web and crankpin.  The crank web serves as a flywheel also.  I had some 3” brass and used a 1” thick slice for the flywheel


After facing both sides true I drilled and reamed a 7/16” hole with a ½” register.  Then I drilled/tapped 5/16” – 24 NF threads.


Turned a piece of ½” stainless to 7/16” diameter to fit the flywheel.  Secured it with  Loctite.  After curing I drilled a 3/16” keyway at the crankshaft junction, inserted a key, added Loctite and finally cleaned up the face.  I made a crankpin to fit.



I made the piston and crosshead using the same approach.  I cut the stock from oversized stock, faced them to length.  Both were drilled/tapped Ό” – 28 NF.  A piston rod was made from 5/16” stock, threaded on both ends.  The piston stock was attached and turned to fit the bore, which turned out to be 1.262”.  The crosshead was turned to fit the guide in the same manner, then milled flats on opposite sides were produced.  Finally, it was reamed to accept the crankpin.



The working end of the engine was assembled and the crankshaft was attached to a portable drill.  Movement is good, with no tight spots or clearance issues.

I just realized this post has me working at each of my three lathes.  How does anyone make do with less?

So far, so good.  I’ll tackle the cylinder heads next.

Cheers,
Phil

[crueby]

Drilling in the joint of the whhel and the shaft for the pin is interesting. Since it was between softer brass and harder steel was there any problem with the drill walking to the side?

[Flyboy Jim]

Following along Phil. Thanks for posting what didn't work out so good, along with what did! 



Jim

[Thor]

 You are making good progress Phil, the engine looks very nice. You are lucky to have three lathes, I only have two, and I would not part with my smaller lathe.

Thor

[philjoe5]

Crueby - I'm using screw machine drill bits.  They're shorter than Jobber length and I am not seeing a problem with them walking in this application.  I suppose if they did a bit I wouldn't notice here since its a blind hole for the key.

Jim, Thor - thanks for looking in.  I can see light at the end of the tunnel now

Cheers,
Phil

[philjoe5]

Working on the cylinder heads I squared up a piece 2” x 2” aluminum.  I drilled four clearance holes for attaching to the cylinder and drilled/tapped a 5/8” – 24 hole for the packing gland.



To minimize a lot of interrupted turning on the lathe I milled away most of the excess on the end with the spigot.



I made a blank packing gland by turning some brass true, cutting 5/8-24 NF threads and drilling with an “O” drill (0.316”) for the 5/16” piston rod.  I used an adjustable wrench to hold a hex die, and turned the chuck by hand while feeding the die onto the workpiece using pressure from the tailstock drill chuck.  Brute force, but it did the trick.



I set up the work in the 4 jaw by indicating on the blank packing gland that was screwed into the cylinder head.


Turned the spigot on the end.


Cut off the work on the bandsaw.  Then I faced the cylinder head to its specified thickness of Ό” and turned a register for the cylinder.


Installed the lower cylinder head (without packing gland) and checked for clearance issues.  None were noted.


That's the latest progress.

Cheers,
Phil

[b.lindsey]

 It's coming along well Phil. Nice project to be following along on and I enjoy your updates.

Bill

[Don1966]

Looking good Phill missed a few updates but caught up now.

Don