My Modified Build of Elmer's #3 O.C.R.

[Metal Butcher]

Oh no, not another build of Elmer's #3 O.C. with Reverse! The members that have been following the Team Builds are probably racing for the back button. But wait, this is a modified version. It's 50% larger and the valve/bearing block is reversed. To add some visual interest the cylinder and columns are made from hexagonal bar stock. The bearing block is bronze bushed for durability. A little additional length was added to the base to make room for the valve lever. Since I like cylinder heads, I added one for cosmetic reasons. The bore is now 9/16 inch and the stroke is 3/4 inch. I'm trying ideas and making changes as the build progresses, similar to the way a sky scraper is built.
Below is a photo of the roughed in parts I did over the last 2 days.

"It won't be long now!", said the butcher, as he sliced off a thick piece. ;D

MB

 

[seagar]

I for one am very interested in following your build,so please keep up the good work.

Ian.

 

[stevehuckss396]

I have'nt been around very long so I dont know what Elmers #3 looks like. Do it for us new guys!!

 

[Metal Butcher]

I have'nt been around very long so I dont know what Elmers #3 looks like. Do it for us new guys!!

It is TB-1 in Team Builds.

Here is a link to the plans: http://groups.yahoo.com/group/Elmers_Engines_1/files/

 

[4156df]

MB,

Please take us along for the build. Lots of pictures, please. It seems I learn something from every build.

Thanks,
Dennis

 

[cfellows]

Hey MB,

Glad to see your post. I've been contemplating one like this for the past couple of days. I've been feeling the need to complete a project and simpler engine seems like the answer.

I am going for a 1/2" bore and plan to incorporate my slave exhaust valve in the head to give it a bit more bark when it's running.

This is also good practice for my CAD skills using Alibre.

Chuck

 

[Metal Butcher]

Hey MB,

Glad to see your post. I've been contemplating one like this for the past couple of days. I've been feeling the need to complete a project and simpler engine seems like the answer.
Chuck

I'm feeling a little burned out after 29 builds, and now with this flu bug I have, an easy build was needed just to keep me moving forward. This model with its up sizing and cosmetic changes is not at all difficult or time consuming.

MB

 

[Metal Butcher]

The 1 inch crank disc was faced and bored .250" in the lathe and then cut off at 1/4". A flat piece of scrap was mounted in the mill/drill. After a zeroing out it was drilled and tapped for a 1/4" hold down bolt. With the disc bolted face down, the table was shifted 3/8" and the disc was drilled #44 and reamed 3/32". After a 3/32" pin was installed (using removable contact cement) the profile was milled using this same set-up. The photo was staged after the fact.

Using a spin fixture one pair of opposing 1/2" flats was milled on a 3/8" brass bar leaving it 1/4" thick for the crank pin end. In this set-up the 1/8" crank pin and 3/32" wrist pin holes were drilled and reamed on center at 1-1/2". Then a simple profile was turned using the tail stock center in the lathe. This was eye-ball work to suite. The tiny bit left at the piston/tail stock end was removed with an Exacto saw after the cut off on the crank pin end, closest to the chuck. It could be sawed off in the lathe prior to parting off.

This photo shows the 9/16" x 9/16" piston with a central 3/16" wrist pin hole already reamed. The crank disc and piston rod are shown after a little file and sand paper clean up.

That's all for now. MB

 

[Philjoe5]

Hey MB, nice work :bow: I'm with the other posters - keep it going...it's interesting and I'm learning stuff too ;D I like the profile you put on the crank.

Cheers,
Phil

 

[Metal Butcher]

Since "Honey" is busy and doesn't want my company I decided to do one more post and machine the valve.
I decided that 1 inch diameter would go well with the larger 1-1/8” raised valve area on the bearing block. I faced and beveled the outer surfaces in the lathe. After drilling and reaming the 1/8” through pivot hole a ¼” center cutting end mill was used to cut the recess .156” deep for the spring. Then I cut the valve disc off at 1/4 inch thick.
I clamped it standing up in the vise of the M/D, zeroed out, and centrally drilled the 3/32” lever hole .200” deep. This needs to be done before drilling/milling the passages since it is used for locating the 4 drilled starter holes and for rotating the valve during milling. After a simple jig is drilled and tapped for a 5-40 hold down screw and a guide line scribed at 45 degrees the disc is bolted with the faced side down and tight. A drill bit was inserted in the lever hole and directly in line with the scribed guide line. Then the 4 holes are drilled .062” deep .250” off center to match the pattern used on the bearing block. I use the thickness of a feeler gauge added to the proposed depth of hole to get all the holes drilled the same using my simple quill mounted 1 inch dial indicator.
You can see the scribed guide line just below the drill bit in the photo.

For the channel milling the screw is loosened just enough to allow the valve to rotate. During assembly I put some rubber cement on the screw to restrict movement. One layer of paper was placed between the valve and jig to prevent it’s finished face surface from being scratched. A 3/32” end mill is lowered about .020” into a starter hole to begin the milling. I rotated the valve slowly since the work piece is hand held. The milling is really simple and easy to do.

Modified Valve Specs:
1” in diameter ¼” thick
1/8” pivot hole (the bearing block is tapped for 5-40)
3/32” lever hole and port channel width.
¼” Spring recess .156” deep
Spring I will use is, .240” diameter, .032” wire diameter, .500 long-Enco #240-0575
-MB

 

[Maryak]

MB,

I am enjoying your style and technique. :bow:

Following along with much interest.

Best Regards
Bob

 

[Metal Butcher]

Today I'm making the crank shaft which acts as the valve. To begin I cut an over size length of .250" round shaft. To locate the 3 flats that will be milled, the valve block port locations were measured starting from the very front of the block, and then lines were scribed on the shaft. Prior to this I decided 1/2 inch of the shaft would be proud of the front to act as an out put for a drive pulley if desired. To simplify the scribing a brass bushing was clamped at the 1/2" starting point. The lines for the 1st flat were scribed at 1-5/8" to 2" and the 2nd flat at 1-7/8" to 2-1/4". The 3rd flat for the crank disc set screw was scribed at 1/4" from the proposed shaft end that will be flush on the crank disc. The excess was trimmed and its length rechecked again. The final total length is 3.740".

The shaft was set up in the spin index for milling. This is an easy eye ball job that will produce accuracy of plus or minus .010” or less. Since the surface finish of the flats doesn't matter I used a well worn 1/4" end mill. All the first cuts were centered between the lines and subsequent cuts were carefully advanced to the scribed lines. The depth of the cut was set at .032". The index was 0 and 18 for the 2 overlapping port flats on opposite sides, and 27 for the crank disc set screw flat at the end of the shaft. Measurements show that a 15/32 spacer will be needed between the crank disc and bearing block due to the base being 1/2" longer than the 50% up scaling of the other parts.

This photo shows the milling process complete.

This is a photo of my low tech DRO (Dial Read Out), it gets the job done well enough.

-MB

 

[ksouers]

MB,
Very nice work. I like your dial indicator set up, too.

Don't knock the lowly dial indicator. It is probably the most versatile measuring device in my shop. I have several, for many years it was my ONLY means to accurately measure table and head movement on my mill. Though the DRO is nice, there are times I still prefer using an indicator. I use them exclusively on the lathe.


Kevin

 

[Metal Butcher]

MB,
Very nice work. I like your dial indicator set up, too.

Don't knock the lowly dial indicator. It is probably the most versatile measuring device in my shop. I have several, for many years it was my ONLY means to accurately measure table and head movement on my mill. Though the DRO is nice, there are times I still prefer using an indicator. I use them exclusively on the lathe.


Kevin

No, no, I'm not knocking the dial indicator or my set up. Its the difference between being lost, and knowing exactly where I'm going with the quill movement.
I use the calibrated hand wheel dials for table moves, and that works well to. To avoid the occasional mistake when counting turns I rough scribe the work piece using a so-so set of dial calipers. This occasionally shows up a gross counting error to save the day. On my 9x20 lathe I have 2 dial indicators pushed by adjustable rods.This set up can produce one precision part after another. Before these simple improvements my work was so bad that I just about gave up.
Now when make a mistake its my fault, so I just shrug it off, try harder, and produce a satisfactory part.

Have you seen my post- My new drill bit finds a home? :big:

Link to a picture of my lathe set up:http: http://groups.yahoo.com/group/Elmer...ode=tn&order=ordinal&start=1&count=20&dir=asc

-MB

 

[rake60]

Great thread Metal Butcher!

I'm loving your approach to machining the parts for the Open Column.
Looking forward to the next installment.

Rick

 

[cfellows]

Hey MB,

I see you have the same mill/drill that I have. I bought mine from Enco about 15 years or so ago. Gonna have to make that analog "DRO" like yours. How did you fasten the Dial Indicator to the Mill?

Chuck

 

[Metal Butcher]

Hey MB,

I see you have the same mill/drill that I have. I bought mine from Enco about 15 years or so ago. Gonna have to make that analog "DRO" like yours. How did you fasten the Dial Indicator to the Mill?

Chuck

Hi. The swing bracket was attached to the 2 lower existing holes holding the builders plate by hand drilling and tapping for slightly larger SAE cap screws, number 6 screw I believe.
I made a new threaded depth stop screw with the top 5/8" machined down to .375. A rectangular block 5/8" x 5/8" x1-1/2 long was reamed 3/8' through the top of one end, and the other end was milled out from the front as far back as I could go without running into the vertical hole. The milling was just wide enough for a tight fit on the indicators lug. After a proper locating a cross hole was clearance drilled through one side (Slotted end), and the other side was drilled and tapped 1/4-28 for a bolt which goes through the block and the indicators lug hole. Tightening the bolt compresses the milled end slightly and clamps the indicator snug in the block.

After a few attempts at milling with the way the quill droped, and the useless calibrated spider handle dial, something needed to be done. I saw the basic idea in a book (somewhere?) and adapted it to my mill.

I just can't imagine how anyone could deal with this problem! With out this set up the depth of a simple blind hole was a nightmare, and milling a piece to proper thickness nearly impossible!

-MB

Edit: The indicator bracket is held on the 3/8 end of the quill depth stop screw using a 6-32 set screw.

This really simple set up works great! If anyone needs any more info then just ask!

 

[Metal Butcher]

On Elmer's plans, the transfer of air/steam is accomplished using a copper tube between the valve/bearing block and the cylinder. My modification eliminates the bending and soldering required by Elmer’s original plans. I decided to use 3/16" model pipe connecting the cylinder and bearing block. Although there are other ways to accomplish the connection, I decided to use a simple adjustable union. I made round unions in the past that worked well on other builds. Then the idea of continuing the hexagonal theme by incorporating it in the design of the union came to mind.

The picture below shows one half of the union being cut off on the lathe after the first machining steps were completed.

I used a larger piece of a hex with a central spigot tapped 10-40 to index the parts during the drilling and tapping. Since the parts themselves are a hex their mounting needed to be parallel with the indexing block. To line up the parts with the block, a parallel was held against the part while it was rotated into position lining it up with the front jaw on the vise. Blue Locktite was used to eliminate the possibility of the part moving. This line up method proved simple and effective.

To eliminate the possibility of the tap breaking, the drill chuck was held very slightly open to guide the tap. I used what I call a "Tapping Disc" (knurled aluminum disc with a set screw to hold the tap) to the rotate the tap. I have not yet broken a tap using one of these discs. I have snapped plenty of 4-40 taps using a tap wrench or by jogging the power switch. You would think one would have been enough! ;D

The photo below shows one union half being drilled prior to tapping.
The other half was clearance drilled for the screws.

I usually rough draw a part and attach it with a magnet to the machine I'm using. Later when the part is finished the drawing goes in the rubbish. After a few days I can't understand my own gibberish anyway! I hope someone out there can understand the picture below.
EDIT: The diameter of a round union should be .575" using the bolt spread and the spigot diameter in my drawing. The older round union is a smaller bolt circle with a very thin threaded spigot wall.

4) This last shot shows an earlier round union and the two hex unions I made today. This build requires only one union, I got carried away and made two.
I should have filed and sanded the stock prior to machining. After cleaning up one union (shown in pic) my fingers said... no more!

-MB

 

[4156df]

MB,

This is a very informative and useful thread. Thanks for sharing, and please keep it up!!

Dennis

 

[Metal Butcher]

Today I'll make the final parts needed to complete my modified version of Elmer’s engine. The reversing valve handle was made from 3/32" drill rod and then I added a simple brass knob turned and drilled in the lathe. I used a piece of slightly protruding #44 rod inserted into one port hole of the bearing block and then installed the valve. It was rotated back and forth to get the proper location for the two 1/16" valve stop pins. The 1/16" stop pin holes were drilled .189 deep into the bearing block. These pins will be held in place with Locktite applied during the final assembly.

The 3/16" model pipe was cut to length using measurements taken on the partly assembled motor. The ends were threaded in the lathe using a 3/16-40 die. Two pieces of 3/16” pipe 5/8" long were threaded on only one end. They will be used as the intake pipe and the exhaust pipe. The bend in the piping is accomplished with a threaded 90 degree cast bronze elbow. Later in the day I will make a thick gasket for the piping flange and also the cylinder head.

With the build nearing its end the wood base needed to be made. I used a 1/2" thick piece of walnut and I cut it to size with a powered miter saw and used a router to profile the edge. After the three bolt holes were drilled the first coat of Tru-Oil was applied.

This is my first year using a powered miter saw and router. In the past my wooden bases were hand made using a hack saw and disc sander!

-MB