Building Elmer's #29 Mine Engine

[Philjoe5]

MB - I'm sure the problem is on my end. I think it's something like what Bob is experiencing though I have dial-up.

Thanks for that tip too Bob, but I've had no luck trying to reload the page.

I had this problem a year ago, then it suddenly went away. Can you say "sudden unintended acceleration"? And geez I don't even have a floormat under my computer :big:

Cheers,
Phil

 

[Metal Butcher]

#32 I managed a few of those pesky little parts yesterday. To start making the 'rocker arms' I drilled and reamed the needed holes on brass stock milled to the proper dimensions. Below I'm milling the radius's on the two 'rocker arms'. I machined them on opposite ends of a longer piece of stock to make the milling t safer using a hand held rotating technique.

#33 After the outer radius was milled the cutter was shifted to the inside and lowered down to the same height as the previously milled out area that is half the thickness of the total height of these parts. Now I was able to do the inside radius. Sorry, I deleted the wrong picture again. I defiantly need a new computer, I can barely see what I'm posting and deleting!

#34 With the radius's finished, the excess material between the two 'rocker arms' was cut out using the band saw. To create the taper I held the pieces together with dowel pins and filed the taper on both pieces by hand.

#35 After one side was finished, I flipped the parts over and did the same filing on the opposite side. I forgot to mention that I tapped the ends for the 2-56 set screws after drilling the 3/32" and the 1/16" holes in both ends. 2-56 set screws?, Elmer must have run out of the small ones! :big:

#36 The radius's on the small ends were roughed out using a 42" belt sander, and finished up with hand filing. Since the pieces are just over 3/8" long it would have been very dangerous (down right stupid!) to attempt the radius's with an end mill. I could have made a fixture to make it safe to use a end mill, but this was much quicker and easier.

#37 The two 'links' were strait forward mill, drill, ream, and then radiused by rotating them against a cutter using a 1/16" pivot pin. The 'rockershaft' piece was created using the same steps and methods used on the 'rocker arms' and out lined previously.

-Rick

 

[zeeprogrammer]

MB...any chance you could make the pics a little larger? So I can see what it is you're making? :big:

Enjoying your thread as usual. ;D

 

[Metal Butcher]

MB...any chance you could make the pics a little larger? So I can see what it is you're making? :big:

Enjoying your thread as usual. ;D

Thanks Zee! Those silly parts are really small. I hope I can make it through this build without loozing my mind. Loozing my mind... Loozing my mimd... :big: :big: :big:

 

[Deanofid]

Aw heck, Rick. You know you like the small bits. You must.. You're good at it!

Making fine progress.

Dean

 

[Metal Butcher]

Aw heck, Rick. You know you like the small bits. You must.. You're good at it!

Making fine progress.

Dean

Hi Dean. Its all about fear!

I was afraid, very afraid of having to make them twice!

I focused my self into a different dimension of sight and sound.

When I snapped back to the real and current dimension the parts were finished.

It was a very strange experience! :big:

-MB

 

[ksouers]

... without loozing my mind. Loozing my mind... Loozing my mimd... :big: :big: :big:

No problem, MB! I was always told you had to have something before you can lose it

 

[Philjoe5]

I'm enjoying the progress reports MB. Now, the pictures are downloading OK. Could have something to do with that giant iceberg that got knocked loose :
Your parts are looking good. Course, I have to put on my headband magnifier to see 'em, but that's OK.
Cheers,
Phil

 

[1hand]

Great job on the small parts. You definitely have to be on your game when working in them tolerances.


Well done, and informative as always. Thm:

Matt

 

[Metal Butcher]

Hi, Kevin, Phil, and Matt. Thanks for stopping by to see my progress.

The overall size of this model is about right for my needs. The seemingly small parts that Elmer includes in the drawings are probably meant to be proper scaling. Its this very reason that I decided to stick with the original dimensions on the small tedious parts. They could easily be modified to simplify the construction. However, to do this would seriously alter the character of this beautiful design.

-MB

 

[Metal Butcher]

#38 In today's post I'll show how I made the 'crosshead guide' assembly. I started by cutting two rectangles from a flat 1/16" brass plate. I drilled the 1/16" hole through both plates. Then I milled out the 3/16" 'crosshead' slot, and milled the stepped profile seen in the photo below.

#39 I made a two piece filing button to guide my filing while I produce the 7/32" radius shown in the drawing.

#40 The small radius on top was milled by rotating the work piece against a small end mill.

#41 After the radius's were finished a little bit of sand papering was used to finish up the pieces

#42 In the lathe I machined up the face of a 1" piece of brass and machined the outer diameter down to 15/16". This will be the lower part of the 'crosshead guide' assembly. I drilled and reamed a 1/4" hole in the center before removing the collet and work piece from the lathe.

#43 The next machining steps require the use of a 'hex' collet block. Since it will be used in a vertical position, I checked it for squareness in that position. The squareness check showed that the bottom face of the collet was perpendicular to the sides of the block. If needed I would have chucked the block and collet in the lathe for a light truing cut on the bottom of the collet.

#44 Two slots that position the upright parts of the 'guide' will be milled into the disc. Their center lines will be located with calibrated table moves, and their length will be achieved by milling between scribed stop lines. The only accurate way I could think of doing this scribed layout of the stop lines was to use my surface plate and height gauge. This was the very first time I used my height gauge for this type of layout. Its a nice accurate tool, and I liked working with it, once I figured out how to use it.

#45 To center the spindle on the center line of the work piece I used the conical end of my edge finder. I have developed a good feel for this method by using the tip of my finger nail to 'feel' for a step that indicates an improper line up between the two surfaces on the edge finder.

#46 I milled out the two 1/16" slots with a four flute center cutting end mill. I started the first cut in the middle by lowering the quill .020" and traversing slowly to one end and then to the other. The following passes were from end to end with the quill lowered .025" at each stop till a depth of .120" was reached. To keep my view unobstructed, and the cutter free of chips, I used 2 lbs of air pressure delivered by aquarium air line tubing. The key to success is low air pressure for safety, and very, very, slow speed of cutter advance. I usually pull up a chair and try to relax with hand cranking this size of end mill.

#47 With the quill already zeroed out on the work piece, and a work stop in place the next logical stop was drilling out the six 'bolt clearance holes for the screws that will bolt the 'crosshead guide' to the top of the 'cylinder'.

I used a center drill to spot all six locations by indexing the collet block, and then I switched to a #43 drill to finish up by drilling all six 'bolt clearance holes'.

#48 The work piece and collet were returned to the lathe to drill out the center hole to the specified size, and to part off the disc.

#49 I machined up a 'space block' type of fixture with a drilled 1/16" through hole. This enabled me to accurately line up and space the parts for soldering.

#50 I used a very small amount of flux to control its flow distance, and the flow distance of the following molten solder. This minimized and controlled the visible size of the solder joint. I worked exactly as planed, and the result can be seen in the picture below.

#51 To finish up the 'crosshead guide' assembly I added a 1/8" round brass spacer that was drilled all the way through for the specified 1/16' line up pin. It seemed to me that the pin alone could be easily bent.

That concludes today's progress report.

-MB

 

[Deanofid]

It looks really nice, Rick. Clean soldering job, too.

Dean

 

[mklotz]

Very nicely done, MB.

I don't trust the center cutting feature on such tiny endmills. Whenever I have to make a blind slot like that, I drill a slightly undersized hole at each end of the slot. That way the mill isn't cutting much when I downfeed. Also the holes act as visible markers to prevent me from overshooting at the end of the slot due to inattention.

Your final product looks really great.

 

[Philjoe5]

Nice work MB. Keep the progress reports coming and thanks for taking the time to post the photos of your work.

Cheers,
Phil

 

[cfellows]

Beautiful work, MB. You gotta be proud of the way this is coming together.

Chuck

 

[ozzie46]

" Metal Butcher" !!! Harruuummmpppphhh!

Thats just false advertising.


Nice job MB. :bow: :bow: :bow: :bow:


Ron

 

[gbritnell]

Hi Rick,
Great work on the crosshead. I see you radiusing the ends of parts by hand and I know you have good luck with it but one of these days we'll have to have a quick tutorial on using the rotary table. I have to agree with Marv, it's not that they won't plunge cut but there's not enough room for chip clearance and when they clog, click, there goes the endmill.
George

 

[kvom]

Nice build going on there! ;D

And thanks to Marv and George for the slotting drill tip. I recently milled some 1/8" wide slots in aluminum using a 1/16" endmill while blowing compressed air to clear the chips. Predrilling the ends will be a good practice that I'll follow.

 

[Metal Butcher]

Thank you!, Dean, mklotz, Philjoe5, cfellows, ozzie46, gbritnell, and kvom.

Your compliments and interest in my current project are appreciated. You make the effort needed to post my progress reports worth while!

Marv and George, thank you for the tip and explanation. It all makes perfectly good sense to me, and I understand the out lined benefit of pre-drilling at the ends of milled slots.

I forgot to mention an idea that I had and tried when milling the 3/16" slot in the 1/16' flat brass plates. I milled it out with a 1/8" end mill first, and finished up with the required 3/16" end mill. I felt that the final cut would come out smoother if it had less material to remove, and that the smaller load could effectively minimize 'cutter deflection'. It proved to be a good idea, and that two cuts produce a better finish than one.

-Rick

 

[Blogwitch]

Very nice work indeed.

For anyone building more than one of Elmer's engines, it might pay you to make up a drilling jig.
Elmer tended to use standard sizes for a lot of his cylinders, and with one of these, you could drop it on and have all the holes drilled in minutes.

Bogs