Building Elmer's #29 Mine Engine

[Metal Butcher]

#1 Well, after sinfully wasting two days admiring my own work, Its time for me to start another build. Its amazing how fast time can pass while watching an engine run.
I've wanted to add Elmer's #29 Mine Engine to my shelf of completed projects even longer than the #41 and #33. I allways considered it on the difficult side when compared to all of Elmer's other engines.

At the start of November 1st I set a goal to build ten engines by April 1st. And It looks like I should meet my goal with the completion of this build.

Below is a picture of a few extra parts I made while working on my previos builds. The cylinder is almost finished, the eccentric and crank disc is finished, and there are enough pieces to choose from to solder up an eccentric strap of proper length. All of the other extra parts are specific to my previos builds. There is a good amount of small fiddly parts to be made, but overall this build shouldn't be too difficult. I will try to add a reversing mechanism similar to what Blogwitch and Daves Wilmhurst used on their versions of the #29 Mine Engine. It appears to be a simple mechanism the shouldn't be too difficult to engineer. I wonder why I haven't seen a mechanism like this up until now, or on a horizontal mill style engine.

#2

-MB

 

[Philjoe5]

Hey MB, I'm looking at your start date and the pile of parts you've already got and I'm feeling . Namely because I started my Mine engine in early January and I haven't got a much bigger pile of parts ;D

I'll be watching your build with much interest.

Cheers,
Phil

 

[1hand]

Now I see how the making "practice" parts is a big help. :big: Great thinking. Thm:

Matt

 

[Metal Butcher]

Now I see how the making "practice" parts is a big help. :big: Great thinking. Thm:

Matt

A lot of the extra parts 'were' either for back up and/or practice. But plan 'B' was to build the #29 if everything went well, and it did.

I would have built the #29 any way, but going over the same territory with certain parts three times seemed a bit silly, and a good thing to avoid. Plus, with a few parts semi finished I can concentrate on goofing off a bit.

Maybe a bit more than usual! :big:

-MB

 

[cfellows]

Looking forward to it MB. The mine engine is one of Elmer's best designs (one of many) in my opinion. I'm sure your build will be a magnificent example (No pressure there, huh?).

Chuck

 

[BigBore]

ALL RIGHT! I'm multi-tasking. Now I'm copy/pasting and making PDF's of two builds of basically the same engine. This is going to be great. This engine is really impressive and I'm sure I'll learn a lot. Looking forward to these.

Ed

 

[Metal Butcher]

Hey MB, I'm looking at your start date and the pile of parts you've already got and I'm feeling . Namely because I started my Mine engine in early January and I haven't got a much bigger pile of parts ;D

I'll be watching your build with much interest.

Cheers,
Phil

The start date is not totally accurate since the few extra parts I'll be using and show were made last month. I saw your progress and I think your coming along just fine.

Not to sound like I'm bragging, but I built 29 engines in the same time frame last year. They were simple builds with a most of them being duplicates. At one point I was power tapping 4-40s, and doing other silly things that I don't do any more. Speed without accuracy is point less. After all this is a hobby, not a contest to see how many taps or drills we can break!

Thanks for showing interest in my builds.

-MB

 

[Troutsqueezer]

MB, I would like to see a picture of your engine display. Must be quite a conglomeration. I imagine you'll have to put the camera in wide screen mode to get them all in one shot, eh?

-Trout

 

[Metal Butcher]

ALL RIGHT! I'm multi-tasking. Now I'm copy/pasting and making PDF's of two builds of basically the same engine. This is going to be great. This engine is really impressive and I'm sure I'll learn a lot. Looking forward to these.

Ed

Thanks Ed. I can't wait to see you start making a mess of your own shop! :big:

I was looking over the plans and this is a fine looking engine design, and probably one of Elmer's finest. I'm all pumped up and ready to start making a mess of the place.

I think I'll start adding some easy to follow dimensions and machine moves to make any follow up builds a little easier for the next guy.

-MB

 

[Metal Butcher]

MB, I would like to see a picture of your engine display. Must be quite a conglomeration. I imagine you'll have to put the camera in wide screen mode to get them all in one shot, eh?

-Trout

Hi Trout. I'm definatly going to shoot a picture of the entire collection, I promise! Probably around April 1st.
Its not at all that big. Most of last years build were duplicates that found new homes.
And the few I built prior to joining the forum are... well.. not that great.
I'll keep my promise, but remind me if I forget. :

-MB

 

[Metal Butcher]

Looking forward to it MB. The mine engine is one of Elmer's best designs (one of many) in my opinion. I'm sure your build will be a magnificent example (No pressure there, huh?).

Chuck

Thanks Chuck.

No pressure at all.

The audience can only complain.

No chance of being hit by thrown vegetables or fruit on this stage! :big:

-MB

 

[Metal Butcher]

#3 I'll start today's post by showing the the milling set up used to square up and size the plates and blocks that will become the main structure of my build. I generally use aluminum due to its low cost and ease of machining. I carefully picked 6061 over 2024 for the pieces, to make the drilling and tapping a bit easier. The 2024 that I have is also difficult to file smooth without running into the pinning problem that can cause scratches that are difficult to remove.

#4 Below are all of the structural pieces machined to accurate dimensions, and checked during the milling steps, and afterwards to be sure their square.

#5 The original plan (page 125) show the floor to be the same width as the sub base. However, the general drawing (page 144) shows a 'floor' ledge all the way around. I wanted the floor to have an equal protruding ledge on all three sides, and also the same amount in front of the bearing block. So I drew up my own dimensions for a new 'floor' plan. Below is the drawing with the new dimensions I used, and it also includes the mill table moves should any one care to go this route.

#6 Below is the 'table' being drilled for the six 2-56 screws that mount it to the 'cylinder'. the four corner holes were drilled #32 for 4-40 screws. In the drawings I changed all of the 5-40 to 4-40 screws to simplify the build. I do not have any 5-40 screws, and I could only find flat head 4-40 x 1'' long screws to go up through the base.
I'll get back to the 'table' later on in this post.

#7 I spent a little extra time to draw up the machine moves for drilling the six bolt hole pattern in the 'table'. It helped to eliminate the usual chaos and confusion I go through working off of scattered about papers with math calculations. I followed it and the cylinder bolted on perfectly. So I guess is safe to use the info to save your self some time if your building along, or planing to build one in the future.

#8 This group shot shows the progress made so far.

#9 Below is the 'base' being slotted. The taper (draft) on all the sides of the 'base' and 'sub-base' will come last. I'm milling the 9/16" wide by .250" deep clearance slot for the 'crank'. I centered the spindle at .9687 from the bearing block end and milled it out with several light cuts using a 9/16" end mill.

#10 Milling two steps is the first operation needed to create the profile on the bearing cap.
I set the end mill at .125" down from the top of the 'bearing block, and eye balled the cut up to the scribed line. With one side done, I rotated the piece 180 and with one slow pass duplicated the cut on the other side.

#11 The first step in profiling the larger out board 'bearing' block was to reduce the width of the upper part to .750" by milling off .250" from both sides.
Once I reached the scribed line the hand wheel was zeroed out. The piece was flipped over- and- up against the vise stop to duplicate the cut on the opposite side when the hand wheel reached the zero mark.

#12 The bearing cap profile was done the same way as the smaller 'bearing' cap. Lower the cutter .125" from the top and bring the cutter in-and-up (Y-table movement) to the scribed line, rotate and repeat with out a need to move the cutters position by traversing the X-table movement..

#13 The last bearing cap I profiled, I did the whole thing with a file. Nooo, not this time. I did a little trimming that will reduce the filling time by about seventy five percent.
My fingers are still sore, but my finger prints are slowly coming back! :big:

#14 Skip this picture and go to the one below. I goofed, this one was supposed to be deleted. :

#15 This ones better! I determined the angle part of the bearing' block to be 20 degrees. I attached an angle plate to the fixed jaw of my vise with double sided tape (double stick). To set up the piece I added a 1/4' tool bit under the reduced area. Its important to get this right by shimming with cellophane tape if necessary. After the first side is cut away there isn't much to support the piece for an accurate set up when the piece is flipped over to cut the opposite side.

#16 Here is a picture of how-not-to-do this decorative hole. I know better and should have done this while the 'bearing' block was still a full rectangle. To prevent a collapse of the 'bearing' cap hole I added the 'filing button' to give it support, and luckily it was originally machined up to be a fit tight in the bushing hole. I was lucky that it worked without a problem.

#17 In the picture below I machined out the slots for the connecting rods. After plunging through with a 3/16" center cutting end mill I traversed the table along the X-axis till the end mill reached the scribed line. I zeroed out the hand wheel and traversed in the opposite direction to reach the other end and scribed line, and wrote down the number on the hand wheel. After returning to the center of the slot I raised the quill and flipped over the piece. The second slot was duplicated by using the scribed lines as a guide to reach the previously noted hand wheel positions.

#18 The horizontal lines are the center line of the end mill, and the vertical line figures are for scribing the end of cut lines.

Let me know if you would like any additional details or clarification.

-MB

 

[Twmaster]

Rick, I just love following your builds. You take such nice photos and give pretty nice descriptions of the process at hand. Thank you.

 

[Metal Butcher]

#19 I milled the taper (draft) on the 'base' and 'sub-base' using a five degree tapered three flute end mill. The height of the cutter was setup with a clearance of .005" above the vises jaw using a feeler gauge. Then I made test cuts on a scrap piece as the cutter was brought inward. It took several cuts and adjustments using an eye-ball method to get a small step on the lower part of it in the vise. This "step" was filled off to see if the taper would extend all the way down to the bottom of the work piece. I needed to move the cutter in one more .001", and with a bit more file work the taper was satisfactory. Now I could cut all four sides on both pieces with one cut and one return pass (climb cut), with out moving the cutter. The return pass smooths up the original cut and returns the cutter to the starting position to cut the next side. This is a very easy method that gives good results.

In the picture below you can see the "step" near the bottom of the side closest to you.

#20 I got anxious to see the progress and loosely stacked the parts together.

#21 I used my usual simplified method to make the 'columns'. A stop rod was mounted in the tail stock chuck and brought up to the 1/4" column stock that was set up sticking out of the head stock chuck about a 1/4". The hand wheel on the tail stock was zeroed out, and the carriage mounted cut off tool was adjusted using a rule to get it in position.

After backing off the 'stop rod' I cut the first column. It was .005 oversize in length. Not a problem, I simply moved the carriage .005 towards the tail stock, re-set the hand wheel to zero, brought the stock forward towards the stop rod, clamped it down with the three jaw, backed off the stop rod. And cut the next column. Using this method I was able to cut three identical length columns. Rather than cutting a fourth column, I trimmed the first one down in length to match the other three.

I finished up by drilling and tapping both ends on the four columns with 4-40 thread's. Now I can use any choice of hardware I wish to mount the 'table' that supports the 'cylinder'.

#22 On the bottom of the columns threaded rods were installed with a 1/4" left protruding. These will thread into the 4-40 threaded "through holes" in the 'base' to meet the screws (half way) that come up from underneath and through the 'floor' and 'sub-base'.

#23 Last time I filed "bearing cap profiles" my fingers took a toll. This time I used a damaged tool makers vise to hold the work pieces, and added an inexpensive clamp to reduce the chances of over filing onto the flat portion of the caps.

I bought this vise specifically for filing, and forgot about it, and its purpose up until now.

#24 With both sides of both 'bearing' blocks filed to shape all that's needed now is to blend file marks with some sand paper.

#25 I assembled the parts for a test fit, and every thing fits perfectly. On this project I'm following Troutsqueezer's approach and building from the ground up!
On my previos builds I bounced around like "A tennis ball in a heated match". :big:

-MB

 

[Metal Butcher]

#26 I managed a full day down in the shop yesterday and made a few very time consuming parts. Neither one of the parts were remade or duplicated. Its hard to believe that I only made the two parts. :

I didn't have any 3/16" square stock so I used 1/4" steel square to make the cross head. I turned the two diameters and threaded one end, and then reversed the piece and did the same on the opposite end. No, I'm not showing off my well maintained and manicured fingers! The reason I include my finger(s) in certain pictures is to give my finicky camera a focus point.

#27 The 'cross head' mounting point was centrally cross drilled with a # 41 drill as shown in the plan. And then I milled down all four side equally to reduce the square area down to the specified 3/16". I could have milled the blank first, but decided that it would be a bit easier this way. It eliminated the need to protect the final surface from the chuck jaws with brass shims.

#28 After a few swipes with a file to remove the marks left over from the milling operation the part was finished.

#29 For the 'valve crossbar' I used the same 1/4" square stock. I followed the same steps to produce the two diameters on one side and reversed the piece in the chuck to duplicate them on the opposite end.

The diameters on this part are much smaller then on the 'cross head'. The 1/4" square section came in handy to secure the part while cross drilling the 1/16" ends with a #70 drill for the "cotter wires." The tiny #70 drill bit looks silly in my 1/2" chuck. I just remembered that I have a small "pin chuck" I could have used! Oh well, next time.

#30 Without any further need for the oversize 1/4" square section, it was milled down to the 3/16" x 3/32" specified in the plan.

It took a lot of will power to keep myself from modifying these tiny parts to something a little larger and more manageable. One of my original parameters for this build was to stick closely to the original plans, and avoid changes as much as possible.

#31 I focused on making these two parts as close to perfect as I could. With them finished up I feel it was time well spent. I can now move forward and on to the next few parts that will also require a good amount of time and patience.

I have to admit that this engine has a lot more fussy/tiny parts then I have ever encountered on a previous build. It took me two years to get enough experience and courage to tackle this project. Now that I'm on my way, and there's no turning back.

-Rick

 

[Philjoe5]

Nice work MB. You're making good progress. For some reason not all of the pictures are downloading presently.

Its hard to believe that I only made the two parts.

I know what you mean. I spent several hours today just milling the steel blanks for my bearing blocks and I was not removing a lot of material. Not much to show for it.

Keep up the good work and photos

Cheers,
Phil

 

[Metal Butcher]

Nice work MB. You're making good progress. For some reason not all of the pictures are downloading presently.

I just checked, and the pictures are uploading OK on this side of the pond. Down loading? ???

Probably just a temporary glitch. I can't access the forum two to three times a week, and sometimes for over an hour on a bad day. Never hear any mention of any one else having this problem.

Thanks for the compliment Phil.

Rick

 

[ksouers]

You're a glutton for punishment with those tiny parts, MB!

I'm enjoying this, though. I'm right there in the mud with ya!

 

[Maryak]

Nice work MB. You're making good progress. For some reason not all of the pictures are downloading presently.

Phil,

This happens to me from time to time when I use multiple tabs and grab a heap of bandwidth. Try reloading the page. This usually works for me and I have a wireless modem which can be a real PITA when everybody is home in the evening here.

Best Regards
Bob

 

[NickG]

Yep, nice work MB glad I've found this thread, I really like the Mine Engine.

Nick