Model Engine Maker
Engines => From Plans => Topic started by: toolznthings on May 14, 2018, 09:31:37 PM
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Hello All !
Finished another engine just before the N.A.M.E.S. show so now I have some time to do a post on the build process. Made to double size with modifications to the fastener
sizes for proportion and thread size. The plan dimensions are spot on for the links, etc. Went to square columns instead of round.
Started with the cylinder using a piece of 1144 round stock and made a block to the overall cylinder size.
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Hey Brian,
Another double size engine coming together. I’ll be following along... :popcorn: :popcorn: :popcorn:
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excellent, I love making double size elmers but I have not made this one yet :)
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Getting started on machining the engine cylinder from the squared up stock.
At the mill drilling through the block to give a starter hole for machining at the lathe. The cylinder bore is offset in the material.
After drilling a boring head is used to provide a undersized short bore for indicating the block at the lathe.
Indicating the locating bore and the face of the block in the four jaw chuck. Accurate indicating will insure that the bore will be on location and straight through
block and in position end for end.
After boring through and on size a tail stock center is added for turning the round end boss. A like operation is preformed on the opposite end.
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More machining on the cylinder ...........
From the finishing operations at the lathe the cylinder is set up at the mill to cut the two slots and drill three holes for the passages that will come from the steam chest.
The slots for the entrance to the cylinder bore were cut next on each end.
A separate setup is made on a tilt table to drill and ream the passages from the slots in the cylinder ends to the end slots milled earlier.
Center of the bore is located before the cylinder is set at the proper drilling angle. Stops are set so the cylinder opposite end can be machined by turning
the cylinder end for end.
The next operation drills and taps the exhaust port in the side thru to the drilled holes done when cutting the passage slots.
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Thought I had posted already but apparently not, even though I have been watching. Very nice work on the cylinder. The finish looks great too. Thanks for posting this one.
Bill
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As always,
Thanks, Bill :)
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Coming along nicely Brian! :popcorn: :popcorn: :popcorn:
That's an interesting tilting table you are using there. Could you post some more information about the table? Appears to be the right size to fit in the mill vise. I like it! :ThumbsUp:
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Brian,
Looks good, I will be following along. I appreciate how you are photo documenting the build process.
Art
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Finishing the cylinder and starting the cylinder head and base ............
Drilling and tapping the 6-32 holes for the steam chest was the next operation followed by drilling and tapping the cylinder ends, also 6-32.
At the lathe the cylinder head is being machined from brass. The outboard end of the head is turned and will be drilled and taped for the packing nut and thru bored for the piston rod.
After parting off and leaving stock the opposite side is machined with the register diameter that fits the cylinder bore. Cylinder bore is 1.000".
The base for the cylinder starts off being machined from round stock aluminum. A diameter to match the cylinder bore is turned on the opposite side X .062" long.
This disc will be machined square in the up coming operations.
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Finishing the cylinder ends ...........
Using my setup block to machine the final size of the cylinder bottom that will be square. Added some layout lines for reference I milled two sides in one setup. Measuring
across to establish the size. The second setup finished the last two sides. In a later setup using the mill vise the mounting holes were drilled. ( not shown )
The cylinder head was drilled using my small three jaw chuck mounted to a base plate and held in the mill vise. Clearance holes for 6-32 screws.
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Machining the piston rod and piston assembly ...........
Started by silver soldering a piece of brass to the piston rod stock leaving extra rod length. Set up in a 5-C indexer to machine the shape of the rod end and drill
and ream for the connecting pin.
At the lathe the rod length was machined and the diameter for the 10-32 thread to attach the piston was turned. Single point chased the 10-32 thread part way leaving
a straight section of the diameter.
Brass stock for the piston was faced,drilled,bored and taped. A test fit of the rod to the piston was made. A straight .188" diameter on the rod and a matching bore in the piston keeps everything aligned so the two can be dis-assembled and re-assembled.
The piston was fastened to the rod and a face cut was made to establish the piston width. Center drilled for the lathe center.
The piston O.D. was turned and a threading tool added some groves for oil.
The finished assembly where the piston can be removed for assembly to the cylinder head with the packing nut.
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The parts you have made so far looks fantastic and some nice pictures + text :ThumbsUp:
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Beautiful work Brian! I truly enjoy seeing the different set ups. :popcorn: :popcorn: :popcorn:
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Machining the piston packing nut and eccentric strap end ............
At the lathe I chased the packing nut threads and turned a diameter to leave stock for the hex end. Reamed to fit the piston rod.
Held in the indexer the hex end was milled.
Picture of the completed cylinder assembly.
I bored a blank piece of brass stock to final size to match the eccentric and set it up at the Tormach. Finding center with the dial indicator for part zero.
The brass blank is thicker than the finished part so the profile was only machined slightly deeper than the finished thickness.
Soft jaws were machined to hold the part from the first operation so the final thickness can be machined.
A later operation will machine a cross slot to hold the 1/8" x 3/8" strap that will complete the assembly of this part. ( future pictures )
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Great updates (and pictures). Still following along and enjoying the build.
Bill
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Great updates (and pictures). Still following along and enjoying the build.
Bill
Thanks ! :)
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Another finely crafted engine Brian. I really enjoy your documentation.
gbritnell
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The finishes you get are something to strive for. Very nice! :ThumbsUp:
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Finishing the eccentric strap and crank ...........
Set up the cam end of the eccentric strap to machine a .125 slot thru the end. Had to machine a piece of 1/8" x 1/2" to 3/8" wide for the link that
attaches to the cam end.
Made a setup to drill and ream two holes to pin the link. The far end of the link is reamed to .125" for a pin. ( not shown )
Machining a blank for the crank at the lathe. Faced, bored for the crank shaft and finished to thickness of .188".
Set up on the Tormach to machine the outside contour. Using a shoulder bolt thru the center bore and a SHCS thru the outboard hole. Aluminum plate
drilled and tapped for the set up.
Thanks for the comments and views so far ! :) :ThumbsUp:
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Upper platform and connecting rod assembly .........
Upper platform or " table " machined from aluminum that will support the crank bearing blocks.
The connecting rod assembly has two ends and a threaded rod. The small end machined at the manual mill and the circular end done on the Tormach.
The connecting rod has 10-32 threads chased on both ends.
The larger end is a simple mill,drill, tap and ream operation.
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More nice work. About time for a family shot perhaps :)
Bill
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More nice work. About time for a family shot perhaps :)
Bill
A little ways to go , more parts to view. :)
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Machining the arms,links and eccentric .....
Two arms required and manually machined with several setups to mill ,drill and ream.
The links were drilled and reamed leaving stock and the reamed holes were used to fasten the stock to a fixture plate for machining the outside
contour at the Tormach.
The eccentric stock was bored and offset in a four jaw chuck for turning. Drilled and tapped for a set screw to complete.
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Coming along nicely Brian! :ThumbsUp: :ThumbsUp: :ThumbsUp:
I always enjoy seeing your different set ups. :popcorn:
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Machining parts for the steam chest .....
Setup on the Tormach to machine thru the center of the brass block and machining the round boss.
At the manual mill the reamed hole for the valve rod was completed along with the tapped hole for the packing gland.
Machining the packing nut threads at the lathe and the thru hole for the valve rod.
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Valve rod machining .............
Silver solder a piece of brass on the end of steel stock for the end link.
At the lathe I turned the brass to true up and establish the length ans .375 diameter.
The overall length was finished next and the 10-32 threads and pilot diameter were turned next.
Using a indexer the final shape of the brass end was finished. Set up in the mill vise with tall jaws the end slot and reamed cross hole completed the rod.
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Flywheel and some assembly .........
Machined the flywheel blank at the lathe and machined the spokes at the Tormach.
Assembly of the steam chest and cylinder.
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More very nice looking parts Brian. Still following along with interest.
Bill
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More assembly pictures ......
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Things are in the final stretch now Brian. Shouldn't be long before you have a nice runner there.
Bill
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Beautiful :ThumbsUp:
Thomas
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Some pre-assembly pictures I forgot to post showing the finished parts.
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Nice collection of parts Brian. I love the flywheel too!!
Bill
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Nice collection of parts Brian. I love the flywheel too!!
Bill
As always, Thanks !
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Excellent family shots! Thanks!
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Finishing the build ......
Thanks for the views and comments !
Brian
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The engine runs great ! Happy with the plans and the overall project.
https://www.youtube.com/watch?v=e-41GdqoLwQ
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Hello Brian,
Man I love that slow-motion running on your beautiful engine, great job.
Have a great day,
Thomas
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Stunning Brian. Very well done!!! And a lovely runner too.
Bill
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Beautiful and I think a great show piece.
I think people would really enjoy seeing that action.
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Artistic build and poetic motion :ThumbsUp: :ThumbsUp:
Whiskey
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Really nice looking engine, and I love how slow it can run.
So, how much of that is from the design of the engine, and how much is from it being 2x size? Seems like the larger flywheel would really help allow it to turn slowly and keep going.
Nice engine, Brian. You should feel good about that!
Kim
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"So, how much of that is from the design of the engine, and how much is from it being 2x size? Seems like the larger flywheel would really help allow it to turn slowly and keep going."
I machined everything paying attention to accuracy so there would be minimal friction with all the parts assembled.
Fortunately the dimensions on the plans were spot on which eliminated any problems. The flywheel is not exact 2X scale. Used the material I had on hand.
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Great job Brian. Love watching it run.
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Brian,
I like the way it runs so nice at low speeds. The motion is interesting.
Kudos
ShopShoe
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Nicely done Brian, it looks and runs great!
Dave
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Hi Brian, a beautiful looking engine and it does run sweetly. Congratulations, it is really impressive, and great to see a different alternative to a cross head in action.
A double scale flywheel will have a larger moment of inertia in proportion to the I fine size, so while the smooth slow running always indicates accurate workmanship, the scale factors basically mean the flywheel should be more effective than the one on the smaller machine.
Basically, moment of inertia is proportional to mass times radius squared. So if you double the scale, the flywheel will have eight times the mass, but the larger radius means the moment of inertia will be 8 X 4 = 32 times. The work output of the engine is proportional to the displacement, so with the same pressure, 8 times the smaller engine. If we assume this is in proportion to the work required to be stored in the flywheel to turn past the dead centres, the flywheel moment of inertia is probably still four times larger in proportion to the model size. So even if you used a bit smaller one because it was at hand, it is still most likely larger in proportion, and that always improves speed regulation (reduces speed fluctuation within each revolution) and more easily carries the engine past the dead centre at slow speed.
MJM460