Author Topic: An Upshur Farm Engine (slight return)  (Read 57246 times)

Offline tvoght

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An Upshur Farm Engine (slight return)
« on: July 27, 2012, 01:43:09 AM »
This build was started on another site, and I've decided to continue it here. To make it a complete document, I'll have to repeat all that's been said from the beginning.
For all who have seen this before, please bear with me until we catch up to present day.

I've really enjoyed the build to this point, and I think the Upshur Farm Engine plans are probably a great choice for anyone undertaking their first internal combustion engine.

As always, I welcome any and all criticism.

Here goes.

--Tim

Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #1 on: July 27, 2012, 01:44:14 AM »
While sticking to the plans for all critical dimensions, I'm taking
some license with the appearance of the frame and cylinder. The plans call
for the frame to be built of 1/4 aluminum plate, but I have some cast aluminum
tooling plate on hand that I want to use. It's 5/16 thick, and I'm going to
use the extra thickness in places to add decorative touches in relief.
In the following photo, I've rough sawn a couple of side frame pieces
and clamped them on top of each other on a sacrificial tooling plate of the
same material. The sacrificial piece was a little small, and the lower right
corner of the work pieces extended over, thus the weird clamping of a little
corner piece for support.



Here, I've side-milled the bottom and right sides, cutting a little into
the tooling plate. Referencing from the machined sides, I drilled two screw
holes where the back plate will attach to the sides. The side-milled
surfaces looks a little rough... By the way, whereas the plans have the
frame fastened by cap screws clearly showing all around, I intend to hide
all the screws in counterbores and then plug the counterbores to give the
appearance of a one-piece cast frame (to be painted).



The clamps were then switched opposite to mill the other two sides.


Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #2 on: July 27, 2012, 01:46:22 AM »
I clamped the milled-to-size side plates side-by side in the vise to
shape their top edges. Since the frame is to be one piece when finished,
the crankshaft can't be installed by removing one of the sides, as in the
original design (which has the bushing holes bored directly into the
sides). This one will have bushing caps to be removed for crankshaft
access. Ahead of the bushing caps is a protrusion where the cam gear axle
will mount. This is all a little fancier than the original, in which the
side plates had flat, featureless top edges.



I drilled and counterbored for the bushing cap screws (with markings so I
can hopefully put the caps back where they came from after I separate
them). I drilled first for 6-32 tapping deep enough to go well past
the caps and into the sides, then enlarged for 6-32 clearance just past
the depth of the caps. Note that I accidentally cut too deep when I
milled the top of the cam axle mount to height. As luck would have it,
that feature is only needed on the left side, so the boo-boo will be
milled off of that other plate.



Here I'm preparing to saw off the bushing caps. There were unanticipated
clearance issues here, but I finally worked it out, still knowing I would
not make it all the way left without getting into the cam axle mount.
I went as far as I could on one side, then on the other, stopping just short
of hitting the other feature.



The plan was to finish the cut with the saw blade held between my fingers.
Slowly and awkwardly back and forth. It worked, and the operation wasn't as
onerous as I thought it might be.



With the bushing caps removed, the area where they had been was milled
level, and the cam mounting feature was rounded over. Yikes, I have a bit to
learn about locating the rounding-over bit. A bit of filing is in order...



The bushing caps were cinched side-by-side on a parallel in the vise, and the
mating surface with the sides milled flat. The caps were then flipped, and
the top corners rounded. Better this time. Maybe I'm getting the hang of it.



Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #3 on: July 27, 2012, 01:48:14 AM »
Back to the tooling plate, where it took some effort to get the plates
aligned with each other and square to the mill. I had previously drilled
the screw holes well into the tooling plate so that I could use drill bits
as alignment aids when clamping the sides back down. This helped some,
but was still too sloppy for good alignment. For final alignment, I used
some short parallels along the edges and aligned with the mill cut in the
tooling plate. Had I known that's how it would end up working, I'd have cut deeper
into the tooling plate to give a good solid edge to align the parallel
with (I've got a nifty set of small 3" long parallels which performed
admirably here). I've experimented with a variety of edge-finding
apparatus, and now I'm using a collet-mounted hardened rod with
cigarette papers or feeler gauges to touch off the part. It's working
for me. You see the rod here. The top and right edges were found, and
the DRO zeroed for the center of the crankshaft bore.



Once clamped down, and with the top edge located, I re-attached the bushing
caps (did we miss the part where I tapped the side plates 6-32 for
the caps?). I then center drilled, drilled and reamed the crankshaft
bushing bores (drilling well into the sacrificial plate). I then counter-bored
the screw holes on both side plates.



Back in the vise, and using a bushing to aid alignment, I prepare to
angle off the back at a 45 degree angle.


Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #4 on: July 27, 2012, 01:49:14 AM »
I cut out the frame front on the rotary table. No tooling plate was used,
since the stock is 5/16" and the finished plate will be 1/4" thick. I'll cut
a little deeper than a quarter inch and then flip the plate and cut to
thickness to release the part. It's a little more complicated than that,
because I'm going to leave a full-thickness decorative feature on the front
of the plate. You'll see further down. A little paper template is used
to help me in aligning the clamps without interference.



I drilled and reamed a 3/8 hole at the cylinder center location and four
screw holes where the sides attach. I intend to use these holes to help
with alignment when I flip it for adding the decorative feature.
We'll see I have a little trouble with that.



Here, the sides and bottom have been milled to a depth of .29.



The top arc has been cut to the same depth, and the cylinder hole opened up,
though still not to size, I intend to bore the cylinder hole and face the
front in one operation when the frame is together as one one piece, and there
is a dummy crankshaft rod installed for square alignment.



The plate is flipped and I use my handy-dandy locator rod to center it up
and give me the center of the rotary table as a reference. The plan was to
use the four screw-holes as aids to align to the axes, but that attempt
failed because I forgot to lock down the rotary table! We'll see further down
how that resulted in my decorative feature being somewhat misaligned.



Here you can see where I've outlined the rectangular feature with a ball-end
mill and then milled everywhere else to a depth of .0625 to release the part
and reduce it to a depth of .25. I'm just about to cut it free here.
Notice that the upper half or so is .031 thicker. Again, the plan is to
face that off and bore the cylinder hole in a later step when the frame is
assembled. Some other features will be added at that time, too.



There it is. The misalignment of the relieved decoration is not real obvious
in this shot, but it is visibly out when viewed straight on. I'll clamp it
down later and square it up with the ball-end mill.

« Last Edit: July 27, 2012, 02:07:48 AM by tvoght »

Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #5 on: July 27, 2012, 01:50:08 AM »
The frame's back plate is made a lot like the front plate. I clamp a piece
of stock to the mill table and Mill the outline .270 deep.




I align the machined edge to the mill slot by sticking 5/8" dowel pins in
the slot and holding a parallel (or a square for perpendicular alignment)
against the pins. I then have a reference to press the workpiece against.
I've lined this up so I can squarely put another decorative feature on this
part.



The decorative feature is milled .0625 deep with a ball end mill, and then
the surrounding area with an end mill to the same depth, ending with the
outer edge to separate the part.



Here is the freshly separated part, and you can see remaining material where
the part separated. That will have to be filed away. Worse, It seems I went
a thou or two deeper with the ball-end, meaning a good deal of cleanup to
get rid of that groove. Live and learn.



Here it is after a lot of cleanup with file and emery.



I drilled and tapped holes along the edge where the side plates attach, and
then on an angle block in the vise, milled the 45 degree angle that will
match the angle at the back of the frame sides.



I just had to fit the completed parts together for a look-see.



Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #6 on: July 27, 2012, 01:51:38 AM »
The front plate with the crooked decorative relief on it was clamped down
on the mill table (straight this time) and the feature trued up with a
ball-end mill.  I now have the 4 plates of the frame as I want them at
this stage. As I said, the idea is to make this frame appear as one
monolithic piece instead of 4 plates screwed together. I cleaned
everything up in soap and water, let it dry out, and then stuck it together
with 609 loctite. With everything lined up just so, I tightened the screws
down hard.

I turned down a quarter inch aluminum rod in the lathe to the size of the
counter-bores for the screws. Then I cut off eight little plugs (manually,
with a hacksaw), facing off after each cut.

I mixed up a small batch of JB Weld, and smeared a glob on the smooth end
of each plug, then plugged each counter-bore with one. The hack-sawed ends are
protruding (as you see in this photo), and I intend to file or mill them
flush later on. When the frame is painted, I hope there is no trace of
these. Think it'll work?


Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #7 on: July 27, 2012, 01:52:51 AM »
The one-piece frame was clamped down true, and areas were reduced to 1/4"
thick so that the cam and push-rod will have the proper dimensional
relationship to the cylinder. The forward area of the sides was reduced to
meet up properly with the front plate.



Clamped on the other side, again the forward area was reduced to meet the
front plate.



I put a .500 ground rod through the reamed crankshaft bushing holes and
clamped up straight against the side of a large v-block. I indicated the rod
to be sure it was parallel to the mill in the y and z axes, Then I cleaned
up the front plate with an end mill.



I bored to size the hole where the cylinder sleeve will seat in this
setup. The two cylinder mounting stud holes were drilled and tapped in
this setup as well (not shown in this shot).



I like the appearance of depth I got here. It's got some character.
I'm pretty happy with the way the plugs in the screw counter-bores worked out.
They're mostly invisible, except on in front that was mostly milled away.
On that one though, the JB Weld fills the void and there is a smooth surface,
it's just a different color.



Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #8 on: July 27, 2012, 01:55:47 AM »
I made a cylinder sleeve tonight out of cast iron (durabar).
I began by making a plug gauge with progressive diameters of .748,
.749, and .750. Here is a closeup.



The durabar comes oversize. The nominal 1" stock came in at about 1.1.
I started by turning it down to 1". Action shot!



The ends were then turned down to .875. I still haven't learned the good
and right way to turn a part like that to the left; between the chuck and
a right shoulder. I struggled with various tools, trying to match cutting
depths and to get the length to the shoulder right. The results are useable,
but I wish I knew how to do this.



I drilled in successive steps to 11/16" and then began boring. I had been
dreading this. I don't like boring. Using a telescopic bore gauge, I brought
it to .748, and then checked it with my plug gauge. Pretty close. The .749
step of the gauge went through, but not the .750. I took one more boring pass
at the same setting. After that, the .750 step passed.
After cutting off, I checked the other end, and the .750 step passed there
too. The feel suggests there may be a couple of tenths of taper from end to
end.





Here it is after cutoff.



--Tim

chuck foster

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Re: An Upshur Farm Engine (slight return)
« Reply #9 on: July 27, 2012, 02:32:57 AM »
looking good tim  :ThumbsUp:

i have never built this engine but i know a few people who have and they say it is a great engine to build.
you look like you are off to a great start and in a short time you will have a nice little engine to play with i mean run  ;D

keep us posted on your progress.

chuck

Offline rudydubya

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Re: An Upshur Farm Engine (slight return)
« Reply #10 on: July 27, 2012, 03:19:17 AM »
Thanks for putting your build over here Tim.   :ThumbsUp:    I'll be following along with interest.

Regards,
Rudy

Offline gbritnell

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Re: An Upshur Farm Engine (slight return)
« Reply #11 on: July 27, 2012, 04:21:24 AM »
Excellent work Tim and excellent documentation. I know how much time it takes to stop and take good pictures while your working. The extra detailing sure looks nice.
gbritnell
Talent unshared is talent wasted.

Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #12 on: July 27, 2012, 12:36:40 PM »
Thanks Chuck, Rudy, and George for commenting.

The Upshur plans suggest two possible ways of making a built-up cylinder
for the horizontal water-cooled version of the farm engine. I chose one
which uses a common hardware store item, which is a 'tailpiece' for a
lavatory drain - a piece of chromed thin-wall brass tube.
I first had two turn two aluminum rings to slip over the turned-down ends
of the cylinder sleeve. I don't have pictures of the process, but I chucked
a 1.5" piece of 6061 rod and drilled and bored it for a slip fit over the
sleeve ends, then turned outside to slip into the brass tube, and then
parted off the rings. Here are the rings slipped onto the sleeve. They
will later be loctited.



Here you can see how the sleeve slips into the hole bored in the frame
front.



And finally, here is the tube I got at the big home improvement store.
I chose this method of building up the cylinder because it seemed simple,
but I realize I have a problem: cutting the thin-walled tubing to length.
Does anybody have any ideas? The best idea I've got right now is to make a
sort of expanding mandrel out of wood, and cut it off with a cutoff tool
in the lathe. The cutoff doesn't have to be perfect I guess, because I
can face it off smooth after it is JB welded to the rings (which will be
loctited to the sleeve). Still, I don't want to distort the tube in the
process.



Thanks for watching my build!

--Tim

Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #13 on: July 27, 2012, 12:38:13 PM »
I wanted to get that thin-walled tube cut and out of the way, so
I proceeded with a variation of the wood mandrel plan I outlined in the previous post.
If it's possible to hurt a metal lathe's pride, I did my best here. I
chucked up a piece of hardwood and turned it down for a slip fit inside
the tube. I'm sure many are offended.



I sawed off the round chunk and slipped it inside the tube for support,
then chucked the tube. On this first try, I tried protecting the tube with
paper and not tightening the jaws much. I was going to cut gently.
Purists please note I have already mostly cleaned up the sawdust.



The cutoff results were a little strange. As I cut with the cutoff tool, a
brass band occurred to the right of the cut. As if the silvery coating was
stripping off over there. I cut through and discovered my cutoff portion was
too short. There is in fact a step detectable with the fingernail between
the brass portion and the silvery part.



I tried again, this time using pieces of aluminum Indiana license plate
at the vise jaws to protect the tube. I tightened down good. This time
I got a good cut at the correct length.



Trial fit.



The water hopper, which Upshur assures us is a purely decorative feature,
comes next.

Until then,
--Tim

Offline tvoght

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Re: An Upshur Farm Engine (slight return)
« Reply #14 on: July 27, 2012, 12:40:18 PM »
Now I get to a part I had been looking forward to. The water
hopper. This is pure style, and the part that will give the engine its
personality. I started by chopping off a hunk of 6061 on my newly-
acquired import band-saw. I squared it up in a series of milling vise
operations.



The next step was to setup an angle block at 45 degrees and bevel the
upper four edges.



Then I milled out the hole at the top. I'll be milling the cavity from the
bottom to meet up.



I cut an inset portion on each side. This is not only decorative, but will
provide a clamping surface for later operations.



Then I set up the angle block for a 5 degree incline and milled the sides.
I'll mill until I reach the where the inset portion meets the upper bevel.



Like that.



I clamped the part upside down in the vise. You can see here where I clamp
at the insets. I'm using accurate aluminum tooling plate as clamping parallels.
I'm preparing to mill out the semi-circular tunnel that will seat on the
cylinder tube. Using an end mill that has seen better days, I chop out a
goodly portion in preparation for stepping out the circle with a ball end
mill.



The step-off procedure proceeds.



That's done. Of course a CNC machine would be nice, but I wonder if it
could be as satisfying as this.



Finally, I hollow out the water cavity to meet up with the top hole I cut
out earlier.



All machine operations complete.



Getting the idea. I want to slightly radius the hopper edges by filing, I
hope I don't ruin it in the process.



Thanks for viewing,
--Tim

 

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