Lauson LA build

[b.lindsey]

That is some really beautiful work Craig. The detail is incredible!!

Bill

[Art K]

Craig,
This engine is really starting to take shape. I must admit never having heard or seen of the Velstro attachment for a mill before, but I can see how handy it is in the right hands. I also wouldn't have thought of pushing the valve seat/guide in before moving on. Experience really counts, thanks for the tip.
Art

[Craig DeShong]

Bill, Pete, Art, Admiral, Dave, and all of you following but haven’t commented; thanks for your interest.

After two more solid days of work (sure is nice to be retired - I highly recommend it for everyone) I’ve done about all I can do to this chunk of aluminum I’m calling the main block.  Yes, there are a few tool marks here and there that I’d prefer weren’t present , but no major errors and it’s about as good a job as I can expect myself to accomplish.  I’m quite pleased with it.

I didn’t take other than one picture, that of cutting the fins.  Once again the rotary milling head made this task pretty straightforward.


The remainder of the work consisted of milling the receiver for the breather assembly and then boring the 1 ½ inch hole to receive the cam cylinder.  Boring this huge void through so much completed work was nerve wracking to say the least.  Had I not done the 3-D modeling of this part, so that I was assured of what was going to be removed and what would stay I’m not sure this would have been successful.

Of course, while removing the part from the milling vice I cut my thumb on one of the sharp edges before I had a chance to file them all down and that reminded me of a story I’ll share with you.

Years ago I had just completed my first machining venture- can’t even remember what it was.  I took it over and showed it to Larry DuFour (who was my main mentor, an aside here: Larry is a VERY talented model maker , don’t let the caliber of my work influence your opinion of Larry; after all, the teacher can only do SO much ).  Larry rolled it around in his hands, handed it back to me and said, “It’s not done yet”.  When I asked him what he meant he wouldn’t say.  I took it back home and yes, a few of the measurements were off my several thousandths.  “How could he tell?” I asked myself?  I worked on it some more, took it back and handed it to him.  Larry, again rolled it around in his hands, handed it back to me again and repeated “It’s not done yet”. 

Anyway, finally he informed me that a piece isn’t complete until all the sharp edges have been filed off, a lesson I remember and a mistake I haven’t repeated.

So, after taking a file to all the edges and reducing the lethality of this part, I’m calling it done, at least for now.

This is probably the most complicated thing I’ve hacked out of aluminum to-date, I guess we always need to push ourselves.  As you look at these photos I’ll remind you that several other parts are added to this piece to form the original block.  It was beyond my talents to fabricate the final block as one part.  I had printed a few 3-D views I kept for reference as I worked on this piece and this helped me to visually see what I was attempting to achieve.

Here is a view from the back of the block.  You can clearly see the intake manifold.  The cut-out on the left rear is the receiver for the crankcase breather.  The cylindrical hole through the right side receives a cylinder that forms a receiver for the camshaft.



Here is a view of the power take off side with the round bearing cover receiver.



A view of the front of the block.  At some time I’ll need to revisit this area to mill out the mount points for the kick start assembly.  I’m going to let that go for now.



The magneto side of the block with the valve spring cavity.  The hole in the front of the block receives a protrusion in the front of the cam cylinder, use to adjust the cam shaft as it rides on the cam mandrel.  This will become more obvious in the months? To come.



Finally a view straight on from the rear and front of the main block.

[b.lindsey]

Craig, are you still in touch with Larry? We had some communications a few years back. His dad was quite an engine enthusiast ad well .

Bill

[Craig DeShong]

Bill

His son Jason is still in the area and I see him at shows from time to time.  Larry moved to Maryland and we've fallen out of touch.  I saw him last at Cabin Fever when he was exhibiting his LA France fire engine.

[b.lindsey]

Ah ok, I wasn't aware that he had moved.

Bill

[Craig DeShong]

Thanks again for taking the time to read through my ramblings.  

With the majority of the work on the major bock component behind me I turned my attention toward the cam cylinder/housing.  On the original engine, this “part” is cast as part of the block.  I couldn’t think of how to begin to machine this as one part, thus I chose to fabricate the cam cylinder separately and then affix it to the main block component.

Here I give you a picture of this cam cylinder, mounted to the main block.  A little feathering with filling compound and some paint and I’m thinking it should look to be as one unit.



This is a view of the rear of the block.  The governor cover will eventually attach here and cover the flyball/weight governor that rides behind the camshaft on the cam mandrel.



With the cam cylinder in place it was time to think about fabricating the cam mandrel.  This is a rod that affixes to the threaded protrusion in the front of the cam cylinder (see first picture in this post) and upon which the camshaft and governor flyweights ride.  Here you should see the cam mandrel in place.



I would have preferred to fabricate the cam cylinder from aluminum (it would have been easier) but I had reservations on the strength and fatigue characteristics of aluminum where the camshaft and governor are supported by the cam mandrel which is only attached at the front of the cam cylinder by the threaded front of the cam cylinder.  I though steel would hold up better; thus I took the effort to use steel in its fabrication.

I’m eager to get the crankshaft and camshaft in place and then fabricate the helical gears that drive the camshaft and see how this all works out.  This is where I’ll be focusing my attention in the immediate future. 

[Craig DeShong]

Winter made a re-appearance here in North Carolina so shop time for the last few days has been limited.  I was occupied Saturday at the first show of the season at Lillington with the Sandhills Antique Farm Equipment Club.  It was a bit chilly in the early morning but it warmed up nicely as the day progressed and the rain held off as forecast. 
 
I did manage to get out to the shop Sunday and Monday to work on this engine.  Unfortunately, a bonehead error caused me to reject my first attempt at a PTO bearing cover.    Possibly with a little extra effort expended in another direction, I might have been able to convert the piece into an acceptable drink coaster, but certainly not the bearing cover which was my goal.   Fortunately I found another candidate piece of aluminum so I able to begin afresh.  Below is a photo of the completed bearing cover:



Next was the magneto bearing cover.  Here I’m milling out voids that occur on the full size.  They don’t seem to serve any purpose; I’m assuming they are there to reduce weight and material in the casting?



Below is a view of the completed magneto bearing cover.

 

Finally I give you a few photos of these covers mounted on the block.




I also got a start on the crankshaft today, more on that in the next post.

[b.lindsey]

Craig, you are moving at warp speed on this one, looks great though.

Bill

[Dave Otto]

Nice progress Craig.

Dave

[gbritnell]

Truly outstanding work Craig! This is my favorite type of work, carving shapes from solid aluminum.
I'm following along with great interest.
gbritnell

[Craig DeShong]

Before I begin, thanks to Bill, Dave, and George for their support and comments, and thanks for all the rest of you for your curiosity in opening this thread and seeing what’s going on. 

George: lots more imitation casting work to follow 

 Without followers, making these posts is rather pointless.
 
Tuesday I started on the crankshaft.  I used to use 4140 annealed steel for these but I found that I can make a serviceable crankshaft for a fraction of the cost with standard hot rolled steel (and I can get it locally); I wouldn’t want to use cold roll: it would warp up like a pretzel.

This piece wasn’t especially long, but when I faced it, I thought I’d use my steady rest to help the three-jaw chuck in supporting this piece.  Also, I don’t get to use the steady rest that often and you don’t want to miss an opportunity to play with ALL your toys.    Here I’m facing the piece of steel so I have a good, flat end to work with.


Now that I have it faced I’m reducing the diameter to the correct overall dia.



After this I sawed the piece to rough length and then faced the other end to get it to the correct length.  I then located and center drilled the centers of the two ends and then center drilled the two offsets (one on each end) for the connecting rod journal.

It was at about this time  that I realized that at this correctly sized, reduced diameter, were I to cut a round cylinder around the offset center (for mounting in a collet or chuck for turning the connecting rod journal) I would be removing material needed for the finished crankshaft.   Had I thought of this before cutting the piece to length, I could have provided for this and then once the connecting rod journal was turned, removed the extra material.

Oh well,   On to plan “B”.     I decided to turn (work) the piece between centers.  To do this I needed to fabricate a centering pin to place in the lathe chuck or collet (I didn’t have one), and I also needed a lathe dog (didn’t have one of those either) to make the work piece spin with the lathe.  Two side-tracked projects later, I was ready to begin fabrication of the connecting rod journal portion of the crankshaft.

Here is the setup I used.  I was originally planning to use my indexing head with a collet to hold one end of the crankshaft, but there was no way to affix the lathe dog to a collet.  I used my dividing head with its three jaw chuck instead.  Actually, I’m not sure how well a traditional lathe dog would have worked.  For this operation I needed to control the rotation (forward as well as backward) of the work piece.  The “lathe dog” I fabricated does this.


A better view of the “working part” of this operation.



The procedure, as I’m sure you surmise, is to keep cutting across the work piece as the piece is rotated and the mill table is raised.  All I’m trying to do here is remove stock.  The distance across the journal should be ½ inch when complete.  There just isn’t enough room to do this work efficiently on the lathe.  Even on the mill I still spent several hours working this connecting rod journal down to a near finished size where I could transfer the work to the lathe to finish.



After MANY passes, I have about as much material removed as I need.



Now, with the work transferred to the lathe, it’s time to finish this journal.  I don’t know about you, but this kind of work makes me very nervous.  With the work swinging in a wide arc and the tool reaching in so far, it just seems to be a potential recipe for disaster.  You definitely want to keep your attention on what you’re doing.  Here I’m enlarging the journal width and putting a finished face on the left side.



Repeating the process on the right side.



With the two sides faced and the width to the correct size I’m reducing the journal to the correct diameter (as well as leaving a small shoulder on each side.  I’m doing this with a parting tool, ground flat.  I was getting some chatter that was leaving shallow flats on the journal face.  I couldn’t seem to eradicate this; I tried raising the tool a bit, lowering the tool a bit; nothing seemed to eliminate them.   Fortunately they were quite shallow and by leaving the journal diameter a thou. or two oversize I was able to eradicate them with a minimum amount of filing.  After a light dusting with some emery paper, I’m calling this journal complete.



With all this nerve wracking work complete, next I’ll be moving the workpiece to mount on the true centers and start working down the ends of the crankshaft toward the center.

[Brian Rupnow]

I am watching the developments daily, and am impressed by your progress and your machining skills.---Brian

[Craig DeShong]

Brian, I thank you for your kind words.  I also thank everyone else who is following this thread who hasn’t specifically posted a reply, and again, those of you that have in the past.  Thanks for your interest.
Over these last two days work continued on the crankshaft.
Before placing the work in the lathe, I made a spacer to fit with a resistance fit alongside the connecting rod journal.  This was done so that pressure while turning the piece between centers would not collapse the journal.  I have a friend who solders these spacers in place.  I use hot glue.  It seems to hold the spacer well and the cleanup is a breeze.


Now begins the mindless, laborious task of turning down both ends of the crankshaft.  Here I’ve just started on the PTO side.



Here I have the PTO side near completion.  I usually leave both sides a little oversize until I’ve reduced both shafts to near diameter, then I go back and finish both.  Maybe this is overkill, but with the amount of material I’m removing, I don’t want any stresses in the material to pull the crankshaft out of true.  I’m thinking any out-of-true situation can be rectified by several light passes on each shaft side when I bring them down to their final diameter.



Here I’m just starting on reducing the diameter of the magneto side of this crankshaft.  The lathe was running around eight hours to remove the excess stock on both sides of this crankshaft.  It was a busy day.



Next, not shown, I placed the near complete crankshaft back on the mill, held between centers with a collet in my indexing head on one side and a dead center on the other.  With this setup I formed the crankshaft counterweights from the round center sections.  I meant to take a picture of this but… well… you know how it goes.
Finally, I needed to put a ¼-28 thread on the magneto side.  This, with a nut, holds then flywheel to the crankshaft.  I did this, mostly with the lathe and then finished with a die.
 

After this I cut in a keyway on the PTO side for a pulley.



One more operation that is required to complete this crankshaft is cutting a taper on the magneto side end on which the flywheel is mounted.  I won’t be doing this now however, the flywheel with its taper needs mated to the crankshaft and I’ll do that operation when I fabricate the flywheel: many months from now.

Here is a look at the finished crankshaft.  It’s hard to believe this started out as a 2” diameter cylinder; though the chips in my trash can allude to this.



Finally, a view of the crankshaft as mounted in the block.  Everything looks good to me, and the crankshaft spins freely in the bearings.

[crueby]

Nice job on the crankshaft!   

I had not thought of hot glue for that kind of spacer. I assume some more heat softens it again - anything particular needed to remove any residue?