ET Westbury Side Paddle Engine

[derekwarner_decoy]

Hi PD's.......& I understand kvom a little of the inherent inaccuracies when using C-Lok pins

1. Never use a hammer to tap home a C-Lok pin...they are RC 45+  so will act as a broaching tool as they guide their own way toward miss alignment
2. Whilst the SPS Technologies [Unbrako Group] now Indian owned...do not reference.......the geometry of the chamfer on the C-Lok pin ends as it is not conducive to correct alignment even when gently pressing the said pins home & such pressing of an off axis C-Lok pin will crack the Loctite bond......
3. Could I suggest miniature BS Standard taper pins inserted to taper reamed holes [between components] would offer unsurpassed accuracy  ......
4. After some trial assembly & confirmation of ZERO [0.000"] miss alignment you can gently press the taper pins out & reinstall with Loctite Super Stud Lock........ the taper pins will last last a million years +.....so .....Derek

kvom will know.....but here is a link for other members http://shopswarf.orconhosting.net.nz/taperpin.html

[kvom]

I started to remake one of the cranks today, this time using some 12L14 for the webs and shouldering the pin:



I have put some loctite on the pin ends to set up until tomorrow.  The total width measured from the outside of the webs is .04" oversize.    This is "semi" on purpose as my rod ends are .03" too wide.  I think I can safely take off .02 from the outer side of each web if needed.



I won't fix the crankshafts until the engine is ready for a trial fit.

[kvom]

The first task today was to drill and pin the crank webs to the pin.  This went well.  I started the roll pins by tapping with a hammer, but then pressed them in fully with the vise jaws.  One of the conrods was test fitted:



Next I undertook drilling the first pair of bearings.

Here's the setup in the milling vise, with the inner frame being clamped by the hornblocks.



There is a couple of thousands play between the bearing and the hronblock, so I used a shim from a soda can to clamp down the bearing with the retainer plate.  Note that I obtained the center from measuring the inner edge of the hornblock.

Then drilled and reamed:



Then the the same with the outer frame, although clamping in the vise was trickier because of the curve leading into the hornblock.  Still it seems to be all good as the drill rod passed through the assembled frames turns pretty easily:



Before leaving the shop I set some drill rod for the crankshaft into the webs with loctite;  next time, after it cures, I'll pin it to the webs.  Also need to make the other crank and drill the other two bearings.

[kvom]

Spent a good part of the afternoon in the shop.  The first task was to drill and pin the crankshaft to the crank webs, then mill out the portion of the shaft between the webs.  Then I finished drilling the bearings for the other two frames, allowing a test setup of the four frames.  Here's the result, including the crank:



The good news is that with the two center staybolts in place, the 3/8" length of drill rod turns smoothly while passed through all four bearings.  \

The bad news is that the holes for the outer staybolts in the outer frames seem to be ~.04" higher than in the inner frames.  I checked my CAD drawings and they are correct, so I have no idea how they became displaced.  I can still install the outer staybolts, but that causes the frames to flex slightly and jam the alignment rod.  I will enlarge the holes in the inner frames slightly to correct this.  As shown in the photo, the height of the staybolts varies on .004" from one end to the other, so the  engine is quite level side to side.

Now that I have a crank and can connect the frames for testing fits, I proceeded to mount one of the cylinders to get an idea of how much the bearing sides will need to be trimmed.  To do this, I needed to finish fitting the previously turned piston to that cylinder. 

That's when I discovered that the conrod threads were crooked on one end.  I had cut the threads with a die on the lathe, but that wasn't good enough.  So I proceeded to make two new piston rods with the 10-32 threads on each end single-pointed to ensure they are concentric.  Once they were done, I needed to remake the piston, which needs to be turned "in situ" on the piston rod.  So this meant facing/turning/drilling/tapping some 1" brass rod, then parting off and screwing onto the piston rod.  Then the final diameter is turned with the piston rod chucked in a collet.

[kvom]

I'm now on a 2-month trip, so any engine progress will be deferred until November at the earliest.

[kvom]

I got back from Nepal a week ago, but a combination of jetlag and a chest cold have kept me out of the shop until this weekend.  Today's goal was to rough out the two lifting links, pieces that connect the lift arms to the expansion links.  These are somewhat "delicate" as ET says, so it took me some thought as to how to make them.

Material is 1/4" diameter drill rod.  First a length is chucked in the lathe collet, and i faced the end and center drilled it.



The rod and collet were then transferred to a square collet block and secured in the mill vise.  A vise stop was used to ensure repeatability. A 1/4" carbide endmill then milled a flat .055" deep 1/8" from the end of the rod.  Leaving the spindle locked, I turned the block over, positioned against the vise stop, and milled a matching flat on the opposite side of the rod.  Next a 1/8" hole is drilled through the rod.centered on the flat.  

Next the collet block is moved to the surface plate, and the drill rod is pulled out ~ 2".  The height gauge is used to set the milled flat parallel to the plate.



Back to the mill vise.  I used the 1/8" drill bit in the existing hole to zero the DRO, then moved the X-axis 1.625" to establish the location of the flat/hole on the other end.



The collet and rod are then placed back on the lathe to turn down the shaft between the flats.  The non-chucked end is supported by a live center.  First I used a parting tool to turn down the right end of the shaft to provide space for a turning tool.



Then the rest of the shaft was turned.



After some polishing of the shaft with emery cloth and scotchbrite, I parted off the link.  After the first one, it took only about 15 minutes to make the second.



In my next shop session I will grind off the center-drilled portion and do some cleanup filing on the ends.

[kvom]

A bit more progress this afternoon, although nothing picture-worthy.  The first job was to mill the sides of the main bearings to plan, and test fit the crank and outer staybolt for spacing between the frame.  By measurement it looks good, but the true test will be when the entire drivetrain is in place.

After that, I found a piece of 12L14 in the material drawer and used that to mill the webs for the second crank.  Afterwards, I used 3/8" drill rod as before for the crankshaft and pin, setting them in place with loctite and using a .500 gauge block to set the spacing between the webs.  The assembly will cure overnight, and then will be fastened permanently with roll pins.  Essentially the same construction as the first crank.

[kno3]

Looking at the cylinders I must ask why are they so big in relation  to the piston diameter? There is a huge amount of metal in there for such small pistons.

[kvom]

The plans and the subsequent castings have the body of the cylinders necked down in the center, making the cylinder less bulky looking.  I machined the trial aluminum cylinder that way, but decided that I like this look better.