Parsell & Weed Horizontal IC Engine

[Roger B]

Good work on some rather fiddly parts    Still following along 

[b.lindsey]

Thanks guys!  I thought I had shown how I did the rounding in the first guide but I guess I didn't. There will be another occasion to do so shortly I am sure. Kim, the RT could be used but this in this case might have been more set-up than needed. The rounding is strictly aesthetic so doesn't have to be that spot on as long as it looks decent.

I did get the pin made this morning though it took two tries. Nothing special there but there are a few pictures below. You can see in the last picture that there is a gap between the head of the pin and the pushrod guide. this will be filled in by the governor arm outboard mounting lug. The inboard mounting lug will fit in the gap of the center piece thingy (the one with the roller)

Bill

[cwelkie]

One more piece done ... nicely.
The more (little) pieces I see you complete, the better my appreciation for this design.  Certainly lots to keep one interested and challenged.
Charlie

[zeeprogrammer]

What happened with the 1st pin?
I see the slitting saw. That's where I've always had problems.

[Tennessee Whiskey]

Professor,  your turning these fiddly bits into pieces of engine jewelry  . I like the way you roll  .

Cletus

[b.lindsey]

Thanks Charlie, Zee and Cletus.  Zee, the first pin was a bit tight in the pushrod guide holes and I buggered up the slot some trying to get it in and out. Since I had already parted it off it was all but impossible to chuck it up again and polish a few tenths off of it. So I just made a new one and checked the fit PRIOR to parting it off. Should have done that the first time. The slotting saw works well. I just touch the lower side of the blade to the top of the screw....lower it by half the thickness of the saw blade, and then lower again by half the diameter of the screw head.

[b.lindsey]

A couple had asked about the rounding procedure. This isn't as good an example, but I made a new rocker arm today as well (there was one aspect of the other one I wasn't happy with) and did the same things though it wasn't quite as long on rocker arm. The original square area where the mounting hole passes through needs to be rounded into as near a circle as possible. In this case I inserted a 1/8" pin, rested it across the vise jaws and set the cutter above the center of the pin by the prescribed radius of the desired circle. This its just a matter of taking cuts (along the y-axis), rotating the part a bit and taking another cut, etc.  Then I did the same to the opposite side. A little filing to smooth the resulting facets and its plenty good for a non critical job like this one. Maybe the couple of pictures below will give a better idea.

Bill

[Flyboy Jim]

A couple had asked about the rounding procedure. This isn't as good an example, but I made a new rocker arm today as well (there was one aspect of the other one I wasn't happy with) and did the same things though it wasn't quite as long on rocker arm. The original square area where the mounting hole passes through needs to be rounded into as near a circle as possible. In this case I inserted a 1/8" pin, rested it across the vise jaws and set the cutter above the center of the pin by the prescribed radius of the desired circle. This its just a matter of taking cuts (along the y-axis), rotating the part a bit and taking another cut, etc.  Then I did the same to the opposite side. A little filing to smooth the resulting facets and its plenty good for a non critical job like this one. Maybe the couple of pictures below will give a better idea.

Bill

Thanks Bill, I've got the picture now ..............literally!

Jim

[yogi]

Great progress Bill! Those guides turned out fantastic 
Thanks for your rounding technique. I have filed that for future use... 

[b.lindsey]

Yogi, it certainly isn't original with me. In fact I probably saw someone else here do it and filed it away myself. 

Achim, I meant to reply to your comment as to the fixations (screws) for the pushrod guides. Four 2-56 screws per guide...yep...I don't think they are going anywhere, but that is what the plans called for 

Bill

[littlelocos]

Bill,
Really enjoying the build.  Outstanding work!
The four 2-56 screws were an addition from the original plans which only called for two located on the top.  I added the wrap around and other two in fear that the two would work loose.  The full-size engine had two lower screws coming in horizontally; however, the size of the cylinder collar didn't allow room for that so I moved them all the way around.

I never cease to be amazed at the different ways to go about skinning a cat.  I did the pushrod bearings both at once and then cut them apart to finish.

I also use filing buttons for many of my rounded parts.

See pics below.
Enjoy!
Todd.

[Mosey]

I'd like to see how you used the filing buttons.
Mosey

[b.lindsey]

Interesting idea Todd about making them together and then cutting apart. I was fortunate I guess in that they lined up well even making the separately. Like you say though, lots of ways to skin a cat,

Bill

[littlelocos]

Hello Mosey,
The filing buttons basically serve as guides to help produce flat sides and square corners.  They rotate as the file passes over, keeping them round and guiding the file over the part.  For small radii, this method works very quickly and is reasonably accurate.  The one photograph shows a rounded foot next to an un-rounded one.  Filing took less than 5 minutes per foot.  The part can be held in a vise or run along a flat file laid on the bench and using the button as a wheel.

Enjoy,
Todd.

[b.lindsey]

A few pictures I didn't get posted last night and a  new part started tonight. I had loaned my only 4-40 tap to my senior design group so couldn't tap the rocker arm support arm or the through hole for the tappet. Ordered a new 4-40 tap from amazon last week and they sent a 6-32 labeled as a 4-40. The replacement came in yesterday so I got that tapping done to show how the rocker arm looks in place. Good thing too, I was informed today by the senior design team member that obviously chose the short straw that my loaner tap had been broken. I kind of expected that to be honest so no big deal. Anyway that's what is shown in the first three pictures.

Then I got a start on the governor arm. The shape of the part is shown in picture 4. I started with a length of 3/8" square brass and milled it down to the required dimensions. I thought it would make the profiling easier to go ahead and mill out some of the unneeded stock like the gap between the legs but milled the entire length of the part (photos 5 & 6). While I still had a basically square part, I went ahead and located and drilled the holes as shown in the last two pictures.

Tomorrow I hope to turn the round end while there is still enough parent stock to mount in the 4 jaw chuck, and then the rest of the profiling can be done or that is the plan for now.

Bill