Another Rupnow Air Hit n Miss Engine

[bmac2]

This is the spoke pattern I came up with. Used a center drill to mark out the corners. That is some soft aluminum, no wonder I got it for free. Have to see how this is going to come out.
Drift off topic here for just a minute. In the picture you can see I’ve taken the battery out of my Chinese calipers. I was lucky if I got a month out of a battery whether I was using it a lot or it just sat in the drawer. Checking on the internet I found out that with some of these cheaper calipers, when you turn them off all that does is turn off the display. A quick check for this is to open the jaws, turn the unit off, move the jaws and turn it back on. If the display shows the new reading it’s only the display that’s shut off with the switch. By removing the battery at the end of the day I’m getting about 6 months or better out of a battery. I’m going to save up my birthday money and one day get a good one.

 

[bmac2]

LET THE CHIPS FLY!
Oh. That looked a little rough.

 

[bmac2]

Separated the 2 parts with some heat and cleaned up they don’t look bad at all.
15 1/4 oz each. Heavy?

 

[bmac2]

In for a penny in for a pound I guess. On to the hub for the governor flywheel.
The hub is ¾” so I used parallels to scribe a center line and locate the 2 holes for the backing plate.

 

[bmac2]

Not knowing any better a few years ago I bought one of these sets of things that looked a lot like drill bits but make funny triangle shaped holes of odd sizes. The numbers marked on the box are a little confusing because they don’t relate to the drill thing in that position. They do make good setup pins. In this set #32 to #36 measure the same size so I’m using 2 of them to setup the hub to mill the clearance slot for the weight arms.

 

[bmac2]

Used the lathe to align the parts and press them tougher with Loctite and I’ll put on a fillet of JB weld epoxy after everything sets up.

 

[motoseeya]

Nice very nice. You do gooood work. I hate fly wheels too lathe to small:rant: but I keep at it maybe someday.;D

 

[bmac2]

Motoseya you’re too kind. I think the secret to having stuff look good is to have the camera just slightly out of focus. I know on the lathe a lot of the time I’m using the tool that’s easiest to set up but not necessarily the right tool. If/when I get this thing running I’m going to hit the books.
If you want to see some BEAUTIFULL work on small equipment checkout Davewild’s Linford two stroke build.

http://www.homemodelenginemachinist.com/f31/linford-two-stroke-21643/

 

[barnesrickw]

They used to use that out of focus technique on Cybill Shepard.

 

[bmac2]

The Sliding Cam and Actuator Bushing.
I must say this is the part that I have been dreading. The notch in the sliding cam is a very close fit for the actuator, and the two parts have to align correctly on the ¼” shaft.

 

[bmac2]

Making the blanks was not a big deal as both are ½” so to drill and ream the hole. Cut the steps in the actuator. Cut the grove in the sliding cam and parted them off.

 

[bmac2]

It’s time to close my eyes and tell myself to trust the math. Actuator Bushing
Part OD = .563
Finished size = .375
Difference = .094 on each side
With the actuator bushing on a parallel in the vice I set the Z axis dial indicator to 0.

 

[bmac2]

Milled off .094

 

[bmac2]

Flipped the part over and repeat

 

[bmac2]

I love it when the math works

 

[bmac2]

The Sliding Cam. Used my home made edge finder to Pin pointed off the edge to establish 0, 0 then used the DRO to find center and milled the .375 x 0.1 notch.

 

[bmac2]

I can’t believe it but I just had to deburr and cleaned them up and they fit!

 

[bmac2]

After reading Brian Rupnow’s build log I’m not going to bother with the 0-80 cap head screws. I live in oil country and my Screw Guy looks at me funny when I ask for things under ¾ inches. I going to make a small pin the same diameter as the head on a 0-80 cap screw and Loctite it into place. This way I get two of my favorite things all in one part. Stainless Steel and tiny parts.

 

[bmac2]

There’s enough meat on the actuator so I’m going to use a 2-56 set screw
Somewhere there’s dictionary that shows:
irony
i·ro·ny
noun:
The expression of one's meaning by using language that normally signifies the opposite, typically for humorous or emphatic effect.
E.g. “The only 2-56 set screws available are 5/8 of an inch long”

Oh well it’s easier to cut them than make them

 

[bmac2]

Disaster. :fan: Went to punch the spot for that wonderful SS pin and didn’t think to support the grove. This bent the side down and when I tried to straighten it out it snapped.