Rudy's Radial 5 at Half Scale

[Tennessee Whiskey]

I'm so late on this one I feel like I should have to sit in the corner for awhile . Bill, the parts are in true Lindsey fashion, beautiful. Mike,(Lou's brother-in-law) was having mumblings of starting an engine after seeing everything at CF and he loved the radials especially. Being a Sherline man, between yours and Kim's, this may be my "bait". Now, if we could figure out how to get you, Kim  and GailNM together in the shop we'd have these suckers running on Coleman juice in no time flat
 
Whiskey

[Don1966]

Bill I like the use of the thumbnail for size reference. Just makes it stand out there. Your moving right along buddy.   
 
Don

[b.lindsey]

Thanks guys. Have run into a bit of an issue though. As I have been going along I am redrawing the full size parts down to half size to look at while machining. I was redrawing the crankcase today and noticed the screw clearances are very thin. Rudy's original design used 2-56 hardware with a major OD of .086". Since 00-90 hardware is a bit tricky to find (not even McMaster or MSC lists it) I was planning on using 0-80 which I have on hand along with taps and dies. I am 99% sure I can make 0-80 work on the brearing housing and valve chamber mounts to the crankcase, but not at all sure I have the real estate to do that as far as mounting the 5 cylinder flanges to the crankcase. 0-80 has a major diameter of .060 so obviously doesn't scale down to half of a 2-56 thread. AS Zee would say....CRAP!!  Anyway and going to have to draw out the cylinders now and see if there is a way to modify the crankcase depth and the cylinder flanges to gain some needed thousandths of space.  Does anyone have a viable source for 00-90 SHCS's here in the US?  Also...dreeves...if I may ask, how did you get around this issue.  I do see where Micro-Mark does have 00-90 taps and dies which helps some but they only stock brass round head screws and I would prefer SHCS's.

Stay tuned

Bill

Edit:  Microfasteners also has taps and dies but again only round or hex head 00-90 in brass...beginning to think their ain't no such thing as a 00-90 SHCS 

[Tennessee Whiskey]

Bill I bet you could press fit them and use pins with a head for the "look"

Whiskey

[Don1966]

Bill have you tried Small Parts they are owned by Amazon now.

Don

[mklotz]

Here you go...

http://www.fastener-express.com/00-90-x-18-socket-head-cap-screw-stainless-steel-qty-50.aspx

and only fifty cents apiece.

Be sure to order the appropriate hex wrench.  The smallest I have is 0.028 AF and I'm not sure it would fit.  When you get the wrench paint it fluorescent yellow so you can find it when you drop it in the swarf.

[b.lindsey]

Thanks Marv, the 1/8" length would work for the cylinders too. Now I just need to find out the head diameter and the socket size....028" is the smallest I have too. The other option I have is to use round head slotted screws but even then I will have to turn the heads down some making it look more like a phillister head screw. Not terribly realistic but then the model really isn't that prototype-ish to start with being air driven and such. I will try to give these folks a call and see if they can provide the diameter and wrench size info.

Thanks again!!

Bill

[mklotz]

Now, if you were really serious about this you would turn your own, single point the thread and swage the socket.  Do a dozen of them and you get a free week's stay in the rubber room of your choice.

[Tennessee Whiskey]

That's what I was thinking, don't you have the thread cutting attachment for the Sherline? 

Whiskey

[b.lindsey]

I am quite sure it wouldn't take but one Marv. though I do recall seeing pictures of either George B. or Jerry Keiffer having turned 000-120 ones if memory serves. That may be over on the Crafstmanship Museum site though they weren't socket head screws. Its kind of maddening when the head size of a 00-90 is too BIG for an applicatioin. Meanwhile I have emailed your source and will hope to hear back from them. They are pricey but if they work it would keep the SHCS theme going.

Bill

[b.lindsey]

Yep I do Eric, but even doing 20 of these (4 per cylinder x 5 cylinders) makes the $.50 per each price seem rather cheap!! Then as Marv points out, there is the sanity issues to consider   

Bill

[Tennessee Whiskey]

The sanity issue is the big one, I know. If all else fails maybe you can sub them out to Jo

[Dreeves]

Bill, I'm away from the house. I will let you know what the bolt circle I used on mine sunday night. I used 0-80 shcs on the cylinders.

Dave

[b.lindsey]

Many thanks Dave. I've got some fixtures and other things I can work on in the meantime before making any swarf on the crankcase.

Bill

[b.lindsey]

Regardless of  the fastener situation mentioned above, the holding fixture for doing the flats on the crankcase and locating it for the many holes that will need to be drilled on bolt circles had to be made so I worked on that this afternoon. I started with a piece of 2.125 dia. aluminum, faced both sides and trued up the diameter down to the chuck jaws (photo 1). The two required steps were then turned and the center drilled and tapped 10-32 compared to the 1/4"-20 called for in the full size plans (photo 2). The piece (still in the lathe chuck) was transferred to the rotary table on the mill to drill and counterbore 2 clearance holes for 10-32 SHCS's which is the normal hardward for Sherline's t-nuts (photo 3). I had already made the two separate sizes of caps to be used with this fixture and they are shown in photo 4 along with the front of the fixture and how they will fit together. Photo 5 shows the back of the fixture with the Sherline t-nuts in place. The last photo shows the mill table with the rotary table on it and already centered. The fixture was attached then to the rotary table (while leaving the RT centered with the spindle) and gently nudged until the machined OD was also concentric with the spindle and center of the RT.  Mostly this fixture will be used with the RT in the vertical orientation for milling the flats on the crankcase, boring the cylinder holes, etc but it will also be used in the horizontal position for drilling the attachment holes for mounting the bearing housing and valve housing to the front and rear faces of the crankcase. That's it for now, more tomorrow ...

Bill