# Development photos of HD timing side



## BillC. (Jan 6, 2010)

These are images from Keycreator and the NC toolpathes... This was machined out of 7075 aluminum...


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## BillC. (Jan 6, 2010)

Found some more photos of the HD engine...


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## BillC. (Jan 6, 2010)

A couple more..


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## gbritnell (Jan 6, 2010)

Really neat stuff. I sure miss having those capabilities. It looks like this engine is gioing to be about 1/3 size? What kind of machine are you using?
gbritnell


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## BillC. (Jan 6, 2010)

I converted an Enco floor knee mill for these jobs - and more...I stand and watch this machine work....and that's really saving time!

The HD engine is 1.25" X 1.44" which makes it just under 1/3 sized. It was sized for the dp of the gears in the timing side but somehow I boo booed and missed. The gears must be hobbed too (I built a dedicated gear hobbing machine years ago).

Thanks,
Bill C.


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## BillC. (Jan 6, 2010)

The timing side cover ('cam cover') takes 11 hours total time to machine due to the .005" stepovers so the machine is started and I walk away (hard to do since I like to watch). This CNC machine has become the center point in my shop and it is always running something. How did we ever get along without computers!!!???

Thanks,
Bill C.


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## kustomkb (Jan 6, 2010)

Beautiful parts Bill!

Do you have a picture of an assembly drawing?


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## BillC. (Jan 6, 2010)

Thanks Kevin,

Yes, I made some drawings and as I make a part, I convert it to solid. The drawings are very basic and are actually modified as the solids are made from them. This is a Pan Head bottom with Shovel Heads and barrels and I've tried to stay as near aesthetically as possible to the model being a true scale but we all know that isn't totally possible. They just don't make tapered roller bearings this small...

I'll post an end view drawing....

Thanks,
Bill C.

I'm using dowel pins for the pinion shaft and crank pin so that needle bearings can run on them without a hardened race being necessary. Micro 100 tool steel cuts them very nicely but the threading is done with carbide - very slowly fed.

I have been admiring your engine being cranked - wish I were that far along. Are there other photos of your engine on the forum?

The second photo is how I develop the solid to the drawings....


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## kustomkb (Jan 6, 2010)

Thanks Bill,

That's really nice.

All of my photo's are here;

http://picasaweb.google.com/kustomkb/Hoglet02#

and the build is here;

http://www.homemodelenginemachinist.com/index.php?topic=1831.0

Clarence, who gave me his cam drawings is building a shovel head. He's calling it the "Shovlet"

At the bottom of the page here;

http://www.telusplanet.net/public/celias/Hog_Pix.htm

I look forward to your progress. :bow:


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## BillC. (Jan 6, 2010)

Fantastic!

Man I'm happy to find this forum!!!!

Bill C.


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## mu38&Bg# (Jan 6, 2010)

Are you going to do any finishing to remove or reduce tool marks? Will a vibratory finisher or bead blaster give it a polished or cast look? I want to build an engine the same way. But to finish it off I'd like to be able to remove the tool marks. Polishing with hand tools works, I've done that before.


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## BillC. (Jan 6, 2010)

Yes Greg, 7075 finishes very well and will actually polish up to a sheen like chrome. The cases will probably be polished then glass beaded to somewhat resemble a casting. But the tool marks do work off quite well with decreasing grits of wet-or-dry, then some jewelers rouge.

The initial idea was to make castings and I did start making patterns....

Bill C.

 notice the botch on the lower right...!!! That's when aluminum came into the picture.


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## mu38&Bg# (Jan 6, 2010)

Sounds good. Did you use a corner radius end mill for the finishing pass? That depends on how tight things are and if you have any negative full radii, and whether or not you have the software to do radius cleanup, where you would want to use a ball mill. I'm working with some 7075 right now, but nothing interesting. Thanks!


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## BillC. (Jan 6, 2010)

The finishing cuts were radially cut at .33 degrees with a 1/8 ball end mill - working in the lower photo.

7075 is the best of the aluminum's to work with because it isn't the least bit gummy as other aluminum alloys are and will throw the chips away from a dry carbide cutter - no clogging and sticking to the cutter. I use a 'kool mist' system and have run out during a lengthy cut without a problem. Sometimes even just run dry....It's strong as steel too.

Bill C.


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## kf2qd (Jan 6, 2010)

Nice work. Not a Harley fan... BUT I would love to build one about that size to put into a Honda Rebel frame. Will have to continue to save the pennies...


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## BillC. (Jan 6, 2010)

Now kf2qd,

 If you ain't a Harley fan, why would you want to violate a Honda frame with a Harley Davidson look alike engine? Honda's are first class technology and engineering. Harley Davidson on the other hand is well suited to those who enjoy finishing out a major purchase, have dirty fingernails, bad breath and enjoy the sound of a P&W radial engine hitting on seven of nine - then the rev. Oh yes!

Bill C.


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