Machsupport Forum
General CNC Chat => Show"N"Tell ( What you have made with your CNC machine.) => Topic started by: BClemens on March 15, 2009, 11:27:02 PM
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This is what is going on with this machine at this point. This is a flawed part because; too much hurry; forgot details in part; forgot to tell pp which side of line in a segment, etc, etc, etc. But its working....and pretty well at that!
This is fruits of the labor (and advice and troubleshooting) of the good folks here on this forum. God love 'em! They just blindly keep plugging advice, sincerity and good cheer into the posters here...and get things working.... thank you all very much, names are known.... and appreciated.
Here is a photo of a much hurried part to just make something right away......!
Bill C.
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Hi, Bill
Look's great, Beat's cutting Air or nothing at all for sure, Next one will be perfect, Wooo-Hooo.
Chip
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Hey Chip, do you recognize what this part is?
Bill C.
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Heeeeey ,
It's the drive side of a Harley engine case.
And , a nice job it is.
Ed
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Yes. The intent is to cast these cases. I've straightened up the programming on this side to do another one and the cam side is nearing completion. Have a full plan set in CAD, just need time to make the parts. 1.25" bore X 1.443" stroke - pan bottom, shovel top.
Bill C.
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Very interesting project Bill , as I use to work on the full size HD.
Don't forget to keep us updated. Are you making all the parts for this project ?
Ed
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That is realy nice machining .
Marcel ;D
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Yes, I will keep updates coming. This drive side case part was finish cut radially with a 1/8 ball at 1/2 degree steps. The next one is programmed for 1/3 degree steps to get a better initial finish (don't like sandpaper). The only parts that I have purchased so far are some ball and needle bearings, and the needles will need to be modified.
The crank is assembled as the early HDs were so a hardened crank pin with needles is what is intended. The forked rods will need to be tool steel too. Scaling the engine has required gears of an oddball diametral pitch so I must make them.
Too many of these hobbies and too little time to devote to them. This day job is really getting in the way! This is why I stopped and converted a mill for CNC because there is no way that these patterns can be made as accurately as this by conventional methods. I've tried...
Thanks,
Bill C.
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KeyCreator....Toolpaths are complete. Part coming!
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Looks real good Bill . but wheres' the cavity for the rotary breather?
Just wondering.
Whats the scale?
Ed
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No holes in these parts as machined at all; they will be conventionally machined in the finished 'castings'. The breather is above the scavenge pocket, lower left in the gearcase. The scale is .36, so it's a bit over 1/3 of full sized. The HD engine is tough to fully scale much smaller than this... Parts get to dainty.
This program was also run on mohogany an proofs fine. 7075 is next.
There is also a twinkie in the works and it's actually easier to work with - but it will have gears - no stock chain!
Bill C.
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Cam Cover
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Nice little piece of maching right there, beautiful job- 8)
Dave
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The programming on that part was a mother bear! But, Mach 3 machined it anyhow....165,000 lines of code.
Thanks for the compliment!
Bill C.
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Driveside 7075.....
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Good stuff Bill! I enjoy looking at the pics.
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It kills me to reduce a nice sized block of 7075 to chips but there IS a part in there. The contour alone takes away about 1/3 of the total piece, all sucked up into a vacuum cleaner. The total weight of the block is reduced by about 90%. The miser in me is showing up now....
Thanks for the compliment. I'll keep some photos coming.
Bill C.
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Lookin good Bill, Cases from 7075.
But , Why the patterns then ?
I've got a couple billit blocks to make a full size HD , my own design, with a big block chevy crank and rotary valve heads.
But no time. Where do you find all this time ?
Ed
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Good question Ed...We're having the same difficulties! The intent was to make castings but after thinking about it, there just isn't time to make castings and build this engine at the same time. Besides, this milling machine was sitting there and it doesn't care if it is cutting air, wood or a piece of 7075.
Your engine sounds like a monster V twin - tell more about it....
Take a look at solenoid operated valves for an engine that size. The event timing can be tuned as well as the ignition advance curve. There are a couple of sites on the net by experimenters in this stuff. The heads would be simple and there is no cam - what a savings in power. There is enough sensor 'garbage' in junkyards to do most any crankshaft position sensing you would need. I'm currently dabbling in a programmable ignition system using a PIC chip (which have become fast enough for just over 10,000 RPMs) that changes the advance as the speed increases in various curves and operating the valves would fall right in there as well.
Time; I operate an electron beam welder at work that is enclosed in a six X six X six foot cube cryogenic chamber and there is vacuum pump down time (down to 7E-5 Torr) and then part cool down time between welds = time. I usually spend much of that time doing CAD work on various projects for the lab (and myself) so these CADs of the HD engine and NC programming that take lots of time are conveniently done at work. That leaves home shop time in the shop! But today (Saturday), I'm at work. We have had problems with the cryo system so I've lost welding time and many parts have piled up to do.... Need any CAD or programming done?
Bill C.
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Tell them if there gonna tear up, fix, or modify stuff, they need to do it on another shift. It's cutting into to much of your personal time.
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Beautiful job Bill ,
BUT , don't forget , if its Aluminum , its gotta be POLISHED , and 7075 will buff out like chrome.
My design for the rotary sleeve valve. would run at 1/4 crank speed , chain driven. No cam, no valves , no rocker arms , no pushrods. no lifters.
no valves to bend or float. unlimited compression ratio.
But I can't tell all or everyone will have one before me. LOL.
And , your job, sounds like excellent fringe benefits. Do they also pay you ? ha ha
Ed
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Thanks Ed - I was thinking about sand blasting the cases to resemble a casting....then the polished covers and rocker boxes would stand out better but polishing is tempting...
Interesting - rotary valve....must see....wanna see....
Sam, I think they like me here, I'm at work again today - Sunday. My wife says I'm an easy piece - must be true. Money? Was there money involved? They wouldn't want to pay me - that's whoreish...
Bill C.
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Bill,
Don't sand blast. bead blast with glass bead. Much finer and better finish, But get all the machining marks out first. Scotch brite wheels.
I used to bead blast harley cases after a major rebuild, made them look like new.
Rotary sleeve valve , is nothing new. They tryed it in the 20s on small engines but had trouble with sealing. My sleeves would be mounted on sealed bearings with teflon outer seals. No oil needed to the heads. Dirty oil comes from the heads on a poppet valve engine, which will be eliminated.
The sleeve would be about 2" in diameter with a long slot through , which matches the ports , supported on both ends , hence , 1/4 crank speed.
Ed
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Ed! You NEVER glass bead an aluminum engine casting because you will forever continue to see glass beads in your oil. The stuff gets into the pores of a casting....A billet is another situation - the pores are minute and almost non existent to a glass bead. I've seen many Harley engines die an early death from glass beads. And - you're right about the finish on this 7075 - it would look much better than sand blasting.
Your rotary valve with the new plastic formulations now will probably be a success, in which case is patentable. That could make a fantastic cottage manufacturing opportunity and make some serious money. There's a good place for stock loading, tool-changing, and easily duplicatable NC machine(s).
Bill C.
BTW: Your web site is grand! Us old guys need to inspire some of the younger crowd to do something with their hands - you're in motion!
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Thanks Bill,
I've done many Harley motors with no problem. After bead blast, they were cleaned in parts cleaner. All holes were cleaned with a water pick , and final cleaned in hot water. AND , When I thought they were clean , I did the whole cleaning procedure over again, The cleaning process , took longer than the rebuild. ;) they're all still running after 20 years.
Ed