Author Topic: Flathead V-8  (Read 143145 times)

Offline ///

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Re: Flathead V-8
« Reply #210 on: February 27, 2015, 03:25:32 AM »
Awesome work George!
....
This is one of those jobs where total concentration is a must, unless you want to make 2 of these things.
So if you're making a quad-cam would you need even less concentration than a twin-cam? Good news!  :Lol:
« Last Edit: February 27, 2015, 03:29:49 AM by /// »
Simon

"The reality is that without cheap imported machines, I would be spending my time doing something less creative and less enjoyable" - Captain Jerry

Offline ths

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Re: Flathead V-8
« Reply #211 on: February 27, 2015, 04:49:46 AM »
I think that there's more than just concentration involved in that job (or any of your work). Much appreciated. Hugh.

Offline fumopuc

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Re: Flathead V-8
« Reply #212 on: February 27, 2015, 05:09:15 AM »
Hi Vince,
I use drill rod for all of my camshafts but they are left unhardened. I would suspect that trying to harden it would induce some warpage and without a means of grinding it would be junk. When using a cam with flat tappets like this one the lifters are also made from drill rod but they are hardened and polished. Over the years I have noticed no noticeable wear using this combination.
gbritnell
Hi George, I am watching and I try to learn. Thanks for the above given explanation. For my good to know and to file away. I hope to need it soon.
Kind Regards
Achim

Offline Brendon M

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Re: Flathead V-8
« Reply #213 on: February 28, 2015, 12:40:00 AM »
Of the methods I've now seen for making cams, this seems the most straight forward. Thank you for demonstrating :)

I would (eventually) like to try a similar method where you rotate the cam as the mill cuts, producing the rough lobe shape in one run. It remains to be seen if for a multi-cylinder cam there would be too much chatter/stress on the cam and components.

http://www.metalstop.com/technical/cam-lobe.shtml
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Offline kvom

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Re: Flathead V-8
« Reply #214 on: February 28, 2015, 03:49:25 AM »
I believe a CNC mill with a 4th axis and headstock could mill cam lobes.  Not much different than what George is doing manually except that the cutting would be continuous.

Draw the cam lobes in the XZ plane and program the tool path as a profile.  Y coord is fixed on the cam axis and Z varies as the cam rotates under the flat endmill.

Offline gbritnell

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Re: Flathead V-8
« Reply #215 on: March 03, 2015, 01:26:33 AM »
Next up is the crankshaft. Since I discovered 1144 steel I make all of my crankshafts from this material. It cuts great and the nicest part is there is virtually no warpage, even when making small cranks like the one for my inline 6 cylinder engine.
I chucked up the stock and supported the outboard end with a steady rest to center drill the ends. I then made a short cleanup cut on the O.D. so that I could indicate it true when mounted in the 4 jaw chuck. The other end was supported with the live center. The O.D. was finished for the entire length. I cut the nose of the crank down to .075 larger than the finish diameter so I could mill flats without compromising the finished diameter.
The flywheel end was also cut large enough over finish to also have flats cut on it.
The flats would be for indexing the cranks when cutting the throws.
While the stock was getting the flats milled I roughed out the main bearing areas. It's so much easier to cut the heavy stock with an end mill than trying to plunge with whatever type of cutter in the lathe.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #216 on: March 03, 2015, 01:31:51 AM »
I have a large bifurcated tool that I only use for this type of work. I ground it from a .50 high speed lathe bit and reduced the area behind the cutting end for clearance. This took forever to grind so I only use it for making deep cuts like this. There is a radius on the outer corners and on the edges of the center notch. To set it up I first align the edge with my workpiece then using a dial indicator I check the tip for parallelism.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #217 on: March 03, 2015, 01:39:02 AM »
All of the mains were cut leaving .006 for the possibility of warpage after the throws are all cut.
The blank was then put back into the mill vise and the first throw area was roughed down leaving .03 stock.
A set of fixture blocks was made from aluminum. The chuck end will fit the large flange that was left on the stock and the tailstock end will fit the crank nose. Each block has a set screw ground flat to accurately locate on the flats that were milled on the blank.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #218 on: March 03, 2015, 01:48:54 AM »
The driving fixture block was mounted in the four jaw chuck and indicated. I made up a brass bushing with a .50 hole in it to accommodate the end mill shank for indicating. In this case the offset is .562 which give a total offset of 1.125 so I had to use a mike standard to get the extra 1.00 over my indicator travel. It's very important when making the fixture block to center the hole exactly in the direction opposite the offset. The reason for this is when setting the block in the chuck it needs to be perfectly centered so that you don't get a crooked offset when mounting the blank.
By this I mean you could have the fixture block offset in that direction and still obtain the required shift for the throws but the longitudinal axis would be at an angle and the throws would have a taper. 
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #219 on: March 03, 2015, 01:57:52 AM »
With the fixture block set true the crank stock was mounted and locked in place with the set screw. The tailstock block was slid onto the end of the crank and the live center was put into it, snug enough to support but not tight enough to warp the blank.
At this point I realized that my special tool wasn't long enough to finish the throws so I had to grind another 3/16 from the sides of the tool blank. I then put the lathe into a lower speed range and started cutting. When you start to plunge in with this tool even though the tip is split it will chatter if you go too deep so you have to be patient and take what it will give you.
As you can see it finished up quite nicely.
Three more to go.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #220 on: March 04, 2015, 01:52:14 AM »
All the turning is finished, whew!!. Normally when cutting the throws it's necessary to put some packing between the webs that have already been cut but with the size of this crank it cut without any chatter or deflection. The mains are .750 dia. and the throws are .64 dia. These dimensions were scaled from the full sized flathead crank.  I finished up the throws then mounted the shaft between centers to finish the mains. I had left about .008 for a cleanup just in case there was any warpage. I didn't measure with an indicator but to the naked eye it ran extremely true prior to cutting. Now I'll have to make a fixture to hold it so I can cut the stock away from the counterweights and drill the oil passages.
gbritnell
Talent unshared is talent wasted.

Offline Don1966

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Re: Flathead V-8
« Reply #221 on: March 04, 2015, 02:54:52 AM »
That's awesome George, I hope I make it to cabin fever I want to meet you.

Don

Offline steamer

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Re: Flathead V-8
« Reply #222 on: March 04, 2015, 11:12:36 AM »
Beautiful work George!    Cross drilling that would put me into fits! :o

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Offline sshire

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Re: Flathead V-8
« Reply #223 on: March 04, 2015, 11:51:45 AM »
That was like watching a sculptor. Spectacular!
Best,
Stan

Offline Mosey

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Re: Flathead V-8
« Reply #224 on: March 04, 2015, 12:48:20 PM »
George,
Hope to meet you at CF.
Could you do a mockup at CF to demonstrate some of these techniques?
Mosey
« Last Edit: March 04, 2015, 10:03:17 PM by Mosey »