I have it in my head that I'd like to try to grind my own camshafts - starting out with a Briggs & Stratton motor. How can I make my own Cam Grinder? Any online plans? Anyone willing to walk me through it?

Thanks,
Jay

"KnuckleBuster" wrote in message
...

I have it in my head that I'd like to try to grind my own camshafts -
starting out with a Briggs & Stratton motor. How can I make my own Cam
Grinder? Any online plans? Anyone willing to walk me through it?

Thanks,
Jay


--
KnuckleBuster

I saw a small cam grinder that worked off a pattern and was chain driven, as
I recall. Home built affair, and it worked very well. A grinding head much
like a tool post grinder was used to grind the lobes. I have a picture or
two if you'd like to see the concept. Let me know on the side and I'll
send them to you.

Harold

KnuckleBuster wrote:

I have it in my head that I'd like to try to grind my own camshafts -
starting out with a Briggs & Stratton motor. How can I make my own Cam
Grinder?

The question I'd like to ask: Do you really need to grind them? I have
milled some lobes and they look very nice.


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO // Eigenbau-Digitalanzeige
http://www.yadro.de

KnuckleBuster wrote in article
...

I have it in my head that I'd like to try to grind my own camshafts -
starting out with a Briggs & Stratton motor. How can I make my own Cam
Grinder? Any online plans? Anyone willing to walk me through it?

Thanks,
Jay


--
KnuckleBuster


There was an article in Model Engineers Workshop within the last year or so
about building a cam grinder that followed a master cam to produce cams for
model engines.

You might be able to take the concept and blow it up to the size you
need......

Perhaps you should pick up a copy of the magazine and inquire about past
issues.

That sounds exactly like what I'm looking for! I've seen a couple of pictures on the web, but I'm not the best at reverse engineering. If you could send me those pictures it would be great. I'll try to figure something out.

Thanks,
Jay

On Fri, 31 Mar 2006 23:50:38 +0100, KnuckleBuster
wrote:


I have it in my head that I'd like to try to grind my own camshafts -
starting out with a Briggs & Stratton motor. How can I make my own Cam
Grinder? Any online plans? Anyone willing to walk me through it?

Thanks,
Jay

I saw, and admired, this home brew cam grinder at NAMES last year.

http://neme-s.org/NAMES_2005/NAMES_12.htm

This page and the next are pictures of the machine.



Errol Groff

Instructor, Manufacturing Technology
H.H. Ellis Technical High School
613 Upper Maple Street
Danielson, CT 06239

New England Model Engineering Society
www.neme-s.org

Errol Groff wrote:

I saw, and admired, this home brew cam grinder at NAMES last year.

They all have two problems in common:
1.) Where does the master lobe come from?
2.) The disk's axis has to be on the same plane that is built by the
grinding disk's axis and the axis aróund which the disk swings.
In the apparatus shown, the feeler (right of the disk) has to have a
proportionaly bigger diameter than the grinding disk.
If not, you get distortions of the grinded lobe.

Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO // Eigenbau-Digitalanzeige
http://www.yadro.de

I don't have a milling machine, so milling lobes is out of the question for now. I've been puzzled by the setup of machines like the one from the NEMES show - where does the lobe pattern mount and how do you know how big to make the pattern? Wouldn't, as the grinding wheel wears down, need a different size lobe pattern? I think it would be fairly easy to set up, but then I think about the follower setup for the pattern and it throws me off....

Thanks for the input so far! It's got me thinking.

KnuckleBuster wrote:

I've been puzzled by the setup of machines like the one from
the NEMES show - where does the lobe pattern mount

It is the front axle that is driven by the (sloppy) chain.

and how do you know how big to make the pattern?

This construction isn't the best of all. There is an other construction
that uses a master lobe that is 10 times the original size. The NEMES
construction only has a master with a bigger base circle, but the lift
is -guessing by the photo- only 10% more. Much harder to make the master
lobe precise. The other construction uses a pantograph and has a 10
times bigger master. You can file the master out of sheet metal.


Wouldn't, as the grinding wheel wears down, need a different size lobe
pattern?

Yes and no. It depends on the wear. But in principle, a worn disk needs
a new follower.


I think it would be fairly easy to set up, but then I think about the
follower setup for the pattern and it throws me off....

The bigger the difference between the theoretical and the real relation
between follower diameter and disk diameter, the more distrortions you
have. The "sharper" the lobe, the more distortions.

In production, they use _huge_ disks when they do copy cams. But I
think, that more and more cam grinders use CNC. Especially with the
hollow chests of some lobes.

I have seen production cams that were grinded more like a shaper works.
They had quite some facetts and not just a single smooth surface. But
that was in a KIA. :-))

With the macro I wrote for my homebrewn DRO, it takes about 15 minutes
to mill a single lobe.


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO // Eigenbau-Digitalanzeige
http://www.yadro.de