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camshaft grinder

cuttergrinder

Hot Rolled
Joined
Mar 16, 2007
Location
Salem,Ohio
Ive seen a few threads on here about building a camshaft grinder. I am kind of in the process of building one. I have a cincinnati #2 cutter grinder that I bought at an auction for 120.00. It has a really long table and I have an old neglected Sheldon lathe. My plan is to mount the sheldon lathe bed on top of the main table of the cutter grinder with a couple pillow block bearings. This will allow the lathe bed to rock in and out while grinding the cam. I plan to drive the lathe headstock with a 3 phase gear reduction motor that runs 40 rpm. Then put a vfd on it to be able to adjust the speed. I plan to make a dividing head to mount to the lathe spindle and this will also hold the master plates for grinding the cam. I am planning on making a follower wheel the same size as my grinding wheel to roll against the master plates and this will have bearings and mount to the grinder table under the lathe bed. The cam will be mounted between a dead center in the lathe spindle and the center in the lathe tailstock. I need to make a spring bracket to mount to the lathe bed on one end and to the grinder table on the other end to apply pressure to hold the rocking lathe bed against the master lobes while grinding. Any thoughts from guys who have built one?
 
I have never built one but it does seem cool project.
A balls-way grinder may have some long travel variances, they are not always as true as a scraped oil way machine. It is not uncommon to have some end-of-long travel changes because the ball ways are less worn at the end of travel. Taking out a couple of balls at the ends can sometimes help. Cinci replaceable ball way racks are easy to grind and then shim under back to height.
 
We have a pulling tractor and this year we are so far the points champion of our class. Our camshaft is close but I feel it needs tweaked. My plan is to make a few new cams and tweak a few numbers and then run it on the dyno. Most cam companies just dont have the proper lobes for a tractor because they need relatively short duration but really high lift. Also tractors dont turn that high of an rpm so I feel they can live with a little more aggressive lobe than say a car cam that may spin at 8 or 9,000 rpm.

I put an indicator on the side of my cutter grinder table and it only runs out maybe .001 the total length. Not sure how straight the table is though.
 
You will find to grind cams the main factor is the biggest possible wheel so wear isnt a factor.......like a 24" wheel ,or even a crank grinder wheel.............In fact most of the cam grinders Ive seen were extras on crank grinders ..........the actual mechanics of the cam rocking device is easily worked out to suit what you have in the shop...............One of the Prince type crank grinders with the wheel rocking back and forth would be easily used as a cam grinder.
 
You will find to grind cams the main factor is the biggest possible wheel so wear isnt a factor.......like a 24" wheel ,or even a crank grinder wheel.............In fact most of the cam grinders Ive seen were extras on crank grinders ..........the actual mechanics of the cam rocking device is easily worked out to suit what you have in the shop...............One of the Prince type crank grinders with the wheel rocking back and forth would be easily used as a cam grinder.
I'm sure I will wish I had a larger grinding wheel but one thing I have read is with a small wheel you can design roller cam lobes with a concave flank.
 
Impressive, my dad built and serviced camshaft and crankshaft grinders working at Norton Company, Warner & Swasey and later for himself.
 
QT: I put an indicator on the side of my cutter grinder table and it only runs out maybe .001 the total length.
That is good..you can put a strip of tape long-way on the table and mark it
-.001, -.0003 , -.0005, -.001 - or whatever, but only the cam bearing fits matter in thousandth and all within .001 that little variance won't matter.

The grinding wheel was an aluminum pulley with abrasive paper glued (or greased) to it is a good idea because the pully dia + a fresh tape will always be the same size wheel...so the same zero makes size.

I used that method honing close bores, the same length of tape after the overlap wrapped on a bar stock always made the same bore.
 
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Look around Detroit, there have to be a few mechanical cam grinders still floating around. It will be far cheaper than a roll your own. Landis are the ones I recall. The relationship between the master and the finished cam is correct only for a specific diameter grinding wheel, everything else is just close. What material and heat treatment are you planning to use?
 
In the 80's just about every automotive machine shop had a cam grinder, usually in the back corner covered in grime from lack of use. A quick search turned up none for sale, where did they all go? Scrap, Mexico, China, or Pakistan?

If I had to build one, think I'd start with a cylindrical grinder.
 
Look around Detroit, there have to be a few mechanical cam grinders still floating around. It will be far cheaper than a roll your own. Landis are the ones I recall. The relationship between the master and the finished cam is correct only for a specific diameter grinding wheel, everything else is just close.

I'd triple-plus that, it's not a good way to spend your resource of time.

The Landis cam grinders, as I remember, were insane - they had a wheel for every lobe. The crank grinders did for sure. Van Norman or Storm-Vulcan or newer, Berco would be the mechanical ones to look at.

However .... nowadays you can just give an nc grinder the lobe data and get what you want back, There are people who will do that, there are relatively inexpensive cnc cam grinders (Supertec in Taiwan for a cheap one ?) the whole process for a mechanical grinder is not as straightforward as you think.

Because of the rocking motion of the table, the master is not just a bigger version of what you want. The masters are pretty big, 12" or more ?

What you'd do is make a cam by the point to point method on a piece of plate - maybe 3/8" thick ? Then file and polish it smooth, mount it in the machine, then grind the master off the template. Since they were both on the rocking table, that mechanically took care of the difficult geometry problem of how that rocking motion changed the desired cam profile. Then you'd grind the production parts from the master cam.

People don't have to do that no more. NC grinders move the table in and out in a linear fashion. No more rock. Much simpler and easier.

It is so much work to do cams even if you have the right equipment, that making a hashed-up "cam grinder" then expecting it to produce what you want ... let's just say it's not 1955 no more.

Personally, I'd put my time into the engine elsewhere. Let a guy with the nc grinder make whatever you want then put the time in on the dyno instead.

Or at the least, buy Packard's. From the description, what you are planning to do will be crap.
 
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I once reground a cam lobe on a V8 Caterpillar with a die grinder ,down through the hole in the deck surface of the block ......the motor broke a valve spring ,dropped a valve ,and the pushrod was wound around the crank........driver didnt hear any unusual sounds.
 
Look around Detroit, there have to be a few mechanical cam grinders still floating around. It will be far cheaper than a roll your own. Landis are the ones I recall. The relationship between the master and the finished cam is correct only for a specific diameter grinding wheel, everything else is just close. What material and heat treatment are you planning to use?
Most guys are using s7 tool steel and hardened to around 58 to 60
 








 
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