I am repairing an old South Bend Serial #828 made sometime shortly after 1910-11. At some point in its life a woodruff key wore out and it was replaced by a set screw jammed in through the other side of the gear and into the shaft. Getting it out normally was not possible so I had to drill it out and weld up the damage. Once I get the rest of the lathe up and running I will likely be using your method when I make the new shaft. Thank you for helping me with this particular head scratcher.
Great video. The method you showed did the job as well as you could ask for but I am sure the milling attachment will make it even easier. Thanks for the video.
I can personally relate to the task of the woodruff key and it's battle against the forces it must endure and it was a learning experience that stranded me out in the boon-docks and forced me to walk home and abandon my motorcycle due to the failure of a woodruff key. 25+ years ago I purchased what was advertised as a "flywheel weight" for an off-road/dirt bike I owned at the time. This " flywheel weight" directly attached to the existing factory flywheel which increased the rotational mass of the flywheel assembly. The manufacturer of this accessory claimed it would make the power delivery/powerband more manageable resulting in an easier to ride motorcycle. The manufacturers claim was true - The flywheel weight( it was probably around a 1/3 increase in mass) really did change the power delivery characteristics and I was now happy with a motorcycle that was really too much for me to begin with ( this was a Kawasaki KX-500). The flywheel ( which was part of the magneto ignition) mated to the crankshaft on a taper and was locked in place by a woodruff key( a small, weak, undersized woodruff key). The accessory/aftermarket flywheel weight with it's extra mass proved to be too much for the factory woodruff key to withstand and it sheared many times. The external taper surface of the crankshaft( as well as the internal taper surface of the flywheel) was never damaged and I simply kept replacing woodruff keys until I gave up on the flywheel weight and eliminated it all together after which I never had any problems. At one point I tightened the flywheel nut to a point well beyond the factory torque which did not stop the shearing problem. Those stock/ factory woodruff keys were about 1/8" thick and about 3/4" long ( they were actually metric though). The entire fiasco was a big waste of money, a big waste of time and all I got out of it was a big headache.
Another good video Mr Pete, thanks. There's more than one way to skin a cat, and a s Jed Clampett would say, the cat does'nt care for it much either way!
Someone probably already said this but I always thought plated key stock was so you could 'fit' them. Same thing as oversized. Guys where I work hate the stuff but a little rubbing on a file is all it takes.
A much better way of making the clamp would be to add a second "Tee" to the top piece so that both pieces would be clamped in the vice, this would negate any side to side movement.I hope you understood this as I am not a teacher of the same standard as you and find it difficult to explain in writing.Regards John
The N in Mr. Woodruff's name stands for Newt,which was my Grand dads name. Newt Woodruff was my Grandfather,on my Mothers side.. WN Woodruff was my Great Grandpappy.. Born in Milton Pa.
+mrpete222 I think he just had a great idea to solve a problem he had.Deciding to patent it,was the smart thing. Many of us have had ideas others have capitalized on,i'm sure you have Mr.Peterson.
+petee716 I have always been told that woodruff keys are easier (read cheaper) to install when you want to maintain concentricity of a shaft, as well as offering a sort of mechanical fuse service. I think there is something about being mainly for light duty and tapered shafts in the Machinerys Handbook, but I can't provide the reference for that. Mr. Pete could probably give us the page number from memory.
always wondered why they were called "woodruff keys"...thanks for including where the name comes from.... two questions: are they intended to shear off should they reach some point of torque the way a shear pin is intended to do?? other question: does the carriage have any mechanism for elevating the workpiece, allowing you to mount the stock horizontally and engage it from below the cutter? (or is that something that some lathes might have and others would not??)
Why is it that when someone mentions something to do with safety in the comments, they get all this hate, "safety nazi", all that, but when tubalcain prefaces every single video with a title card instructing you to do X and Y to be safe it's totally cool?
I'm pretty lucky... I have the milling attachment. Actually... I think I have all the attachments... taper, grinding, etc. I have two lathes... one in great shape... the other not so much. Going to convert #2 into CNC.
Lyle, thank you for this video, I learned a lot! I have a few questions please; Were you feeding the cutter by hand? It was really too smooth to determine if you were or not; You mentioned that you would limit the cut to 1/4" on the poor man/economy method, can you please explain why?; What type of cutting oil were you using for the mild steel cut. Thanks Mr. Pete! I look forward to your videos every week; please keep them coming!!
+Albion Laster Since the cutter was trying to lift the carriage off the ways a slower speed would have the tendency for you to load the cutter up more and make it worse. You could cut on the back side and push down but then you can't see very well. Or you could use a left hand cutter like the one he had on the bench to cut down and in front but those are not very common. Best to just wait and see the next video where he uses the milling attachment. Mike (o\!/o)
If you wanted to cut the keyseat in a longer shaft, you could mount your shaft holder on top of a block with a clearance hole through it and using a longer bolt. Then you could mount a shaft up to the length to your overhead clearance. Size the block to put the shaft clamp just about as far above the cutter as it currently is below. Longer than that and you will either have to take the lathe outside or tip the lathe so the shaft can be horizontal (kidding of course)
Just wondering about woodruff keys. The pulley in the video had one set screw pushing down on one end of the woodruff key, would that cause the key to rock in the key way and help lock in the pulley. Would be nice to know why you would use a woodruff key verse a straight key. Thanks for the video always like to see different ways of doing things. Have a day
+E Hiebert A properly located Woodruff key is centered under the setscrew and doesn't rock. The setscrew will bite into the key and as the the key can't move axially the pulley stays in place and won't drift as sometimes happens with straight keys and vertical shafts or axial loads. On your drill press make sure to push the key down before you tighten the screw when aligning the pulleys so it says where you want it. Woodruff keys are usually used on shafts subject to cyclic or impulse loads because the deeper engagement won't allow the key to rock and work loose. They are also used where axial location is predetermined, like flywheels, but not on most motors and shafts where location or alignment may vary. Also on tapered shafts a straight key seat is more difficult to cut where a Woodruff key seat is a simple plunge cut. Mike (o\!/o)
Great demonstration Mr. Pete. Thank you for making it. By the way, I notice a LARGE discrepancy in the numbers used for the machine shop tips. Are you holding out on us addicts or have you yet to make the missing videos?
+Joepopa12 Rare is the drill press that would be rigid enough to mill a key-seat satisfactorily. The bearings are meant for thrust not radial loads. There also are no ways to feed the cutter with. So a jig would just be a milling attachment, marginal at best. Tolerances are the same for all key types of the same size. Mike (o\!/o)
When I was a yute way out in the country, we always called them "Jesus keys." You'd go through the process of rebuilding an old car engine, and then when you were putting on the crank pulley, somebody would invariably go, "Oh Jesus - where is that key?"
+zyzzy1944 Chordal height or "M" factor applies to all key-seats. Since the strongest straight key joint has the parting line at the middle of the key and that point is below the top of the shaft the chordal height must be accounted for when calculating depth of cut for different sized keys. And since a Woodruff key must also fit a broached or cast key-way, projection will also be 1/2 key width. Mike (o\!/o)
Google Books has pretty much the entire Popular Mechanics online, except the recent years. books.google.com/ search for Popular Mechanics. You can also search by year (ie. popular mechanics 1943). Try searching for Machinist too, several interesting things come up.
TheHelado36 it is designed to be a week point. The key breaks if overloaded instead of damaging other components like gears or shafts. Lot easier to change a key than replace the shaft.
"More than one way to skin a cat" was one of my dad's favorite sayings. He was a tool maker all his life. Thanks for the videos.
Now that is one good way to skin that cat. Thanks for the good explanation on getting the depth of cut figured out.
+ILGopher Thanks for watching
Another good one.
Glad you mentioned kerosene for lubricant for Aluminum, lot of people do not know that.
Cheers
Wonderful bit of practical ingenuity. Thank you for building it to show us.
Another excellent tutorial. Most ingenius. Thanks for sharing. regards from the UK
I am repairing an old South Bend Serial #828 made sometime shortly after 1910-11. At some point in its life a woodruff key wore out and it was replaced by a set screw jammed in through the other side of the gear and into the shaft. Getting it out normally was not possible so I had to drill it out and weld up the damage. Once I get the rest of the lathe up and running I will likely be using your method when I make the new shaft. Thank you for helping me with this particular head scratcher.
+Gingerly glad I helped
great video nice improv....thanks again
Great video. The method you showed did the job as well as you could ask for but I am sure the milling attachment will make it even easier. Thanks for the video.
Nice video Lyle, have done that several times on small shafts. Thanks
This is absolutely excellent
I can personally relate to the task of the woodruff key and it's battle against the forces it must endure and it was a learning experience that stranded me out in the boon-docks and forced me to walk home and abandon my motorcycle due to the failure of a woodruff key. 25+ years ago I purchased what was advertised as a "flywheel weight" for an off-road/dirt bike I owned at the time. This " flywheel weight" directly attached to the existing factory flywheel which increased the rotational mass of the flywheel assembly. The manufacturer of this accessory claimed it would make the power delivery/powerband more manageable resulting in an easier to ride motorcycle. The manufacturers claim was true - The flywheel weight( it was probably around a 1/3 increase in mass) really did change the power delivery characteristics and I was now happy with a motorcycle that was really too much for me to begin with ( this was a Kawasaki KX-500). The flywheel ( which was part of the magneto ignition) mated to the crankshaft on a taper and was locked in place by a woodruff key( a small, weak, undersized woodruff key). The accessory/aftermarket flywheel weight with it's extra mass proved to be too much for the factory woodruff key to withstand and it sheared many times. The external taper surface of the crankshaft( as well as the internal taper surface of the flywheel) was never damaged and I simply kept replacing woodruff keys until I gave up on the flywheel weight and eliminated it all together after which I never had any problems. At one point I tightened the flywheel nut to a point well beyond the factory torque which did not stop the shearing problem. Those stock/ factory woodruff keys were about 1/8" thick and about 3/4" long ( they were actually metric though). The entire fiasco was a big waste of money, a big waste of time and all I got out of it was a big headache.
+Jayne Gus Good story, Yes, it was undersize for the weight & it became a shear "pin". Thanks for watching
Nice set up using the lathe!
Excellent. Well explained. Very useful....Thank you.
As always, very informative. Thanks.
Great video and a good tool to have in the box.and always in my seat on the front row good day in class
Good lesson , Thanks Lyle !!
+ShawnMrFixitlee Thanks for watching
I will use this to repair a couple of shafts I have
Thanks
Well-done Sir, enjoyed. Mike A. Drover
thanks again sir for a great video...
Thank you for sharing.
Another good video Mr Pete, thanks.
There's more than one way to skin a cat, and a s Jed Clampett would say, the cat does'nt care for it much either way!
+geoffrey abegg thanks for watching--I liked old Jed
Someone probably already said this but I always thought plated key stock was so you could 'fit' them. Same thing as oversized. Guys where I work hate the stuff but a little rubbing on a file is all it takes.
A much better way of making the clamp would be to add a second "Tee" to the top piece so that both pieces would be clamped in the vice, this would negate any side to side movement.I hope you understood this as I am not a teacher of the same standard as you and find it difficult to explain in writing.Regards John
Thanks much teach
The N in Mr. Woodruff's name stands for Newt,which was my Grand dads name. Newt Woodruff was my Grandfather,on my Mothers side.. WN Woodruff was my Great Grandpappy.. Born in Milton Pa.
+Fishkiller 41 Very interesting--he was a smart man
+mrpete222
I think he just had a great idea to solve a problem he had.Deciding to patent it,was the smart thing.
Many of us have had ideas others have capitalized on,i'm sure you have Mr.Peterson.
Great video and very informative as usual. How do you determine whether to use a woodruff key versus a straight key in a particular application.Thanks
+petee716 I have always been told that woodruff keys are easier (read cheaper) to install when you want to maintain concentricity of a shaft, as well as offering a sort of mechanical fuse service. I think there is something about being mainly for light duty and tapered shafts in the Machinerys Handbook, but I can't provide the reference for that. Mr. Pete could probably give us the page number from memory.
A little late but it’s called a “set screw flat” on that shank. What I was taught anyways 🤷
always wondered why they were called "woodruff keys"...thanks for including where the name comes from....
two questions: are they intended to shear off should they reach some point of torque the way a shear pin is intended to do??
other question: does the carriage have any mechanism for elevating the workpiece, allowing you to mount the stock horizontally and engage it from below the cutter? (or is that something that some lathes might have and others would not??)
another great video -- thank you!
the phrase was originally "the proof of the pudding is in the eating" -- but why get technical?
nice video.
+Jeff Moss thanks for watching
Why is it that when someone mentions something to do with safety in the comments, they get all this hate, "safety nazi", all that, but when tubalcain prefaces every single video with a title card instructing you to do X and Y to be safe it's totally cool?
I really wanted to see how to use the atlas milling attachment
Yes thanks
I'm pretty lucky... I have the milling attachment. Actually... I think I have all the attachments... taper, grinding, etc. I have two lathes... one in great shape... the other not so much. Going to convert #2 into CNC.
+askjerry Hi-You have a great shop--I saw your vids.
Lyle, thank you for this video, I learned a lot! I have a few questions please; Were you feeding the cutter by hand? It was really too smooth to determine if you were or not; You mentioned that you would limit the cut to 1/4" on the poor man/economy method, can you please explain why?; What type of cutting oil were you using for the mild steel cut. Thanks Mr. Pete! I look forward to your videos every week; please keep them coming!!
+JC S By hand. Pipe thread oil
she sure didnt like the steel. would slower rpms allow for cutting thicker key seats? or would it just buck and chatter at a lower frequency?
+Albion Laster Since the cutter was trying to lift the carriage off the ways a slower speed would have the tendency for you to load the cutter up more and make it worse. You could cut on the back side and push down but then you can't see very well. Or you could use a left hand cutter like the one he had on the bench to cut down and in front but those are not very common. Best to just wait and see the next video where he uses the milling attachment.
Mike (o\!/o)
If you wanted to cut the keyseat in a longer shaft, you could mount your shaft holder on top of a block with a clearance hole through it and using a longer bolt. Then you could mount a shaft up to the length to your overhead clearance. Size the block to put the shaft clamp just about as far above the cutter as it currently is below. Longer than that and you will either have to take the lathe outside or tip the lathe so the shaft can be horizontal (kidding of course)
+Peter W. Meek GOOD IDEA
Just wondering about woodruff keys.
The pulley in the video had one set screw pushing down on one end of the woodruff key, would that cause the key to rock in the key way and help lock in the pulley.
Would be nice to know why you would use a woodruff key verse a straight key.
Thanks for the video always like to see different ways of doing things.
Have a day
+E Hiebert A properly located Woodruff key is centered under the setscrew and doesn't rock. The setscrew will bite into the key and as the the key can't move axially the pulley stays in place and won't drift as sometimes happens with straight keys and vertical shafts or axial loads. On your drill press make sure to push the key down before you tighten the screw when aligning the pulleys so it says where you want it.
Woodruff keys are usually used on shafts subject to cyclic or impulse loads because the deeper engagement won't allow the key to rock and work loose. They are also used where axial location is predetermined, like flywheels, but not on most motors and shafts where location or alignment may vary. Also on tapered shafts a straight key seat is more difficult to cut where a Woodruff key seat is a simple plunge cut.
Mike (o\!/o)
Thanks for the info
Have a day
can you use the other end of the bar for another size? 2 for 1
Great demonstration Mr. Pete. Thank you for making it. By the way, I notice a LARGE discrepancy in the numbers used for the machine shop tips. Are you holding out on us addicts or have you yet to make the missing videos?
+My Heap Holding out-there are 40 vids in the can
With those tolerances you could prolly make a jig to cut these with a drill press.
+Joepopa12 Rare is the drill press that would be rigid enough to mill a key-seat satisfactorily. The bearings are meant for thrust not radial loads. There also are no ways to feed the cutter with. So a jig would just be a milling attachment, marginal at best. Tolerances are the same for all key types of the same size.
Mike (o\!/o)
I understand the load on the bushings bearings would not be ideal and agree with you there but it would not be hard to make the jig feed the stock.
When I was a yute way out in the country, we always called them "Jesus keys." You'd go through the process of rebuilding an old car engine, and then when you were putting on the crank pulley, somebody would invariably go, "Oh Jesus - where is that key?"
You can get 100pc of 3/16 x 3/4 Woodruff Keys for 9 dollars on ebay.
I have a question for you... What is the purpose of the chordal depth when cutting a woodruff key?
Thanks, Jack
+zyzzy1944 Chordal height or "M" factor applies to all key-seats. Since the strongest straight key joint has the parting line at the middle of the key and that point is below the top of the shaft the chordal height must be accounted for when calculating depth of cut for different sized keys. And since a Woodruff key must also fit a broached or cast key-way, projection will also be 1/2 key width.
Mike (o\!/o)
+Moholo 88 Now I understand. Thanks.
next show us how to make your own keys...
Google Books has pretty much the entire Popular Mechanics online, except the recent years. books.google.com/ search for Popular Mechanics. You can also search by year (ie. popular mechanics 1943). Try searching for Machinist too, several interesting things come up.
Why use keys??? It looks like a weak point! Why not just do a design like we see in front wheel shaft endings?
TheHelado36 it is designed to be a week point. The key breaks if overloaded instead of damaging other components like gears or shafts. Lot easier to change a key than replace the shaft.