That would work....and I have a 5mm end mill.
-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
Threaded Woodruff key
- Thread starter pbiYoung
- Start date
-
- Tags
- keyway woodruff key
yep.. could certainly do that as has been suggested a couple of times already and it certainly may come to that, but customer wanted to preserve the original wheels look if possible. Its allegedly an antique.
Thanks
- Joined
- Apr 8, 2013
- Messages
- 1,980
Epoxy the original half hole to hide it. What's left would look factory I would think.
Make new axle.
Make a fake wheel.
Determine the thread size with a bolt.
Just get some chunk of steel that is large enough to drill a hole that will fit the axle. A large nut would work, bore it to just fit.
Place the fake wheel on the new axle and center punch on the interface line between them.
Drill the hole for tapping the hole.
Remove fake wheel and put real wheel on.
Look through your taps and find the correct size with the maximum amount of taper. You want the threads in the wheel to align and guide he tap while it cuts the axle.
Just do a couple of turns. You just wand a starting thread on the axle.
Put fake wheel on and with the starting thread on axle, align the tap, and tap the hole.
Doing it this way has equal pressure. A blank axle in the threaded wheel may offset and be sloppy.
Now put the wheel on and final thread chase, and you are done.
Sent from my SM-G781V using Tapatalk
Make a fake wheel.
Determine the thread size with a bolt.
Just get some chunk of steel that is large enough to drill a hole that will fit the axle. A large nut would work, bore it to just fit.
Place the fake wheel on the new axle and center punch on the interface line between them.
Drill the hole for tapping the hole.
Remove fake wheel and put real wheel on.
Look through your taps and find the correct size with the maximum amount of taper. You want the threads in the wheel to align and guide he tap while it cuts the axle.
Just do a couple of turns. You just wand a starting thread on the axle.
Put fake wheel on and with the starting thread on axle, align the tap, and tap the hole.
Doing it this way has equal pressure. A blank axle in the threaded wheel may offset and be sloppy.
Now put the wheel on and final thread chase, and you are done.
Sent from my SM-G781V using Tapatalk
Except the new hole location would no linger line up with the existing connecting rod hole. Thanks
This is what I'll do
... and it will also likely allow me to avoid having to add any shims to account for pitch misalignment.
Thanks
Last edited:
- Joined
- Mar 4, 2024
- Messages
- 44
Maybe I'm crazy or something, but couldn't you just go to the next size larger screw? Stick a collar over the axle and drill to the root diameter. Toss the collar, replace the wheel, and drill the half threaded, half unthreaded hole to the new tap drill size.
I don't
This is probably not correct, but "in the field" we call this a "dutchman", or a "dutch key". I think (not sure) that these are technically a round dowel used as a key, but I'm not sure.
What you have there however is an arbitrarily large threaded "dutch key". Usually a threaded dutchman would not be that large relative to the shaft, and that would indicate previous repairs, oversizing the hole for new threads, so that they could be timed to each other. HOWEVER, given the application, I suspect that it might be done on purpose, as I suspect that the axial load might be kinda low on average, but pretty significant at specific times.
You've got two legitimate choices. One is to oversize the hole, and rethread it for the next sized fastener. The other is to start a brand new hole, clocked somewhere else on the wheel. You're looking at the parts, not me, but IF and ONLY IF the parts allow, upsizing the original would be the preferred option if this were done in modern industry. That type of key is still used on occasion. Option B, the other option, is still valid, just be sure there's enough "meat" left on the diameter of the shaft to support the wheel all the way around.
The hole is best drilled with an end mill ifyou can. You can drill it (it doesn't matter if it's offset), but the drill doesn't want to be where it oughtta be, it wants to fillow the "joint" between the two pieces. That offsets the intersection between the screw and the joint so that they dont' hit 180 degrees on the screw as you would like them to. Still works though.
The "key" used is typically just a hard set screw, although if the mating surfaces are flat, I have seen well graded bolts installed. That as opposed to "normal" keys, where the standard is for them to be kinda soft.
When tapping those holes, three flutes works better than two or four, all day long. And if you can at all, loctite the parts together, in position, AT LEAST for the tapping operation. Too much movement, tapping across the intersections, strange forces trying to make those parts rotate against each other..... It doesn't matter if you have tho heat the loctite out and take it apart again before final assembly, (although it surely wouldn't hurt anything to leave it), but even if it's only for a "pre-assembly" to make those threads, life will be better if you can fix those parts together while you're milling/drilling/tapping. After that... For as butch as it seems to be, It's actually a remarkably stout anchoring solution. Pain in the tuchus to work on after the fact, but a very stout joint until then.
This is probably not correct, but "in the field" we call this a "dutchman", or a "dutch key". I think (not sure) that these are technically a round dowel used as a key, but I'm not sure.
What you have there however is an arbitrarily large threaded "dutch key". Usually a threaded dutchman would not be that large relative to the shaft, and that would indicate previous repairs, oversizing the hole for new threads, so that they could be timed to each other. HOWEVER, given the application, I suspect that it might be done on purpose, as I suspect that the axial load might be kinda low on average, but pretty significant at specific times.
You've got two legitimate choices. One is to oversize the hole, and rethread it for the next sized fastener. The other is to start a brand new hole, clocked somewhere else on the wheel. You're looking at the parts, not me, but IF and ONLY IF the parts allow, upsizing the original would be the preferred option if this were done in modern industry. That type of key is still used on occasion. Option B, the other option, is still valid, just be sure there's enough "meat" left on the diameter of the shaft to support the wheel all the way around.
The hole is best drilled with an end mill ifyou can. You can drill it (it doesn't matter if it's offset), but the drill doesn't want to be where it oughtta be, it wants to fillow the "joint" between the two pieces. That offsets the intersection between the screw and the joint so that they dont' hit 180 degrees on the screw as you would like them to. Still works though.
The "key" used is typically just a hard set screw, although if the mating surfaces are flat, I have seen well graded bolts installed. That as opposed to "normal" keys, where the standard is for them to be kinda soft.
When tapping those holes, three flutes works better than two or four, all day long. And if you can at all, loctite the parts together, in position, AT LEAST for the tapping operation. Too much movement, tapping across the intersections, strange forces trying to make those parts rotate against each other..... It doesn't matter if you have tho heat the loctite out and take it apart again before final assembly, (although it surely wouldn't hurt anything to leave it), but even if it's only for a "pre-assembly" to make those threads, life will be better if you can fix those parts together while you're milling/drilling/tapping. After that... For as butch as it seems to be, It's actually a remarkably stout anchoring solution. Pain in the tuchus to work on after the fact, but a very stout joint until then.