Chuck thread hygiene

[mklotz]

Doesn't get much simpler than this, as tools go.

Anyone who owns a lathe with a threaded spindle knows that it's important to keep chips and swarf out of the chuck threads. It's just too easy for the stuff to get between the chuck and the register and spoil the chuck centering. Worse yet, it's not impossible for it to jam the threads and make the chuck very difficult to remove - a recipe for a broken back gear if you don't use the proper tools to remove a stuck chuck.

Take a piece of coat-hanger wire and bend it into the shape shown below. If you don't have coat-hanger wire [How could you not? The damn things breed in closets.] use something similar. The wire needs to be mildly springy. Flatten the ends and grind them into the shape shown in the second photo.

In use the device is threaded into the chuck jaws all the way down to the runout groove at the bottom of the threads. Swarf and chips are dislodged and fall into the bottom [or fall out if you hold the chuck over your head] where they can be wiped or better vacuumed. [Remember, compressed air is a tool for relocating swarf to the place where it can cause the most damage. ]

After you've cleaned the chuck threads, it's a good idea to clean the swarf out of the chuck jaws and scroll plate. Backing the jaws out of the chuck will be less tedious if you make a crank or use your electric screwdriver as detailed here...

http://www.homemadetools.net/forum/s...uck-jaws-26219

Once the jaws are out and cleaned, the scroll plate can be cleaned as follows. Push a toothbrush down into one of the chuck recesses so its bristles engage the scroll plate thread. Turn the scroll plate in the direction that would back the jaws out if they were in place. [The electric screwdriver really helps here.] Because the toothbrush is "engaged" in the scroll threads it will be driven outward, collecting swarf on its leading edge as it goes. Continue until the toothbrush completely disengages from the threads and the swarf will drop away onto the bench. If the toothbrush is an old oily one like mine, this procedure will also lightly lubricate the scroll.

One important safety warning: Do not, under any circumstances, return the toothbrush to the bathroom rack.

Bonus hint:

Folks with threaded spindles should thread a length of rod with the same thread as the spindle. Cut off a chunk and put it aside to use as a proof piece for turning female threads on accessories that will thread directly onto the spindle. One of these accessories should be a cap used to protect the spindle thread when no chuck is mounted.

Screw another chunk to a piece of plate. Put holes in the plate for attachment to the rotary table. With this in place, attaching the chuck to the RT is dead simple. Also, the chuck can be easily mounted to the milling table for jobs that might benefit from such an arrangement.

It may be possible to make a more upscale chuck thread cleaner using another chunk of the threaded rod. I haven't given it a lot of thought (because my coat-hanger wire works just fine) but by suitably shaping the end thread it should be possible to make a "bulldozer" that pushes swarf ahead of it. Think about it.

[Toolmaker51]

What? No plans? No process instructions? And the finish of the bulldozer; Deere green or CAT yellow?


Good job Marv; wish I had a nickel for every noob I've had to extract a chuck for. Way back Industrial Arts pupils made these; some rolled spring end round like a spark-lighter.
Before OSHA (or in absence of) a squirt of lighter fluid and CCW'd spindle by hand to 'flush' the tiniest chips out. Tiny ones in thread roots really cause the jams. Leaves a nice film too.

[Frank S]

For my scroll cleaning I have a cheap flat tip screwdriver ground to fit the grove it works great but. a periodic complete disassemble of the chuck is never a bad idea either. And yes I still wash mine in diesel

[DIYer]

Thanks mklotz! We've added your Chuck Thread Cleaner to our Machining category,
as well as to your builder page: mklotz's Homemade Tools. Your receipt:

Chuck Thread Cleaner by mklotz

tags: chuck, cleaner

[mklotz]

Chucks need to be kept clean but it's just as important to keep the spindle nose threads onto which the chuck threads clean and tidy.

My procedure, done before every mounting of a chuck, goes like this...

Put an oily toothbrush on the threads as far to the left (i.e. near the headstock) as possible and run the lathe in reverse at a low speed. The brush will be "unwound" along the threads and move to the right. As it does, it will sweep swarf before it and oil the threads to ease removal of the chuck in the future.

Easy to do, only takes a minute, and can save you from a lot of grief later on.

[Frank S]

When I got my second La Blond the 1953 model I made the mistake of trying to remove the 3 jaw with a spanner since the mount looked as if it had been removed that way before. The chuck would not come off that way so I then I tried to remove the 6 bolts holding the chuck in place And they were now locked in place I knocked the spanner the other way until the bolts became free so I was able to remove them,and the chuck then since I had already changed the seating of the adapter I removed it and cleaned everything I quickly found out that while the spindle is threaded with 23/4"x5 TPI threads the nose was actually an A-1 5" adapter and the inner hole BC was such that when they were tapped they threads actually cut into the outer diameter of the spindle threads as near as I could tell by about .030" on the first thread and about .040". Once I had the nose adapter back in place i had to re true it by shaving a few thou. off both faces and the taper then I had to run a tap into the holes to clean out the threads this cut new groves in the tops of the spindle threads.
both the 3 and the 4 jaw chucks run true so this will not be done again. Unless I come up with a cam lock nose adapter that I could thread the ID to fit the spindle.