WriteON
Member
It's spinning loose when drilling. Is the tapered # 2 bar that goes into tailstock worn? It is time to replace?
Jacobs chuck
- Thread starter WriteON
- Start date
Signed-In Members Don't See This Ad
Signed-In Members Don't See This Ad
Oliver X
Member
It's possible, but unlikely. I'm going to guess it's more likely to be dirty than worn out. I'd start by giving the tailstock and chuck tapers a good clean and inspect them for damage. If there's no apparent damage, I'd see if cleaning did the trick. If you want a definitive answer on that, buy a tube of Dykem Hi-Spot blue. It's a few dollars, and there's a learning curve to using it, but it'll let you know how well the tapers match.
#2 Morse is pretty small, so it may be getting overwhelmed by something in your process. If the drill is dull or being fed too fast into a pre-drilled hole it can be pulled loose. If it's wandering it can be rocked loose.
Anyhow, that's where I'd start before throwing money at it.
#2 Morse is pretty small, so it may be getting overwhelmed by something in your process. If the drill is dull or being fed too fast into a pre-drilled hole it can be pulled loose. If it's wandering it can be rocked loose.
Anyhow, that's where I'd start before throwing money at it.
CHARLES STOPCZYNSKI
Member
Frank, Had the same issue with a large floor model drill press at work some years ago. After some abnormally rough drilling by an employee, the chuck would drop out of the spindle when retracting the chuck to its rest position. After a thorough cleaning, of both the chuck stem and interior of the spindle with a degreaser and alcohol in that order the chuck was re installed, pressed into place with a wood block between the chuck with jaws fully retracted, that is FULLY OPEN. It worked.
Curly
Member
The Morse taper his coming loose from the vibration of drilling. If you hold the chuck back against the tailstock with the left hand as you turn the hand wheel with the right it will stay engaged and not rattle loose.
There are a few tailstocks like the Nova 3000/1624 where the tailstock arbor is threaded on the outside and not the inside like the majority of lathes where you can thread a drawbar into the taper and tighten it. Because the arbor length doesn't change as you advance or retract it it keeps the taper locked in place. The length changes on regular arbors as the handle is turned so a drawbar won't work. That's why you have to hold it.
Pete
There are a few tailstocks like the Nova 3000/1624 where the tailstock arbor is threaded on the outside and not the inside like the majority of lathes where you can thread a drawbar into the taper and tighten it. Because the arbor length doesn't change as you advance or retract it it keeps the taper locked in place. The length changes on regular arbors as the handle is turned so a drawbar won't work. That's why you have to hold it.
Pete
WriteON
Member
Prefer not to touch anything that might spin loose. I did some cleaning and used a new bit. The Chuck spinning loose might have been from a dull bit.
Last edited:
monophoto
Member
Agree fully with Pete.
The only issue with holding the chuck with your left hand while drilling is that if the taper looses its grip, the chuck will start spinning and can scrape or burn your hand. So I slip on a carver's glove whenever I need to hold my chuck while drilling. A carver's glove is made of kevlar which is designed to prevent cuts in the event a carving knife/gouge slips, and is a great way to prevent hand injuries. Also, my carver's glove has rubber beads imbedded in the kevlar which provides enhanced grip on the chuck.
I also wear the carver's glove on my left hand (I'm right handed) anytime I use a dremel to prevent injuries if the tool slips.
Last edited:
WriteON
Member
Not to debate Holding the chuck. Everyone does what's best for themselves however I highly advise against it but that's me. I'm in no way taking a chance on my safety especially for a pen blank. But the carvers glove makes sense. Thanks for all replies... I strongly feel the spinning loose is from a dull bit heating up and grabbing the blank. Will follow up later.
Curly
Member
It would have been helpful for you to give all the information as to why you started the thread. As in.
I was drilling an acrylic blank, dry, straight in without stopping, with a xx/xx" drill bit, at roughly xxx rpm and suddenly the drill bit and chuck started to spin. Once I turned it off I found the blank was hot and there was melted plastic in the flutes. The bit is well used and somewhat dull. "Is the tapered # 2 bar that goes into tailstock worn? It is time to replace?"
With a complete picture of what was going on you would have gotten more appropriate answers from the gitgo.
Now when I advocate holding the chuck back against the tailstock I am not telling you to use a death grip on it, wrapping your fingers and thumb completely around the chuck. Only the tips of a couple fingers and thumb so it stays engaged with the taper. That way if it does come loose your fingers will slip off and your instinct to let go kicks in. if you have a death grip on it the tendency is to fight it which could result in injury. I should have said so in more detail with my post, so I screwed up by not being more clear as well.
Pete
I was drilling an acrylic blank, dry, straight in without stopping, with a xx/xx" drill bit, at roughly xxx rpm and suddenly the drill bit and chuck started to spin. Once I turned it off I found the blank was hot and there was melted plastic in the flutes. The bit is well used and somewhat dull. "Is the tapered # 2 bar that goes into tailstock worn? It is time to replace?"
With a complete picture of what was going on you would have gotten more appropriate answers from the gitgo.
Now when I advocate holding the chuck back against the tailstock I am not telling you to use a death grip on it, wrapping your fingers and thumb completely around the chuck. Only the tips of a couple fingers and thumb so it stays engaged with the taper. That way if it does come loose your fingers will slip off and your instinct to let go kicks in. if you have a death grip on it the tendency is to fight it which could result in injury. I should have said so in more detail with my post, so I screwed up by not being more clear as well.
Pete
WriteON
Member
Same here.... as for not fully explaining. Much vague-ness on my end. My apologies. We're 100% good. All on the same team. We're buddies. All replies appreciated.
Last edited:
WriteON
Member
Drill chuck still spinning out. Sometimes starts to rotate before making entrance. Bought a new chuck with #2MT arbor. Still no good. I did clean the spindle...did not help. I'm considering buying new tail stock spindle. This problem is new. Everything was ok for a while. Any comments?
Jet JML-55 Tailstock Spindle
Curly
Member
Curious when you put the chuck in the tailstock is the tailstock fully retracted or out an inch or so. Fully retracted the taper will never engage.
WriteON
Member
Understood. Tail stock is advanced to the proper length. What puzzles me is this is a new problem...has not happened for years, I did my best to get the arbor seated properly without forcing or abusing the chuck/arbor.
howsitwork
Member
I can recommend using a shot gun brush to clean the taper out. I also cap my spindle with a nylon top hat when not in use to stop debris entering.
However you say "starts to rotate before making entrance ", that sound to me like the tang is not engaging in the tailstock rather than debris .
Can you shine a strong light up the hole to see if there are any burrs to stop it engaging?
However you say "starts to rotate before making entrance ", that sound to me like the tang is not engaging in the tailstock rather than debris .
Can you shine a strong light up the hole to see if there are any burrs to stop it engaging?
WriteON
Member
I did what I thought was a good cleaning. I removed and "studied" the inter wall. For some reason the drill chuck assembly grabs tight but comes loose.
This is the very reason I developed the Tail Stock Draw Bar.
See video at:
The tool is available at:
See video at:
www.speakeasypen.com
WriteON
Member
I might give it a try. As for the #2MT cleaner …. Please describe.
monophoto
Member
I see that Speakeasypen has a morse taper cleaner, It appears to be plastic with ridges, but the description of how the ridges are attached is confusing.
On my previous MT1 lathe I used the 'Green Weenie' cleaner sold by Craft Supplies - its just a tapered piece of molded soft plastic (hdpe perhaps) that you insert and twist to remove any dust or debris inside the female taper. It worked well, but when I upgraded I gave it to the guy who bought my old lathe. For my new MT2 lathe, I opted to buy a brass 20 ga shotgun barrel brush from Dick's Sporting Goods - it cost about a third what Craft Supplies was asking for the Green Weenie, and works just as well. I had to make a handle for it, but that was a simple turning project.
As to the tailstock drawbar - I don't understand how it works. The tailstock of my lathe does have a bore that can accept a drawbar (on some lathes, the tailstock ram is solid), but the problem is that use of a drawbar interferes with extending the ram. I can see how it might be possible to use a drawbar to fix the jacobs chuck arbor into the tailstock, and then move the entire tailstock in and out to drill, but I can't see how the ram drive could be used if a drawbar fixes the chuck arbor in place.
But a more serious problem is that the arbors on most jacobs chucks are double ended - a morse taper on the end that mounts in the lathe, and a JT33 taper on the other end that fits into the jacobs chuck body. It's not uncommon for that JT33 taper do uncouple allowing the chuck body to separate from the arbor.
WriteON
Member
I think I understand the drawbar. It does makes sense using one. It travels until the spring compresses and then gets reset. However I depend on the tail stock handle to turn the spindle and the drawbar prevents continuous free movement (for me). Also my lathe is close a wall on the tail stock side… but I might buy/try one. I would use it for certain applications. MagicBob is into good designs.
EDIT...question for Bob about the spindle cleaner. Is it turned under (slow power) or hand turned to clean.
Last edited:
howsitwork
Member
Louie
I have never had a J 33 taper come free of the chuck body so that's a new one on me. I suggest clean it well, petrol or white spirit, also the socket in the chuck. Then press them together by putting them i. the tailstock and a block of wood between it and the headstock then extend the barrel to squeeze home. Getting a J33 out again is a whole new ball game , I used a large press and set of jacobs tapered wedges CAREFULLY to extract it. To be honest given the hassle, if I hadn't loved the chuck , I would have sold it on and bought another with the morse taper I needed instead of extracting and changing the morse taper.
WriteON
Member
Same... No problem on 33 coming out. I did use a punch with a spacer on butt end of the Jacobs and knocked out the J33.
WriteON
Member
howsitwork
Member
Several friends who are machinists recommend drilling and tapping a hole through the base of a jacobs chuck. (where the arbor fits ) BEFORE fitting it to its arbor so if you ever need to remove it you can put grease into the hole and using a long bolt of grub screw hydraulically separate them .
DO NOT DO THIS on keyless chucks they work on a different mechanism might damage its internal working mechanism !
DO NOT DO THIS on keyless chucks they work on a different mechanism might damage its internal working mechanism !
use it by hand, the white stripes are like a Magic Eraser from Mr. Clean and clean it pretty good
WriteON
Member
Next...Not sure what size (thread) draw bar I need, I'm using the TM32 chuck w/TM33 arbor. Thanks. Frank
Last edited:
MT2 chucks have a 3/8"-16 thread and MT1 have 1/4"-20
monophoto
Member
That matches my experience. You can easily make a drawbar using components readily available at most hardware stores.
The headstock bore in my MT2 lathe will accommodate a 3/8" drawbar, but the bore in the MT2 tailstock will not - the largest drawbar that will fit is 1/4". And the tailstocks of some lathes are solid and can accept any drawbar.