How to stop chucks from coming out...

I have a few useful drive chucks, one Jacobs chuck, and one chuck with a small faceplate and a screw sticking out from the centre. These can be very handy for turning spinning tops, but I have the problem that the chucks come loose from the headstock every minute or so when turning, which is really annoying. I'm ramming them into the head of the lathe pretty hard and they are really solid when I start, but with the work of the chisel, they loosen up real quick and come out. Anyone got any tricks for stopping this? Apart from using the tailstock, which I do, but once I do the point of the top, this needs to come away. The other obvious answer to this is to do the point last, but sometimes I want to touch up some of the rest after the point is done. Any other ideas, or have I already given the good answers to my own question?

I am interested to know too. I have considered using a draw bar like on an R8 collet but that would mean tapping a tread in the back of the chuck spindles


Dave the turning cowboy

turning wood into art

I would use my morse taper reamer and ream inside of the spindle.

You can get plastic ones which clean the gunk out but if the taper is damaged you need a proper HSS reamer.

You could try rolling a piece of cloth back abrasive into a taper and using this to clean the taper.
Warning: use a slow speed and hold the abrasive lightly with your fingers.
DO NOT put your finger into the taper with the lathe turning.

I think I may have I sourced my reamer from McJings.

If required, I use a hammer and a block of wood to inserting a centre firmly.

Before someone screams about damaging the bearings, my lathes have tapered roller bearings and I have been doing this for more years than I care to remember without any damage.

Hope this helps,

Cheers
Tim:)

Sounds very much like you are using morse taper (MT) based accessories like the Jacobs Chuck to hold your work pieces. The MT system is designed so that the compression forces of the tailstock hold the drive securely in the headstock spindle. With some cuts like V cuts or cuts on the headstock side of the detail you actually generate forces that draw the MT drive centre out of the headstock spindle. That becomes very unsafe as the workpiece with the MT drive attached can be thrown from the lathe.

To overcome the drive working loose from the "away cuts" a drawbar can be used through the headstock spindle to retain the MT drive

http://www.penturners.org/forum/f14/...lstock-103791/ photo of a drawbar lower down the page.

or you could go for a much safer option again like a Vermec collett chuck that screws directly on to the headstock spindle.

http://vermec.tripod.com/PDFs/ER32_Page.pdf

Mobyturns, you are a legend! I found the picture of the threaded "draw bar", and thought wow, that's a cool idea. On looking at my chuck, it had a thread in the back of the MT. Figuring I there might be something useful sitting around that I could use, I checked in the large box of unidentifiable rubbish that I inherited with the lathe, and lo and behold, there is a matching threaded bar in there with screw handle on the other end. I had no idea what that was for until now. Looks like a home made job, but this is exactly what it is for! You've made my night, thanks!

All it takes is someone to post a comment and information is passed on. What a great result. :2tsup:

I'll echo those words above Moby, I sort of figured with a MT chuck other than using a tail stock that a draw bar (like the r8 collet set up) must be the only way.

Surf dabbler. Glad to hear your chuck already has a thread in the back of the MT. From what I have been able to find out myself this drawbar set-up is more typical in metal work applications but I like the idea.



Dave the turning cowboy

turning wood into art

Sounds like you've solved the problem,but for the interest of others,it is not hard to fit a draw bar to a jacobs chuck.I just drilled a hole in the tail of the chuck and tapped a hole to fit a bit of allthread which sticks out through the hollow centre.A bit of wood turned to fit the recess in the brake handle and a nut on the end . The nut has sinced been replaced with a brass nurled knob which a mate turned up for me.
Ted

:2tsup::2tsup::2tsup::2tsup:

An old "trick" is to clean out the taper, then dust the morse taper with powdered chalk, then re-insert. Even so, with heavy cuts that cut away from the headstock will probably cause the chuck to come out. The threaded rod through the headstock is definitely the better solution.

Jim

Quote:

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Originally Posted by surfdabbler

Mobyturns, you are a legend! I found the picture of the threaded "draw bar", and thought wow, that's a cool idea. On looking at my chuck, it had a thread in the back of the MT. Figuring I there might be something useful sitting around that I could use, I checked in the large box of unidentifiable rubbish that I inherited with the lathe, and lo and behold, there is a matching threaded bar in there with screw handle on the other end. I had no idea what that was for until now. Looks like a home made job, but this is exactly what it is for! You've made my night, thanks!

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Quote:

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Originally Posted by DaveTTC

I'll echo those words above Moby, I sort of figured with a MT chuck other than using a tail stock that a draw bar (like the r8 collet set up) must be the only way.

Surf dabbler. Glad to hear your chuck already has a thread in the back of the MT. From what I have been able to find out myself this drawbar set-up is more typical in metal work applications but I like the idea.

Dave the turning cowboy

turning wood into art

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Safety is the name of the game - or staying on the lathe longer and out of emergency rooms. :D

A word of caution - the MT2 comming out of the headstock spindle is not the only hazard with this setup. :oo: The Jacobs Chuck also has another taper fitting - the MT2 spindle usually has a Jacobs taper (or another) into the Jacobs Chuck body which can also seperate. A Google image search of "Jacobs Taper" will illustrate the point.

Drilling on a drill press or using a Jacobs Chuck in the headstock with tailstock support is fine. Take away the tailstock support & they become unsafe on the lathe.

For that reason I am not a supporter of using Jacobs Chucks to hold small work pieces for turning, or sanding/ buffing pads etc even with a drawbar. :no: I don’t and will not use them in that manner. An MT2 collett chuck is a safer option (with drawbar) but a dedicated threaded collett chuck like Vermec’s ER25 & ER32 setups is by far the safest option for small work.

The ER25 & ER32 collett chucks have multiple uses. :; They can be used to hold sanding arbors, or buffing pads etc. With an M14 bolt with the head cut off to make a threaded arbor one can make sanding faceplates from standard 100, 115, & 200mm angle grinder pads plus use interface (oops) pads for sanding and use them very safely. The collett chucks open up a whole host of options that are far safer than using the Jacobs Chuck in the headstock.

Personally I would never use a Jacobs chuck for anything but drilling in a lathe either.

The er32 collet chucks are the ones I have been looking at.

Now that you mention 25 I will check that out too


Dave the turning cowboy

turning wood into art

Quote:

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Originally Posted by Mobyturns

A word of caution - ... The Jacobs Chuck also has another taper fitting - the MT2 spindle usually has a Jacobs taper (or another) into the Jacobs Chuck body which can also seperate.

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My Jacob's chuck is threaded onto the taper, so I think it's pretty safe there. I had a moment's panic where I wondered if the thread was unscrewing because it's in the head instead of the tail, but of course it does the opposite job at that end, so it's all good. :)

The AAW has just added a video by Alan Zenreich to their Fundamentals program - "Using a Drawbar with a Morse Taper Drive" http://vimeo.com/93999983