How big should a lathe chuck guard be?

I am going to make or buy a guard for the chuck on my Clausing 5914 lathe. The question is how large the guard should be.
The advertised swing is 12", although the absolute max is about 13" over the bed.
There are two chucks and one faceplate. The chucks are 8" (3-jaw) and 10" (4-jaw), and the faceplate is 10". The 3-jaw also has big clunky soft jaws.
The commercial units made by Flexbar are what one mostly sees. There are two units that are plausible for this lathe. Data from Enco:
FK505-4016 is a half-circle of radius 6", is 6" wide along the bedway, and is offered for chucks up to 8". This seems a bit too tight, even though the guard is suggested for lathes up to 12" swing.
FK505-4017 is a half-circle of radius 8", 8" along the bedway, and is offered for chucks up to 10". This obviously works, but the guard seems a bit too big for the lathe, even though the guard is suggested for lathes from 12" to 16" swing.
What experience do people have here?
Joe Gwinn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Better measure your swing again. My 5914 will only swing about 12 1/4" over the ways. It's the back V way that hits first. Make the guard as tight as you can to accept the max workpeice. 12 1/2" dia. If you buy one, the 4016 model makes sense. How often will you turn something between 12 and 12 1/4"? You could probably tweak it to clear the extra 1/4" if you had to have it. Tom
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Right you are. It's 6-3/32 inches from center (the center pip on a piece of steel in a 5C collet) to the near edge of the rear V rail.
Why is it necessary to make the guard as tight as possible?
Joe Gwinn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I don't think it's necessary, just desirable to keep the stray coolant from spraying out from under the cover. I haven't used a guard on a lathe in decades but think about one when I ponder flood coolant. I'll be adding a chip/splash shield on the rear of the pan soon. The flood coolant follows and then I presume the chuck guard. Let us know how it all works out. Post pics if possible somewhere. Tom
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Escaping coolant is why Iggy put a rubber skirt on the front of his guard, and why one installs the guard such that the guard reaches past the tips of the chuck jaws. I plan to do both.
And, "chuck jaws" has to include those big clunky soft jaws, which also are a danger because of their propensity to clip the lathe operator. Man would that hurt.

Sure.
Joe Gwinn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I would say that width may be more important than radius, to some extent. You need the guard wide enough to extend at least a bit beyond the chuck jaws. Secondly, the guard should prevent coolant from being thrown at you, so it needs to either go lower than the chuck's middle, or else you ned to add a rubber splash guard to it. My guard is for lathes with 15" swing, and my lathe is 13". It seems to fit reasonably well.
i
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes. I plan to mount the guard to ensure this, even if the back of the chuck isn't fully covered. Only 1" gap between headstock and cover is required to achieve this.

I do plan to add rubber skirts front and back. The 5914 has a deep chip pan, but no backsplash shield, so the back skirt is needed.
And a rubber apron on the toolpost, covering the carriage and compound.

This sounds like the FK505-4019 Flexbar guard, which is for lathes with 16-20" swing. What is the length? (This is the largest dimension, being the diameter of the circle.)
Anyway, for the 5914, this suggests use of the larger of the two plausible guards.
Joe Gwinn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Swing does not really have much to do with the issue.
Using the largest chuck, back out the jaws until they have about half engagement in the scroll or worm and measure that. I would go about 2" bigger diameter than that for a 1" clearance in the worst case when holding a large diameter. That measurement may be pretty close to the face plate diameter.
Personally those splash guards are more trouble then they are worth unless you are doing a lot of production turning with flood coolant. But each to his own.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
p.s.
The guard only helps with coolant thrown off by the chuck, until the tool gets to the guard stuff is still being thrown around.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

True, but most of the long-distance coolant flinging is done by the chuck. I plan to put a little shield on the carriage if needed.
Joe Gwinn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 14 Jul 2009 10:04:47 -0700 (PDT), David41616

Agreed. My lathe came with a Flexbar shield and I never use it.
--
Ned Simmons

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

This implies that the 6" radius guard is correct. OK.

I am not doing production, but I am gearing up for flood cooling, as it seems to work far better than anything else.
Joe Gwinn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I think they are are unsafe and never use one. I do use a plexiglass shield on a magnetic holder to prevent splash when required. Steve

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Why are they unsafe?
The little plexiglass shield wouldn't work for me because the coolant goes in all directions.
Joe Gwinn

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Wait until the first time a bunch of swarf suddenly wraps around the tool, work and chuck and start whipping snot out of the guard. If you insist on using one make sure it is solidly mounted and you are always using chip breaker tooling.
Would love to hear your report in about 6 months time. :)
Dave
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

Aside from some damage to the guard, this actually sounds like an advantage to me. If that long chip didn't hit the guard, it would hit something else, like me.

Sure.
Actually, with the coolant I've been getting very long chips when parting 1018 off. If under power feed, often it's one big chip, if I don't interfere. These chips are not that heavy, but can be quite sharp-edged. And I have already had cases of flailing-nest syndrome.
Joe Gwinn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 15 Jul 2009 10:23:41 -0700 (PDT), David41616

I use the factory Hardinge splash guard on both the HLV-H and the TFB...flood cooling and use them both all the time. I use high sulpher oil in both lathes at 1800-3000 rmp..and it sure saves cleaning up a hell of a mess.
Gunner
"Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam"
Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.