Clausing 5418 Question

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Rick_B

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So I'm finally putting together my Clausing lathe after a move from NY - everything was going well until I got to the saddle. On this machine the saddle has a gib between the saddle and bed on the rear of the saddle. The gib attaches to the saddle and rides on the underside of the bed. On the front of the bed there is, according to the parts list, a registration bar that also attaches tot he saddle and rides on the underside of the bed. My machine came to me with two shims between the registration bar and the saddle. When I assemble all of this I am getting some lift on the front of the saddle - lift in terms of there is movement of the saddle upo and down when I lift the front of it.

My assumption is that there should not be any movement of the saddle when the gib and registration bar are assembled. I removed both shims from the registration bar thinking that would tighten it up but it still had movement.

So first question - is my assumption right that the saddle should not move up and down when assembled? If so is here an adjustment for this problem?

Thanks
Rick
 
Rick,

I can't of course know what was in the mind of the designer at the time but I don't think so. It has always been my assumption that whether installed on a flat bed or a V-bed lathe, the carriage hold-down bars (I don't consider them as gibs in the practical sense) are there to ensure that the carriage won't come off of the bed accidentally regardless of what happens. In normal operations as a lathe, the reaction force vector applied to the carriage would always be within the 180 degree arc from toward the operator through the straight downward direction to away from the operator. Exceptions may occur while using a milling attachment or during drilling or boring operations but the feed and speed should be constrained such that the reaction force is not strong enough to physically lift the carriage off of the ways. The only time this should be exceeded would be during an abnormal event when one would expect that prevention of injury to the operator or serious damage to the machine would be more important than preventing damage to the work piece.

My suggestion would be to reinstall the two shims and ignore the fact that you are strong enough to left the carriage off of the bed.
 
Thanks Robert - I should mention that the gib and registration bar won't allow the saddle to actually come off the bed. I should also mention that there is another part referred top as a clamp that could be adjusted to keep the saddle from lifting but I have always thought that clampwas more of carriage clamp to lock the carriage in place for specific operations like parting. However, the clamp could likely be adjusted to eliminate the "lift".

Rick
 
Right. That is their purpose. I wouldn't lose any more sleep over the slight amount you can lift the carriage. Run the carriage all of the way to the end of the bed. If you can, I wouldn't worry about putting the original shims back in. But if it gets harder or impossible to move the carriage, you have some bed wear nearer the headstock. And you'll either need to put the shims back in or live with how far the carriage will go.

The adjustable clamp is the carriage clamp. It should only be used in two positions, full on and full off. It is not there to prevent your being able to lift the carriage a few thou. Just wait enough years and you won't be able to lift it anyway. :eek:
 
Hi Rick,

I can't lift my saddle off the bed at the head stock or end of the bed of my 5418. I'd go with Robert's suggestion and put the shims in place and see how easily the carriage moves at either end of the bed. Adjust the shims as required so the carriage moves freely.

I have a Rockwell 10 x 36 lathe that does a nice job and doesn't have any registration bar on the front bottom of the carriage (manual page is below) other than the carriage clamp. Like mentioned above, in use the normal cutting forces are pushing the carriage down onto the bed.

Bruce

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OK - so this morning I tried a few things. with the rear and front bars installed on the saddle, no shims on the front and no apron installed - I found that I couldn't move the saddle beyond about 12" from the spindle nose (LOO spindle). I loosened the front bar bolts - still no movement. So I loosened the rear bar bolts and I got free movement all along the bed. I discovered that if I tightened up the rear bar at either the head stock or tail stock end and tightened the front bar with no shims I was able to get smooth movement of the saddle all along the bed. Playing with the adjustments it appears there is definitely bed wear about 8" from the spindle nose. With the rear bar adjusted to get movement along the entire bed - I was feeling some lift on the rear of the saddle at the wear point (6-8" from the spindle nose. The front of the saddle didn't seem to change at all in terms of lift. I decided to try and quantify the movement of the saddle - at the wear point of the bed I measured .002" lift at the rear and .011" at the front. On either side of that wear point I was getting zero rear lift and .005 to .006" at the front.

So I'm concluding from this that:
1. The shims are not needed (they would lower the front bar and make the lift even greater
2. I have a bed wear issue
3. The front lift shouldn't be an issue - given the cutting force direction
4. I should adjust the rear bar to allow full bed movement and live with the 3 to 4 inch area where there is some slight rear lift - hoping the weight of the apron when installed will help with this issue

Any thoughts?

Thanks
Rick
 
OK - moving on to another issue. I tested the lathe today with a simple cutting operation on a 1" diameter stock. I immediately notices that with the spindle running (drive selector in neutral so no gear train activity at all) that I got a very disturbing noise when I engage the cutting tool with the work piece. I tried to capture it on the linked video - the first half is just the spindle running and the second is with the tool engaged. The video is not great and I am still attempting to get it uploaded from another device.


It seems with just the spindle running that the noise with the tool engaged has to be bearings - either bad bearings or bearings that need adjusted. Any thoughts?

Thanks
Rick
 
Regarding the noise issue under load - while waitingfor responses/ideas/thoughts - I decided to try the only thing I could think of other than pulling the spindle. I checked the take up nut at the rear of the spindle. While it was not loose - I did snug it up a bit. I also made sure that the spindle rotated roughly a full revolution when spun by hand (according to the manual). After this preload adjustment the noise under load went completely away and the lathe ran much quieter when not under load. In addition the surface finish improved 1000% after the preload adjustment. At this point I think I am going to call this issue resolved - unless there are other thoughts/ideas that would indicate more investigation would be prudent.

Thanks
Rick
 
Hi Rick,

Glad you got the spindle thing figured out. On your bed, it's a 50-year old lathe and will likely have some idiosyncrasies you'll have to be aware of and work around. I've read posts where guys have had their beds reground; no idea the cost there but probably not cheap. That's about the only way I'm aware of flattening out a hardened bed.

Bruce
 
I agree Bruce - I would likely look for a replacement lathe before I jumped into a bed regrind. My plan is to adjust the saddle to the less worn spots at the ends and live with the, what I think, is slight wear in the middle. If that causes problems then option 2 will be to adjust it to the worn area and work around any issues. I generally am working in a small area of the bed and I'm not making parts for the space shuttle :)

Thanks
Rick
 
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