Telescoping leadscrew shields

[Ironman]

After repairing my lathe apron and finding it packed with cuttings and swarf, I have been think about it.
There is only one way to have got that stuff in there, it was drawn in by the lead screw.
I have been looking at video about these and when I found them for 6 buck plus freight I thought what the hell and got a couple.
There may be a dark side that I don't know about. Anyone use these things?

[digr]

I have never seen them before. They look like they should work fine.

[Ironman]

I am going to make the necessary bits to install these shields and I'll post the pictures as it progresses.

[LKeithR]

Originally Posted by Ironman

...There may be a dark side that I don't know about. Anyone use these things?

I've never had them on any lathe of my own but I've been in shops that did and watched them working. I can't see any reason not to use them--worst case scenario you rip them off if they cause problems but I don't see that happening...

[Ironman]

Thanks. I can see no problems either, but I sure could with the apron filling up with cuttings like it did. I'm hoping to prevent that, as I can't always remember to disengage the screw when not using it, and my theory is that is when the chips are transported.
I also took the opportunity to move the thread dial to the right side of the apron

[clive]

I have them on my lathe, never had any problem with them.

[Ironman]

So today I got started making the endcaps of the springs I used a bit of well pipe for the big ends and just took a light cut on the inside and squared the ends. Then I started to machine the aluminum sleeves that ride on the lead screw. I'm inventing as I go because I haven't found any how to stuff on this.
The end caps are a press fit into the outer sleeve that the spring sits in. The small end caps were from some extra weld in sleeves I had made for something. They got a second life as the small end spring cap. I machined some nylon press in ends for these sleeves.

Tomorrow I will see how well I did on the bore for the lead screw. It has 3 thou clearance but may need more and I will have to ream it then.

[Ironman]

Last week has been working on my truck and my sons rig as well.
Today I found the time to complete this project.
It required some reworking and now I see why they don't sell end caps for the spring and nobody has a howto on it.
I had carefully measured the spring bore on the big and small ens in the full collapsed position so I made the center guide on both ends with at least 1/8" of room. When assembled on the bench and compressed it all was fine.
Well, God laughed.
When assembled and installed it would jam up. I realized the outer guide needed to be much larger, as the spring was expanding more than I had counted on. So I pushed things apart on the press, cut more material out of the outer guide shell, and threw away the outer shell on the small end. I also trimmed the big end of the spring with a zip disk to be square at full extension. So finally it worked on the bench and the lathe.
As every lathe is different, anybody installing these aftermarket will have to figure it out on their own sort of like I did.

At this time, although I have the materials and spring to do both sides of the carriage, I am going to leave things at the moment with the left side only protected. This way I can spot any issues and decide if I want to do the right side.
As an example, when you get the carriage all the way over to the right where the spring is almost full extended, the shield will rotate with the screw. You can stop it with a finger touch, and a single self tapping screw into the back of the big end of the shield end plate will stop that...if I think I need it.

[greywynd]

Part of that may be due to the spring sagging and then rubbing on the leadscrew. Might be better to let it turn with it, versus rubbing all the time?


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[Ironman]

Basically there is no contact, but when there is no spring pressure it will rotate, but at that point I am almost at the end of my travel, and up against the tailstock, so it is free to spin by hand. One 'bearing' is nylon and one is aluminum so there is no harm to the screw. The sag in the spring is about 3/8" and the smallest point of the spring is 1.62" with a 1" lead screw.