# HF 7x10 Mini Lathe Lead Screw and Pillow Blocks



## NF6X (May 18, 2020)

I have an older Harbor Freight 7x10 mini lathe, model 33684, which I allowed to get rusty and decrepit. I'm now fixing it up and upgrading it with lots of fun stuff from Little Machine Shop: metal gears, quick change tool post, carriage lock and stop, 4" 3-jaw chuck, holder to use a Proxxon tool as a tool post grinder, etc.

The lead screw feels much tighter than I think it should when I try to turn it. Removing it and cleaning/re-lubricating helped a little bit, but it still feels awfully tight when both pillow block are screwed down to the casting tightly. The lead screw and pillow block bearing surfaces look smooth, and they aren't among the areas which got rusty. Either pillow block spins smoothly by itself, but the lead screw gets tighter when both pillow blocks are screwed down. I'm wondering if maybe something warped such that the two pillow blocks are no longer lined up properly. It does not seem to be insufficient end play; I can adjust them such that I can move the lead screw laterally a tiny bit, and it's still tight. I'm wondering whether I might be able to flap out the inside of the right end pillow block to prevent the binding, since it doesn't seem to me that a tiny bit of looseness at that end should produce problems as long as the lead screw doesn't flap around enough to hit the disengaged half nuts.

Before I try anything I may regret, I'm wondering if this is a known issue and/or if anybody has advice about how to address this. This is the main thing that prompted me to join H-M. If there are any upgrades I might want to consider buying/making for the lead screw or its pillow blocks while I'm at it, I'd love to hear about them. Maybe better bearing surfaces? Add some sort of oilers there?


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## NF6X (May 18, 2020)

Discussion of my lead screw binding has broken out in my other thread about the compound dial. Linking here so that future historians will be able to find it:









						HF 7x10 Mini Lathe Compound Dial Binding
					

I have an older Harbor Freight 7x10 mini lathe, model 33684, which I allowed to get rusty and decrepit. I'm now fixing it up and upgrading it with lots of fun stuff from Little Machine Shop: metal gears, quick change tool post, carriage lock and stop, 4" 3-jaw chuck, holder to use a Proxxon tool...




					www.hobby-machinist.com


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## royesses (May 18, 2020)

Check the lead screw and pillow blocks without the gears and not having it engaged. They should spin freely. You may need to elongate the mounting holes in the pillow blocks so as to adjust for free spinning.


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## NF6X (May 19, 2020)

I'm not going to say that the lead screw feels good, but I think I have the pillow blocks finagled around to where it's tolerable. The LMS instructions helped by giving me some ideas of how to use the half nuts to help put the lead screw in the right place at each end while I fiddled with the pillow blocks and apron until it didn't feel too bad. I measure just over 0.001" of end play in the lead screw now, and I think that's about the best I can expect from it. Thanks for the help!


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## royesses (May 19, 2020)

That sounds good. You need some end play or it will bind. Good job making it workable.

Roy


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