Issue with lead screw not disengaging

I think you have drag in these pieces .......altho I don't think it's going to hurt anything. As far as
difficulty changing gears, you should be rocking the chuck while moving the gear lever. If this is a new problem then you might will want to disassemble the gear box and figure out what has changed.
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jcp said:
I think you have drag in these pieces .......altho I don't think it's going to hurt anything. As far as
difficulty changing gears, you should be rocking the chuck while moving the gear lever. If this is a new problem then you might will want to disassemble the gear box and figure out what has changed.
View attachment 479344
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I really appreciate you taking the time to help me. I'm relieved it's not an issue that will cause any harm. The machine was a big investment for me, so I am trying to take extra care of it. Thank you!
 
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jdsantiagojr said:
I replaced the gear oil on the apron and gearbox a couple months after receiving the machine with 75W80 gear oil from amazon (https://www.amazon.com/gp/product/B000CPCBEG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1). It has been about a year now. Do you think I should empty and replace the oil ? If I empty it should I open it up ?
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Gear oil is the wrong oil for any part of your machine, Some gear oils will damage bronze or brass, The correct oils should be listed in your manual. But I will say that most lathes in this class use a Mineral oil in the 10 to 20 Wt class of viscosity and have additives for wear and pressure. It is Generally referred to as "Turbine Oil" Many a lathe has been ruined by putting Gear oil for differentials and transmissions. If you put gear oil in your headstock also, Then your bearings in the headstock are starving for oil because these lathes work on a splash system to lubricate the headstock bearings, And the 85-90 gear oil will not splash up to the top of the headstock and ruin the bearings. I am not familiar with your machine and I don't know if your headstock has a Labyrinth style gearbox or not.

But it is always best to follow what the manual specifies when it comes to lubrication. Ways should use "Way Oil" also because using the wrong oil there can cause chatter.

I know about this from experience, I once had a lathe that I got for cheap because the Headstock was filled by the original owner with 90 wt gear oil, It fried the bearings and I replaced them.

This Lathe was purchased new by an old machinist who was accustomed to the old WW2 lathes that actually used 90 wt Gear oil in them. These newer lathes don't use it anymore.
 
IMO the heavy gear oil is causing the drag on the gears and shaft and should go away with the correct oil.
 
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I read your manual and referred to the lubrication section and it does call for 85-90 gear oil, But I looked at Grizzly equivalent lathe, Which has a slightly different tranny on it at least compared to the controls. Grizzly calls for ISO 68 or equivalent, Which if I remember correctly is 20 wt turbine oil. ISO 32 is 10 wt.

It seems strange to me that Heavy gear oil is specified on your lathe and almost no others in that class use it, But use Mineral oil. Anyway your manual does call for it. Maybe I would ask PM if that's correct?

They ae also specifying 85-90 gear oil for the apron which has a brass gear that mates to the worm gear?
 
Harry Knutz said:
Gear oil is the wrong oil for any part of your machine, Some gear oils will damage bronze or brass, The correct oils should be listed in your manual. But I will say that most lathes in this class use a Mineral oil in the 10 to 20 Wt class of viscosity and have additives for wear and pressure. It is Generally referred to as "Turbine Oil" Many a lathe has been ruined by putting Gear oil for differentials and transmissions. If you put gear oil in your headstock also, Then your bearings in the headstock are starving for oil because these lathes work on a splash system to lubricate the headstock bearings, And the 85-90 gear oil will not splash up to the top of the headstock and ruin the bearings. I am not familiar with your machine and I don't know if your headstock has a Labyrinth style gearbox or not.

But it is always best to follow what the manual specifies when it comes to lubrication. Ways should use "Way Oil" also because using the wrong oil there can cause chatter.

I know about this from experience, I once had a lathe that I got for cheap because the Headstock was filled by the original owner with 90 wt gear oil, It fried the bearings and I replaced them.

This Lathe was purchased new by an old machinist who was accustomed to the old WW2 lathes that actually used 90 wt Gear oil in them. These newer lathes don't use it anymore.
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Hi Harry. I checked the manual for this machine, and it recommends using 75W80 gear oil for the gearbox. I use way oil for everything else. This message has made me curious to learn what other owners of this machine are putting in the gearbox.

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Harry Knutz said:
I read your manual and referred to the lubrication section and it does call for 85-90 gear oil, But I looked at Grizzly equivalent lathe, Which has a slightly different tranny on it at least compared to the controls. Grizzly calls for ISO 68 or equivalent, Which if I remember correctly is 20 wt turbine oil. ISO 32 is 10 wt.

It seems strange to me that Heavy gear oil is specified on your lathe and almost no others in that class use it, But use Mineral oil. Anyway your manual does call for it. Maybe I would ask PM if that's correct?

They ae also specifying 85-90 gear oil for the apron which has a brass gear that mates to the worm gear?
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That is great idea. I sent them a message earlier and hoping to get response soon. I will post here as soon as I do.
 
I received a message from Precision Mathews shortly after sending mine

The 75/80 is fine and what we recommend in the manual. Are you saying that the leadscrew will sometimes turn when you have the feed rod selected? This is harmless, and you'll find it doesn't actually have any force behind it. One thing I can point out about using Diff oil is not to buy the kind for limited slip differentials. It has additives that aren't useful to your purpose.
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A little late to this party, but my 1130v also behaves like this but I've never grabbed the leadscrew to find out if there's no power behind it. My lathe only started doing this after I had a minor crash, so I assumed that something in the gear train got slightly tweaked; looks like I should rip into my gears but it's not a giant problem, only a slight annoyance.

I will say though that in OP's video switching those levers (specifically the feed direction) all while under power cause me to cringe a little. I've always understood that it's best practice to stop the chuck first and only then switch the feed direction, else you are forcing the gears to mesh. Granted, it's not like he was running it very fast, but still...
Anybody have a thought on that, or am I just being too cautious?
 
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