Thread: HELP! Lathe failure

Originally Posted by shedhappens

RC said,
"I see it even says on the plate next to the II "Available with slow spindle only"

it seems funny, the lever to the right is in the fast position, so by my way of thinking that feed gear should not have engaged in position 2 ?

or was it not in that position when testing the gears ?

Yes, that was just me moving levers, spinning gears (by hand), etc, to try and figure out how the gearbox worked. Once I get it back together I will check out the "interlock" that RC mentioned.

As a mechanic for 40 yrs this is the way i do wheel brgs
Make sure the brg cones are seated with hammer and punch, if they are turning in their housings Loctite them in.
Assemble shaft and cones and tighten nut firm,spin the shaft and back off the nut till loose, then retighten nut using 1 finger on the wrench to preload the brgs you are looking for about 1/3 the pressure of your first tighten.
If you are using new bearings i would use 2 fingers to allow for bedding in, you could use lite oil on brgs during assembly.
Diff reconditioners would use a spring gauge to set preload [ something like Scales to weigh a fish] in the old days, you could search the Web to set preload this way.

Hope this helps.

Originally Posted by Vernonv

Anyone have any tips on how best to adjust the tapered roller bearings on reassembly?

Machtool Phil is your man. Until he comes along some searching will keep you busy, especially on PM. Is it just a single bearing at each end? As I understand it there are two main ways to measure preload: rolling torque and temperature rise. You should be able to hold your hand on the housing after extended running at high speed. But if it's not fairly warm they're too loose.

Originally Posted by whitey56

As a mechanic for 40 yrs this is the way i do wheel brgs
Make sure the brg cones are seated with hammer and punch, if they are turning in their housings Loctite them in.
Assemble shaft and cones and tighten nut firm,spin the shaft and back off the nut till loose, then retighten nut using 1 finger on the wrench to preload the brgs you are looking for about 1/3 the pressure of your first tighten.
If you are using new bearings i would use 2 fingers to allow for bedding in, you could use lite oil on brgs during assembly.
Diff reconditioners would use a spring gauge to set preload [ something like Scales to weigh a fish] in the old days, you could search the Web to set preload this way.

Hope this helps.

Ok, I've done a a few wheel bearings, so can see where you are coming from. I have on occasion used the spring gauge to check preload, when I know what the figure should be. Trouble is this is an old lathe (1948) and I don't have any technical info on it.

Originally Posted by Bryan

Machtool Phil is your man. Until he comes along some searching will keep you busy, especially on PM. Is it just a single bearing at each end? As I understand it there are two main ways to measure preload: rolling torque and temperature rise. You should be able to hold your hand on the housing after extended running at high speed. But if it's not fairly warm they're too loose.

There are two tapered roller bearings in the chuck (right) end of the housing (one on the outside and one on the inside of the housing wall) and a non-tapered roller bearing (or maybe very slightly tapered) on outside of the left end of the housing.

Mine has the opposed pair at the front too. Here is my thread on PM about adjusting mine: Do Graziano Spindle Bearings Need Adjustment?. Phil weighs in at #20. YMMV.

Thanks Bryan (and Phil) ... sounds like the way to go. Will give it a go tonight when I reassemble.

Ok, job done. Thanks all for your input.

... and here's a tip for you - don't start the lathe with the clutch disengaged, the lid off and the headstock full of oil ...

Originally Posted by Vernonv

Ok, job done. Thanks all for your input.

... and here's a tip for you - don't start the lathe with the clutch disengaged, the lid off and the headstock full of oil ...

Great Vernon,
At least I'm not the only to do that.
Woo Hoo.

Phil

Originally Posted by Steamwhisperer

Great Vernon,
At least I'm not the only to do that.
Woo Hoo.

Phil

Makes one hell of a "rooster tail". Luckily I hit the clutch lever quickly and minimised the mess ... and I wasn't standing directly in front of it.

"Splash lubrication?" "checked"

It's an outstanding splash.

Originally Posted by Vernonv

Ok, job done. Thanks all for your input.

... and here's a tip for you - don't start the lathe with the clutch disengaged, the lid off and the headstock full of oil ...

Pleased to hear things fixed

Must say the splash is something I'd fall for based on past history -

I've done it with cars
I was used to push rod engines, then worked on a new-fangled overhead cam engine - started it to see if thinks were right - they were and the oil pump worked well
- the chain driving the cam shaft that is ----

HI,
Glad to Hear You got it Sorted and glad to Hear that You avoided the Oil.