Mellor lathe.

[Richard.]

I’ve just timed mine on it’s slowest speed spencer. I literally keep it at this travel speed for everything as it always seems to produce a nice finish with the small cuts my lathe will take.
At 50 revolutions of the chuck my apron has moved 5.1mm. Whether that’s right or wrong I dunno but I’ve no intentions of changing it as my finishing is lovely.

 

[God mode restorations]

I’ve just timed mine on it’s slowest speed spencer. I literally keep it at this travel speed for everything as it always seems to produce a nice finish with the small cuts my lathe will take.
At 50 revolutions of the chuck my apron has moved 5.1mm. Whether that’s right or wrong I dunno but I’ve no intentions of changing it as my finishing is lovely.

It's a funny ol set up is the Mellor lathe. Having a front lead screw for threading and a rear screw for power sliding and surfacing. The rear is geared through the tumbler so I don't think I can reduce it. It explains it on lathes uk.

 

[Richard.]

It's a funny ol set up is the Mellor lathe. Having a front lead screw for threading and a rear screw for power sliding and surfacing. The rear is geared through the tumbler so I don't think I can reduce it. It explains it on lathes uk.

But do you have to use it like that spencer. What’s stopping you using the front lead screw for cutting and setting up your own feed speed with your gears? I understand that’s a pita if you want to swap quickly between a cut and a thread but hey that’s what a lot of us (me included) have to do.
Why don’t you time your lathe like I have with the rear screw doing the driving to see if it’s anything near what I’m getting.

 

[God mode restorations]

This is the part that explains it on lathes uk .
I have to read it a few times as this faffing dyslexic gets the better of me at times.

 

[God mode restorations]

But do you have to use it like that spencer. What’s stopping you using the front lead screw for cutting and setting up your own feed speed with your gears? I understand that’s a pita if you want to swap quickly between a cut and a thread but hey that’s what a lot of us (me included) have to do.
Why don’t you time your lathe like I have with the rear screw doing the driving to see if it’s anything near what I’m getting.

I will do that tomorrow Richard.

 

[eLuSiVeMiTe]

Twice the feedrate of @richard then.

 

[Hood]

8 Thou per rev or as I prefer 0.2mm/rev is more of a roughing feedrate so bigger nose rad and deeper cuts.

 

[Windy Miller]

Try grinding up a vertical shear tool, and take very fine cuts - no more than about a thou. Just use it for the finishing cuts after you've roughed it down.

 

[God mode restorations]

Goodies turned up. Some of em.

 

[eLuSiVeMiTe]

Goodies turned up. Some of em.View attachment 140648

Look forward to seeing the results.

 

[God mode restorations]

Look forward to seeing the results.

Yes. The mt1 reamer is for gently cleaning up the tailstock taper. Cutter for a small gear. And tools. Happy days

 

[addjunkie]

Hope you got spare inserts too?

 

[God mode restorations]

Hope you got spare inserts too?

Yes mate. But not a good day. As I explain below

 

[God mode restorations]

Got the machine set up. Took a few runs. Smoother but not brilliant .put the centre on.a little better but no great. Took a couple more runs. Some are ok and others rough .So I swapped the tool for the finishing tool. Now this is totally faffing strange .it would start out rough then go smooth and back to rough again. Then the spindle decided to stop dead. Turned machine off. Couldn't turn it by hand.so took the spindle out and all looks ok

. I going to walk away from this for a week as it's doing my head in. I wish I could post something positive guys.

 

[eLuSiVeMiTe]

Odd.


Idle curiosity spencer. What speed is your motor running?

Any idea what your spindle speeds are.

Locking up would suggest the bearings got hot and expanded.

Max spindle speed for that was listed as 700rpm.
Highlighted section.

 

[God mode restorations]

View attachment 140715 Odd.


Idle curiosity spencer. What speed is your motor running?

Any idea what your spindle speeds are.

Locking up would suggest the bearings got hot and expanded.

Max spindle speed for that was listed as 700rpm.
Highlighted section.

1425 rpm. Same as the original motor. Pulley is the same as that came off the original.

 

[eLuSiVeMiTe]

Where you in top speed when it locked up ?

 

[God mode restorations]

No mate. Slow speed. It didn't clonk or anything. Just stopped. There is no visable signs of wear . Will put it back together tomorrow as just try again. I now no it's not a tool problem.

 

[eLuSiVeMiTe]

No mate. Slow speed. It didn't clonk or anything. Just stopped. There is no visable signs of wear . Will put it back together tomorrow as just try again. I now no it's not a tool problem.

Very aware of speed atm.
My motor should be a 6 pole
Motors running a 4 pole so about 500rpm too fast.

Checked speeds with the mechanical tacho I aquired yesterday and within spec on the 2 slower speeds but can't use top until I get my 3p motor sorted.

 

[MattF]

No mate. Slow speed. It didn't clonk or anything. Just stopped. There is no visable signs of wear . Will put it back together tomorrow as just try again. I now no it's not a tool problem.

You're shimming the top bearing blocks when refitting, to allow some slight expansion clearance?