MetalworkingFun Forum › Machinery › Lathes v
Problem with lead screw/half nut/s

Thread Modes
Problem with lead screw/half nut/s
Swarf_Newbie Offline
Freshman
**
Posts: 45
Threads: 15
Joined: Sep 2018
Location: Liverpool
#11
08-10-2019, 10:06 AM
(08-10-2019, 09:19 AM)Highpower Wrote: Bent lead screw, worn/loose/tight v-belt, loose/tight change gears, worn/loose spindle bearings.... yada, yada, yada.
All depends on how far down the rabbit hole you want to go I suppose.

Changing the hard lumpy Chinese v-belt on my lathe to a Fenner linked belt made a big difference in the finishes I got after changing it. I still have to be vigilant with sharp tools and short stick-outs though.

Fair enough Thumbsup 
I'll stop worrying about it, looks like me and Vinny have the same problem.
If I hand feed, no "waves".
Thanks for the replies folks, food for thought.

Cheers.

Roy.
Light travels faster than sound!
This is why some people appear bright until they open their mouth!
Preserve nature...…….Pickle a squirrel! 
Reply
Thanks given by:
Swarf_Newbie Offline
Freshman
**
Posts: 45
Threads: 15
Joined: Sep 2018
Location: Liverpool
The following 2 users Like Swarf_Newbie's post:
EdK (08-10-2019), Hopefuldave (08-16-2019)
#12
08-10-2019, 12:56 PM (This post was last modified: 08-10-2019, 12:57 PM by Swarf_Newbie.)
After spending all afternoon on it...…………………..it's sorted!

Turned 1.2mm from the rear leadscrew bracket/bearing.
(Using a lathe while the end of the leadscrew is help up with string is NOT my idea of fun!  You Suck )

I may never be able to wear those trousers again! Rotfl 

Cheers.

Roy.
Light travels faster than sound!
This is why some people appear bright until they open their mouth!
Preserve nature...…….Pickle a squirrel! 
Reply
Thanks given by:
Highpower Offline
JAFO
******
Posts: 4,495
Threads: 187
Joined: Feb 2012
Location: Missouri, USA
#13
08-10-2019, 05:58 PM
(08-10-2019, 12:56 PM)Swarf_Newbie Wrote: After spending all afternoon on it...…………………..it's sorted!

Turned 1.2mm from the rear leadscrew bracket/bearing.

Roy, so you are saying you faced off 1.2mm from the base of the pillow block, to move the right side of the lead screw closer to the lathe bed? 17428

Or you shortened the width of the bracket bearing? I'm just trying to understand exactly what the fix was here.
Willie
Reply
Thanks given by:
TomG Offline
Alt. Whipping Boy
*******
Posts: 3,799
Threads: 184
Joined: Jun 2012
Location: Farmington Hills, Michigan
The following 4 users Like TomG's post:
Dr Stan (08-10-2019), EdK (08-11-2019), Highpower (08-11-2019), Hopefuldave (08-16-2019)
#14
08-10-2019, 08:03 PM
It's not unusual for the Chinese made machines to have dimensions that are out of spec. Some other things to check would be the parallelism of the spindle centerline to the ways and the height of the spindle centerline to the centerline of the tailstock.

Tom
[Image: TomsTechLogo-Profile.png]
Reply
Thanks given by:
Swarf_Newbie Offline
Freshman
**
Posts: 45
Threads: 15
Joined: Sep 2018
Location: Liverpool
#15
08-11-2019, 09:04 AM (This post was last modified: 08-11-2019, 09:05 AM by Swarf_Newbie.)
(08-10-2019, 05:58 PM)Highpower Wrote:
(08-10-2019, 12:56 PM)Swarf_Newbie Wrote: After spending all afternoon on it...…………………..it's sorted!

Turned 1.2mm from the rear leadscrew bracket/bearing.

Roy, so you are saying you faced off 1.2mm from the base of the pillow block, to move the right side of the lead screw closer to the lathe bed?   17428    Correct, Mr Highpower! Thumbsup  

Sorry, didn't make myself very clear.

Cheers.

Roy.
Light travels faster than sound!
This is why some people appear bright until they open their mouth!
Preserve nature...…….Pickle a squirrel! 
Reply
Thanks given by: Highpower
Swarf_Newbie Offline
Freshman
**
Posts: 45
Threads: 15
Joined: Sep 2018
Location: Liverpool
#16
08-11-2019, 09:06 AM
(08-10-2019, 08:03 PM)TomG Wrote: It's not unusual for the Chinese made machines to have dimensions that are out of spec. Some other things to check would be the parallelism of the spindle centerline to the ways and the height of the spindle centerline to the centerline of the tailstock.

Tom

I've already sorted that thanks Tom.

ATB.

Roy.
Light travels faster than sound!
This is why some people appear bright until they open their mouth!
Preserve nature...…….Pickle a squirrel! 
Reply
Thanks given by:




Users browsing this thread: 3 Guest(s)