Project of the Month built by driller1432

Help Support Home Model Engine Machinist by donating using the link above or becoming a Supporting Member.
Home Model Engine Machinist > The Tools and Tips > Tools > Southbend toolpost, terrible finish

Reply
 
Thread Tools
Old 07-11-2017, 08:04 AM   #11
PopAlexandra
Junior
 
PopAlexandra's Avatar
 
Join Date: Jun 2017
Location: Cluj-Napoca, Romania
Posts: 8
Default

Quote:
Originally Posted by 428Bird View Post
I bought a Chinese CXA quick change for my lathe and I am extremely happy with it. For what I'm doing, it's excellent.

Britt Bettell
I second that. Works just fine for my small projects. Good quality/price ratio.


PopAlexandra is offline  
 
Reply With Quote
Old 07-11-2017, 09:48 AM   #12
Blogwitch
Ex Bogstandard
HMEM_SUPPORTER.png
 
Blogwitch's Avatar
 
Join Date: Dec 2008
Location: Crewe, UK
Posts: 3,527
Liked 663 Times on 497 Posts
Likes Given: 66

Default

N,

There is usually more to problems than the obvious.
Because you have a fairly old machine, have you checked for flatness of the toolpost mount and the flatness of the under surface of your lantern holder? If they aren't totally flat, your toolpost could be minutely wobbling on it's mount causing the centre height to change as you start cutting. I had to surface grind the top of a Myford ML10 topslide because of that type of problem. After he fitted a QCTP onto the reground surface, everything was perfect.

Are your gibs adjusted up and lubricated correctly? If not, that can cause the tool tip to rock up and down.

One thing you shouldn't do is hold tipped tools in a lantern type of holder. Tips are ground or moulded to exact angles for optimum performance and are designed to work when the tip toolholder is perfectly horizontal. Your type of holder doesn't allow that, as it has the tip height adjust on it. OK for HSS ground tips that can be altered by grinding to give a few extra degrees of clearance but not for the exact angles required by tungsten tips.

John


__________________
If you don't try it, you will never know if you can do it!!
Blogwitch is offline  
goldstar31 Likes This 
Reply With Quote
Old 07-11-2017, 11:21 AM   #13
goldstar31
 
Join Date: Feb 2010
Posts: 1,471
Liked 328 Times on 281 Posts
Likes Given: 520

Default

My comments deleted

Regards

An older N
goldstar31 is offline  
 
Reply With Quote
Old 07-11-2017, 04:07 PM   #14
Naiveambition
 
Join Date: May 2012
Posts: 235
Liked 37 Times on 29 Posts
Likes Given: 21

Default Southbend toolpost, terrible finish

If I can remember correctly, I tried a high speed steel , and a carbide bit. Carbide tip was worse.

My toolset came with a bunch of high clearances bits so ima try that. As for the machine, the bed is dated 1929 but the rest of the parts are variously dated up thru the 50s. The bes as a whole still has all frosting marks on it except the high traffic area.
Admittingly I have no experience to relate to except my 7x10 that's nice, quite, and do the job slowly.... Whereas the south bend can be super aggressive, loudish, shakes the table🤓🤓. The shaking is from the pulley system as it rotates it bounces the tension plate for the motor. I've tried to soften it by weight . And while better, still needs addressed. This setup is not typical unless you mount the countershaft on the wall.

The Latern toolpost does have a rocker shim and I am using the Armstrong tool holders. I think all of them have some degree of rake built in.
The south bend manual is kinda vague on instructions so. Is the rocker the center adjustment or do I also shim on top of the rocker?
Attached Thumbnails
image.jpg  
Naiveambition is offline  
 
Reply With Quote
Old 07-11-2017, 04:59 PM   #15
goldstar31
 
Join Date: Feb 2010
Posts: 1,471
Liked 328 Times on 281 Posts
Likes Given: 520

Default

As I can claim being part of a pre-WW2 generation and sort of still feel at home with flat belts and hard and fast pulleys and all the delights of having graduated in the University of Hard Knocks, you might do a lot worse than forget '7 by whasits' and carbides and all that Jazz and load up your printer with 500 +sheets and print out Robert Smith's Advanced Machine Tool Work which is still available as a pdf. YOUR machine and its multitudes of set ups is there.

No photos or that sort of thing but decent write ups an d sketches on procedures.

In a fit of idiotic charity, I donated my copy of the book and have regretted it ever since.

Forget those with 'wise saws and modern instances' and immerse yourself in sheer practical engineering.

Regards

the Ancient N
goldstar31 is offline  
 
Reply With Quote
Old 07-11-2017, 10:23 PM   #16
doc1955
Gone
 
Join Date: Aug 2009
Posts: 955
Liked 53 Times on 52 Posts
Likes Given: 22

Default

Here is a very easy way t set your tool height on the lathe. And nothing special is needed.

__________________
Gone!
doc1955 is offline  
ROB 123 Likes This 
Reply With Quote
Old 07-11-2017, 10:54 PM   #17
kuhncw
HMEM_SUPPORTER.png
 
Join Date: Apr 2008
Posts: 529
Liked 61 Times on 59 Posts
Likes Given: 9

Default

What material are you cutting when you get the poor finish?

Chuck
kuhncw is offline  
 
Reply With Quote
Old 07-12-2017, 01:44 AM   #18
Naiveambition
 
Join Date: May 2012
Posts: 235
Liked 37 Times on 29 Posts
Likes Given: 21

Default Southbend toolpost, terrible finish

I also am a super fan of all things old , quite simply cause they work well and are well made. So when I am not figureing out why it won't do what I want, I am usually missing one little thing, and then it's bliss.
I was turning stainless I think, possibly a good tool steel.
Same with the lathe. I'm hoping it's just a rake issue. I just can't understand the need for rake built into the holder vs being level.
What's the disadvantage or advantage of this system. The tooling used in my book are different from what I have. So again no real reference. I will look at the book goldstar suggests

I like the smallness of the Latern , but only accepts 1/4 in. Bits, so if I can I will use it often. Will build a toolpost for other bigger toolbits I can use.
Naiveambition is offline  
 
Reply With Quote
Old 07-12-2017, 01:53 AM   #19
kuhncw
HMEM_SUPPORTER.png
 
Join Date: Apr 2008
Posts: 529
Liked 61 Times on 59 Posts
Likes Given: 9

Default

A good finish on some types of stainless steel, 304 for example, can be a challenge. Have you tried test cuts in 6061 aluminum, brass, and perhaps 12L14 steel?

Chuck
kuhncw is offline  
 
Reply With Quote
Old 07-12-2017, 02:58 AM   #20
10K Pete
 
Join Date: Jan 2009
Location: Nordland, WA, USA
Posts: 499
Liked 108 Times on 97 Posts
Likes Given: 177

Default

Quote:
Originally Posted by Naiveambition View Post
I'm hoping it's just a rake issue. I just can't understand the need for rake built into the holder vs being level.
Tool holders with a built-in rake angle are for just that purpose. Saves you having to grind the second angle on the rake surface.

The no-rake holders were for brazed carbide tools.

I wish I had a set of Armstrong holders in 1/4", 5/16" and 3/8". There are some jobs where they are much easier than a QCTP.

Pete


__________________
Just tryin'.....
10K Pete is offline  
 
Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sibling pups, terrible 2's? chucketn The Break Room 5 04-16-2014 11:25 PM
A sin! (Southbend Lathe) 90LX_Notch The Break Room 1 02-24-2012 02:38 PM
Terrible Day At Work! rake60 The Break Room 9 05-04-2011 02:42 AM
Southbend 10K Stan Buy / Sell / Trade / eBay 0 06-23-2009 12:47 AM
Terrible postal service. Bogstandard The Break Room 10 09-07-2008 11:41 AM



Newest Threads






- Top - Member List