What's new
What's new
By:
Advanced search…

Threading on the SB9

B

bluearc

Aluminum
Joined
Sep 21, 2012
Location
pennsylvania
How is the threading dial locked after the right number is selected to cut threads, so far I have been experimenting changing gears for different threads with coordinating the dial however, I am unable to locate info on how to lock the dial on the number selected to repeat the passes.
Having no instruction at all in the use of a lathe and being new to the SB9 I read a number of publications on the SB9 and nowhere was I able to find a step by step procedure on manually changing gears, a few illustrations and gear change charts were available, I have been a welder for years and am not unfamiliar with using shop equipment but the lathe is different territory .
So far I have been able to do a lot with it except threading.
thanks
 
You never lock the thread dial. When you close the half nuts on the line selected the dial stops turning until you open the half nuts. You wait for the same line or number to come up again and close the half nuts to continue threading. Many you tube videos to watch. It's easy!
 
" How to run a Lathe " has a chapter on cutting threads in the lathe .
For much more info find " Screwcutting in the Lathe " by Martin Cleeve . ISBN-13:978-0-85242-838-2
 
Bluearc, Find a copy of South Bend's "How To Run A Lathe". Besides explaining thread cutting it will give you other needed information for your lathe and should probably be considered the cheapest/best purchase you could ever make after buying your lathe. eBay for an original copy or Lindsay Books for a reprint. Looks like Lindsay still has them available for $7.95 as well as the Sheldon lathe version...both are about as well written. Here is a link to Lindsay, but hurry as the company is in the process of shutting their doors.
Lindsay: Great Lathe Books
 
vettepicking said:
its like jumping on a moving train. just wait, wait, then go! somtimes you fall under the wheels. haha
Click to expand...

As with his example of a moving train, the dial moves as a result of the screw (train) turning and the apron stopped (you). When the apron and the screw are moving at the same rate, half nut closed, the dial stops moving.
 
to understand the thread dial it may help to think of it like setting the distributor on an old V8 -

depending on where(number on the dial) on the leadscrew you engage the halfnuts you are "retarding" or "advancing" the timing.

the dial gives you a way to always engage the halfnuts(set the timing) at the same point on the leadscrew to cut a specific pitch.

hope that makes some kind of sense, it was the best anology i could come up with. :)
 
Just to add a little confusion :D
As your lead screw is 8tpi you don't need a dial for threads that are multiples of 8 as anywhere the half nuts engage will be correct.
8, 16, 24 etc.

And two thumbs up for Martin Cleeve's book. Even though he used a Myford 99% of it applies to any lathe.
 
You must log in or register to reply here.

Similar threads

S
Metric Threads -
Replies
3
Views
368
animal12
A
M
Cross slide screw
Replies
6
Views
305
animal12
A
B
WTB : SB9 18/54 compound gear
Replies
1
Views
297
bugman53
B
D
Acra lathe thread dial
Replies
0
Views
156
DanlM
D
M
thread chasing dial
Replies
5
Views
307
macsonboy
M








 

ABOUT PRACTICAL MACHINIST

With more than 10.6 million unique visitors over the last year, Practical Machinist is the most visited site for metalworking professionals. Practical Machinist is the easiest way to learn new techniques, get answers quickly and discuss common challenges with your peers. Register for the world’s largest manufacturing technology forum for free today to stay in the know.

Learn more about us.

STAY CONNECTED

Facebook Instagram YouTube LinkedIn Pinterest Twitter Tiktok

Register Become a forum member. Register today.

Sign Up Sign up for our e-newsletter.

© 2024 Copyright Practicalmachinist.com. All Rights reserved.

Back
Top