Page Index Toggle Pages: 1 [2]  Send TopicPrint
Hot Topic (More than 10 Replies) Octagon....ala Pope (Read 1653 times)
bg7m
Junior Forum Member
**
Offline



Posts: 21
Location: North Georgia
Joined: Jan 21st, 2009
Re: Octagon....ala Pope
Reply #15 - Apr 19th, 2017 at 9:08am
Print Post  
Great work!  Love seeing those old lathes still doing work.
  
Back to top
 
IP Logged
 
SBoomer
Full Member
***
Offline



Posts: 248
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Octagon....ala Pope
Reply #16 - Apr 19th, 2017 at 4:15pm
Print Post  
SSShooter,
The octagon you see is straight. Doing a straight octagon section on a pre-tapered barrel is where all the work is at. Each setup has to account for taper in two planes. The barrel is shimmed off both surfaces that touch the vice. Once a flat is correctly established, the opposing side is only shimmed in one plane. After a flat and perpendicular flat are established, no shimming is required on opposite flats. The remaining four "angled flats" start the routine all over again. To establish the first 45deg flat, I clamped a vee block to the barrel and trammed its bottom surface....that facing the chuck. None of the final four flats referenced the first four by vice contact. I shimmed off the small wedge of remaining original cylindrical taper on the round barrel between flats. Whew....that was too much.  Cheesy
  
Back to top
 
IP Logged
 
SSShooter
Frequent Elocutionist
*****
Offline



Posts: 2212
Location: Southern NJ
Joined: Aug 1st, 2010
Re: Octagon....ala Pope
Reply #17 - Apr 19th, 2017 at 9:27pm
Print Post  
Indeed. Almost as much as the actual set-up.  Wink
Thank you for the effort (explanation).
  

Glenn
Back to top
 
IP Logged
 
jhm
Senior Forum Member
****
Offline



Posts: 463
Location: georgia
Joined: Sep 4th, 2011
Re: Octagon....ala Pope
Reply #18 - Apr 20th, 2017 at 9:06pm
Print Post  
Never mind the barrel...... I want that lathe!


JMH
  
Back to top
 
IP Logged
 
SBoomer
Full Member
***
Offline



Posts: 248
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Octagon....ala Pope
Reply #19 - Apr 20th, 2017 at 10:30pm
Print Post  
She's a keeper! Here is a pic of the day I brought it home via sled. I am 8 miles off the grid on a non-plowed road from December 1st to mid-march'ish. It was single digits that day and it took 2 trips. The restoration kept me busy the whole winter. I am still looking for period tooling like the lantern toolpost and toolholders. I really want the overhead countershaft assembly so I can run it with an old hit & miss engine. Each size of South Bend lathe had a matching sized countershaft. I have found 11" and 15" but no 13" yet.
  
Back to top
 
IP Logged
 
GT
Junior Forum Member
**
Offline



Posts: 62
Location: Northeast Wyoming
Joined: Jun 28th, 2015
Re: Octagon....ala Pope
Reply #20 - Apr 21st, 2017 at 2:09am
Print Post  
SBoomer,
Nice job on the barrel, thanks for the reality check.  It's been many years since I've had to use machines in this manner Smiley I've bought mills of different types, super spacers, dividing heads, excess tooling, etc. even CNC's just to prevent ever having to perform operations and setups like this... again.   I do know the process and I admire your ambition.  Thanks for posting. 
Here's a wedding band I did early winter just to see if I could come close to the picture in John Campbells book.  Done a few more since, similar and different, they make a barrel original.  Haven't tried the inlay style yet but it's on the list.
Greg
  

"It has been my experience that folks who have no vices have very few virtues." - Abraham Lincoln
Back to top
 
IP Logged
 
SBoomer
Full Member
***
Offline



Posts: 248
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Octagon....ala Pope
Reply #21 - Apr 21st, 2017 at 9:56pm
Print Post  
GT, that looks perfect! How did you carry the knurl around the radius of the band? Did you do a straight knurl and then hand file to carry it around the edges?
  
Back to top
 
IP Logged
 
GT
Junior Forum Member
**
Offline



Posts: 62
Location: Northeast Wyoming
Joined: Jun 28th, 2015
Re: Octagon....ala Pope
Reply #22 - Apr 22nd, 2017 at 1:42am
Print Post  
SBoomer,
I spent quite a bit of time experimenting, thinking along the lines of what you mentioned, knurl then file, even made a concave knurl.  What I found out that worked slick and easy was a single knurl holder and very high quality roll.  The roll has to have crisp edges, nothing fancy on the holder - a piece of 1/2" square stock, drill and ream a through hole the size of the hole in the roll - a short hardened dowel for the axle and you're in business. 
Use the knurling formula to determine exact initial diameter to begin with (the knurl pitch, (ex. .040) divided by pi, and the result of that dividing evenly into the diameter. You can pick a size real close to the diameter desired - generally smaller as the kurling increases diameter slightly)  If this sounds confusing PM me and I'll email a more detailed step by step with examples.
Start the knurling process on the top of the prepped band, I took it close to depth in a straight on position, then I backed the tool out, re-positioned the roll at a slight angle and if you enter the form gently the roll picks up the lead, repeat this process until desired results are obtained.  I donned my magnifying visor and dressed the knurl with a very small file for the finish touches, under a scope at 40x it's a little coarse but with most eyeballs it looks good.  I've done a couple this way and moved on... the silver inlay is next... maybe gold?  Wink
Greg
  

"It has been my experience that folks who have no vices have very few virtues." - Abraham Lincoln
Back to top
 
IP Logged
 
Page Index Toggle Pages: 1 [2] 
Send TopicPrint