Need better solution for gears on South Bend 13"

J

jbarton

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Wow talk about a surprise... I found the gears I need to replace in the Martin Sprocket and Gear catalog. These are on the reverse chuck... specifically the 27 and 30 tooth gears. Well the 30 tooth is $36 the 27 tooth is $314. I about fell out. Is this normal? The 30 is a stock gear while the 27 is not but is listed in the charts. These are 16DP 20 deg with 7/8" center hole.

Any body got a better solution? Thanks in advance.

-John Barton
 
This guy has a lot of parts and a good reputation: http://www.plazamachinery.com/ Although, I'm told that he has some health issues so it's sometimes difficult to contact him. You can always ask around here, maybe place something in the "wanted" area.

Hope that helps,

-Ron
 
jbarton said:
Wow talk about a surprise... I found the gears I need to replace in the Martin Sprocket and Gear catalog. These are on the reverse chuck... specifically the 27 and 30 tooth gears. Well the 30 tooth is $36 the 27 tooth is $314. I about fell out. Is this normal? The 30 is a stock gear while the 27 is not but is listed in the charts. These are 16DP 20 deg with 7/8" center hole.

Any body got a better solution? Thanks in advance.

-John Barton
Click to expand...

John,

I don't know what model Southbend you have but if it is very old I would be surprised if the original gears are 20 degree pressure angle. I have an old SB and it has 14 1/2 degree pressure angle gears. Check with some of the Southbend guys before you purchase in case I am wrong. They have a Yahoo forum.

Benny
 
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I dont know of any SB lathe that uses gears with a 20 degree Pressure angle.
All the ones I am aware of use 14-1/2

Now I dont know much about the later Taiwan made lathes

This person,

Michael Schetterer [finegrainmetal@hotmail.com]

Has been making gears for the Yahoo SB group for several years now. His work is very good and his prices are reasonable.
 
Ok... now I'm confused and will have to double check what PA I have on these gears... The way I determined what gears I needed was by going to the Martin catalog and using the number of teeth as the start find the DP and pressure angle that matched the OD and (ID) for the gears I had... the only ones that were close was the ones that were 16DP 20PA.

To be specific they were TS1630BS 7/8 AND TS1632BS 7/8. The 27 tooth is not listed as a standard but is listing in the 20 deg horse power ratings so I guessed that the number was TS1627BS 7/8 and Martin came back with the over $300 price.

This set is the reverse for the quick change. the set that is driven off the rear of the head. So it has to match that gear.

As a double check I built the gear set in Autodesks Inventor using its gear creation. And the numbers came out the same... even the distances (center to center) came out really close to what I had measured. Here is a pic I have of the set. The 27 and 30 tooth gears are the ones that are warn really badly. Others have some wear but not bad.

endview.JPG

endview.JPG
 
Froneck said:
Are the center distances fixed? Or can you change pitch diameter? Do the two gears mesh with only each other so you can change angle to 14.5" They actually run quieter. Did you look at change gears, usually change gears come in odd sizes. Also check Boston. I had to fix the Power Feed box in a Bridgeport, I think I needed a 27 tooth gear. Kaman from Williamsport PA was able to locate one in CA for $40 +shipping. I still have the old gear someplace, I can check to see what size it was.
Frank
Click to expand...

The centers are fixed on these. This is the revese gearing... Anybody know why they would use 27 tooth gear? I would think it would be a 30 to match the other gear... I'm sure there is a reason... I'm prob just not thinking about it.
 
Benji said:
I dont know of any SB lathe that uses gears with a 20 degree Pressure angle.
All the ones I am aware of use 14-1/2

Now I dont know much about the later Taiwan made lathes

This person,

Michael Schetterer [finegrainmetal@hotmail.com]

Has been making gears for the Yahoo SB group for several years now. His work is very good and his prices are reasonable.
Click to expand...

Well I've got a real mystery on my hands then. This one was made in 1943. I'm going to look at this some more before I do anything. Thanks for the help.
 
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