Help with South Bend lathe please...

Hi JP,

The gear is not a single idler gear. It is a reduction gear and was available in different ratios. Search under Southbend and also Hercus lathes. If you cannot find one in the UK, they are available in Australia.

I just did a search and found a 72/18 tooth compound gear for $69. (approx ₤40) at Australian Metalworking Hobbyist. Other ratios are also available. (Probably cost that much in postage.)

http://australianmetalworkinghobbyist.com/store/index.php?route=common/home

The spacer washer on my lathe is about 1/8" thick. You could easily make your own if it is required.

Paul.

Edited By Paul Lousick on 12/02/2015 11:54:36

that's it!! Compund gear!!!

I've found a couple on ebay UK!! the original one is 72/18 and the ones I found are not the same but doesnt matter.

I just want it to connect to the lead screw so I can have the power longitudinal feed.....
I can then adjust the longitudinal feed speed by changing the load of gears I already have... I think that will work?

http://www.ebay.co.uk/itm/BOXFORD-LATHE-COMPOUND-GEAR-18-54-TEETH-LATHES-MILLING-DRILL-ENGINEERING-TOOLS-/191507744210?pt=LH_DefaultDomain_3&hash=item2c96c045d2

http://www.ebay.co.uk/itm/54-18-Tooth-Compound-Change-Gear-For-Boxford-Lathe-With-Bush-Bolt-Assembly-/121562745282?pt=UK_Home_Garden_PowerTools_SM&hash=item1c4db449c2

Hi,

You are getting good advice here but do you know about the Southbend user group on Practical Machinist ?

**LINK**

What they don't know about SB's is probably not worth knowing.

Theres probably a tried an tested way of doing this on your machine and those guys will be able to tell you what it is.

Tony

Hi JP

Before you go out to buy anything I suggest you have a look on the www.lathes.co.uk website for info on South Bend and Boxford lathes. Tony usually gives a list of the change wheels for each model and you can compare that list with what you've got and see just what you are short of. The compound gears aren't just paired up at random but form part of a series of gears designed to give you the ability to cut threads of specific pitches as well as giving the fine feed - you might as well get the correct gear to go with your others. As other have said it's also worth joining the various South Bend or Boxford user groups on places like Yahoo. They usually have opertaing manuals and parts list for the various models that you can download as well as giving you better access to folk who use the machines and have been there and got the T shirt.

Don't be put off by comments about Yahoo's current "unfriendly" format - it isn't that different to what it was, you can still access what you could before - most of the issues that folk have had is due to a "blinkered" approach!.

thanks for that info, been reading a bit more and looks like the guy I emailed yesterday was right mentioning that I needed a 80t idle gear and he has one for £18....

looking at the screw cutting chart, and bear in mind im only interested in the longitudinal power feed, I do need that 80t gear.

I can set it up as shown on FIG1... or even FIG2.
That 80t gear is always present on both setups, then I can put the other gears as I have those.

And here's some very useful bit of information (added in case someone ends here with the same questions as myself)

There should be a total of 17 gears - 14 of these have the 9/16" keyed bore.
The tooth counts are 16, 24, 32 (quantity of 2), 36, 40, 44, 46, 48, 52, 54, 56, 60, and 80.

The remaining three have the 5/8" bore, no key.
The tooth counts are 80, 72/18 and 54/18, the latter two known as compound gears.

The three smooth bored gears can only be used as idlers, of course.

In addition to the square head bolt/sleeve/nut that you're missing, there is also a spacer with 9/16" keyed bore that moves the screw gear to the left, allowing mesh with the idlers for reduction.

Edited By JP Santos on 12/02/2015 16:16:56

Try this guy in the US

http://plazamachinery.com

http://plazamachinery.com/files/Metal-10-11-2015.pdf