Newbie with a 405 but no gears

M

MauledByBears

Plastic

Joined

Apr 27, 2017

• Jun 17, 2018

• #1

Hi

I was given a SB 405-Y by a friend as-is: meaning it only had the gears that are in it. This is my first geared lathe, my other lathe is a Pratt & Whitney 3C, so this is new territory for me.

Is there a list somewhere of all the gears included with the 405 when it was new? I know the DP is different from the later versions of the 9 and 10k lathes, but I'm not sure what else is different. It doesn't seem like anyone's selling a full set on eBay and those things aren't cheap!

Anyone have an idea where I can look? 3D printer-friendly CAD files for the 9 and 10k lathes are easy to find on Thingiverse, but they're all 18DP and not 20. Is it as simple as going into CAD and copying these gears and just changing the pitch?

Thanks

 

J

johansen

Stainless

Joined

Aug 16, 2014

Location

silverdale wa

• Jun 17, 2018

• #2

You could print 18dp gears at an appropriate scale, then bore out the hub and re cut the keyway.

I have a set of plastic gears and they really need metal inserts for the bore, the key will strip out the plastic and getting the diameter just right is a pita. ( depends on the printer and the plastic)

 

M

MauledByBears

Plastic

Joined

Apr 27, 2017

• Jun 17, 2018

• #3

That's a good tip about the inserts! I was hoping to use the prints to cast some gears out of aluminum so I wouldn't have to worry about stripping them as quickly.

Normally I'd just print a set of the 18DP and run with it, but I don't think they'll mesh with the spindle gear. The threading index chart on my lathe shows the 24T spindle gear used for everything. I'm not sure how exactly it's fixed to the spindle, I haven't taken a very close look at it/tried to take it apart yet. I'll include some pictures.



It looks like I'll need the following: 24T, 28T, 30T, 33T, 36T, 39T, 42T, 45T, 48T, 54T, 60T, 69T. From what I've read the 1:2 and 2:1 idlers might be 40T and 80T gears on the same axis. As you can see all my info is kind of fragmented. That's why I was wondering if there was a source (preferably a SB catalog or parts list or something)

 

I

iwananew10K

Diamond

Joined

Sep 12, 2010

Location

moscow,ohio

• Jun 17, 2018

• #4

That model uses 20DP gears.

 

C

Christian James

Aluminum

Joined

Sep 26, 2016

• Jun 18, 2018

• #5

I could knock up a set of STL's if you need them.

 

M

MauledByBears

Plastic

Joined

Apr 27, 2017

• Jun 18, 2018

• #6

Christian James said:

I could knock up a set of STL's if you need them.

Click to expand...

Thanks! I'm happy to do it myself, my question was more about how it would be done and what gears I need. I guess I could just make all that are in the index plate and if I need an idler or something, cross that bridge when I get to it.

 

B

bou

Plastic

Joined

Feb 2, 2015

Location

Canada, Quebec

• Jun 18, 2018

• #7

You can use Autodesk Fusion 360, it's free for personal use and has a tool to auto-generate gears.

 

M

MauledByBears

Plastic

Joined

Apr 27, 2017

• Jun 18, 2018

• #8

bou said:

You can use Autodesk Fusion 360, it's free for personal use and has a tool to auto-generate gears.

Click to expand...

Thanks bou, that's my plan. My question is more related to what gears I need to make. Information seemed pretty sparse so I was hoping to get a little information here before the trial-and-error approach and hope I don't need too many idlers or compound gears to complete a set.

 

B

bou

Plastic

Joined

Feb 2, 2015

Location

Canada, Quebec

• Jun 18, 2018

• #9

If you check here :

South Bend Model 5, 205, 405 & Type 15 lathes

They list the supplied gears for the 405 lathes.

 

M

MauledByBears

Plastic

Joined

Apr 27, 2017

• Jun 18, 2018

• #10

bou said:

If you check here :

South Bend Model 5, 205, 405 & Type 15 lathes

They list the supplied gears for the 405 lathes.

Click to expand...

Thank you! This is exactly what I was trying to find. I'll make the STL files and post on this thread when they're done to attach them in case anyone in the future needs to make themselves a set.

 

D

Don Kinzer

Cast Iron

Joined

Mar 18, 2002

Location

Portland, OR USA

• Jun 19, 2018

• #11

MauledByBears said:

Is there a list somewhere of all the gears included with the 405 when it was new?

Click to expand...

If you can wrangle a spreadsheet you can work up a set of gear combinations which will provide the carriage movement needed for the various thread pitches that you're interested in having. Basically, knowing the leadscrew pitch, you can calculate the gear ratio required to effect any particular carriage movement per revolution of the spindle. Once you know the gear ratio needed for each of the screw thread pitches you want it is simply a matter of selecting the set of gears that will work within a tolerance that is acceptable using the fewest number of gears.

 

C

Christian James

Aluminum

Joined

Sep 26, 2016

• Jun 20, 2018

• #12

Fusion seems only available free to educators and students :-(