View Full Version : 1933 Southbend Model 420-ZB Toolmaker Lathe Restoration/Rescue

09-20-2011, 11:11 PM
I thought I would start a thread showing my efforts to rescue/restore; not to 100% original condition/appearance, but 100% functionality with my own sense of aesthetics. . .not everyone will like the paint job that I'm going to do, but to each their own.

I'm a Tool & Die Maker apprentice (starting my second year this month) and so far I have obtained a 1909 Monarch 16" x 72" lathe and this 1933 Southbend Model 420-ZB Toolmaker lathe.

This lathe was sold to me as a Southbend 9" Workshop Model C lathe; the individual who sold me the lathe didn't know very much about it (or about lathes in general). He bought the lathe hoping to recondition it and then learn how to use it. He decided he was in a little over his head and that's how I came to own this lathe. I bought it for $150 (disassembled) without a motor/horizontal drive assembly, change gears, or any chucks. It came with two lantern-style tool posts, one tool holder, an extra cross-slide, and a rebuild kit (new oil wicks and wipers, etc). The only apparent problems with the lathe were a braze repair made at some point in the past to the apron, the cross-slide handwheel had a broken handle, the handwheel shaft was bent, and the belt tensioning lever clevis pin was bent.

After some research (and help from members of this forum and another machining forum) I discovered that the lathe was a Toolmaker lathe and not a Workshop Model C lathe.

I probably should have taken more initial pictures of the lathe, but I didn't think to do that. . .I'm photo-documenting this build more thouroughly now, but don't worry I didn't miss much at the beginning.

Here is what the lathe looked like when I brought it home.

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-snc7/306952_288146997868807_100000205277807_1374431_413 103657_n.jpg

09-20-2011, 11:25 PM
The braze repair to the apron had quite a bit of filler material on both the front and the back (too much in my opinion) so I decided to fix this. . .this is one of the things that I didn't think to get a picture of before I started fixing things.

As an apprentice project I disassembled the apron, set it up on a Bridgeport, and milled the filler on the front of the apron as close to flush with the original base material as I could without disturbing any more of the apron than had already been done. Next I hand filed, sanded, and used a Dremel to blend the filler into the apron's original contours.

Here are pictures of the apron after I did the above:

http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/320988_288655484484625_100000205277807_1376247_163 4712815_n.jpg

http://a8.sphotos.ak.fbcdn.net/hphotos-ak-ash4/318575_288655541151286_100000205277807_1376248_213 1959328_n.jpg

Next I used some Evercoat Rage Gold body filler and put a very slight skim coat over the repair area. After allowing the body filler to become just tacky I took a sheet of 80-grit and sandpaper and pressed it into the body filler to simulate the pebbly cast appearance of the apron. . .I'm hoping that by doing so the repair will be "invisible" to the casual observer.

http://a4.sphotos.ak.fbcdn.net/hphotos-ak-ash4/308514_289599654390208_100000205277807_1381217_662 479235_n.jpg

Next thing planned for the apron will be primer and paint.

While I'm on the subject of the apron here is what I did to repair the bent handwheel shaft. Here's a picture of the repaired shaft first so that you will know what I'm talking about.

http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash4/311349_290785444271629_100000205277807_1385759_102 3832837_n.jpg

The part of the shaft which was bent was the smaller diameter portion with the hole through it. . .where the handwheel was pinned on. I'm assuming the lathe was either dropped or knocked over causing the bent parts and broken handwheel handle.

I chucked the shaft up on a 10EE in a collet chuck, and parted off the small diameter portion of the shaft and I drilled a hole into the shaft. Next I machined a replacement with a stud to be inserted into the hole in the shaft out of 4140. I machined the stud for a 0.002" clearance fit and slid it into the shaft with some red LocTite. The only thing that remained to be done was to drill a 0.141" (if I remember correctly) hole through the shaft for the taper pin which holds the handle in place.

The last repair I needed to make to the apron was to replace the broken off and missing handle. I set the handwheel up on a Brideport and milled a flat onto the face of the broken handle and then drilled a hole through it. I machined a pin that would slip into the hole through the handle. . .after that I used an arbor press to push the broken portion of the handle out of the handwheel. My mentor at work had an extra handle which looked like the other handles on my lathe in contour and looked to be a proportional and comfortable size; conveniently the hole through the handwheel was already the correct size to tap it for the thread of the handle. . .I threaded the new handle in place and you can see it in the first picture of this post.

09-20-2011, 11:44 PM
Excellent start. This had better go on for at least 15 posts to join other
epics of restoration. Keep up the photos and commentary!! The guys
here drool over articles like this.

09-20-2011, 11:44 PM
Looks like the right man got it in the end...;) Good job and please post more pics as you progress.

09-20-2011, 11:46 PM
The same day that I repaired the bent handwheel shaft I machined a new clevis pin for the belt tensioning lever. . .here is the old bent clevis pin; it's hard to see the bend in this picture, but it's there and the threads were damaged to the point that the nut would no longer thread on as well:

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-snc7/294855_290794974270676_100000205277807_1385780_201 9549426_n.jpg

and here is the new clevis pin made out of 4140:

http://a4.sphotos.ak.fbcdn.net/hphotos-ak-snc7/300864_290785504271623_100000205277807_1385760_849 846649_n.jpg

09-21-2011, 12:07 AM
I have spent all my other efforts on stripping the old green and the new machinery gray paint off of the lathe; I'm down to the last two parts to strip: the tailstock (new machinery gray) and the headstock (old green). . .these should be done by the end of the week at the latest.


http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash4/303197_288655204484653_100000205277807_1376242_528 334239_n.jpg

headstock with stripped spindle shaft caps

http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc7/299229_288655367817970_100000205277807_1376245_115 2565367_n.jpg

tailstock housing

http://a8.sphotos.ak.fbcdn.net/hphotos-ak-snc7/296002_290798097603697_100000205277807_1385788_163 3372785_n.jpg

09-21-2011, 12:07 AM
I just finished stripping the lathe bed tonight

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc7/317214_290799730936867_100000205277807_1385792_104 9293382_n.jpg

The ways look to be in really good shape; there are some dings in the V-ways just in front of the headstock (probably from someone being careless either changing chucks or removing parts), but these dings shouldn't affect the carriage since they are so close to the head. . .the rest of the ways look really good. Hopefully I'll get around to checking them with an indicator soon.

http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/298926_290799777603529_100000205277807_1385793_183 6947555_n.jpg

I blasted the feet yesterday

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-ash4/313293_290799810936859_100000205277807_1385794_877 893069_n.jpg

I also need to get rid of the rust off the spindle pulley cones and clean up the back gear shaft; I will probably wait until just before re-assembly for this so there isn't time for them to re-rust while I'm working on everything else. . .and I believe that I will be using a twin arm banjo instead of the single arm banjo it came with.

http://a3.sphotos.ak.fbcdn.net/hphotos-ak-ash2/166988_290799660936874_100000205277807_1385791_220 981007_n.jpg

Hopefully I'll be spraying primer tomorrow on most of the parts and the base color coat on Friday.

09-21-2011, 12:10 AM
Excellent start. This had better go on for at least 15 posts to join other
epics of restoration. Keep up the photos and commentary!! The guys
here drool over articles like this.

Looks like the right man got it in the end... Good job and please post more pics as you progress.

Thanks guys!

Let me know if there is anything in particular you would like pictures of at this point in time. . .like I said I will start spraying primer and base color coat this week.

09-21-2011, 07:17 AM
Did you use a taper pin reamer on the holes before installing the taper pins?

09-21-2011, 09:21 AM
Did you use a taper pin reamer on the holes before installing the taper pins?

Not yet, will do that today while I'm thinking about it. . .thanks for reminding me.

10-03-2011, 11:56 PM
Haven't forgotten about this thread, but I haven't had much free time lately. . .with the holidays up and coming and the weather taking a turn for the worse I've been busy getting the last of my outside work done and getting an early start on the holidays.

I hope to have some updated pic's and progress to share with you guys next week.

11-11-2011, 11:26 PM
Hey. . .I haven't forgotten about this I've just been pretty busy (again). . .our renter's moved out of our rental property so I've been busy getting it ready for the next set of renters, but I'm currently working on getting the horizontal drive countershaft assembly. . .hopefully I will close on it tomorrow. . .then I will have all the parts for the lathe and I will be ready to get back to work on it. . .sorry for the little hiatus, but you know how it is. . .I really bought this as a winter project anyway so getting as much done over the summer as I did was a big bonus to me!

Tony Ennis
11-12-2011, 09:48 AM
Keep it coming. People may not be commenting, but I bet their reading.

11-12-2011, 10:32 AM
Yes we are!:)

11-12-2011, 10:53 AM
These preWar SBs are some of the best restorations I've seen. Looks like yours is well on it's way to being one of them

11-15-2011, 08:40 AM
I got outbid on the horizontal drive assembly at the last minute (I was out of the house) so I'm back on the hunt for that again (at a reasonable price. . .I was gonna get this one for $80 plus S/H), but I was able to find some of the gold foil I needed for the paint job. . .


pretty close to what I was looking for, I was looking for the gold foil with the frosting appearance similar to that of nice new ways though. . .but a good start.

12-23-2011, 05:44 PM
I was finally able to get a countershaft assembly from a fellow forum member on a different forum. . .

I'll post pic's once it gets here. . .and get back to work on getting this thing going since the countershaft assembly was the last piece I needed.

12-23-2011, 06:05 PM
Real nice work, great looking job!!!!!!!!!!!!!!!!

Yup, looking forward to seeing the rest and assembly and trial runs.

Thanks for posting this!!

12-23-2011, 06:18 PM
Thanks. . .wish the progress was faster, but life is full of unexpected twists and turns that keep us from getting things done when we want to. . .plus I'm taking my time to make sure I get it done the way I want it and I don't have to go back and re-do something because I didn't do it the way I wanted to do so that I could just "get it done". . .I'm getting kinda of tired of going back and "fixing" things so I'm trying to avoid doing that anymore. . .

. . .kinda hard sometimes though when the significant other would rather see forward progress than listen to why you need to wait to do something.

Hopefully I'll have some pic's and progress for you guys soon!

01-12-2012, 08:47 PM
Horizontal Drive Assembly/Countershaft Assembly showed up in the mail yesterday. . .I've started working extended shifts so I'm too tired to take pic's right now. . .

. . .I'll post some pic's over the weekend.

01-12-2012, 08:58 PM
Thanks for keeping up the thread. It looks like nice work thus far. Keep it up, we will hold you to it and be judging later on. :p Jk.

01-13-2012, 02:53 PM
Before you start assembly, put the saddle on the ways and an indicator on the saddle and indicate the tailstock ways as you move the saddle back and forth. This will give you the amount of wear in the main ways and help you decide if you want to go the extra mile and have the bed ground. My 10K shows .005" and turns straight so I'm not doing anything about it. Peter

01-13-2012, 08:45 PM
Before you start assembly, put the saddle on the ways and an indicator on the saddle and indicate the tailstock ways as you move the saddle back and forth. This will give you the amount of wear in the main ways and help you decide if you want to go the extra mile and have the bed ground. My 10K shows .005" and turns straight so I'm not doing anything about it. Peter

Thanks for the tip!!!

03-11-2012, 04:02 PM
I'm back on this again. . .now that the weather is starting to get warmer (for the most part, despite the rain, snow and cold of last week) I can start painting parts for final assembly.

Before I paint anything I'm gonna re-assemble/pre-fit everything to make sure I haven't forgotten to make/repair any missing/damaged parts.

Everything is all laid out on what's serving as my indoor restoration table (my drafting desk with a piece of 1/2" corrugated cardboard over the top to protect the drafting surface) so hopefully I'll start re-assembly/pre-fitting tonight and start painting next weekend.

Only thing left to purchase for this thing to be fully functional are some chucks and change gears. . .I have none of either for this particular lathe.

So stay tuned for progress on this project.

04-19-2012, 08:41 AM
Sorry the progress has been slow and sporadic on this project guys. . .I just got started with the pre-assembly (before paint to make sure I have everything, everything I have is actually for this lathe, and I have repaired/replaced any have actually been fixed).

I have found a few more things needing some attention. . .primarily the saddle at this point. At some point the lathe was dropped and/or knocked over on it's side. This broke the handle off of the cross-slide lead screw (with part of the lead screw still in it); the lead screw needs replaced, the gib for the back of the saddle is broken, and the handle is bent slightly. Luckily (I thought) the lathe came with an extra saddle, but it turns out that the extra saddle is not for this lathe (or at least is not the same as the one I have and the matching apron); it is slightly larger. The lead screw is 1" longer (12" vs. 11", but I think I might be able to use it anyway by just turning the extra inch off of the end) and the apron mounting screws are farther apart (8" CTC vs. the 7" CTC mounting holes in the apron I have). I plan on machinig a new gib for the saddle, hopefully I can modify the longer cross-slide lead screw (I have to get it out of the other saddle first though), and I'm hoping I can get the bent part of the handle out and press a new piece in.

Here's my question, how do I get the handle off of the lead screw on these older lathes? I removed the set-screw from the graduated sleeve and once I remove the handle it will come right out, but it appears there is a peened over (?) piece holding the handle in place. Looks like a flat-head screw with a hole bored in it. . .then a domed pin (with a center in it) was pressed/peened (don't know which one) in place to hold the handle on. How do I get the retaining pin out? Wondering if there is a trick to this before I get frustrated and become "creative".

I will post a pic of the assembly after work today.

I think after I get this issue resolved/repaired things will start moving along at a nice clip.

Thanks for the help!

04-19-2012, 10:02 AM
This is something to b proud of. Fantastic job ur doing,and i love how u used the sandpaper to simulate the casting. Great job. Keep the pics coming.

04-19-2012, 08:55 PM
Thanks Ogre. . .turns out I will be able to repair the broken cross-slide leadscrew.

I'm gonna chuck it up in the a mill, mill the broken part off, bore a recess into the lead screw and press a slug (OD will match the OD of the lead screw) into the leadscrew. . .then I'm gonna drill a hole for a roll pin into the lead screw/slug. . .then I'll chuck the lead screw up in lathe and turn the slug down to the correct OD and face it to the correct length. . .lastly I will press a roll pin to make sure the new pressed in part won't ever spin inside the lead screw.

By turning the new extension down after pressing it into the leadscrew you shouldn't even be able to see that it was repaired or is two separate parts!

One of the older guys at work said not to modify the 12" cross-slide lead screw as that saddle is probably for the telescoping taper attachement. . .so I'll be on the lookout for the correct saddle to match it eventually.

04-19-2012, 11:36 PM
Here are some pic's. . .

The broken gib for the saddle. . .I'll be machining a new one of these:

Bottom view

Top view

and here is the broken cross-slide lead screw and bent cross-slide feed handle: