I have never actually had to do a similar repair but have worked in shop where it was done. A row of holes was drilled along the roots of the broken teeth and shorts bit of bright mild steel driven into them to act as a re-enforcement. Another trick was to build a dam around four or five good teeth. The dam was filled with lead. The result was a gauge which could be used a check of pitch and form.
A guy I took a short welding class from would pre-heat cast iron in a wood stove, then toss the part back into the fire after welding and leave it as the fire and embers died down overnight. A couple of other things that might be worth mentioning? Using fire brick is safer than building brick. Fire brick doesn't absorb water and so it won't burst from high heat. More important for oxy-acetylene welding (which you never want to do on concrete either, for the same reason). Also, you want to keep the acetylene tank vertical. Acetylene isn't pressurized, it's dissolved in acetone and a filler material. If you tilt the tank, you can end up with acetone coming through the regulator. Regs say something like 24 hours vertical before hooking up if you have the tank on its side at all. I'm sure that's more than needed in most cases, but it's almost certainly safe. I've also been taught that you only open the tank valve on acetylene a half turn or so...you want to be able to close it quickly if there's a problem. Oxygen and other high pressure valves get opened all the way so there's no leakage around the valve stem. Just passing on what I've been taught. What you did obviously works for you. My lessons were more OA welding, and not acetylene alone but there seemed to be some overlap. Thanks for showing the repair. -- Mike
I saw the comment you made on poor old chap's video. I haven't had a chance to watch yours yet, but I thought I'd tell you I grew up about 15 miles from the South Bend Lathe factory and went to school with a guy who's dad worked there.
Thanks! Yes I used a serpentine belt also, but didn't remove the shafts to install it and had to split the belt and stitch it back. I will get another belt (I have several) and actually take the shafts out and install the belt without splitting it as the stitching is starting to tear out of the belt... oh well! I am watching your videos on the SB now! Thanks!
Thanks brotha I've had it apart so many times it's driving me crazy. The original owner really had some messed up stuff going on. Cobbled spindle shaft, flats for set screws made with an angle grinder, completely off axis, wrong spindle pulley,bunch of wrong hardware,broken transverse gear,now this vibration, I've got it narrowed to the headstock pulley or bull gear,hopefully not the shaft.Xp I'm going to be making some video for a forum I'll get it up soon. Maybe you can take a look. Thanks
Good vid. I have found that silver solder wears down pretty fast. The brass brazing would probably last longer. I have found the best way whenever possible is to silver solder in a new piece of the base metal, in this case some cast iron. Faster to solder and you can easily get it back to full size for machining. Keep up the good work. A noob with a SB 10 K
Man this is a great video. I recently bought an old Atlas craftsman lathe. It's got a horrible vibration in the rotating assembly somewhere. I'm hoping its not the headstock shaft. I'm going crazy trying to find it. Great work on the gear by the way.
Hi friend. Can you share the specs of drive belt that you are using in your lathe? I see K050500, but i don't see the length. Thank you in advanced. Congratulations for excellent video. Regards from Brazil.
wow that looks great. How strong is that silver flux though compared to the actual cast iron? I have the same type of gear (2 of them) on my Nc machine. good idea incase i lose a tooth.
would it have been possible to make a toolbit in the profile like a tooth n cut it in the lathe like you did a keywey slot? maybe even with an index head or somthing...
Nice tutorial! thanks! Is your flat belt split and tied or is it one piece? If one piece how did you get it on the drives? I have a 9" SB, and I cut the belt and stitched it with nylon cable lacing cord (pretty strong), but it is a pain!
can I use the same method on fixing the headstock bearing bore? my headstok have missing some corners and there is a cut inside the bore I think somebody tried to push the spindle from the back and that caused the spindle lip cutting from the bore! my plan is to do the same what you are doing to fill the missing parts, then sand the extra brazing, then insert a honing cylinder sanding stone with 4 handles to re-sand and polish the area! is that will work? here is my headstock:( so bad I think so) thank you fro your inputs again
Probably not the best idea. In all honesty these lathes can still run fine with really scored bearings. If you want to fix it your best bet is to line bore the headstock and fabricate some new bearings from bronze and press them into the headstock. It's a labor intensive and expensive process and it needs to be done extremely accurately.
Nice work! One thing that I've found works great for prepping cracked cast iron is to use a carbide burr in a die grinder. No grit to contend with and it leaves a nice smooth finish.
I have to do just about the same thing for the second time I don't Logan back gear but the large gear I don't know why I keep knocking teeth off that damn thing unless it's just so damn old I don't know?. So what I'm going to do is I have two assemblies both missing teeth I'm going to cut out to teeth in one block and then cut the meeting side with a slitting saw off of the damaged gear and then shape the two teeth to fit in the female half hopefully I'll be able to do this and get the gears teeth to line up perfectly and I've been getting pretty damn good with brass brazing so I'll just plain old Breeze it in. They say brazing cast iron makes it as strong if not stronger than the original piece well we'll see. I have no doubt that I'll be able to do it I just got to get a nice pocket cut to accept the teeth with a little extra room for brass.
hmmm if you had a TIG welder you could weld the new teeth in pretty easy very controllable and very clean problem is you need the helmet and shielding and the practice working on something that small you need a steady hand and a good eyes and also the pre-heating could you use a barbeque :P they work well getting it warmed up for the pre heating and also post heating but good job with that I i don't think i be as confident repairing with oxy it just flows too much to be controled for me
I don't believe they've had manufacturing in South Bend for a few decades. The brand is apparently still alive and being made somewhere. I think Wikipedia said Grizzly dealers are selling their machines. There is a website for SBL you can find it through Google or other search engines. Their website has history and old pictures of the factories. I believe that the company was started by the same brothers that had O'Briens Paints.
I did exactly the same brazed repair to my Boxford Model C lathe Backgear about 40 years ago and it's still working smoothly today.
I'm a new gunsmith and I really appreciate your detailed info on the equipment you used, options and advantages/disadvantages. Thanks!
I have never actually had to do a similar repair but have worked in shop where it was done. A row of holes was drilled along the roots of the broken teeth and shorts bit of bright mild steel driven into them to act as a re-enforcement. Another trick was to build a dam around four or five good teeth. The dam was filled with lead. The result was a gauge which could be used a check of pitch and form.
A guy I took a short welding class from would pre-heat cast iron in a wood stove, then toss the part back into the fire after welding and leave it as the fire and embers died down overnight.
A couple of other things that might be worth mentioning? Using fire brick is safer than building brick. Fire brick doesn't absorb water and so it won't burst from high heat. More important for oxy-acetylene welding (which you never want to do on concrete either, for the same reason). Also, you want to keep the acetylene tank vertical. Acetylene isn't pressurized, it's dissolved in acetone and a filler material. If you tilt the tank, you can end up with acetone coming through the regulator. Regs say something like 24 hours vertical before hooking up if you have the tank on its side at all. I'm sure that's more than needed in most cases, but it's almost certainly safe. I've also been taught that you only open the tank valve on acetylene a half turn or so...you want to be able to close it quickly if there's a problem. Oxygen and other high pressure valves get opened all the way so there's no leakage around the valve stem.
Just passing on what I've been taught. What you did obviously works for you. My lessons were more OA welding, and not acetylene alone but there seemed to be some overlap.
Thanks for showing the repair.
-- Mike
I saw the comment you made on poor old chap's video. I haven't had a chance to watch yours yet, but I thought I'd tell you I grew up about 15 miles from the South Bend Lathe factory and went to school with a guy who's dad worked there.
Thanks! Yes I used a serpentine belt also, but didn't remove the shafts to install it and had to split the belt and stitch it back. I will get another belt (I have several) and actually take the shafts out and install the belt without splitting it as the stitching is starting to tear out of the belt... oh well! I am watching your videos on the SB now! Thanks!
Thanks brotha I've had it apart so many times it's driving me crazy. The original owner really had some messed up stuff going on. Cobbled spindle shaft, flats for set screws made with an angle grinder, completely off axis, wrong spindle pulley,bunch of wrong hardware,broken transverse gear,now this vibration, I've got it narrowed to the headstock pulley or bull gear,hopefully not the shaft.Xp I'm going to be making some video for a forum I'll get it up soon. Maybe you can take a look. Thanks
Nice job
Good vid. I have found that silver solder wears down pretty fast. The brass brazing would probably last longer. I have found the best way whenever possible is to silver solder in a new piece of the base metal, in this case some cast iron. Faster to solder and you can easily get it back to full size for machining. Keep up the good work. A noob with a SB 10 K
Man this is a great video. I recently bought an old Atlas craftsman lathe. It's got a horrible vibration in the rotating assembly somewhere. I'm hoping its not the headstock shaft.
I'm going crazy trying to find it. Great work on the gear by the way.
Hi friend. Can you share the specs of drive belt that you are using in your lathe? I see K050500, but i don't see the length. Thank you in advanced. Congratulations for excellent video. Regards from Brazil.
I work in the motor trade we used ours for repairing radiators
Acetyline is frowned upon in the uk
wow that looks great. How strong is that silver flux though compared to the actual cast iron? I have the same type of gear (2 of them) on my Nc machine. good idea incase i lose a tooth.
That is only the second torch of that type i have seen in 30 years
We would drill and tap for steel screws where the teeth are missing then braze in the area.
would it have been possible to make a toolbit in the profile like a tooth n cut it in the lathe like you did a keywey slot? maybe even with an index head or somthing...
Awesome job! I have exactly the same thing to do on my south bend 9 headstock . Will Sp15 silver solder work as well ?
Nice tutorial! thanks!
Is your flat belt split and tied or is it one piece? If one piece how did you get it on the drives? I have a 9" SB, and I cut the belt and stitched it with nylon cable lacing cord (pretty strong), but it is a pain!
can I use the same method on fixing the headstock bearing bore?
my headstok have missing some corners and there is a cut inside the bore I think somebody tried to push the spindle from the back and that caused the spindle lip cutting from the bore!
my plan is to do the same what you are doing to fill the missing parts, then sand the extra brazing, then insert a honing cylinder sanding stone with 4 handles to re-sand and polish the area!
is that will work?
here is my headstock:( so bad I think so)
thank you fro your inputs again
Probably not the best idea. In all honesty these lathes can still run fine with really scored bearings. If you want to fix it your best bet is to line bore the headstock and fabricate some new bearings from bronze and press them into the headstock. It's a labor intensive and expensive process and it needs to be done extremely accurately.
Nice work! One thing that I've found works great for prepping cracked cast iron is to use a carbide burr in a die grinder. No grit to contend with and it leaves a nice smooth finish.
i guess I'm kind of off topic but do anyone know of a good site to stream newly released series online ?
@Willie Hayes Flixportal :P
@Khalil Diego Thank you, I went there and it seems like a nice service :) Appreciate it !
@Willie Hayes Happy to help :)
What are the drill chuck things called in the background ? There are 2 of them in that silver thing next to lathe
Tailstock drill chucks. Standard drill chuck mounted on a Morse taper arbor.
I have to do just about the same thing for the second time I don't Logan back gear but the large gear I don't know why I keep knocking teeth off that damn thing unless it's just so damn old I don't know?. So what I'm going to do is I have two assemblies both missing teeth I'm going to cut out to teeth in one block and then cut the meeting side with a slitting saw off of the damaged gear and then shape the two teeth to fit in the female half hopefully I'll be able to do this and get the gears teeth to line up perfectly and I've been getting pretty damn good with brass brazing so I'll just plain old Breeze it in. They say brazing cast iron makes it as strong if not stronger than the original piece well we'll see. I have no doubt that I'll be able to do it I just got to get a nice pocket cut to accept the teeth with a little extra room for brass.
hmmm if you had a TIG welder you could weld the new teeth in pretty easy very controllable and very clean problem is you need the helmet and shielding and the practice working on something that small you need a steady hand and a good eyes and also the pre-heating could you use a barbeque :P they work well getting it warmed up for the pre heating and also post heating but good job with that I i don't think i be as confident repairing with oxy it just flows too much to be controled for me
Why not machine the gear off and replace the gear?
I don't believe they've had manufacturing in South Bend for a few decades. The brand is apparently still alive and being made somewhere. I think Wikipedia said Grizzly dealers are selling their machines. There is a website for SBL you can find it through Google or other search engines. Their website has history and old pictures of the factories. I believe that the company was started by the same brothers that had O'Briens Paints.
joyzee
Nope Boston :-)