| Jumping out of back gear
(Feb 16, 2001) |
Back gear question (Jun
22, 2004) |
| Back Gear Question (Mar
19, 2001) |
Back gears (Sep 3, 2004) |
| Back Gear for Heavy 10
(Aug 23, 2001) |
BackGear Howl (Heavy 10)
(Sep 20, 2004) |
| SB 10k Backgear Problem
(Nov 12, 2002) |
Noise from area backgear pin
(Oct 19, 2004) |
| Back gear pinion tooth repair
(Dec 30, 2002) |
Heavy 10 popping out of back
gear (Oct 20, 2004) |
| 9B Back Gear Problems
(Jan 22, 2003) |
Smoked back gear on 9"
(Dec 4, 2004) |
| 9" Backgear help (Apr 22,
2003) |
Back Gears on 10K (Jan
24, 2005) |
| Lathe won't run in back gear
(Jan 2, 2004) |
|
| |
| Jumping out of back gear |
| I have
a 50's vintage model A with quick change gear box. When I try to
engage the back gear with the machine in the forward direction, it
will disengage on its own by rotating the shaft back over the
eccentric and then disengage completely. its as if the eccentric
won't go over far enough to lock over but the gears are fully
meshed. Is there any way to adjust this? some one once told me that
there was a fix it kit for this, but no luck with south bend. dennis (220) |
| I've posted a couple
pictures in the files section. The pictures are from a SB lathe
book. They show the proper procedure for adjusting the back gears.
Bob
(226) |
| Dennis, You
didn't mention what size lathe you have. If you have a 9" or 10K
(light ten) lathe, then the following instructions might help. If
you look at the headstock casting, you may have already noticed the
two projections that support the backgear and its eccentric shaft.
If you look (or feel) underneath these projections, you will notice
a bolt (on the forward projection next to the threaded end of the
spindle) and a setscrew with a locknut (on the rearward projection)
Under the bolt is a spring and a brass "shoe" that provides tension
for the eccentric shaft. If you tighten this bolt, you will increase
the friction on the eccentric and prevent the backgear from "kicking
out." South Bend states: "Tighten until tension will hold gears in
mesh on heavy cuts but not so tight that eccentric shaft is hard to
operate." The rear setscrew and locknut control the backgear
engagement or depth of meshing of the gears. By loosening the
locknut and adjusting the setscrew, the proper mesh can be obtained.
Too tight a mesh will "howl" and too loose will "rattle." The way I
adjust them is to: 1) Release belt tension on the cone pulley, 2)
Loosen locknut and back out setscrew about one turn. 3) Engage
backgear fully, 4) Screw in the setscrew to take up any clearance,
5) Place your hand on the bullgear and try "rocking" the backgear,
6) If the gears are meshed tight, screw in the setscrew a little
more, 7) If there is a barely perceptible "rock" to the backgear,
then the backgear is adjusted correctly. Tighten the locknut, 8) If
the gears are too loose or "rock" too much, loosen the setscrew. The
proper amount of clearance between gear teeth is .002". This amount
is small but is perceivable using the "rock" test. Make sure the
locknut is tight and double check the clearance before running your
lathe. Also, NEVER engage or disengage the backgears while the lathe
is running. That is the way gear teeth get stripped off. Webb
(227) |
| Back Gear Question |
| About the Back Gear, Is it only designed to be
engaged while in the forward direction? It kicked out when I ran in
reverse. Or does it just need to be adjusted. Mike
(349) |
| The manual
describes adjusting it so it won't pop out. I'm not sure if the file
area has a copy of the manual but if you don't have it, someone in
the group can send it to you. Paul R. (350) |
| The pages from the
manual are in the files section. dennis
(352) |
| Back Gear for
Heavy 10 |
| I have a
tooth missing on my heavy 10. It's the large 80 tooth back gear
that's mounted on an arm with a long slot in it. I think it would be
called the Idler gear. Does anyone have one that they would be
willing to sell? Chris
(1350) |
| Chris, Don't know
if its the same, but I've got an extra 80T gear off a 9" SB. Have
you a part number for your gear? Paul R.(1353) |
| Paul, I have
absolutely no idea what the part number of this gear is or whether
or not a SB 9" will fit on the heavy 10. I scraped off quite a bit
of greasy crud off the gear in an attempt to find a part number but
to no avail. Presently I do not own a manual for the Bend but will
try to get one this week. I will get back to you and the as soon as
I have some definitive data. Chris (1354) |
| Marty, As you can
see below some of the text in your reply and my posting seems to
have undergone some jumbling. Please confirm the name and part
number as being "Quill Gear Part Number PT18". Is this correct?
Chris (1356) |
| Chris, Here is a
scan of the end gears for a South Bend Lathe "Heavy Ten" (New Model
- aka: Double Tumbler Gear Box). Check out the gear number 84 on the
diagram. Webb (1358) |
| Chris, Just for
completeness, here is a scan of the end gears for a South Bend Lathe
"Heavy Ten" (Old Model - aka: Single Tumbler Gear Box). Check out
the gear number 83 on the diagram. Webb (1359) |
| Marty, This may
seem like a dumb question but why is it called a "Quill" gear? When
I hear quill I think of the tail stock quill. Also, I keep seeing
the term "SB 10L" but I don't see that designation on my lathe. What
does 10L designate? My model number says CL8187AB and Serial number
13362RKX16. I was told this was a heavy because SB also made the 10"
with a smaller 1-1/2" spindle nose. Do I have this all straight?
Chris
(1360) |
| Chris, Have you
checked out the South Bend Lathe web site? They have a page that
will explain the catalogue number on your ID. plate. Check out:
http://www.southbendlathe.com/catno.htm As to the SB 10L - the "L"
stands for "Large Spindle." there were two spindle sizes for the
Heavy Ten. Most are the large spindle type (1-3/8" through hole) but
some were made with the smaller spindle (1" through hole). These are
the SB 10R lathes. Webb (1361) |
| If
you're talking about a "large gear mounted on an arm with a long
slot in it" it's NOT a "Quill Gear"! I think everybody is going off
on Chris's initial confused post. My understanding is that he's
talking about an idler gear in the gear train from the spindle to
the gearbox (like Webb indicated in his posting of the diagram). The
Quill Gear (at least on the 9") is a single-piece shaft with a small
gear on one end and a large gear on the other end. The small gear
meshes with the bull gear and the large gear meshes with the cone
gear. Paul R. (1363) |
| Chris,
There seems to be some confusion between Marty and myself as to
which gear you are inquiring about. I noticed in your first posting
the this was the 80 tooth gear "that's mounted on an arm with a long
slot in it. " I took that to be the idler gear on the end of the
lathe. Marty, on the other hand, assumes that you are referring to
the "Quill Gear" (No: 95 on the accompanying scan). If Marty is
correct, then he gave you the correct part number for that part
(PT18R1). But if I am correct in my assumption, then the part
numbers for the "Idler Gear" are (AS33R3 for the "Two Tumbler"
model; PT652R2 for the "Single Tumbler" model). Please let us know
which gear you are referring to. Webb
(1364) |
| Have
you a part number for your gear? Or try measuring OD, width, bore,
and keyway size. Anthony (1368) |
| If this actually is the large gear on
the back gear quill, the number is PT18R1. Anthony
(1369) |
| Chris, I haven't
tried this yet myself, but a friend of mine is a welder, he says to
drill and tap where the tooth is broken, install a couple machine
screws, build up the tooth with weld, and then shape it with a die
grinder. It is possible that brazing may hold instead of welding it
and the brass would be easier to work with. Larry (1370) |
| Chris, I can't
claim this as an original idea, but I had a missing tooth on my 9"
SB back gear, and used JB Weld to basically mold a new tooth in
place. I drilled a couple of small holes into the gear where the
missing tooth was, inserted a couple of sections of cutoff nails,
mixed up a little JB Weld (from auto store) and cemented the nails
in place as support posts. Make the posts a little shorter than the
height of a tooth. I let this set up for a day. I then mixed a
little more JBW and liberally covered the posts and let this set up
for a short while until it began to harden slightly, but was still
workable. I then inserted a small piece of plastic baggie between
the gears, and rolled the fabricated gear into the adjoining gear to
mold the new tooth in place. I let this set up for a day and have
been using it since with no problems. Once the tooth hardens, you
can trim the tooth to make the job look neat. With a little grease,
you can't even tell it's a "false" tooth! Don't think a dentist
could do any better. Needless to say, I'm a real JB Weld fan now!
Have found numerous uses for it around the shop. Great stuff!
Jim ps: make sure the area around the tooth is cleaned with lacquer
thinner prior to cementing the posts in place.
(1372) |
| Webb, Thank you
very much for the scan of the gear train. It will be very useful to
me until I get my own manual. Chris
(1383) |
| The gear
I'm referring to is the large 80 tooth (in my case 79 ha) gear
marked item # 84 on the Newer model diagram. As I recall it is
always meshed with the gear connected to the input shaft to the
threading gears. The forward and reverse tumbler gears also mesh
with it when the lever is moved up and down off of the center detent
position of neutral. That said, I think it might be best for me to
wait until I get back home from this trip so the machine is in front
of me. I would hate to drive everyone up the wall with erroneous
information. You guys have been great though and I'm more excited
than I've been in years. This SB is fulfilling a wish I've had since
I was a kid. Can't wait to clean her up and make chips! Chris (1384) |
| SB 10k Backgear
Problem |
| I
recently purchased a SB 10k that was restored. When I run it in
backgear the spindle cone (item 46 in the SB CE3457 Parts Manual) is
getting very hot (expanding) and trying to seizing to the bull gear
(item 50). When I shut the lathe down the spindle cone is very hot
and when you take the lathe out of backgear you can not rotate the
spindle cone independently of the bull gear with the pin still out,
until it cools. It's like there is a clearance issue between the two
parts. This is also causing the rpm to change as the spindle cone
heats up. Does anyone have any idea what the problem could be and
recommend a solution. I have never pulled a spindle out of a
headstock, but do have some mechanical ability. John (7170) |
| Is there lube
inside the cone? (7171) |
| First thing to do
is to get some oil into the cone. There is a recessed screw in the
middle pulley. Unscrew it and you'll see that it has a
needle-valve-like tip. Stick the nozzle of the oiler as deep into
the cone as you can and pump oil into it. There is sort of a spiral
groove on the inner surface of the cone that I suppose is to
distribute the oil. It may be crudded up - if that's the case you'll
have to pull the spindle and clean the grooves, but try first just
loading the baby up with oil, run it until it feels warm, then add
more oil. While you're at it you might just check to make certain
that everything else on your lathe has been lubed. I was terrified
the first time I pulled my 10k spindle. But it is not that big a
deal and if the above doesn't work, get back to us and I or someone
else will be glad to walk you thru it. Frank (7172) |
| I think
most folks are using grease in the back gear spindle. I removed the
lubrication access screw and replaced it with a grease zerk and
pumped it full. Some lathes have "oil" stamped into the back gear
and some have "grease". This must reflect a change in philosophy at
SB over the years. There has been a lot of discussion on list about
what kind of grease to use. I think the consensus is a Teflon based
product. Search the archives for "lubrication" and see what you
find. Glen (7173) |
| I've always wondered how the heck one is supposed to get the grease
out of that squeeze tube SBL recommends into there. (7177) |
| Does a
grease zerk have clearance? I've been wondering how to get grease
into this thing. It is stamped "grease" but I've been told to use
oil. Same with my cone pulley. It, too, is stamped "grease" but I
use oil. I worry about getting lube to the ball thrust bearing.
Should I worry? Frank (7178) |
| There is no direct
path from the cone for lube to get to the thrust bearing on mine;
the thrust bearing is behind the cone. I give it a splash of oil
when I top up everything else. Anyone here had better or worse
results using grease? Having open headstock I'm leery of using
grease in the open bearing because it can trap chips. (7180) |
| Yes, that was the
fist thing I checked. I'm almost sure the tolerances between the
cone and gear are to tight for some reason. Is there suppose to be a
bushing between the two parts? I don't see one in the parts manual?
John (7197) |
| Frank, I
received a lube chart with my lathe and the fist thing I did before
using it was order the recommended SB oils and lube the lathe. The
cone currently only has the recommended Teflon grease in it. I'm
sure this has been discussed at length before, but what oil do you
recommend I use in the cone. I have and use all three SB oils on
other parts of the lathe. The jeweler that restored the lathe is
very meticulous, so I'm positive the groves were cleaned prior to
reasonably, but the Teflon grease has probably filled them. Does the
tailstock need to be aligned after removing and replacing the
spindle? John (7198) |
| If the cone is too
tight against the gear it will begin to heat up there first. Try
running it until it begins to warm and see if the cone is uniformly
warm (suggesting lube problem) or if it is heating up more on one
side. Frank (7201) |
| I pulled the
spindle out of my 10k to find some light grind marks in the area
where the cone pulley runs. It s not perfectly round at this
location and I was wondering if this is normal. The cone pulley
seems to spin freely when rotated by hand, but I think this could be
contributing to the problem of the cone pulley sticking to the bull
gear when the bull gear pin is pulled. Does anyone know how the
spindle surface is manufactured where the cone pulley is located
(i.e. ground and polished, hardened, etc.)? If I need to have this
area of the spindle ground, what is the recommended maximum
tolerance I can have between the spindle and cone pulley? The
journals look great. P.S. Or is it cheaper to just by a used
spindle? John (7288) |
| Frank, the information you provided me with was
invaluable, especially the trick about using the paper clips. I
removed the old grease that was caked into the cone pulley and tried
using some oil, but the oil is getting thrown onto the edge of the
cone pulley and I m afraid it could saturate the belt. I've ordered
some of SB Teflon Grease and should have it by next week. (7291) |
| On a related note,
anyone know why my clean, lightly oiled bullgear pin is stiff enough
to require pliers to move it? it wasn't like that when I bought the
lathe, and the pin and hole are very clean, just a light film of
oil, and no burrs I can find. Will I hurt anything polishing .001 or
so off the OD of the pin? (7294) |
| John: I've just
this evening had a spooky, somewhat similar experience to yours. I
was knurling a long piece between centers and noticed that the bull
gear was rubbing against the cone when I applied a left lateral load
(as in using the live tailstock center!) Would you check out your
lathe and see if this is happening to you also? Essentially the cone
pulley is acting like a thrust bearing and it is weird. I wonder if
I didn't get the bull gear far enough to the right side when I
reassembled the thing. Where do you get the SB grease? And how do
you manage to get it into the pulley? Frank (7295) |
| Isn't there a
spring-like gizmo on the inside of the bull gear that prevents the
pin from coming out? That might be the culprit Frank (7296) |
| With it [the little
spring wire clip] removed the darn thing is still tight. I can't figure how the hole in
the bull gear would get smaller but it acts like it has, a few
tenths. marks in the pin is the cone pulley? (7300) |
| John and others,
The back gear Teflon Grease can be bought from Fastenal Company as
Permatex P/N: 62642 Super Lube Synthetic Based Lube with Teflon, 3
oz Net Wt Tube $5.34 each. See the following URL for local outlets:
http://www.fastenal.com/default.asp Jim (7301) |
| Just a thought. On
my 9" SBL, there are two holes 180 degrees apart in the cone pulley.
Could it be that you always engaged the looser of the two before and
now are attempting to use the tighter hole? Also are there any burrs
on the pin? Paul R. (7302) |
| Jim, I already
placed my order with LeBlond, so I'll have to wait until I need
another tube. John (7320) |
| Frank,
I was knurling a long piece between centers and
when I applied a left lateral load (as in using the live tailstock I
was turning a slender piece between centers. I m not convinced that
it is interference between the cone pulley and the bull gear though,
because there does not appear to be any wear at this location and
the cone pulley gets uniformly hot. This might be contributing to
the issue of the cone pulley binding with the spindle though. to you
also? Essentially the cone pulley is acting like a thrust gear far
enough to the right side when I reassembled the thing. The bull gear
is a taper fit on the spindle and appears to be all the way on. I
pulled the keyway out and reinstalled it to make sure there was no
interference. get it into the pulley? I ordered the CE1625 Teflon
Grease from LeBlond (888) 532-5663 for $18.00. I m going to
disassemble the spindle and apply a thin coat to the spindle and the
inside of the cone pulley. I m also going to apply some inside of
the groves of the cone pulley. My thought on this issue is more is
not necessarily better, because it could start to hydraulic if too
much is used. Periodically I m going to add a pinch to the cone
pulley and let the centrifugal force distribute it along the
spindle. I don t recommend pumping it full of grease because the
additional grease and pressure could defeat the purpose. Just my
$0.02. I m open to other suggestions though. John (7321) |
| My distributor
today told me it was discontinued. He showed me some specs tables
and there are many greases with the same specs. Frank (7322) |
| Back gear
pinion tooth repair |
| I have a
1960'S Hercus (SB clone) in pieces. I'm in Australia. The smaller
gear (pinion) on the back gear assembly has a partially broken
tooth. There has been discussion recently (here?, rec.crafts.metalworking?) on repair methods. It seems that my
options are 1. Do nothing, and suffer noise and wear. 2. Build up by
welding and re-hog the tooth. (I don't have a mill, and the lathe is
not operational) so that would have to be commercial. 3. File or
grind a flat where the tooth was, silver-solder a small section in
place, and file to shape. 4. As for 3, but use pins instead of
silver solder (to avoid having to heat the back gear assembly to
silver-solder temperatures). There doesn't seem to much of a market
in Hercus spares these days. I suppose I could try Ebay assuming the
SB part is identical, but US prices, plus shipping costs and delays,
make that rather unattractive. Anyone got an opinion? :-) Any
Australian members know of a local source? Rob
(8371) |
| 1 or 3 would be the
best bet. Probably 3, solder vs. weld. brazing might by the best way
to go. wrt shaping the tooth, don't discount filing. filing can be a
very powerful and accurate way of removing metal. I think another
way that you could do this in the lathe as long as the carriage was
operational and use it like a shaper. I have never seen anything
written up on it anywhere. maybe there is geometer article floating
out there somewhere....? I have done this to cut a couple of keyways
and to clean up splines on a shaft a few times. Just done by trail
and error. basically fix the gear on an arbor and chuck the arbor in
your lathe and use the tailstock to keep the arbor centered. Get the
bit in the right place using a good tooth as a guide. Rotate the
spindle to index the gear to the right place. I think you said it
was an idler gear, then maybe use the backgear to index with. Shave
off a bit at a time by traversing the carriage and bit across the
gear. dennis (8373) |
| Our group member
from the Netherlands has recently made a tooth repair by drilling a
couple of holes into the gear and tapping with an appropriate size
tap. After inserting a couple of screws, he filed the replacement to
approximate the shape and used some "kneadable epoxy" to fill out
the tooth. Glen (8374) |
| I made a
couple of pictures of the repair I have put it in the photo album off
this very nice group this is the name off the map -First time repair
off a Gear- Good luck I have no experience how long it will hold.
Maybe steel pins are better or welding. Who knows may tell it.
Bert (8382) |
| 9B Back Gear
Problems |
| First the Taper Pins wouldn't come out.
Ended up drilling one out and the other is still stuck, but know its
got a broken punch stuck about half way through it. The set-screw
bolt that holds the spindle in position also was rusted. Had to
drill it out. Hopefully I'll be able to re-tap it. Since there is
one taper pin out, I think I should be able to still get the spindle
out. I can get it to move about 3/8", but then it just stops. I'm
assuming the spindle presses on the handle, correct. I'm afraid to
use my press in this type of scenario since I'm not really sure how
it goes together. Anybody have some suggestions. What about getting
the taper pin out. There's a punch stuck through one side which is
what I was using to push the broken drill bit out the other side. Or
should I just chop it of with a bandsaw and try to find a
replacement?
(8839) |
| You don't say if
the taper pin that did come out is at the headstock end or the
tailstock end of the back-gear shaft. According to my parts book,
one taper pin holds the tailstock-end eccentric, the other holds the
handle-which-is-also-the-headstock-end-eccentric. There's supposed
to be a 'stop screw' [a setscrew with a locknut] under the
headstock-end of the headstock casting which limits eccentric
travel, and on some lathes there's a regular setscrew with a spring
and shoe under the tailstock-end which sets eccentric holding
tension, although my ca. 1936 9-inch lacks this latter
setscrew-spring-and-shoe. Also the grease screw in the middle of the
backgear--there's gotta be some sort of a narrow spot in the shaft
to give a place to get some grease in there. Could something be
hanging on the end of the grease screw? (8841) |
| Having just run
into this same problem recently, I think I know what has happened.
The setscrew bolt on the headstock side has a reduced dia. that
rides in the slot in the eccentric shaft. Someone at some point had
evidently gave the shaft a shot to move it, and the reduced diameter
had broken off and was still in the slot, even though the setscrew
had been removed. On yours, if you drilled out the setscrew, you
probably got the threaded portion, but the reduced diameter portion
is still there, holding the shaft from moving. Enlarge the dia of
the hole where you drilled out the setscrew, get the piece out (it
may fall out one the hole is enlarged, then just make a similar
larger size screw when you go back together. Okey (8843) |
| I know what you're
saying, but do you think would he get a full 3/8 of movement before
it hangs if that were the case? (8847) |
| Yep, the shaft will
slide 1/4 to 3/8 with the broken piece in there. Okey (8854) |
| Forget about it for a few weeks and
then go back to it and it will probably fall apart. I'm not
kidding. I have been thru the same thing hundreds of
times. Patience. Mike (8857) |
| Welcome to the
oddball techniques machine repair world. There are often unusual
methods needed to recover otherwise unusable and unrecoverable parts
on these critters, and many here have used them. In the past, have
used a carbide burr or carbide drill in a Dremel or similar rotary
hand tool to remove the broken punch, setscrew, drill bit, and then
continue with drilling the hole thru using a drill press or such. I
have seen folks take a carbide masonry bit and grind a proper metal
cutting edge on it by hand with a diamond hone, then use it to
gently drill out a stuck or broken-off hardened steel item such as a
setscrew. A carbide drill or end mill can be used similarly either
in a drill press or a hand grinder with careful method and very
carefully controlled pressure. EDM and other electric cutting
methods can work also on some of these situations but are usually a
lot messier and more expensive. This is a wonderful opportunity to
exercise your imagination and ingenuity. My first inclination is
usually to find the most economical way to get the offending item
removed using careful work in increments so you can see how you are
doing. This takes volumes of patience and often means you will
sharpen that bit a few times before the job is done, but it usually
gets there. It also recovers items that otherwise would go into the
scrap bin, with mucho $ handed out for replacement parts. if you
need the machine working right now - the better method would be to
get another part and save the one you have for later rework when you
have the time to go at it carefully.
(8882) |
| 9" Backgear
help |
| Isn't there a
friction screw/spring/shoe assembly installed on the underside of
the right headstock boss? (10379) |
| According to an
assembly drawing I downloaded there is just such an arrangement. I
have just installed a new Head stock on my 405Y. I fabricated this
assembly with a 5/16 fine thread screw, a spring from Sears
Hardware, (and this is the week point) and a shoe turned from a 3/8
rod. It holds the back gears in OK but I think I could use more
spring pressure. I have no idea what the spring really looks like. I
also fabricated the backgear stop from a piece of 5/16 fine thread
all- thread by turning it to 1/4 inch for about 3/8 of an inch.
(10380) |
| Lathe won't run
in back gear |
| southbendlathe@yahoogroups.com
writes: It will engage the spindle but then the motor won't turn
it. I must be doing something wrong Did you disengage the bull gear
from the spindle? (16183) |
| That sounds
interesting. I just don't know what the "bull" gear is. I did mention
I was very new to this lathe or for that matter any metal lathe. I
sure wish that book would show up soon. Could you explain what you
mean a little better please? What I am doing is putting the small
lever that runs the drive screw in the neutral position (middle)
putting the backgear into the spindle and applying the clutch. The
motor slows a bit and the belt slips. I then stop the operation and
scratch my head.:-). I know this is a simple thing but I'm not about
to mess around too much and hurt something. Tom (16189) |
| Tom, go back from
your chuck, spindle bearing. Right behind the spindle bearing is
the face of your bull gear, roll spindle around and you will see a
pin on the face of the bull gear this is what locks the bull gear to
the pulley stack. Some pins a spring loaded pull out and quarter
turn. Will unlock bullgear from pulley stack and your back gear will
work. Mine has a block with a bolt in it. Loosen bolt slide block
down tighten bolt and back gear works. Duane (16190) |
| On the spindle,
near the collets side of the head stock, just behind the front
journal is a large gear. This is the "Bull Gear" It is keyed to the
spindle. The Belt pulleys are not keyed. They would be free to turn
except there is a pin. It goes through the Bull gear and into the
Pulley. On the back end of the pulley is a smaller gear. If the pin
is in place when you engage the "back Bears" then to whole system
will be locked. Nothing will turn and the belts will either slip or
the motor will stall. If the pin is pulled out, (There should be a
detent, it may be tight and you may need a pair of needle-nosers )
then the small gear on the pulley will engage the large back gear.
This gives a reduction. The pulleys and the small gear are now free
to turn on the spindle. (Be sure that you oil the pulleys, there
should be a small screw covering a hole with the word oil.) The
small gear turns the large back gear, the large back gear turns the
spindle and you have a double reduction. I have described the
operation on a SB-9. The 10K is identical. The Heavy 10 may differ
slightly but should be similar. Jim B.
(16191) |
| Correction The
small gear turns the large back gear, the large back gear turns the
BULL GEAR and you have a double reduction. Jim B. (16192) |
| The heavy 10 is the
same. There is a cast recess for your fingers on the side of the
bull gear. There is a wire spring inside and a notch on the side of
the pin. Just pull the pin out about 3/8" and you will feel the
spring restrict any more movement. This keeps the pin from going
back into the pulley. The pin is about 1/2" in diameter with some
knurling on its small head. JP(16193) |
| JP, Jim and Duane, I have it running now. I bet you don't have to
explain that one too often. So I just have to pull out the pin and
just leave it? I tried to turn it but it doesn't seem to make any
difference. I hope it doesn't try to pop back in while it's
turning. It does seem to stay put though. It is a rather awkward thing
to get at isn't it?. I know not to change gears with the lathe
turning but is it ok to go from forward motion to reverse with the
little lever on the far left while turning? What is that lever called
properly? I'm sure glade you guys are around to give me a hand. I
suppose the book will tell me the spindle speeds? That oil hole you
spoke of, is it the one on the pulley itself? I did see it. I see a lot
of oil holes in fact. There are a few on the compound and cross slide
as well. Do they need oiling very often? Mine seem to be painted in
place in some cases, I may be mistaken on this. The previous owner is
a well known machinist and he really looked after this lathe. When
you change the belt to another speed (slide to a different step)
should the motor be off and do I need to open the door in the base
and move the pulley down there as well? One more thing, should the
compound slide be easy to turn? Mine turns but it isn't all that
free, you really have to crank on it. I sure hope I'm not being a pest
here but like I've said I really want to do well by this machine.
Tom (16195) |
| Tom, it is not a
good idea to change gears or directions with the spindle turning.
RichD (16196) |
| Tom, That's the
reversing lever, for the lead screw. Spindle stopped when changing
gears or reversing with the lever. Motor off when changing belt on
pulley sheaves, if you value your fingers. Oil all of the oil holes
every day that you use the lathe and top up all oil cups. Under the
back cover there are holes in the gear hubs near the center, these
are oil holes as well but not marked. Spindle oil in the spindle and
apron cups and way oil everywhere else. Oil is cheap, worn parts are
not. Oil everything except the leather belt. Put a couple of drops
of way oil on the backgear faces as well. On the cross slide and
compound there is a large head Allen bolt to the left side of the
handwheel. This is the gib adjusting screw. There is a locking
screw along the side of the cross slide and compound in line with
the gib screw. Loosen the locking screw and then you can adjust the
gib for tightness. The slide should travel freely but have no slop
with everything well oiled. After you adjust the gib screw tighten
the locking screw. You may find that the cross slide will be tighter
at the ends rather than the middle, this is due to wear in the area
most commonly used but is generally no problem unless it is
excessive. JP (16197) |
| I think the "lever
on the left" you are referring to is the "forward/out of
gear/reverse" lever. You should not reverse the lathe with the lever
while it is running. Bring the lathe to a complete stop before
engaging this liver. You could mess up the spindle gear. You may
need to turn the spindle by hand to fully engage this lever. Again I
am speaking from the stand point of a 9" or 10K lathe but the "Heavy
10" should be similar. there is an in between position where the
feed gears are not engaged. The oil hole on the 9" and 10K is on the
middle pulley. You need to lubricate the pulleys when running in
back gear. If you don't run in back gear this is not a concern. Do
not change belts with the motor running. I guess this is an under
drive and if so yes you need to open the door to change the belt
position on the spindle. If the compound is tight first be sure that
it is well oiled. You can adjust the gibs with the series of set
screws on the side. They will need to be tight enough to remove any
play but loose enough to allow relatively free movement. If the
lathe has not been run is some time it would not hurt to loosen the
compound and remove and clean and oil it and reinstall it. Duane (16198) |
| When you release
the belt tension and move the belt on the upper sheave it usually
moves on the lower one as well but it is a good idea to check it.
You will feel a difference in the belt tension arm if it is not
aligned. Release the belt tension when you are done using the lathe.
Don't engage the belt tension with the motor running either, some
people do this but it can shorten the life of the $60 belt. On the
compound, if adjusting the gib screw doesn't fix the problem it may
mean that the leadscrew nut had been misaligned when the compound
was taken apart and put back together. Holler if that's the case, its
an easy fix. JP(16199) |
| Mistake, the gib
adjuster screws are on your right when facing them. JP (16200) |
| Back gear
question |
| When I engage the backgear, it runs fine but
slowly starts to disengage itself. I have to hold the engagement
lever down to keep things in gear. Is there technique or adjustment
to keep the backgear firmly engaged, or am I missing something here?
Dave
(19761) |
| Dave, I'd suggest
not running it in BG until we figure out how to adjust the
engagement properly. Suggest you check al the gears and clean each
tooth of ant crud. If I recall the BG engagement lever rotates on an
eccentric shaft. I'll look in my SB book tonight and see if there is
an adjustment procedure. The heavy 10 is a nice, versatile lathe,
Given good care it will last several life times. Eric (19763) |
| Look in the "files"
section under Techinfo and you will see a file for back gear
adjustment. It shows a picture gives you the SBL directions on how
to do the work. Chris
(19764) |
| First thing I
would for sure find how to run a lathe put out by South Bend years
ago. They are very easy to find , Ebay is just an example. Your back
gear lever sounds as if it is pretty loose? there are two adjustment
cap screws on the back gear shaft. The left side just keeps the
lever from rotating too far. the right end closest to the chuck goes
into a eccentric, and will snug things up for you. just tighten it
enough to take out some of the slop and see if that is not better.
Also there is a lot of info on this site in the faq section also a
section for fellas and gals with there first lathe. Dee (19765) |
| Chris: The techinfo on backgear adjustment you directed me to
seems right to the point. Dave (19766) |
| The
adjustment procedure is in the parts manual. There are 2 set screws
with nuts on them under the eccentrics at the back of the lathe. The
one nearest the chuck pushes a spring against a brass plug that
tightens the shaft, it should be adjusted for a firm (not hard)
movement of the lever. If the gears begin to disengage when running
in backgear then tighten it a little. The other setscrew should be
loosened until the gears just bottom and then tightened about 30 to
45 degrees. The gears will just be off the bottom. Lock the nuts,
grease the shaft and make some chips or threads. JP (19770) |
| There are two
screws. One sq. head underneath on the chuck end and one on the back
side that is slotted with a lock nut. Snug them up a bit. (19773) |
| Back gears |
| I just bought a 10"
South bend that has a missing tooth on the larger of the back gears
(Quill Gear?). I think the part number is PT18R1. Any
recommendations would be appreciated. I've run the back gears and
everything seems fine but I'm afraid to put a load on them by
turning anything. (20758) |
| Howard, I had the
same thing on mine. I sent the gear to Miller Fabrication in the
links and they did a fine job of repairing it. The cost was very
reasonable. I also see back gear sets on Ebay all the time.
Paul (20759) |
| BackGear Howl
(Heavy 10) |
| When running my
lathe in backgear, I get a lot of howling (especially at high speed)
I have made the necessary adjustments to the backgear as suggested
by the SB Parts manual. The brass gear (small one) on the spindle
does show some wear. I used some way oil on the gears which didn't
help, and then some Teflon grease on them. (The same grease that you
use inside the backgear shaft) I have never heard another SB running
before, and I don't know what is acceptable for noise.
(20993) |
| The SB 10" Heavy
does make a characteristic hum in back gear but it is a pleasant
running noise. "Howling" in my experience would be indicative of a
bearing that is lacking oil (lube). Does your lather have a small
access screw on the BG shaft? Mine does and you squirt oil in it.
Eric (20994) |
| Yes I keep the
backgear shaft lubed with the "superlube" as described in the FAQ.
The entire lathe has undergone a restoration, and the backgear shaft
assy has been rebuilt, and the gears have been cleaned/inspected.
Everything looked normal with the exception of the wear on the brass
gear on the spindle. Maybe I should take a close-up picture of it and
post it so you can give me an opinion. "Howling" may not be the best
way to describe the noise. It pretty much sounds like gears meshing
together, just really loud.
(20995) |
| I don't know if it
is the same set-up as on a 9" lathe, but on my 9's there is an
adjustment for the gear mesh. I seem to remember that it was a screw
that bumped against the eccentric that pulls the back gears in. Glen
(20996) |
| Noise from
area backgear pin |
| I have
a South Bend Lathe that I think is a Junior from about 1927. I am
almost ready to be able to use it, just got it wired up last
Saturday. I was test running it and noticed a noise that seemed to
come from the pin that must be pulled before engaging backgears. I
wonder if anyone is familiar with any kind of noises from that area,
and if this is normal or bad? I can put up with it if it is normal,
but I don't want to do any damage if it is not. Jim (21397) |
| Could be a worn pin
and hole. With the pin engaged how much play is there between the
bull gear and pulley? In other words hold one and try and rotate the
other. There should be almost no play. Ed P (21402) |
| I don't think the
noise you described is normal but it maybe due to wear on the
pulley/spindle assembly. I suggest that you investigate the cause of
the noise. If you find something then you can choose whether to fix
it or not. If you don't find anything then you will probably have to
live with the noise. Just watch in case it gets more noticeable.
Either way you will get some piece of mind. I'd check the fit of the
pulleys on the spindle, the thrust bearing and whether it is
noticeable when you turn it by hand. If the pulley bore is worn then
it will wobble on the spindle as it rotates. It's also possible the
pulley is moving laterally on the spindle and bumps up against the
bull gear. Either of these movements will cause wear on the
engagement pin and the hole it fits in. This will only get worse
with time. When I changed the belt on my 1963 9A (last month), I
started getting a clunking sound that appeared to be coming from the
same area of the headstock. This only occurred when running the belt
on the two larger headstock pulleys. When rotated by hand there was
a barely perceptible tight spot that occurred once per revolution. I
took the headstock apart, carefully cleaned everything and checked
for any looseness. I never found what caused the noise but after I
put it back together it was gone. Because everything seemed to fit
quite well, I suspect I had a piece some grit in the thrust bearing.
John (21403) |
| Heavy 10
popping out of back gear |
| In
running some test cuts I noticed that with a heavy cut 0.100 in
steel in the slowest back gear speed with very slow feed, the back
gear lever starts moving backwards until it disengages. The chips
were coming off nicely with no sign of excess heat or strain on the
motor, and the lever started moving backwards very slowly. I first
cleaned all the hardened grease out of the gears and re-greased. It
still pops out under a heavy load. 2 questions. Will back gear
levers generally pop out under too heavy a cut? There is an
adjustment screw on the housing behind the back gear lever, I tried
a couple adjustments but it doesn't seem to tighten anything. I
don't know the exact adjustment procedure for this situation.
(21409) |
| What exactly is
your feed rate? How sharp is your bit? that may be too much for your
lathe. These machines are not THAT rigid. No, but they can. This is
a common problem with many lathes, they need proper adjustment. Look
in the the files section and maybe the FAQ for info on how to do it. dennis
(21411) |
| A few things I
would do differently. I would not have grease on the gears, oil yes,
grease no, it holds swarf. Second a 0.10" cut on steel may be a bit
high. Back to your original question. The screw under the backgear
eccentric nearest the chuck is a spring-loaded and applies a friction
to this eccentric and helps hold the gears in engagement. To begin
the adjustment, this screw should be loosened so the backgear moves
easily. The screw under the other eccentric away from the chuck is a
stop. Loosen it (out) and engage the backgear so the gears bottom
into each other, then adjust this screw so the gears just come off
the bottom. Lock the stop nut. Now go back to the spring loaded
screw and tighten it so the lever shows a some resistance. This one
holds the gears in engagement under normal cutting conditions. You
can also hold a finger on the backgear lever while cutting and if
you feel any random pulsing on it you might want to check your
spindle bearings. JP (21415) |
| South Bend will
give the clearance on the gear mesh. They are not supposed to
bottom. It puts added stress on the gears and wears the bore or
shaft. They are also less noisy if you allow the clearance. Paul
(21420) |
| JP and Paul,
The adjustment went well. Lever spindle snugged up nicely, then the
lock screw backed the gears off bottom. I used the earball clearance
method. Too much bottom causes a characteristic whining noise. I set
the screw in just enough to quiet the back gears down and allow them
to be hand turned.
(21424) |
| I checked the files
for a back gear spindle adjustment. None to be found. Anyone know
how to make that adjustment? There's a flat set screw with a locking
hex nut. When turning it inward the back gear lever appears to
deflect further backwards and doesn't seem to tighten up. Bear in
mind, I know not what I'm doing. (21426) |
| The instruction ARE
there-
http://groups.yahoo.com/group/southbendlathe/files/Techinfo/Backgear%20Adjustment/ (21429) |
| That's the stop, on
the back. The spring loaded one is on the other eccentric on the
bottom. JP (21439) |
| Smoked back
gear on 9" |
| I
recently purchased a 9" Model C lathe. The
only problem that I can see is that the previous owner brazed some
teeth on the small gear of the back gear. Anyway, where can I get a
new back gear or do a much better repair? or, is there a way that I
can create a mechanism where If it ever happens again, I can just
get a replacement from a place like McMaster-Carr? Also, what is the
correct gear pitch and pressure angle. I am thinking 16 diametral
pitch and 14.5 degree pressure angle? (22568) |
| I'm not sure, but I
THINK 16 and 14.5 is right. Those assemblies turn up all the time on
eBay. You could also bore a replacement gear and press it onto the
turned-down hub of the old one maybe. (22572) |
| You can count the
number of teeth and add 2. Then divide this number by the outside
diameter of the gear in inches to get the pitch. Pressure angle is
14.5 deg. You should be able to get a steel gear relatively easy to
make this up if that is the route you take. JP (22573) |
| Back Gears on
10K |
| I recently joined
the group after purchasing a SB 10K lathe, and I read over the
entire FAQ. I know it tells you where to find the file on Back Gear
Adjustment, and in that folder it only has instructions on adjusting
a 13 or 16 inch lathe, not a 9 or 10 inch. My Back gears pop out
immediately upon startup, and they seem to be meshed to tight against
their mating gears too. I can hold them in place while the lathe
runs, and it works just fine, but there is a lot of force pushing
them backwards. The only things I saw to adjust this was two
set-type screws underneath the eccentrics, and they didn't help. I
can't figure this one out. Shawn (24239) |
| Shawn, You are
on the right track. My 10K jumped out also. I tightened up the 2
setscrews then the locknuts and that cured the problem. Mine also
stayed in if I held the handle. Try the setscrews again it should
work. Bob (24240) |
Shawn, I have the
South Bend procedure for adjusting the back gears in a 10k. The set
screw at the front sets the drag and the one at the rear is the stop
which controls the depth of mesh. The front set screw should be
tighten just enough to keep the gears in mesh, no more. The back
gear lever should not be hard to operate. The rear set screw should
be adjusted with back gear running and set to provide minimum noise.
A howling noise indicates too little clearance, a rattling noise too
much. Ed P
(24249) |
