| Metric conversion (Aug 4,
2002) |
9"
Metric gear question (Nov 20, 2003) |
| Metric Module Change Gears
(Nov 20, 2002) |
Metric Question (Dec 27, 2003) |
|
9w/10k 127/100 gears (Jan 24, 2003) |
Metric Conversion Gears (Aug 30, 2004) |
|
Metric-gearing spreadsheet (Feb 2, 2003) |
Metric transposing gears
(Jan 13, 2005) |
| Source for Inexpensive 127/100
Metric Transposing (Mar 6, 2003) |
Metric Model B/C Gear Chart
(Jan 30, 2005) |
| Metric gear help! (Oct
21, 2003) |
|
| |
| Metric conversion |
| I have been looking into a way to cut metric gears on my SB Heavy 10
without buying the expensive SB package. I have a paper solution in
which I am now confident, but I was going to wait until I had
actually implemented it to provide a report. However, I have gotten
enough requests (some be direct email) that I think it makes sense
to report on the paper design, and separately report later on
actually implementing it. Let me apologize in advance for the long
post, including the 25 KB attachment. I hope I don't clog too many
mailboxes. Perhaps at some point it will make sense to put this
stuff on a web site, but I don't have one. Attached is an Excel
spreadsheet I used in the analysis. A lot should be self-explanatory,
but the top part is just the English threads on the Heavy 10
standard QC gearbox. If you are not working on a Heavy 10 you will
need to do one of these for your lathe (if you want to follow my
approach). Note rows are related by factors of 2 on most QCs,
simplifying making the table (using the Excel "copy" function, and
non-fixed addresses (no $)). The 2nd group is the same QC gearbox
positions, but with a 127/100 gear set added (or any others you want
to play with, like 47/37- just change the 100 and the 127 in the
title line above that group) and with the result expressed in metric
pitch (=25.4/TPI). If you are doing this for another lathe, each
entry in the 2nd table is just the corresponding entry in the 1st
table times the ratio of the two new gears and divided into 25.4 to
get metric pitch (again, the copy function makes this easy). The 3rd
group is the same as the 2nd, but changes the stud gear (which is
the 1st gear in the chain) to values other than 40 teeth (by
multiplying by 40/( new # of teeth), and the gear on the input shaft
of the QC gearbox relative to 56 (now multiplying by (new # of
teeth)/56). The inversion comes from the fact that the 56 tooth
input gear is a driven gear, rather than a driving gear. If you are
doing this for a different lathe you may need different values than
40 and 56 for the standard gear values. The 3rd group works like the
2nd, in that you can put in stud gear tooth counts and input gear
tooth counts in the heading line, and the table gives you the metric
pitch corresponding to each QC box setting. Again, each entry in the
3rd table is just the corresponding entry in the 2nd table times the
appropriate ratios. The bottom part is a list of standard ISO metric
thread pitches, which I extracted from a metric bolt supplier
catalog (Metric and Multistandard), plus a few pitches I could cut
"for free" with the same gears. For each pitch the table shows the
combination of stud and input gears (in the column titles) and the
TPI setting on the QC gearbox in the table which cut that metric
thread pitch. I confirmed each of these entries by using the tool
above with the stud and input gear choices shown in the column
titles. Some (many?) pitches can be cut with more than one
combination of stud and input gears (as well as different TPI
settings on the QC box). By the way, the gear and TPI combinations
from SB (more later) give the same results in my spreadsheet,
confirming the method. You can find stud gear and input gear
combinations which give you the metric pitches you want by trial and
error and the above spreadsheet. However, I used some simple
formulas to make sure I didn't miss any useful combinations. Pitch
(in mm) = 25.4/TPI (always true) With the addition of metric
conversion gears we get: Pitch = 25.4/((127/100)*TPI) = 20/TPI (true
for any lathe using 127/100 metric change gears) From this it is
clear why a setting of 4 TPI produces 5 mm, 8 produces 2.5 mm, etc.
Also, 5 TPI produces 4 mm pitch, 10 produces 2 mm, 20 produces 1 mm,
etc. These 2 series of pitches appear to be the only metric pitches
achievable with the standard stud and input gears. If we change the
stud and input gears (and include the 127/100 gears) we get the
equation: Pitch = 20/(TPI*(input/56)*(40/stud)) = (28*stud)/(TPI/input) where
"input" and "stud" are the tooth counts of the respective gears
used. Note this only applies to the SB heavy 10, with a 40 tooth
standard stud gear and a 56 tooth input gear. For a different lathe
with different standard stud and input gears you may get a number
other than 28 (but the form will be similar). Rearranging we get:
stud/(TPI*input)
= pitch/28From this you can take each pitch you want to get and find
values of stud teeth, input teeth and TPI setting on the QC box
which satisfies the above equation. For instance, for 0.8 mm (or
0.4, .02, 0.1, etc) we get (using 4/5 as 0.8):stud/(TPI*input) =
(4/5)/28 = 1/(5*7)It is convenient to leave the right side as a set
of prime factors, to find gear choices. You need a gear with all of
these factors somewhere. The stud gear needs to satisfy all the
factors in the numerator (except powers of 2), and the combination
of input and TPI need to cover the factors in the denominator. In
this case, any stud gear which is a power of 2 (like 32) combined
with an input gear containing a factor of 7 (like 28 or 56) and a
TPI setting containing a factor of 5 (like the "5" column) will
work. The other rows below TPI = 5 give you the submultiples of the
pitch of 0.8 (like 0.4, 0.2, etc). Note that an input gear
containing a factor of 5 (like 40) and the TPI column containing 7
also works. I used this "factor" approach to find candidates for all
the interesting pitches, and then checked them with the spreadsheet
described above. Where more than one set of stud and input gears
were suitable I picked gear combinations which minimized the number
of gears I would need to buy. You can ignore powers of 2 in choosing
gears, since the rows of the QC gearbox differ by factors of 2. You
can also multiply a common factor (like 3 or 5) times both the stud
and input gears, which sometimes helps. So I managed to cut all the
interesting metric thread pitches with 2 gears (beyond the basic 127
and 100), while SB calls for 6. Am I three times as smart as SB? No.
SB picked a different set of targets. I decided that I didn't need
anything bigger than 5 mm (which covers all standard pitches up to a
diameter of about 30 some mm). SB chose to include 5.5 mm and 6 mm.
5.5 mm needs 44 teeth (by my analysis as well as apparently, SB's),
and 6 mm needs 48 teeth. SB also chose to include 1.3 mm, which
requires a 26 tooth gear, and 1.4 mm, which requires a 28 tooth
gear. There were also several other pitches I didn't include (0.9,
1.1, and 1.2 mm) which use the same gears in the above list. The
list of ISO standard metric pitches I found does not include 0.9
1.1, 1.2, 1.3 or 1.4 mm (perhaps these were more common in the
1950's when SB defined this solution). Once SB had a broad
repertoire of gears, they chose to change only the stud gear to get
the various metric pitches, and they always retain the 56 tooth input
gear. I allow any combination of input and stud gears from the set
of 32, 36, 40 and 56 (where 40 and 56 come with the lathe). So doing
metric pitches my way requires a few extra minutes of setup for some
pitches (you always have to remove the input gear anyway to go from
English to metric, since it gets reversed with it's spacer to mesh
with the 100 tooth gear which is axially offset). So that is the
story. Two extra gears (plus 127/100) get you all the standard ISO
standard pitches from 0.1 mm to 5 mm. My plan is to just do this for
now, and if by chance I need one of the esoteric metric pitches,
scrounge the additional gear later. I suppose of some of the others
fall into my lap at an attactive price I will buy them, but I think
the chances that I will need any but the listed pitches is small. So
the only practical issue (for the Heavy 10 owners, with 16 DP
gears), is how to join the 127 and 100 tooth gears available from
Boston Gear into a single combined gear which can rotate freely on
the standard SB arbor (which carries the 72 tooth idler in the
standard configuration). I'll report on that after I have done it.
Frank Attachment: [not stored]
(5574) |
| Frank, I,
like many others, are waiting for you to do the same for the 10K and
9" Model A. Jim
(5575) |
| Jim
I'm not as familiar with the 9 and 10K Type A lathe arrangements.
From the very sketchy picture of the QC panel in the 9" and 10K
parts list, it looks like the top row needs a 40 tooth spur gear and
works with row A, and all the others rely on a 20 tooth gear. The
parts list shows that the standard QC input gear is 56 tooth, just
like the heavy 10 (at least for mid 1950's 9" and 10K lathes). I
believe that while the chart says to use a 20 tooth stud gear and
row A to cut 8, 9, 10... TPI, that leaving the stud gear at 40 tooth
and using the B row instead will also produce 8, 9, 10 TPI (even
though the B row says 16, 18, 20, etc), and a 40 tooth stud gear
with row C will cut 16, 18, 20 TPI, even though the chart says to
use 20 tooth and row B. If so I think what I described for the heavy
10 works equally well for the 9 and 10K, except you will run out of
room for very fine pitches. So use the stud and input gears in my
table's columns (i.e. ignore the 20 tooth stud gear), and for values
of TPI my chart which call for 8 TPI or greater, set the gearbox to
twice that TPI. So where I say 8, you set to 16 (i.e. use the B
row), and so forth. That says that for some of the fine pitches
which call for high TPI values, using this method you won't have
them on your QC box. I think the highest TPI on your lathes is 224
TPI. By leaving the 40 tooth stud gear and doubling the entry in my
table, the highest entry in my table you can do is 112. If so you
can cut everything on the chart down to 0.2 mm, but not those below.
Actually, you can get to 0.125 by using the 20 tooth stud gear and
the TPI setting of 160 (without any doubling). For the rest you will
need other gears. But 0.2 mm is a pretty fine metric pitch, so being
able to cut everything from there up with a simple arrangement may
be a reasonable compromise. This is just a 1st order assessment, and
someone with a 9 or 10K should double check my thinking (or perhaps
even try my hypothesis that the 40 tooth stud gear and the B row
cuts 8, 9, 10 etc rather than 16, 18, 20 etc). The real issue of the
9" and 10K folks is that those lathes use 18 DP gears as I
understand it, and Boston Gear only sells 16 and 20 DP. So you
either need to find another source for 127 and 100 tooth (or 47 and
37 tooth) 18 DP gears, or you need to do some kind of a mix and
match solution where the 127 and 100 tooth gears and the stud and
input gears they mesh with are 16 DP while everything else is 18 DP.
I don't know if that is feasible or not. Somebody with a 9" or 10K
will need to take over from here. I also noted after I sent my
report that I attached a slightly out of date spreadsheet. The 0.08
mm entry on the bottom which says that 224 TPI will cut it is wrong
(it needs another gear). There are also one or two other metric
threads which my arrangement will cut (like 1.4 mm) which I didn't
bother to put in the table because they weren't ISO threads, but
they are in SB's table. I think everything else is OK. I note I left
the heading for the 3rd group at 32 for the stud and 50 for the
input, which don't cut any interesting metric threads (I don't
remember what I was doing with those). But if you set the stud and
input choices (in the header before the 3rd table) to values from
the column headers in the bottom chart, you should get groups of
metric pitches in the 3rd table corresponding to the TPI entries in
that chart. Frank
(5577) |
| Frank, Back in 58 when I received my 1st
SBL Catalog #5800 the Metric Transposing Gears for the 9" and 10K
Model A SB Lathes sold for $14.75 (Catalog #CL1957NK). The 10" Quick
Change Metric Transposing Gears were $67.25 (Catalog #CL1957R).
Things change! Jim (5586) |
| Jim I have a
1958 catalog as well, although I hadn't bothered to look up the
transposing gears. What is intriguing is that the 10L gears were
more than 4 times the 9 and 10K gears, which I am at a loss to
explain. 18 DP doesn't make them that much less expensive, and I
expect the 9/10K requires about the same number of loose gears, or
even a few more. To get calibrated to today's prices, a 10L toolroom
bench lathe was about $1800 then, and was $16K a few years ago from
SB, so those metric conversion prices would now be in the range of
$120 for the 9-10K (pretty reasonable) and perhaps $500 or so for
the 10L (not so reasonable). Frank
(5597) |
| Frank, I'm
watching what you are doing with your heavy 10" as I also have a 13"
SB with the Taper Attachment and all the bells and whistles. I
believe the heavy 10" and the 13" can use the same gearing for
cutting metric threads. Keep me informed.
(5604) |
| Metric Module
Change Gears |
| L.G.M.van Lelieveld writes:
I make
up mind here the 24 teeth on the spindle are not in a good shape
anymore I stop with the DP inch gear wheel from Southbend I must fix
the teeth on the spindle Anyway So I machine this off and make a
Module 2 Gear on it. And take the right number of teeth an take all
Module 2. i have already bought for 20 dollar here 4 gears 40 72 80
and 36. about 20 mm thickness I can buy more off these also with
other number of teeth thanks for all the help You might want to
reconsider using 2.0 mm module gears, which are the equivalent of
12.7 DP. South Bend change gears for the 9" lathes are 18 DP. Metric
equivalents are: 20 DP = 1.27 mm module 18 DP = 1.4111 mm module 16
DP = 1.5875 mm module A likely metric equivalent would be 1.25 mm or
1.5 mm module. The problem with the bigger gears is there is less
flexibility with varying the train of gears between the stud and the
lead gear, you can quickly run out of space. With smaller gears you
can substitute an idler with more teeth to take up the space or even
use two idlers. I would favor 1.25 mm module. They should be more
than ample in strength. Anthony
(7431) |
| Anthony I will look for module 1.5 1.27 or something like
that isn't available today I build everything together Only the
gearbox isn't ready I must place a few cylinders in the spindles
holes Tomorrow I take a few pictures. How can I post them here in this
News Group Are there Max size or DPI ? for the Pictures ??(7433) |
| The alternative I
suggested was 1.25 but, as you say, it might not be available. It
would be interesting to know what gear tooth counts you can get in
1.25 and 1.5 mm module, along with some sample prices. Also, I
believe there is or has been a chart in the files or photos for gear
setups for metric threads using an SB with inch lead screw and QC
box. Do you have any idea at present what metric pitches you're
interested in? Regarding the photos, it *appears* that the
Yahoo! sites limit the photos to a maximum resolution of 480 pixels
in the large direction, if necessary by performing the reduction in
resolution automatically. I think that if you go to the photo
section of the group site you will be led through the process, but I
haven't done it myself so I'm not certain. Would it be possible for
you to send me the photos directly? I'd like to see them at a higher
resolution. Anthony
(7447) |
| After some communication with Mr. van
Lelieveld outside the group it suddenly occurred to me that the
damaged 24 tooth gear he's trying to replace is on the tail of the
spindle. I had presumed he was speaking of the stud gear. It seems
apparent that if he's going to get this right he needs an original
spec. spindle gear, a reversing assembly with all three gears (he
says his is missing). He may also need a change gear quadrant
(banjo) and at least one idler stud assembly but in a pinch he could
make these. The stud gear, the idler gear, and the input gear on the
gearbox can all be adapted from metric gears, but the spindle gear
and the reverse assembly including gears pretty much needs to be
original spec due to the fixed relationship between the spindle
center and the center of the reverse assembly. Any ideas on where he
might acquire these original spec. items? From his e-mail address I
take it he's located in the Netherlands. Anthony
(7449) |
| Anthony (and Bert)
There have been several reverse lever assemblies, with the pair of
small gears, for a 9" SB on Ebay recently. They sold for about $27,
about $33 and $65 (all $ US). So that sort of sets the price range
(at least on Ebay), as well as indicating a reasonable source of
supply. There was also a change gear quadrant which sold for $27.
Dismantling lathes and selling as parts seems to be the trend on
Ebay recently, so I would expect that more suitable parts will show
up if Bert isn't in a big hurry. I haven't seen the spindle gear,
but I would expect there are some damaged spindles somewhere with
decent gears. If someone on the list has some of this in their junk
pile and doesn't want the hassle of selling on Ebay, we might be
able to find something for Bert for significantly less. Frank
(7451) |
| Mine's worn
bad as well, not so much the tumbler for some reason, but the
teeth on the gear at the end of the spindle are worn about 1/2
thickness. My answer had just been pour the oil to it and get a bit
better before I jump into tearing the spindle apart. (7452) |
| Regarding Bert's
9A missing all the gear train from the spindle to the QC box input,
I don't have an SB 9" but I'm trying to help him sort it out. Can
somebody with a 9A measure the following: Spindle Gear - tooth
count, DP or OD, face width, bore and keyway. Reverse Tumbler
Assembly - for each of the 3 gears- tooth count, DP or OD, face
width, bore and keyway. Also, center distances between: center gear
and forward selector gear; forward selector gear and reverse
selector gear; reverse selector gear and center gear. I believe
change gears are 18 DP. Please verify, also face width, bore and
keyway, tooth counts (20, 40, 56, and 80?). Drawings or sketches,
with measurements, of the change gear bracket (banjo) and the
components of the idler stud assembly. It would also be interesting
to have the same information for equivalent models by Boxford,
Hercus, I know there was a Swedish clone but I don't remember the
name, and any other SB 9A clones. Lets see if we can get Bert the
information he needs and possibly even locate the required parts.
Boxford or any other European source, if direct replacements, would
be more likely to be available to him. Anthony
(7456) |
| Anthony,
The "spindle gear" is actually one piece with the spindle. There is
not a removable/replaceable part. He needs a new spindle or else
grind off the remainder of the teeth, machine (grind?) a keyway and
put a new gear on it. Both of my SB 9's have very worn teeth on the
spindles. I think it's sort of a fact of life with these well used
machines. If someone has a good way of renewing the teeth on a
spindle it would be a good project to try. Maybe the brazing rehobbing thing would work. If someone else doesn't respond before
the weekend, I'll try to get as much of the info you asked for on
Saturday. My wife was an exchange student in the Netherlands and we
both have many friends there. She lived in Arnhem, the target of
"Operation Market Garden" and the subject of the movie "A Bridge Too
Far. She also speaks (and reads and writes) Dutch. I could ask her
to translate if we need it. Tot ziens! Glen (7458) |
| With my bad English
I misunderstood some but now
I am on the
right track again I had seen a picture 0ff the gears nr,s with qc
box a it did not show the reverse tumbler at the top so the gear I
saw was not the gear on the spindle but off the reverse tumbler I
send A email to the Tony@l... with a question off he will send a
gear from the long screw spindle for power feed to the QC gearbox(
that is also missing) but I did (not Yet) received a answer Maybe he
did not understand my question (all reading and writing in English
language improves my knowledge, Its 34 years ago I learned English
writing and never used it afterwards) I really appreciate your help
keep on doing that HI Bert the QC box out. Can or OD, gear and gear;
bore and (banjo) equivalent don't even locate (7460) |
| 9w/10k 127/100
gears |
| I was
wondering about these 127/100 gears. What do they fit, and how would
I tell them apart from other gears, (they obviously have 127 and 100
teeth) I have a box of gears ,some are south bend heavy ten and 10k.
Dave
(8898) |
| The 100/127
gears are necessary for metric threading capabilities on any
inch-leadscrew S.B. 9 or 10K lathe, i.e.: 99% of them I'm looking
for one myself. Bilal (8899) |
| You also need
a few other gears, 48, 44, 36, 32, 28, 26 tooth gears, a spacer and
the metric gear chart, such as shown in the attached image. Rick K.
(8900) |
| Dave. If you want to sell what you have or trade for
something you need, you can email me at peep38k@m... or phone me at
319-378- 9889. Thanks Randy
(8901) |
| Lurch.
I have my gears at a local shop for a quote right now. Mine will be
steel which in my mind are better than cast. The teeth won't break
off as easy. I have the set for the 9-10K and the heavy 10. Shortly
I will have these available with the reproduction charts that I am
having quoted also from another supplier. Randy
(8902) |
| The
127/100 replaces the idler gear in the train from the stud to the
screw gear. Standard setup is stud gear drives idler gear which
drives the screw gear. Metric setup is stud gear drives 127, 100
drives screw gear. This accomplishes a compound gear reduction. In
the inch setup, if you put the same tooth count on the stud and the
screw gear you will cut .125" pitch (8 TPI). In the metric setup, if
you put the same tooth count on the stud and the screw gear you will
cut 2.5 mm. Starting from that point, if you crate a 20% step up
gear train, say 48 stud gear and 40 screw gear, the metric setup
would cut 3 mm. 20% step down, for instance 32 stud and 40 screw
would give 2 mm. Using this case of one compound stage it would be
pretty simple to create a chart of all available gear combinations
and what pitch they would cut. Anthony
(8903) |
| By 127/100
are you referring to what are called the "metric transposing gears"
(or something like that) that allows you to cut metric pitches on an
inch lathe ? It is my understanding, however, that even with these
gears that threading is difficult with an inch leadscrew and that
the half nuts must be kept engaged at all times. Is this correct ?
Metric threads come up once in a while and I always assumed that a
"true" metric lathe would be the best way to go as metric SB's are a
bit rare around here On gears: my 9" Model C is threading gear
challenged ! Any leads on getting some or all? Doc (8904) |
| I was looking
thru the parts sheets for my 10K the other day and noticed that SB
had a metric lead screw option, but didn't seem to have a metric
half nut option. Huh? Frank
(8905) |
| Yep, that's
exactly what they're called. I kept the halfnuts engaged and just
backed the compound out and ran the spindle in reverse to back the
tool up for quite a while before I got my threading dial built...and
for short threads it's still easier and quicker to do it that way
than it is to wait for the threading dial to come around. For the
regular change gears I'd ask around the list and see if one of the
people who has recently converted to a quick-change box will sell
his...or try any of the used-machine-tool dealers like Plaza or
Meridian that are known to the list members. I'm going in about an
hour over to PKE to pick up my new horizontal mill and I'll see what
he has. For the transposing gear, I put one up on eBay--item
#3109930368. Totally off-topic, Bob, have you been getting my emails
OK about the end cover? Lurch (8906) |
| This confirms
my belief that there is a great cottage industry waiting for someone
to start it up. The installed base of SB lathes is enormous. Certain
parts are either impossible to find and/or very expensive. A small
production run of metric gears, for example, would bring the price
down and there would be a market, and a profit for the guy who does
the work. another example- The steady rest I use on my 10k works and
fits just fine, but it isn't SB - someone used an original SB rest
as a pattern and had some castings made. Obviously it is slightly
smaller than the real one, but it works well. The base was machined
to fit the bed perfectly. But, it wasn't cheap! However, if you want
a SB steady rest from Ebay, you'll wait a year and pay even more.
There are probably a dozen or so such items that give us fits when
we try to find them, but are relatively easy to make in small runs.
Frank
(8907) |
| As soon as I
get my shop cleared of all the pieces of that atlas mill that got
cheesed in shipment and get my Sheldon mill set up right I'll be in
a position to make some parts like that. I bought the mill and a
dividing head specifically to allow me to cut gears. But Rome wasn't
built in a day... saw on thereabouts...which well, I make them, part
in over shaper
(8908) |
| A few
thoughts on metric transposing- SB calls for a whole bunch of small
gears in addition to the 100/127, but 36, 32 and 28 (in addition to
the 40 which is already there) will cut all current standard metric
pitches from 5 mm to as small as you want to go. SB provided an
ability to go to 6 mm (requiring the 48 T), and a bunch of oddball
pitches like 1.3 mm (requiring 26) and 1.1 mm (requiring 44 T). Once
they had the whole collection they used them for other pitches as
well. But with the gears above ( and other QC gearbox settings) you
can cut all current standard metric pitches. Someone also mentioned
the heavy 10. Finding gears is not as big an issue for the heavy 10.
It uses 16 DP gearing from the stud gear to the screw gear, so you
can buy Boston Gear 100 and 127 tooth gears (about $95 for the
pair). You need to join them together and install some kind of a
bushing for them to run on as an idler pair, but that is why you
have a lathe. You can buy new small gears (36, 32, 28) from Boston
Gear for ~$30 each (you need to adapt the centers to 5/8"). However,
these 16 DP loose gears are more commonly available from used lathe
suppliers (and generally more reasonably priced), since they aren't
as much in demand. If you are going to cut new transposing gears,
37/47 tooth gears are a possible alternative to 100/127, and likely
more easily cut with the index plates available with most dividing
heads (to say nothing of their smaller size). The associated error
is miniscule (an error of 0.00021, or about .001" for every 5" of
threaded length). Leaving the half-nuts closed is not as big a pain
as it sounds, as long as your lathe can reverse (which they all
could when new). It certainly wouldn't justify finding a metric
leadscrew and metric QC box (IMHO) unless you cut nothing but metric
threads, and even then only if you do a lot of threading. Frank
(8911) |
| 500
dollars for a pair of gears is more than a little excessive! I think
you will find that Boxford gears are compatible with 9" 10"
SouthBends ( I "obtained" a 100/127 to use with my 9" lathes if
needed and I certainly would not have kept it if it did not mesh
OK). UK used tool dealer price for these Boxford gears is usually
around œ40 to 60 and they are pretty common, you can virtually
always buy one off the shelf. Can still be got new from Boxford,
don't know the price but its got to be much less than 500 dollars.
I've still got mine tucked away (as the purchaser of my last 9" had
a very fixed view of a suitable price and haggled a bit too hard) so
if anyone is interested. Clive (8915) |
| Anthony, When I get my scanner set
up that I bought yesterday, I can send you the charts that you are
talking about. The work is already been done on this end. There are
several combinations to obtain different threads, with different
gears other than what is on the factory chart, with the model A
gearbox. I had a guy email them to me several weeks ago, I haven't
had a chance to look over them. He spent, what looks like allot of
time to arrive at this. Randy
(8917) |
| Could you
copy me on those charts, please? Lurch (8920) |
| My name is Randy. I wondered if someone would
reply to a post of mine if I offered something for free. That seems
to be the only way to get anyone's attention. Is there anyone else
while I'm at it? Gee, maybe I should throw in a few sets of gears
when they are finished, along with a few new plates. Randy (8921) |
| In my search for info on SB metric gearboxes I was
provided with the following information: "The SB part number for the
metric half nut assembly (pair) is AS2894NK1 for the gap bed lathe."
Apparently SB has made gap bed lathes at some time in the past about
which I know nothing. What I do know is that the metric leadscrew
was 6 mm pitch, not 3 mm as would be expected. Anthony
(8922) |
| Randy, as I said, it would be easy
to do. It's even easier to accept the efforts that somebody else has
put out. One of these days I'll get back to you with my wants list
for the 10L. I'm waiting for a couple of items to show up from other
sources. Anthony
(8923) |
| Metric-gearing
spreadsheet |
| I finally got the
QC-lathe metric-thread-cutting gearing spreadsheet finished. It's
almost 1Mb. I'll post it to the hobbymachineshopfiles group. (9046) |
| Source for
Inexpensive 127/100 Metric Transposing |
| I contacted Clive
Foster (in England) about a post in which he mentioned he had a used
127/100 metric transposing gear that might fit a Southbend 9. The
gears were from a Boxford lathe which is a Southbend clone (I am
told). Clive went to a great deal of trouble to get the gears to me.
I cannot thank him enough because they dropped right into my lathe
and ran without any trouble!! NOTE CLIVE does not have any more
gears, but he may answer questions in this newsgroup. I thought the
bore was a little large until I realized that the gears mount on one
of those studs that go on the gear banjo. I have a two tumbler gear
box so the sequence was stud gear the 56 tooth gear on the gear box.
My gear box shaft has a small washer, a 20 tooth gear for a spacer
and then the 56t gear. Do NOT try to use the 40 tooth gear for
spacing it is too large and it will catch the 127 tooth gear and
ruin your day! I was cautioned about mounting these large gears but
my old banjo studs offered no problems even though they are a
somewhat loose fit. For the above setup, the formula is: metric
pitch in mm Read the gear box chart for 20 tooth studs but actually
mount the proper stud gear from the above formula. Example: for a
0.65 mm pitch metric, you can use a 52 tooth stud gear and set the
gearbox to 80 tpi. I have a full set of change gears which gave me
the 32, 36, 40, 44, and 48 tooth stud gears called out in the SBL
Metric Transposing Chart. I do not have the 26 or 28 tooth stud
gears SBL shows. I was able to compute the following substitutions:
Using a 56 tooth stud gear: M_pitch Set_Tumblers_tpi 0.35 160 0.7 80
1.4 40 1.75 32 Using a 52 tooth stud gear: M_pitch Set_Tumblers_tpi
3.5 16 0.65 80 1.3 40 Where to get the transposing gears in England
(remember they are Boxford Lathe parts). The gears are inexpensive
over there according to Clive. (I paid under a $100 for mine). Clive
mentioned G M Tools http://www.gandmtools.co.uk are currently
selling used ones for œ 65. This is a lowish price for them so they
probably have reasonable stocks. Also Tony Griffiths site
http://www.lathes.co.uk
claims to offer new Boxford gears at great savings on factory
prices, whatever they are (Clive's guess is comparable to SouthBend
factory prices for similar items). Bill (9639) |
| Metric gear
help! |
| I have a 10 heavy
SB with a single tumbler gear box. What do I need to do to make it
cut metric threads. I have a manual but it is not for my year. Most
lathes have a 100 and a 127 tooth gear but I have also heard of 37
and 57 tooth work with success. Kevin (14546) |
| Kevin, One
way is to swap the leadscrew and half nuts with a metric version.
You can come real close to the 100:127 with 22:28. The 22 and 28
tooth gears are common. The 37:57 mentioned I believe should be
37:47 and are not commonly available. JP (14550) |
| Swapping the
leadscrew would work but I would prefer an option that does not take
an hour or two to do every time I need to cut metric. I think you
are right the 37 and 47 sounds right. I have not heard of 22 and 28?
any idea what gears I would replace with these gears? (14565) |
| Although the 100/127 gear conversion converts imperial pitch to
metric pitch its not a lot of help with gearbox equipped lathes
because the gearbox is still calibrated in terms of turns per unit
length rather than thread pitch which are reciprocally related so
there are very few direct whole number equivalents. With change
wheel lathes this does not matter because once you have the imperial
metric conversion in place you merely select gears on a pitch basis
instead of TPI and who cares if a sensible number in one system
gives an outlandish one in the other. To get direct imperial to
metric transposition on a lathe like the SouthBend equipped with a
simple Norton gearbox requires several gear sets, each handling a
specific range of pitches. Alternatively the gearbox can incorporate
a selectable transposing gear set in the gearbox layshaft assembly (eg
Harrison). I believe the SouthBend set has been previously published
on this group along with a nearly as good alternative using all
stock gears. A reasonable range of approximate metric pitches, close
enough for normally loaded fixings of the nut and bolt variety, can
be obtained directly from the imperial gearbox. I have a spreadsheet
in Excel and PDF formats listing all the approximations up to 10%
error. E-mail me off list if you want it. Clive
(14574) |
| You would
have to make a change gear (dual gear) and kluge it in in place of
the idler between the gearbox and spindle to get an approximate
1:1.27 ratio. Your gearbox may not divide properly for all metric
threads, only a few. I didn't think of that at 3am when I answered
before, I was thinking of change gears and not a qcgb. JP (14576) |
| If you use a
100 and a 127 tooth gear, joined together, they nicely replace the
80 tooth idler, at least on the 2 lever heavy 10. If you use 37:47
(the gears for which, by the way are readily available in the
required 16 DP from Boston Gear and others) you will need to rig up
a different, smaller idler gear to reach from the stud gear (at the
top) to the screw gear (on the gearbox input), or at least I would
have had to on a 2 lever. This in turn will give you two idlers (the
37:47 pair and the smaller idler to reach the rest of the way) and
therefore you need two idler shafts. I decided for this reason that
the extra expense of the 100/127 pair (about $95 for the pair from
Boston Gear, versus about $45 for the smaller gears) made sense. In
terms of the other gears needed, adding a 28 tooth, a 32 tooth and a
36 tooth choice to the existing 40 tooth stud gear gets you all of
the standard Metric pitches smaller than 5 mm. If you really need to
cut 4 mm pitch you will also need a 48 tooth gear. If you need 1.1
mm or 0.55 mm pitch you will need a 44 tooth gear. If 1.3 mm or .65
mm is critical you will need a 26 tooth gear. However all of the
latter are to my knowledge not part of the ISO standard metric
pitches, although the SB metric conversion set would cut them. These
other gears like 28, 32 and 36 show up on Ebay and in lathe parts
dealer's bins from time to time, since they are the more common (or
at least less expensive) 16 DP. If you get stuck, Boston Gear sells
them for ~$19 each (although you will need to bush the centers from
3/4" to 5/8"). When I did my conversion I bought a 100 and a 127
from Boston gear, as well as 32 and 36, and bushed the latter to
5/8". Of course after I made my conversion set the various gears
needed started to dangle themselves under my nose. I have ended up
with an extra 100 tooth (new old stock from another lathe supplier,
but 16 DP and 1/2" wide) and used but decent 32 and 36 tooth gears,
as well as an extra somewhat beat but useable 28 tooth (all 16 DP,
1/2" wide, with the correct center bore). These plus a 127 tooth
gear (joined by you to the 100 tooth) would let you make a very
useable conversion set for the standard metric pitches, assuming a
single lever set is similar to the 2 lever set. If you are
interested I'll sell the set of 4 for $50 (vs ~$100 from Boston
Gear). If this is not your cup of tea, the offer is open to anybody
else interested in metric conversion for a heavy 10. Frank
(14578) |
| That's is the
main problem The single row tumbler has a gear that slides in and
out on the side under the guard to aquire many thread pitches. If I
replace it I will cut my quick change thread cutting ability in half.
It appears there is may be one gear or maybe all three including the
sliding gear that needs to be swapped out. once I find out the proper
combination that will work with single row tumblers I can move on. I
am not in search of every combination under the sun but it would be
nice to have the basic standards. Dave from Meridan machine said
south bend made a special setup for the single row tumblers. He
could not recall how it worked. He also has not seen one for years.
(14580) |
| 9" Metric gear
question |
| Can
someone who has an original set of metric conversion gears can tell
me the what the full set of gears (as purchased from South Bend),
consists of. I have the 100/127 combo gear, but want to know what
other gears are required. (15098) |
| The gears
that come with the metric transposing kit are (assuming you have a
model A): 48, 44,36, 32, 28, 26. You also need the 40T gear. With
the 127-100 conversion gear, all metric pitches are exact. This info
is found in the SB 10K part manual. On the photos on the group, you
can find the conversion chart. If you go on the files, I posted at
the beginning of the week a excel spread sheet with results of
calculations with the various gear set- up. The gear on the gear box
input is a 56T gear. Guy (15101) |
| Metric Question |
| Oh good grief!!! on
another list recently the experts said it was 25.4mm was the EXACT
inch equivalent. Which is it? Is there a gumint web site to see this
in the flesh? RichD (15990) |
| Uh! there is a
wrinkle to this, depends on what you are doing. From an official US
gumint site: Wash State DOT "English-speaking nations agreed to
standardize the relation between the yard and the meter as follows:
1 yard = 0.9144 meter 1 foot = 0.3048 meter 1 inch = 25.4 millimeter
The new length of yard is shorter by exactly two parts in a million.
At the same time it was decided that any data in feet derived from
and published as a result of geodetic surveys within the U.S. would
remain with the old standards (1 foot = 12/39.37 meter) pending any
further decisions. This foot measurement is called the U.S. Survey
foot. This then, is how we came to have two values for foot-meter
conversions. One value, (1 foot = 12/39.37 meter), should be used
when converting a measurement that is based on geodetic surveys. The
other value, (1 foot = 0.3048 meter), should be used for any other
conversions that are not related to geodetic data. Whichever value
is used, it should be used consistently throughout that project. "
Whatever. RichD (15991) |
| New neighbor
stopped by and asked if I could make up some threaded parts for his
boat. Strange character, goes around in a sawdust caked toga, anyway
he wanted them with a 6 milli-cubit pitch. Anybody know what change
gear combo will generate this? JP (15994) |
| Rich Use the
easy way out and forget the controversy and use the only really
accurate calculation. If you have a metric dimension and want the
inch equivalent the calculation is 1.0 x 0.03937 = 0.3937 inches. To
go from inches to metric divide the inch measurement by the same
conversion factor. This gives in both cases a solution accurate to
four decimal places rather than the approximate one given by all
other methods. JWE (16005) |
| JWE, I have
used the 1mm = .03937" equivalent for many years thinking that it
was based on 1M = 39.37" EXACTLY. As has been said, in 1959 the law
was changed to make 2.5mm = 1" EXACTLY. A lot of folks don't know
this. So the above conversion is a round off, but good enough for
most things in short dimensions. Plug it into the pocket calculator
memory. It is very difficult to find the correct info on the web.
Even NIST gives a site for common folk with approximations to make
it easy (1" = 2.5mm). That's not a mistake!!!!!!!! It seems all
metric folk disallow anything not metric, like nothing else ever
existed before. Then there are the metric associations set up to
"push metric" with the silly excuses about the advantages, etc. IE:
"Metric is decimal making calcs easy." Uh-huh! Really. When was the
Inch not decimal? When Starrett made his first micrometer, was it
fractional? I don't think so! Unfortunately schools have gone out of
their way to teach math using fractions. WHY? Anyway, you get the
picture and know ""the rest of the story". RichD (16012) |
| I'm positive
it is a mistake!! It should read 1" = 25.4mm EXACTLY (16014) |
| Graham, I
hope you didn't take that out of context. NIST (National Institute
of Standards Technology, USA) make the statement as a general
simplified approximation to a conversion. (1" = 2.5mm) I tried to
find on their site a statement of the correct and precise equivalent
and found nothing. RichD (16017) |
| Rich, now
I understand what you were trying to say. I still think you
misquoted mm instead of cm. 1" = approx 2.5cm (centimeters) which is
10 times larger than 2.5mm So the beauty of the metric system is not
that's its decimal, but that its based in units of 10. 1" = 25.4mm
1" = 2.54cm (or approx 2.5cm) 1" = .254dm 1" = .0254m. Graham
(16023) |
| NIST has a
very useful PDF at
http://ts.nist.gov/ts/htdocs/230/235/h4402/appenc.pdf (16024) |
| G.. Oops. Yer
correct. R. (16025) |
| Barry, I
missed that one. Very good. Esp the part that says "1M = 39.37008" I
was looking for the official statement of equivalence. That will do.
I think the problem is, the standards are actually under control of
an international authority, and to find out the nitty gritty, you
gotta go there. Me no speakum French, Kemosabie! RichD (16026) |
| Metric
Conversion Gears |
| Usual remedy
for expensive SB original metric conversion gears for 9" and 10" in
US is to source Boxford ones from the UK. These are a direct
replacement and typical dealer price is œ60 - œ70 e.g. G M Tools,
http://www.gandmtools.co.uk/index.html , list them at œ65 ( approx.
$116) and are happy to ship stateside. Best deal on shipping is
naturally if people club together so more than one set per shipment.
Heavy Ten metric conversion gears appear to be unobtanium in the UK
and customs depredations make shipping from US even more uneconomic
than usual. I'm looking into getting a set made up, obviously unit
prices will be cheaper the more sets that are made so if any UK
Heavy Tenners are interested could they please contact me direct and
I'll pursue enquires. Preliminary enquires suggest that price will
probably be œ130-œ180 delivered, depending on number of sets. I may
arrange for the big compound gear to be in derelin rather than steel
it its cheaper unless some-one knows any good reason why its not a
good idea. Obviously it will be quieter. Clive (20703) |
| Are
there suppliers of inch-size gears in the UK? In particular does
Boston Gear have a UK office? Boston Gear will sell you a 16 DP 100
tooth gear and a 16 DP 127 tooth gear (both in cast iron) for
something like $120 for the pair in the US if I recollect. The pair
of them solves the dominant problem. You need to screw them together
and bush them, but that is a relatively simple drill press and lathe
job. I made a conversion set that way for my heavy 10 and it works
fine. I just turned a metric thread last evening. You still need to
find an assortment of smaller 16 DP gears like 48, 44, 36, 32, 28
and 26, again from memory. Actually you only need a subset of these
to turn most of the common metric pitches. The smaller ones can also
be had from Boston Gear (although they need to be bushed down to
5/8"), but there may be other cheaper sources for those in the UK.
Frank
(20706) |
| Unfortunately Boston Gear don't have a UK office so shipping,
customs and VAT make it all rather uneconomic. Its not too difficult
to source 16 DP gears in the UK but I have yet to find a supplier of
cast gears. All the smaller gears, including the 100, are standard
stock machined steel gears from several suppliers at typically œ10
to œ50 (say $18 to $90) each depending on size. The big problem is
the 127 which is a special and the charges for fitting a
non-standard hole size and key-way in the smaller gears. If the
worst comes to the worst I'll cut the 100 and 127 myself, buy in the
small ones and fit the right size hole key-way but I really don't
want the hassle of making the 127 division plate and the keyway
broach not to mention the time needed. Clive
(20721) |
| Metric
transposing gears |
| I have a 10K with a quick-change gear box. Has anyone ever seen
South Bend instructions on how to setup transposing gears and select
the metric threads with the QCGB? What additional gears are
required? The 1942 copy of HTRAL I have makes no mention of
selecting metric threads with a QCGB. Rick B.
(23933) |
| Typical
solution is to transpose gears with a 1:1.27 ratio to the lead screw
drive. (23936) |
| Look at 22158
most of all and also 22171 Jim B. (23939) |
| I have a 10K
and purchased the metric set from South Bend years ago. The
instructions are just a metal plate showing the gear positions for
each thread pitch. There is a 26,28,32,36,44,48 tooth gears along
with a 1" collar and a 100/127 gear combination. Ed P
(23951) |
| There is a
picture of the metric gearing plate somewhere in the group files.
The later HTRAL ( 1950 + ) have the metric chart for the model C in
them. If you cannot find the chart in the files or pictures let me
know and I will send you a copy directly. You will need a 100/127
gear and various others most of the gears required are in the
standard B C set but 2 are not. I have a 10K with a quick-change
gear box. Has anyone ever seen South Bend instructions on how to
setup transposing gears and select the metric threads with the QCGB?
What additional gears are required? The 1942 copy of HTRAL I have
makes no mention of selecting metric threads with a QCGB. (23952) |
| If you go to
Post 19336 by Guy Cadrin he has a Excel Chart/Sheet that will help
anyone wanting to cut Metric on a 9 or 10K SB lathe with QCGB. I
feel this is one of the best post on this site. If you have any
trouble with it just e-mail and I will try to help with what little
I know. Guy has been very kind to many of us. David
(23953) |
| If you want
to see the SB lathe Plate for cutting metric threads do the
following: Go to "Files" right here on this site. Then to down to "Techinfo"
Now go down to "Gears Gearing" It will show three posts- The last
one is for SB 9 10K with QCGB It show you how to set up your gears.
David
(23955) |
| Cutting
metric threads is easy. As mentioned in previous replies to your
post, you need a 127-100 compound gear. this will give you exact
metric threads. as mentioned you will also need other gears. An
alternate solution is a compound gear 47-37. Months ago, I made a
excel spread sheet that computes all the feed rates as well as
thread pitches, metric and US. It is posted on the South Bend Lathe
Pix group
http://finance.groups.yahoo.com/group/SouthBendLathePix/files/ .
Instructions are found in the post No 19336 of this group. If you
have a SB 9 Model A or SB 10K, it works. The difference between the
gear box chart and the spread sheet is less than 0.0001 in. It is a
very useful tool. Guy (23956) |
| That last
photo is the picture I took when I listed that plate on eBay. It
didn't sell and I think I still have it around here somewhere. It is NOS original South Bend. Contact me off list if you are interested
in purchasing it. Jim (23960) |
| Metric Model
B/C Gear Chart |
| I posted the
following to the Boxford group. Can anybody here help with the
requested info for either SB or Boxford (should be the same)?
Anthony
***********
** A couple of days ago I posted a request for scans of the Metric
Model B and Metric Model C change gear charts. I did receive one
response which unfortunately didn't solve my problem. So I thought
I'd be a little more clear. What I'm looking for is the charts to
cut metric threads using a metric leadscrew. I'm interested in both
the B C charts separately because I think there is a minor
difference between the two charts. High resolution would be
appreciated. I already have: Model A, inch threads with an inch
leadscrew. Model B, inch threads with an inch leadscrew. Model C,
inch threads with an inch leadscrew. Model A, metric threads with an
inch leadscrew. Model B, metric threads with an inch leadscrew.
Model C. metric threads with an inch leadscrew. Model A, metric
threads with a metric leadscrew. Model A, inch threads with a metric
leadscrew. Model B, inch threads with a metric leadscrew. Model C,
inch threads with a metric leadscrew. Anthony
(24429) |
| Go to
http://finance.groups.yahoo.com/group/SouthBendLathePix/files/
There is an excel spread sheet which should answer your questions
Also there have been many threads on this subject. Just search the
archives for "Metric threads" JP (24431) |
| As far as
thread cutting the B and C charts would be identical. Both are using
the half nuts for thread cutting. The differences show up due to the
gear reduction in the model B apron which the chart assumes for the
feed specs. That difference should be easy to calculate given either
chart. (24434) |
