John, to pity someone who wants a lathe which is twice the size of yours, and
three times the weight of yours, and with many more essential features than
yours, for less than the price of yours, is to demonstrate irrationality.
Anyone who already owns a metal working lathe is in a position to then make
their own accessories, and therefore does not need to purchase them to begin
with. You evidently found this out only after you had already purchased your
lathe, and now, in order to avoid feeling sorry for yourself, you offer your
"pity" to those who are demonstrating more foresight than you did yourself.
experienced operator would know how to tighten up many parts of these lathes
for better tolerances. Of course, an experienced operator would probably try
to avoid these lathes if they could.
then I use the ones at work.
lathe and trying to say "size matters...never mind the limitations".
In your previous post you introduced the term "pity", now you have introduced
the term "cheapo", and the only explanation which you have so far offered
regarding your use of this problematical terminology is that a first time buyer
purchasing a Chinese Minilathe will need to tune it up, and make some
accessories. And for this, I am supposed to be impressed? Well, no, I don't
think so, John.
One need not be an experienced operator in order to know how to tune up a
Minilathe. One need only know how to read, since I have included this
information at the end of this posting.
Your use of the term "probably" in the sentence "Of course, an experienced
operator would probably try to avoid these lathes if they could" is a
demonstration of uncertainty on your part, and an obvious speculation. That
there are twice as many members in the Yahoo Minilathe group as there are in
the Sherline group is a demonstration of where the experienced operators go.
This is the difference between _speculation_ and _demonstration_.
You'd better hope that you don't lose your job, since you obviously _do_ need a
bigger lathe, which is the reason why you steal time at work to do your hobby
machining. Do this enough times, and you might loose your job for this reason
John, the reason why I mentioned that you sound like you are experiencing
remorse is because you obviously are not happy to simply use the lathe which
you have. Rather, you obviously feel a persistent and rather bizarre need to
somehow try to slander those of us who have the good sense to purchase a lathe
which is not only a superior lathe to the one which you have, but which is
superior to the point of being very obvious in its superiority.
The possible need to tune up, and the probable need to make accessories do not
constitute limitations. They constitute a respect by the manufacturer for the
intelligence of the buyer.
I do not yet have a lathe, though I will be purchasing one in the near future.
I will be purchasing the Chinese Minilathe, and the possibility that I would
end up regretting this decision appears to be extremely remote.
In conclusion, here is some information on how to tune the Minilathe:
Tuning Your Mini-lathe
There are several adjustments you can make to significantly improve the
accuracy of your minilathe. These adjustments, properly done, can improve the
quality of work you can produce. To get accurate, nicely finished work and
minimum chatter, it is important to remove as much play as possible in the
saddle, cross-slide and compound. Try grasping the compound and twisting it
from side to side. If your lathe is properly adjusted you should be able to
move it very little.
Adjusting the Gibs
One of the simplest and most effective adjustments is adjusting the gib screws.
Gibs are metal strips that sit on one side of a dovetail slide, such as the
cross-slide and compound, and which are adjustable to take up any slack or slop
so that the dovetail slide is very smooth and snug.
Looking at the side of the compound rest you will see 3 small set screws
surrounded by locking nuts.
If you crank the compound rest all the way back until the compound lead screw
disengages, you can then slide the top part of the compound free from the
bottom part, exposing the lead screw, dovetails and gib strip. Here's a view of
the underside of the top part of the compound rest.
Viewed end-on the gibs are parallelogram shaped. On the back side of the gib
you will find 3 indentations which act as engagement points for the adjusting
screws. Some owners have mistakenly thought that these indentations were
manufacturing defects - they are not - they are there to hold the gib in place
on the tips of the adjusting screws.
Look at the working face of the gib. As it comes from the factory these are
usually pretty rough. Check my lapping page for information on how to polish
this face to a shiny finish to get even more accuracy and smoothness from the
dovetails. In the picture below, the gib has been polished.
While you have the compound removed, apply a light coating of white lithium
grease to the gib face, the dovetail faces and the lead screw. White lithium
grease is available from hardware stores in small plastic tubes which will last
quite a while.
With the compound back in place and positioned about midway in its range of
travel, here's the adjusting procedure:
Use a 7mm wrench to slightly loosen each locking nut
Start with the middle screw, grip the lock nut with a 7mm wrench and tighten
the set screw using a 2mm hex wrench until the set screw is just snug.
Back off the set screw about 1/4 turn
Holding the set screw to keep it from moving, tighten the locking nut. The lock
nut should not be super-tight, just tight enough to firmly lock the set screw
Repeat for the other two adjusting screws.
Now test the compound slide to make sure it moves smoothly. If you get the gib
too tight it will lock the slide in place so don't force the crank or you might
strip the leadscrew. Just repeat the above procedure but don't tighten the gib
screws quite so much. Try tightening the set screws slowly while you are
cranking the compound back and forth and you can feel the gib start to snug up
the dovetail. This should give you a good sense of how tight the screws need to
You may have to repeat this procedure several times until you get a feel for
it. As you use the lathe, the dovetails and gib will wear down a little over
time so you will need to repeat this procedure periodically.
After you have the slide moving smoothly, try gripping the compound rest at
either end and try to wiggle it side-to-side. There should be almost no play at
The procedure for adjusting the cross-slide is essentially the same. The gib
screws for the cross-slide are on the tailstock side of the slide:
Adjusting Cross-slide Backlash
Grasp the cross-slide at either end and try to slide it back and forth. You
will probably feel a movement of about .100 inches or more. By performing the
adjustment described here you should be able to reduce this movement to about
.020 or less.
The cross-slide lead screw engages with a rectangular brass nut attached to the
underside of the cross-slide by two hex screws. A third hex screw presses
against the top of the brass nut to adjust its height. By adjusting this middle
screw and the two mounting screws, you can adjust the brass nut to minimize
backlash in the cross-slide. It's a crude mechanism, but it works.
Here's a picture of the underside of the cross slide showing the brass nut.
Here's the lead screw:
In the next photo you can see the three adjusting screws near the back end of
the cross slide. The compound has been removed.
This shot shows a a close-up of the nut removed and inverted so that you can
see the arrangement of the adjusting screws.
Here's the adjusting procedure:
Loosen the two outer screws using a 3mm hex wrench
Loosen the middle screw using a 2.5mm hex wrench
Tighten the middle screw until it is just snug
Tighten the two outer screws until just snug
Grasp the slide and slide it back and forth again. By alternately tightening
the center screw and outer screws you can remove as much of the backlash as
possible. Like most adjustments on the mini-lathe, you need to play around with
it a while to get a feel for it. Be careful not to overtighten the screws or
you could strip the threads.
You don't need to remove the cross-slide to adjust the backlash, but you may
want to do so to lubricate the dovetails and leadscrew and to polish the gib
strip. The top of the cross-slide must be removed by sliding it off the back of
the bottom section. One way to do this is to remove the splash guard.
Alternatively, you can slide the saddle off the end of the ways. More on this
Here's an explanation of the procedure by Bruce Simpson:
The two screws you talk about which "tighten" the cross-feed nut
aren't just there to secure it -- they're an adjustment designed to take
up the slack.
If you just torque them down then you will find the handle pretty hard
The nut itself pivots on the center (flat-head) screw and the cap-head
screws either side are their to tilt it.
By tilting the nut you can progressively reduce the backlash. The
goal is to obtain a degree of tilt that minimizes backlash without
unduely increasing friction.
You should adjust these screws with the cross-slide in the fully
wound-in (ie: towards the rear of the lathe) position because it's also
posible to have the nut too high or too low which means it will bind on
the feed screw when it gets to that end.
Play around with the three screws until you get it right.
The technique I use is to slacken the two cap-head screws and use
the middle screw to set the height of the nut (so it doesn't bind when
the cross-slide is wound right to the back)
Then slowly tighten one (doesn't matter which one) of the cap-heads
until you notice the slop starting to disappear. Once you've got the
slack out you tighten the other one so that the nut is then firmly held.
You'll likely find that when you tighten the other cap-head screw that
things free up a little and some of the backlash comes back -- this
means you may have to over-tighten the first screw a little in
anticipation of this change.
Another thing to watch is that you might need a shim behind the
collar on the cross-feed screw where it presses against the cross-
slide. It's not uncomon to have quite a bit of slop here and the
judicious use of some steel or brass shim cut into a washer shape
can work wonders here.
Adjusting the Saddle
When you turn the carriage handwheel, the saddle should move easily along the
ways without binding, but should be tight enough so that there is very little
slop or play. With the carriage about midway along the ways, grasp the carriage
firmly and try to rock it back and forth. There should be very little movement
if everything is properly adjusted. Too much play will cause chatter during
cutting operations and will make it difficult or impossible to get a smooth,
Look carefully at the gap between the lower edge of the saddle where it rests
on the ways and the ways. If the gap opens and closes as you rock the saddle,
there is too much play and you need to tighten the saddle adjusting strips. The
adjusting strips are two rectangles of fairly soft iron located on the
underside of the saddle. There are three adjusting screws and two locking
screws on each strip.
They are tricky to adjust properly, since you can't easily get access to the
adjusting screws while the saddle is mounted on the ways. Therefore, you
usually have to slide the saddle off the end of the ways, make a slight
adjustment, remount the saddle on the ways and test and repeat this process
until you get it right. To make matters worse, the adjusting screws on the
front side of the saddle are obstructed by the half-nut and the pinion shaft.
The set screws with the lock nuts work to push the plates away from the bottom
of the ways, while the three hex nuts work to clamp the strips tighter to the
ways. The goal is to work these two sets of screws in opposition to each
other until the guide strips are as snug as possible on the ways without
causing excessive resistance. Apply a little light oil along the surface of
the ways and work the saddle back and forth. With a little work, you should be
able to get the movement to be pretty smooth with very little slop.
Caution: the metal strips are brittle and will crack at the position of the
set screws if you apply excessive force. Sooner or later this seems to happen
to many lathe owners. I replaced the originals on my 7x10 with new ones I made
Here's a procedure suggested by Bruce Griffing:
I began by removing the saddle. I also removed the apron, though that is not
necessary. On each side, there are 3 socket head cap screws and two
adjusting screws. In this procedure, you remove the two end SHCS's and don't
use them until the end. You begin by alternatly loosening the center cap
screw, adjusting the two adjusters and tightening the center screw until you
achieve a 30 mil gap at both ends of the cast iron strip. In this case the
gap is measured between the iron strips and the saddle. I used a feeler gage
to measure the gap. This should be done for both sides of the saddle.
The next step is to loosen the center SHCS and put the saddle back on the
lathe. Tighten the center SHCS and measure the gap between the ends of the
strap and the underside of the ways. This should be done at both ends and on
both sides. If the gap is zero, go back to the beginning and increase the
initial gap to 40 mils. But it should be greater than zero, so record all 4
values. Remove the saddle again and do some math. If the gap with the ways
was 12 mils then you want to reduce the saddle gap from the initial 30 mils to
19. This will reduce the gap with the ways to 1 mil - the target.
This should be done for both ends of the strip - so it is a balancing act
between the two adjusting screws. Once the correct gap is set at both ends of
both sides, install all of the SHCS's but leave them loose. Reinstall the
saddle and tighten the center SHCS on both sides. If the 1 mil gap is
correctly set, the carriage will move freely at this point. Then the end
SHCS's are adjusted to achieve the desired trade between rigidity and friction.
At this point, you are bending the strips to close the one mil gap at each
This method works very well and is much easier than it sounds. It minimizes
stress on the strips and achieves good balanced retaining force. It may be old
news, but I haven't seen it yet. One minor point - to do this you need some
narrow feeler gages. I actually used shim stock to measure the strip to way
Adjusting the Motor and Drive Belt
The motor is mounted on the back side of the lathe below the headstock. A
toothed drive belt runs from a small toothed pulley on the motor shaft up to a
larger pully on the back end of the spindle. This is normally not visible
since it is behind the gear assembly, but the assembly can be removed by means
of two hex head cap screws located at the upper left and lower right corners of
the casting. It is not necessary to remove this cover to fix the belt
alignment, but doing so will help you to see when the belt is properly aligned.
In the photo above, the belt is slightly misaligned. You can see that it is not
properly centered over the upper pulley and is running pretty close to the side
of the headstock. The motor is canted slightly so that the left side is lower
than the right side - this is probably why the belt is off center and leveling
the motor will probably correct the problem.
The position of the motor and the belt alignment and tension can be adjusted by
means of the motor mounting bolts and positioning bolts. These are located on
the front side of the headstock, behind the electronics box.
To get access to these screws, remove the black plastic shield above the
leadscrew and the leadscrew. To remove the leadscrew,
Remove the pillow block from the right end of the leadscrew
Remove the gear from the left end of the leadscrew
Remove the bushing and key from the left end of the leadscrew
Slide the leadscrew to the right out from the pillow block on the left end.
Now you can get a better view of the adjusting screws.
The two bolts with the washers under the nuts hold the motor in place. Once
loosened, it is easier to adjust these nuts with a 10mm nutdriver (or socket
wrench) than with the open-end wrench that comes with the lathe. The other two
set screws push against the cylindrical motor housing and can be moved in and
out to adjust the position of the motor. Moving the upper screw inward pushes
the upper part of the motor back and tightens the belt. Moving the lower screw
inward has the opposite effect. As the motor is moved, the alignment and
tension of the drive belt are changed.
When properly aligned, the belt should not touch any part of the lathe other
than the two drive pulleys. To correct a problem with the belt rubbing against
some other part of the lathe,
Mark the original position of the motor mount bolts using a Sharpie pen
Loosen the two motor mount bolts
Loosen the alignment bolts
Move the motor by hand until the belt appears to be properly aligned
Tighten the mounting bolts finger tight
Tighten the alignment bolts until they press agains the motor housing
Tighten the mounting bolts firmly
Turn the lathe on at slow speed, check the belt and repeat until fixed.
Removing and Lubricating the Headstock
The lathe spindle runs through the headstock supported at either end by
precision thrust bearings. A keyed shaft runs through the headstock below the
spindle and supports a large and a small plastic gear on either end of a common
midsection. This gear assembly is keyed to be driven by the shaft, but can
slide along the shaft. The HI/LO lever moves a forked piece of metal which
sits between the two gears, thus moving the gears from side to side along the
shaft and engaging them with corresponding gears on the spindle.
Users who have ventured to look inside the headstock have generally found that
there is little or no lubrication on the gears, shafts and levers. On my lathe,
the HI/LO lever seized up after a few months of use, leading me to investigate
the inner workings of the headstock. Once you have gained some confidence
disassembling and reassembling some of the basic parts of the lathe, it is a
good idea to remove the headstock and thoroughly lubricate the moving parts
with white lithium grease or similar lubricant.
Removing the headstock takes quite a few steps, and you should carefully set
aside all the nuts and bolts as you remove them and keep track of where they
came from. The headstock is bolted to the lathe bed by three hex head cap
screws which are very tight and are somewhat difficult to get at. These are
best loosened by means of an 6mm hex wrench driven by a 3/8" socket wrench and
flex-coupling. Some owners have been able to remove them by using a hex wrench
with a piece of strong tubing used as extension for extra leverage.
Here are the steps:
Remove the leadscrew
Remove the pillow block from the right end of the leadscrew
Remove the gear from the left end of the leadscrew
Remove the bushing and key from the left end of the leadscrew
Make sure half-nut is disengaged (or remove carriage)
Slide the leadscrew to the right out from the pillow block on the left end
Remove the speed control box
Unscrew ground wires from headstock casting
Remove the black plastic guard above the motor mount screws
Loosen and remove the two hex head cap screws securing the front of the
Remove the sheet metal cover from the motor in back of the lathe
Loosen the motor mount screws and move motor aside
Loose the single hex head cap screw securing the back of the headstock (in
Lift headstock casting off of ways.
Once you get the headstock off, use your finger or some kind of applicator to
liberally spread grease on the moving surfaces. I recommend that you remove the
HI/LO lever and lubricate the shaft where it passes through the side of the
I have never removed the main bearings or the spindle on my lathe. I have
avoided this under the assumption that their alignment is critical to the
accuracy of the lathe. Some other owners have done this, though, and you
should be able to find out how by searching the 7x10 interest group.
Reassemly is basically just a reversal of the above steps but you will need to
realign the motor mounts so that the drive belt runs freely. The base of the
headstock has a V-groove ground into it which mates with the ways to ensure
proper alignment when the headstock is reinstalled, but make sure no chips or
grit are on the base of the headstock when you reinstall it.
Snip rest of drivel.....
This has got to be the most ridiculous argument I've ever seen in this
group... This dipwad doesn't own a lathe, but proceeds to tell an
experienced lathe operator how the cow eats the cabbage, by cutting and
pasting 400+ lines of bandwidth-wasting text...
Next time use a link, genius...
http://www.mini-lathe.com/Mini_lathe/Tuning/tuning.htm The same stuff with
That is GREAT! You don't own a lathe, but you are an expert on tuning
one up? wow!
we don't have to "steal" machine time at work. We are encouraged to use
the machinery, on our own time, of course.
I've used the lathe at work for myself all of once in 3 years. The mills
are another story. I've used them several times. I only just a sherline
mill this past spring, so I expect I won't be using the ones at work
Just because I have a low opinion of the chinese machinery, doesn't mean
others have to agree. Opinions are like a**holes, everyone has one.
Go on, mr. expert. Tell me how much my sherline mill sucks too, and how
much remorse I have for buying a mill that YOU think doesn't meet MY
needs. Really. The whole group likes entertainment like this.
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