Mini lathe question

[BrooklynBravest]

I have the harbor freight 7x10 lathe.

I bought it used and I had two questions.

1. Am I supposed have more than one wheel for the gauge that spins on the carriage for threading or is just one?

2. The measurement dials for manually advancing the tool post, should they spin freely if I try to move them with my hand or should they only spin with the wheel they are attached too?

Mike spin with turning the handle for the compound slide but it also spins of I turn it independently by hand without moving the slide.

[Harold_V]

1. Am I supposed have more than one wheel for the gauge that spins on the carriage for threading or is just one?

The threading indicator? Just one. If the lathe has an Imperial screw, you have no need for the dial for creating metric threads, assuming the lathe is capable.

2. The measurement dials for manually advancing the tool post, should they spin freely if I try to move them with my hand or should they only spin with the wheel they are attached too?

Mike spin with turning the handle for the compound slide but it also spins of I turn it independently by hand without moving the slide.

The dial should be capable of being reset, but locked firmly, so it spins with the handle. If your dial can be easily moved without turning the handle, it is of little use to you, as the dial is how you take measured cuts. It's VERY important that it can be restrained where it is located. Most dials are locked in place by a thumb screw, or a knurled collar. It's common practice to register a given tool (assuming you're not using a rocker tool post) to the 0 position, then record the desired stopping points for the balance of the tools that are in use.

Harold

[BrooklynBravest]

The dial turns with the screw, and it holds firm unless intentionally turned by hand. It doesn't randomly wander during operation but it has no lock mechanism.

[GlennW]

It's not uncommon at all for smaller import lathes to have friction dials (what you have) on them rather than positive locking with a knurled knob or screw.

[tornitore45]

It is a friction restrain, but it should require some torque to move it.

If it is to loose there is a spring shaped like a "low pitched roof" that rides in a shallow groove
between the inside of the graduated ring and the outside of the drum attached to the screw.

Disassemble and be careful not to loose the little spring. Bend it a little more so that it applies more friction.

[BrooklynBravest]

While I have a thread going I have one more problem.

My tailstock does not perfectly align with my headstock/Chuck.

I used a live center in the tailstock and a 1/2" transfer punch in the Chuck to align centers.

My two issues are
1. The heigh appears to be off by about .5 millimeters. The tailstock side is slightly higher than the Chuck.

2. How do I make sure the tailstock is straight? The tip of the centers lineup but that doesn't mean a drill bit will sit straight, it just tells me where the very tip will be.

[wlw-19958]

Hi There,

While I have a thread going I have one more problem.

My tailstock does not perfectly align with my headstock/Chuck.

I used a live center in the tailstock and a 1/2" transfer punch in the Chuck to align centers.

My two issues are
1. The heigh appears to be off by about .5 millimeters. The tailstock side is slightly higher than the Chuck.

2. How do I make sure the tailstock is straight? The tip of the centers lineup but that doesn't mean a drill bit will sit straight, it just tells me where the very tip will be.

Tailstock alignment is a basic but often overlooked aspect of lathe operation by newbies.
In an ideal world, the tailstock should be aligned with two planes in common with the
spindle; the horizontal and the vertical planes. Also, all the various bearing surfaces in-
volved. Before you can determine the alignment, you have to have some sensitive meas-
uring equipment and know how to use them.

In answer to your first question, lathe manufacturers have used the tolerance of 0.000" to
0.003" high on the tailstock end. Having the tail stock slightly high is an advantage because
the weight of the tooling in the tailstock will make it droop. But .5mm is a bit too much of
a discrepancy (being .5mm is about .0197").

The answer of your second question requires some equipment. Ideally, a test bar that fits
the inside taper of the tailstock ram and a sensitive dial indicator. You can substitute a
known good tool for the test bar (this doesn't provide quite the accuracy for rebuilding a
lathe but it will give you an ideal). A drill chuck with a long dowel chucked in it may work
(it will depend on the accuracy of the chuck and its fit to its arbor).

Good Luck!
-Blue Chips-
Webb

[John Evans]

Try turning a 60* taper on a piece of bar chucked up ,then see what you have using a dead center in the TS. Your inspection equipment is leaving a bit to be desired for accuracy even given what you are working on.

[BrooklynBravest]

Just to clear it up, I'm an idiot.

I had the little welded plate/base to the tailstock spun tbe wrong way and it was pushing the tailstock out of alignment.

Fail.

[Russ Hanscom]

Not an idiot if you identified the problem. The learning curve is steep for most of us at some time.

[LarryMck]

You may want to get a copy of "How to Run a Lathe".

It is published and distributed by South Bend. It is an old book but when I started machining as a hobbie it was recommended to me. Now I have 3 copies. Two that are in excellant shape in my old book collection and one I keep in the shop for the ocasional referance.