Re: Metric threads/Imperial threads
??? ??? I had a store bought tool along those lines , I loaned it
to a guy that took it with him when he moved . It had a micrometer
body that threaded into the plug hole & a adjustable shaft
that would hit the piston top . It's been so long I cant fully
remember just how it worked . I thought it was called a " micro
timer " but it has not come with a google .
??? ??? animal
On 2/16/2023 5:16 PM, d6crawler via
groups.io wrote:
toggle quoted message
Show quoted text
I have a spark plug tool that
I made and I just used an old spark plug and cleaned the
ceramic out of the middle. I then tapped the inside and put a
bolt in with the head cut off and then the end rounded over. I
use it as a positive stop for determining TDC (along with a
degree wheel). I would not consider it for breaking loose
stuck crank bolts - too big of a chance of poking it right
through a piston.
|
Re: Metric threads/Imperial threads
I have a spark plug tool that I made and I just used an old spark plug and cleaned the ceramic out of the middle. I then tapped the inside and put a bolt in with the head cut off and then the end rounded over. I use it as a positive stop for determining TDC (along with a degree wheel). I would not consider it for breaking loose stuck crank bolts - too big of a chance of poking it right through a piston.
|
Re: Metric threads/Imperial threads
??? ??? ON small engines I have used a piece of rope through the
plug hole so the piston will be stopped & then loosed the
crank bolt . Up until recently the availability of impact guns on
some projects was not a option .
??? ??? animal
On 2/16/2023 2:13 PM, Nick Jonkman
wrote:
toggle quoted message
Show quoted text
In my 55+ years as a mechanic I have never heard of
that. I always used an impact gun and never had one that
wouldn't come.
Nick
On 2023-02-16 5:02 p.m., DJ Delorie
wrote:
<eddie.draper@...> writes:
but surely you can get the taps for cylinder head repairs?
Well, probably, but I wasn't fixing a cylinder head. I was making a
spark plug plug tool. You take out the spark plug, insert the tool, and
it prevents the piston from passing TDC so you can remove the crank
shaft nut. Not something most people would be aware of.
|
Re: Metric threads/Imperial threads
??? ??? Yep , My 1940 IH tractor is the same & some old
Harleys use a rather large thread spark plug .
??? ??? animal
On 2/16/2023 2:07 PM, Nick Jonkman
wrote:
toggle quoted message
Show quoted text
Having said that most modern spark plugs are 14 and
18mm, that was not always the case. Back in the model T days
there were common spark plugs with 1/2" pipe threads as well as
7/8" - 18 threads. As a mater of fact I believe that is what my
1944 IH tractor uses. I have a small collection of spark plugs
which I started collecting when I was a kid.? I didn't go out of
my way to do so but picked up odd balls as I came across them. I
have a bunch of Spark plug collectors magazines and there are
some pretty weird shaped plugs in there. Even some with what
looked like a 1/2" course thread. And then there are tiny spark
plugs for models and I have seen several sizes there too.
Just thought I would add another 2 cents worth, Nick
I doubt whether spark plug
manufacturers nowadays use dies, more likely thread milling or
some such, but surely you can get the taps for cylinder head
repairs?
Eddie
------ Original Message ------
From: "DJ Delorie" <dj@...>
To: [email protected]
Sent: Thursday, 16 Feb, 23 At 18:48
Subject: Re: [SouthBendLathe] Metric threads/Imperial threads
"Andrei" <calciu1@...> writes:
|
|
|
| All this discussion of metric threads has raised a question in my
mind. Sorry for being simple, but the only metric threads I ever cut
were small enough that they were done with a tap or a die, never on
the lathe.
|
Did you know that spark plug threads are always metric?
That's a spark plug plug for servicing chain saws. I don't recall the
exact thread, but finding a die for it would likely be impossible.
|
|
|
| Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you.
|
The key thing to understand is what the thread dial does. It indicates
the *difference* between the cut thread and the tool. In general, it
does around once per four inches of leadscrew (and thus tool) travel.
The gearing determines how many times the spindle goes around in those
same four inches; an 8 TPI thread would go around 32 times in 4 inches.
A metric lathe would have a thread dial that goes around, for example,
once per 12cm.
When doing "matched" threading (imperial-on-imperial or
metric-on-metric) you can disengage the thread dial, move the carriage
by some whole number of threads, and re-engage the thread dial; without
messing up your threading operation. The key is "whole number of
threads". If you have a whole number of threads in 4 inches, starting
on the "same number" always drops you into a thread, etc. Same for a
whole number of threads per 12cm for metric lathes.
The problem with mis-matched threading is that there is no metric thread
that is a whole number of threads per 4 inches (or the reverse) so
there's no way to move "a whole number of threads" away. Hence the
extra effort taken to keep the thread dial in the "same leadscrew
thread" so that it stays on the one cut thread you started with.
If you had a leadscrew with 9 threads per attoparsec (tpap), you could
turn any thread that was a multiple of 9 tpap (like 27 tpap) but you'd
need to use the "mis-matched" method for either inch or metric threads,
assuming the change gear fit in your local spacetime.
I suggest using an electronic leadscrew for those ;-)
|
Re: Metric threads/Imperial threads
In my 55+ years as a mechanic I have never heard of
that. I always used an impact gun and never had one that wouldn't
come.
Nick
On 2023-02-16 5:02 p.m., DJ Delorie
wrote:
toggle quoted message
Show quoted text
<eddie.draper@...> writes:
but surely you can get the taps for cylinder head repairs?
Well, probably, but I wasn't fixing a cylinder head. I was making a
spark plug plug tool. You take out the spark plug, insert the tool, and
it prevents the piston from passing TDC so you can remove the crank
shaft nut. Not something most people would be aware of.
|
Re: Metric threads/Imperial threads
Having said that most modern spark plugs are 14 and
18mm, that was not always the case. Back in the model T days there
were common spark plugs with 1/2" pipe threads as well as 7/8" -
18 threads. As a mater of fact I believe that is what my 1944 IH
tractor uses. I have a small collection of spark plugs which I
started collecting when I was a kid.? I didn't go out of my way to
do so but picked up odd balls as I came across them. I have a
bunch of Spark plug collectors magazines and there are some pretty
weird shaped plugs in there. Even some with what looked like a
1/2" course thread. And then there are tiny spark plugs for models
and I have seen several sizes there too.
Just thought I would add another 2 cents worth, Nick
toggle quoted message
Show quoted text
I doubt whether spark plug
manufacturers nowadays use dies, more likely thread milling or
some such, but surely you can get the taps for cylinder head
repairs?
Eddie
------ Original Message ------
From: "DJ Delorie" <dj@...>
To: [email protected]
Sent: Thursday, 16 Feb, 23 At 18:48
Subject: Re: [SouthBendLathe] Metric threads/Imperial threads
"Andrei" <calciu1@...> writes:
|
|
|
| All this discussion of metric threads has raised a question in my
mind. Sorry for being simple, but the only metric threads I ever cut
were small enough that they were done with a tap or a die, never on
the lathe.
|
Did you know that spark plug threads are always metric?
That's a spark plug plug for servicing chain saws. I don't recall the
exact thread, but finding a die for it would likely be impossible.
|
|
|
| Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you.
|
The key thing to understand is what the thread dial does. It indicates
the *difference* between the cut thread and the tool. In general, it
does around once per four inches of leadscrew (and thus tool) travel.
The gearing determines how many times the spindle goes around in those
same four inches; an 8 TPI thread would go around 32 times in 4 inches.
A metric lathe would have a thread dial that goes around, for example,
once per 12cm.
When doing "matched" threading (imperial-on-imperial or
metric-on-metric) you can disengage the thread dial, move the carriage
by some whole number of threads, and re-engage the thread dial; without
messing up your threading operation. The key is "whole number of
threads". If you have a whole number of threads in 4 inches, starting
on the "same number" always drops you into a thread, etc. Same for a
whole number of threads per 12cm for metric lathes.
The problem with mis-matched threading is that there is no metric thread
that is a whole number of threads per 4 inches (or the reverse) so
there's no way to move "a whole number of threads" away. Hence the
extra effort taken to keep the thread dial in the "same leadscrew
thread" so that it stays on the one cut thread you started with.
If you had a leadscrew with 9 threads per attoparsec (tpap), you could
turn any thread that was a multiple of 9 tpap (like 27 tpap) but you'd
need to use the "mis-matched" method for either inch or metric threads,
assuming the change gear fit in your local spacetime.
I suggest using an electronic leadscrew for those ;-)
|
Re: Metric threads/Imperial threads
<eddie.draper@...> writes: but surely you can get the taps for cylinder head repairs? Well, probably, but I wasn't fixing a cylinder head. I was making a spark plug plug tool. You take out the spark plug, insert the tool, and it prevents the piston from passing TDC so you can remove the crank shaft nut. Not something most people would be aware of.
|
Re: Metric threads/Imperial threads
The threads if I remember right are 14mm for most and
18mm for Ford. I have been? a mechanic for about 55 years and have
had the repair taps for spark plug holes about just as long.
Nick
toggle quoted message
Show quoted text
I doubt whether spark plug
manufacturers nowadays use dies, more likely thread milling or
some such, but surely you can get the taps for cylinder head
repairs?
Eddie
------ Original Message ------
From: "DJ Delorie" <dj@...>
To: [email protected]
Sent: Thursday, 16 Feb, 23 At 18:48
Subject: Re: [SouthBendLathe] Metric threads/Imperial threads
"Andrei" <calciu1@...> writes:
|
|
|
| All this discussion of metric threads has raised a question in my
mind. Sorry for being simple, but the only metric threads I ever cut
were small enough that they were done with a tap or a die, never on
the lathe.
|
Did you know that spark plug threads are always metric?
That's a spark plug plug for servicing chain saws. I don't recall the
exact thread, but finding a die for it would likely be impossible.
|
|
|
| Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you.
|
The key thing to understand is what the thread dial does. It indicates
the *difference* between the cut thread and the tool. In general, it
does around once per four inches of leadscrew (and thus tool) travel.
The gearing determines how many times the spindle goes around in those
same four inches; an 8 TPI thread would go around 32 times in 4 inches.
A metric lathe would have a thread dial that goes around, for example,
once per 12cm.
When doing "matched" threading (imperial-on-imperial or
metric-on-metric) you can disengage the thread dial, move the carriage
by some whole number of threads, and re-engage the thread dial; without
messing up your threading operation. The key is "whole number of
threads". If you have a whole number of threads in 4 inches, starting
on the "same number" always drops you into a thread, etc. Same for a
whole number of threads per 12cm for metric lathes.
The problem with mis-matched threading is that there is no metric thread
that is a whole number of threads per 4 inches (or the reverse) so
there's no way to move "a whole number of threads" away. Hence the
extra effort taken to keep the thread dial in the "same leadscrew
thread" so that it stays on the one cut thread you started with.
If you had a leadscrew with 9 threads per attoparsec (tpap), you could
turn any thread that was a multiple of 9 tpap (like 27 tpap) but you'd
need to use the "mis-matched" method for either inch or metric threads,
assuming the change gear fit in your local spacetime.
I suggest using an electronic leadscrew for those ;-)
|
I also reverse under power without disengaging the half-nuts. But I power off after the pass, before backing out 200 on my cross-feed dial. Number 2 and 3 are backwards…lol Sometimes on the last spring passes I’ll bump the cross-feed in just a c-hair to rub the threads instead of using the compound. ? Steve ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Nick Jonkman Sent: Wednesday, February 15, 2023 7:06 PM To: [email protected]Subject: Re: [SouthBendLathe] ER Collet nut ? I also power reverse the spindle.
Nick On 2023-02-15 1:13 p.m., Andrei wrote: I think you got it right, with one caveat: Abom79 was power reversing the spindle
? On 2/15/2023 10:03 AM, mike a wrote: ??? ??? ??? I believe if you have a hand crank on the outboard spindle it will work , but I will not be able to test that theory for a couple 3 weeks. Hit return too fast .
??? ??? My thought is to ??? ??? 1 . Make your pass ??? ??? 2. Back the tool out .???? ??? ??? 3. Power the lathe off leaving the halfnut engaged . ?? ???? 4 . Use the hand crank to move the carriage to original starting point? . ??? ??? 5. Rinse , repeat . ??? ??? but I could also just be pounding sand ??? ??? animal On 2/15/2023 9:18 AM, m. allan noah wrote: ? On Wed, Feb 15, 2023 at 11:53 AM Andrei <calciu1@...> wrote: Yes, that is the plan, anyway. ?
Are you saying you can just disengage the half nut, hand crank the carriage back, and restart on the same number?
On Wed, Feb 15, 2023 at 10:58 AM, Andrei wrote:
The only difference between metric and imperial on using threading dial is that with metric you have to start ON THE SAME mark, every time.?
I had that idea a while ago as I had some parts to make that would have been easier to leave in the chuck and go back and forth to the lathe and mill. I considered using carbide tooling to thread a commercial hex block as there was sufficient wall thickness for the threads. I never got around to it but it is still in the back of my mind. If I had a surface grinder making one would be much easier. I have a 10k and have used the printed gears from Ebay with great success making metric threads. I believe I saw a way to use the threading dial on you tube but never tried it. Something about using the same mark on the dial I believe but don't hold me to it.
--
Bill From Socal
--
"well, I stand up next to a mountain- and I chop it down with the edge of my hand"
?
|
Re: Metric threads/Imperial threads
??? ??? Agree that their probably thread milled . Ive seen &
own 1 or 2 sparkplug taps , but I've never seen a sparkplug die .
Not that they don't exist just not in any of my tool boxes
??? ??? animal
toggle quoted message
Show quoted text
I doubt whether spark plug
manufacturers nowadays use dies, more likely thread milling or
some such, but surely you can get the taps for cylinder head
repairs?
Eddie
------ Original Message ------
From: "DJ Delorie" <dj@...>
To: [email protected]
Sent: Thursday, 16 Feb, 23 At 18:48
Subject: Re: [SouthBendLathe] Metric threads/Imperial threads
"Andrei" <calciu1@...> writes:
|
|
|
| All this discussion of metric threads has raised a question in my
mind. Sorry for being simple, but the only metric threads I ever cut
were small enough that they were done with a tap or a die, never on
the lathe.
|
Did you know that spark plug threads are always metric?
That's a spark plug plug for servicing chain saws. I don't recall the
exact thread, but finding a die for it would likely be impossible.
|
|
|
| Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you.
|
The key thing to understand is what the thread dial does. It indicates
the *difference* between the cut thread and the tool. In general, it
does around once per four inches of leadscrew (and thus tool) travel.
The gearing determines how many times the spindle goes around in those
same four inches; an 8 TPI thread would go around 32 times in 4 inches.
A metric lathe would have a thread dial that goes around, for example,
once per 12cm.
When doing "matched" threading (imperial-on-imperial or
metric-on-metric) you can disengage the thread dial, move the carriage
by some whole number of threads, and re-engage the thread dial; without
messing up your threading operation. The key is "whole number of
threads". If you have a whole number of threads in 4 inches, starting
on the "same number" always drops you into a thread, etc. Same for a
whole number of threads per 12cm for metric lathes.
The problem with mis-matched threading is that there is no metric thread
that is a whole number of threads per 4 inches (or the reverse) so
there's no way to move "a whole number of threads" away. Hence the
extra effort taken to keep the thread dial in the "same leadscrew
thread" so that it stays on the one cut thread you started with.
If you had a leadscrew with 9 threads per attoparsec (tpap), you could
turn any thread that was a multiple of 9 tpap (like 27 tpap) but you'd
need to use the "mis-matched" method for either inch or metric threads,
assuming the change gear fit in your local spacetime.
I suggest using an electronic leadscrew for those ;-)
|
Re: Metric threads/Imperial threads
I doubt whether spark plug manufacturers nowadays use dies, more likely thread milling or some such, but surely you can get the taps for cylinder head repairs?
toggle quoted message
Show quoted text
------ Original Message ------
From: "DJ Delorie" <dj@...>
To: [email protected]
Sent: Thursday, 16 Feb, 23 At 18:48
Subject: Re: [SouthBendLathe] Metric threads/Imperial threads
"Andrei" <calciu1@...> writes:
| | | All this discussion of metric threads has raised a question in my
mind. Sorry for being simple, but the only metric threads I ever cut
were small enough that they were done with a tap or a die, never on
the lathe.
|
Did you know that spark plug threads are always metric?
That's a spark plug plug for servicing chain saws. I don't recall the
exact thread, but finding a die for it would likely be impossible.
| | | Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you.
|
The key thing to understand is what the thread dial does. It indicates
the *difference* between the cut thread and the tool. In general, it
does around once per four inches of leadscrew (and thus tool) travel.
The gearing determines how many times the spindle goes around in those
same four inches; an 8 TPI thread would go around 32 times in 4 inches.
A metric lathe would have a thread dial that goes around, for example,
once per 12cm.
When doing "matched" threading (imperial-on-imperial or
metric-on-metric) you can disengage the thread dial, move the carriage
by some whole number of threads, and re-engage the thread dial; without
messing up your threading operation. The key is "whole number of
threads". If you have a whole number of threads in 4 inches, starting
on the "same number" always drops you into a thread, etc. Same for a
whole number of threads per 12cm for metric lathes.
The problem with mis-matched threading is that there is no metric thread
that is a whole number of threads per 4 inches (or the reverse) so
there's no way to move "a whole number of threads" away. Hence the
extra effort taken to keep the thread dial in the "same leadscrew
thread" so that it stays on the one cut thread you started with.
If you had a leadscrew with 9 threads per attoparsec (tpap), you could
turn any thread that was a multiple of 9 tpap (like 27 tpap) but you'd
need to use the "mis-matched" method for either inch or metric threads,
assuming the change gear fit in your local spacetime.
I suggest using an electronic leadscrew for those ;-)
|
Re: Metric threads/Imperial threads
"Andrei" <calciu1@...> writes: All this discussion of metric threads has raised a question in my
mind. Sorry for being simple, but the only metric threads I ever cut
were small enough that they were done with a tap or a die, never on
the lathe. Did you know that spark plug threads are always metric? That's a spark plug plug for servicing chain saws. I don't recall the exact thread, but finding a die for it would likely be impossible. Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you. The key thing to understand is what the thread dial does. It indicates the *difference* between the cut thread and the tool. In general, it does around once per four inches of leadscrew (and thus tool) travel. The gearing determines how many times the spindle goes around in those same four inches; an 8 TPI thread would go around 32 times in 4 inches. A metric lathe would have a thread dial that goes around, for example, once per 12cm. When doing "matched" threading (imperial-on-imperial or metric-on-metric) you can disengage the thread dial, move the carriage by some whole number of threads, and re-engage the thread dial; without messing up your threading operation. The key is "whole number of threads". If you have a whole number of threads in 4 inches, starting on the "same number" always drops you into a thread, etc. Same for a whole number of threads per 12cm for metric lathes. The problem with mis-matched threading is that there is no metric thread that is a whole number of threads per 4 inches (or the reverse) so there's no way to move "a whole number of threads" away. Hence the extra effort taken to keep the thread dial in the "same leadscrew thread" so that it stays on the one cut thread you started with. If you had a leadscrew with 9 threads per attoparsec (tpap), you could turn any thread that was a multiple of 9 tpap (like 27 tpap) but you'd need to use the "mis-matched" method for either inch or metric threads, assuming the change gear fit in your local spacetime. I suggest using an electronic leadscrew for those ;-)
|
Re: Metric threads/Imperial threads
Part 1:? you cut imperial threads with a metric leadscrew in just the same way as the opposite.? Easy if it is all covered by a built in qcb, but I suspect that if not, you would use a 120 / 127 pair of gears swopped over.? Never needed to do that, others may know better.
Part 2:? Metric threads from a metric leadscrew are done in the same way as Imperial / Imperial, BUT note that the thread engagement dial needs different teeth numbers for different pitches.? These are generally to be found stacked out of the way on the indicator spindle.
Eddie
toggle quoted message
Show quoted text
-------- Original message -------- From: Andrei <calciu1@...> Date: 16/02/2023 16:14 (GMT+00:00) Subject: [SouthBendLathe] Metric threads/Imperial threads
All this discussion of metric threads has raised a question in my mind. Sorry for being simple, but the only metric threads I ever cut were small enough that they were done with a tap or a die, never on the lathe.?
Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you.
Thanks.
Andrei
|
Metric threads/Imperial threads
All this discussion of metric threads has raised a question in my mind. Sorry for being simple, but the only metric threads I ever cut were small enough that they were done with a tap or a die, never on the lathe.?
Part 1 - Metric leadscrew. How do you cut imperial threads?
Part 2 - Metric leadscrew. How do you cut metric threads? Is it as straight forward as imperial on a imperial lathe?
Part 3.- Imperial leadscrew. Allan had a great explanation for how to cut metric threads. Thank you.
Thanks.
Andrei
|
Thanks for the more accurate explanation Allen. This morning I have an M4-.9 thread to cut and I will possibly, even if egg-on-face happens. Honesttly I cut so many Metrics that I dont realize what I am doing; I just do it I guess. Thanks again r
On Wednesday, February 15, 2023 at 05:57:54 PM PST, m. allan noah <kitno455@...> wrote:
Maybe we miscommunicate, Ray, or maybe one of us is wrong. I would like to clear it up, just so that later readers of this thread don't get the wrong idea and scrap a part. So, let me try from scratch.
The thread dial is measuring two things concurrently: the rotation of the leadscrew, and also the linear distance the carriage has traveled. On many smallish lathes, if the leadscrew is not turning, one dial rotation is 4 inches of carriage travel. Nearly any imperial thread you could cut on a small lathe works with such a dial because the thread pitch repeats at least once in 4 inches. So, at a minimum, you can engage on the same mark on the dial anywhere along the bed, and be in time with your previous passes.
This is not the case for metric threads (or module or DP worms) on an imperial lathe
with an imperial thread dial. If you move the carriage such that the thread dial has made one or more whole rotations, you have covered some imperial distance. This distance will not be an even multiple of your metric thread pitch. For example, if you move one full dial rotation right on a 9" or 10L, you just covered 4 inches, or 101.6mm. I cannot come up with a metric thread that repeats evenly in that distance. Interestingly, if the dial went around 3 times (304.8mm), you could cut the seldom-used .6mm pitch using the half-nuts in the 'imperial' way.
Now, the technique DJ mentioned is the one I use. In that case, we are reversing the lathe spindle as well, not just winding the carriage to the right and taking another pass. That ensures that the relationship between the carriage, work, and leadscrew is maintained. It is unfortunately slower, however.
Please feel free to point out any errors in my understanding or explanation, I certainly might have missed something.
allan
But it does work as that is how I have been threading Metric since making the 4 stud gears I needed. Its important to note that when reaching the end of the thread on each pass you STOP the lathe, then dissengage the half nutsand return to the beginning of the next cut, now note; ?just return the carriage slowly untill you can re-engage the half nuts to the marked position from your first cut. And then repeat this procedure untill completing to your desired fit. ?I must impress though, that you should select a spindle speed that allows the spindle to stop fairly quickly or. having a VFD with breaking set light(as I have) allows a fairly quick stop without threat of losing the chuck ;) BTW I have 1947 9A and a 1986 10K underdrive - with a Hitachi VFD
On Wednesday, February 15, 2023 at 09:18:51 AM PST, m. allan noah < kitno455@...> wrote:
Too bad it isn't true.
allan
On Wed, Feb 15, 2023 at 11:53 AM Andrei < calciu1@...> wrote:
Yes, that is the plan, anyway. ?
Are you saying you can just disengage the half nut, hand crank the carriage back, and restart on the same number?
On Wed, Feb 15, 2023 at 10:58 AM, Andrei wrote:
The only difference between metric and imperial on using threading dial is that with metric you have to start ON THE SAME mark, every time.?
?
I had that idea a while ago as I had some parts to make that would have been easier to leave in the chuck and go back and forth to the lathe and mill. I considered using carbide tooling to thread a commercial hex block as there was sufficient wall thickness
for the threads. I never got around to it but it is still in the back of my mind. If I had a surface grinder making one would be much easier. I have a 10k and have used the printed gears from Ebay with great success making metric threads. I believe I saw a
way to use the threading dial on you tube but never tried it. Something about using the same mark on the dial I believe but don't hold me to it.
--
Bill From Socal
-- "well, I stand up next to a mountain- and I chop it down with the edge of my hand"
-- "well, I stand up next to a mountain- and I chop it down with the edge of my hand"
|
"mike allen" <animal@...> writes: right now I don't have a reversing switch on my treadmill motor. I didn't either. Getting the single speed motor (which was installed sometime around 1950) to run backwards was one of the challenges in adding metric to my lathe. I still want to switch to 3 phase with a VFD (and maybe an electronic lead screw add-on) but for now, I got some many-conductor cable and ran all the connections for the starter coil in the motor back to the barrel switch, so depending on which way I turn the motor on, the starter is wired up in forwards or reverse, and the motor starts that way. You have to wait for it to come to a complete stop before changing directions, but it was a cheap fix.
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Re: Reverse tumbler Mod for a 9A
These may be in the files section. Please respect the copyright.
They may help.
Jim B,
--
Jim B
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Re: Reverse tumbler Mod for a 9A
A 10K you mean, not the 10L.
allan
On Wed, Feb 15, 2023 at 7:58 PM Nick Jonkman < njonkman@...> wrote:
You want the one of a 10L the first one on your list
Nick
On 2023-02-15 7:51 p.m., mike allen
wrote:
On 2/15/2023 4:49 PM, mike a wrote:
??? ??? I forgot do I want a tumbler off a
10L or a Heavy 10.
??? ??? WIll? an of these? fit my 9A ?
??? ??? One of them says it's off a 9" lathe but I think it's
maybe off
that other 9" lathe & not the 9A
??? ??? thanks
??? ??? animal
-- "well, I stand up next to a mountain- and I chop it down with the edge of my hand"
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Maybe we miscommunicate, Ray, or maybe one of us is wrong. I would like to clear it up, just so that later readers of this thread don't get the wrong idea and scrap a part. So, let me try from scratch.
The thread dial is measuring two things concurrently: the rotation of the leadscrew, and also the linear distance the carriage has traveled. On many smallish lathes, if the leadscrew is not turning, one dial rotation is 4 inches of carriage travel. Nearly any imperial thread you could cut on a small lathe works with such a dial because the thread pitch repeats at least once in 4 inches. So, at a minimum, you can engage on the same mark on the dial anywhere along the bed, and be in time with your previous passes.
This is not the case for metric threads (or module or DP worms) on an imperial lathe
with an imperial thread dial. If you move the carriage such that the thread dial has made one or more whole rotations, you have covered some imperial distance. This distance will not be an even multiple of your metric thread pitch. For example, if you move one full dial rotation right on a 9" or 10L, you just covered 4 inches, or 101.6mm. I cannot come up with a metric thread that repeats evenly in that distance. Interestingly, if the dial went around 3 times (304.8mm), you could cut the seldom-used .6mm pitch using the half-nuts in the 'imperial' way.
Now, the technique DJ mentioned is the one I use. In that case, we are reversing the lathe spindle as well, not just winding the carriage to the right and taking another pass. That ensures that the relationship between the carriage, work, and leadscrew is maintained. It is unfortunately slower, however.
Please feel free to point out any errors in my understanding or explanation, I certainly might have missed something.
allan
But it does work as that is how I have been threading Metric since making the 4 stud gears I needed. Its important to note that when reaching the end of the thread on each pass you STOP the lathe, then dissengage the half nutsand return to the beginning of the next cut, now note; ?just return the carriage slowly untill you can re-engage the half nuts to the marked position from your first cut. And then repeat this procedure untill completing to your desired fit. ?I must impress though, that you should select a spindle speed that allows the spindle to stop fairly quickly or. having a VFD with breaking set light(as I have) allows a fairly quick stop without threat of losing the chuck ;) BTW I have 1947 9A and a 1986 10K underdrive - with a Hitachi VFD
On Wednesday, February 15, 2023 at 09:18:51 AM PST, m. allan noah < kitno455@...> wrote:
Too bad it isn't true.
allan
On Wed, Feb 15, 2023 at 11:53 AM Andrei < calciu1@...> wrote:
Yes, that is the plan, anyway. ?
Are you saying you can just disengage the half nut, hand crank the carriage back, and restart on the same number?
On Wed, Feb 15, 2023 at 10:58 AM, Andrei wrote:
The only difference between metric and imperial on using threading dial is that with metric you have to start ON THE SAME mark, every time.?
?
I had that idea a while ago as I had some parts to make that would have been easier to leave in the chuck and go back and forth to the lathe and mill. I considered using carbide tooling to thread a commercial hex block as there was sufficient wall thickness
for the threads. I never got around to it but it is still in the back of my mind. If I had a surface grinder making one would be much easier. I have a 10k and have used the printed gears from Ebay with great success making metric threads. I believe I saw a
way to use the threading dial on you tube but never tried it. Something about using the same mark on the dial I believe but don't hold me to it.
--
Bill From Socal
-- "well, I stand up next to a mountain- and I chop it down with the edge of my hand"
-- "well, I stand up next to a mountain- and I chop it down with the edge of my hand"
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Re: Reverse tumbler Mod for a 9A
??? ??? Thank you sir
??? ??? animal
On 2/15/2023 4:58 PM, Nick Jonkman
wrote:
toggle quoted message
Show quoted text
You want the one of a 10L the first one on your
list
Nick
On 2023-02-15 7:51 p.m., mike allen
wrote:
On 2/15/2023 4:49 PM, mike a wrote:
??? ??? I forgot do I want a tumbler off
a 10L or a Heavy 10.
??? ??? WIll? an of these? fit my 9A ?
??? ??? One of them says it's off a 9" lathe but I think it's
maybe off
that other 9" lathe & not the 9A
??? ??? thanks
??? ??? animal
|
Jim_B
