Buying my first new lathe. Chinese or Chinese?

[Dabbler]

Do you know of any good tutorials on checking the head stock and tail stock alignment that you would be willing to point me to?

I've been looking for great tutorials for our 'beginner tutorials' section. PM me if you find one also.


Here's how I've done it for over 40 years:

When you are setting up the lathe you need to first get the ways *approximately* in a single plane. I call this alignment - but a more common term is leveling. That is because the easiest way to get the ways ready for setting up the lathe is to use a machinist's level. But any level that is sensitive to .005 (or even .010) per foot will do.

You can then align the headstock. That is done by turning a short piece of easily cut material - aluminum, soft steel, whatever you have, that is 1" in diameter or greater. You check that the *headstock only* is cutting a perfect cylinder, accurate to you best measuring device.

You then need to align your tailstock. I use a 'dial test indicator' to do this. but you are free to explore alternatives. I chuck my DTI in the 3 jaw chuck. Then I position the carriage, DTI and tailstock barrel so that I can sweep the inside of the tailstock taper with the tailstock barrel just contacting the tool post. My DTI holder is long enough to do this, but you might have to fashion an extension.

Now comes the magic. Once you have proven that the retracted barrel of the tailstock is on centre, you then crank out the barrel, which is held by the tool post. This causes the tailstock to move outwards from the chuck and DTI. You then adjust the tailstock so it reads true again. You might have to go back and forth a few times, depending on the design of your tail stock.

Then and only then, can you do the 2 collar test, which gets you to under tenths of a thousand of an inch on tapers. I've never need to do this step.

 

[mac1911]

Before you go down the rabbit hole of checking, headstock alignment, we twist, tail stock, alignment run out and all the other fun stuff do this first

Set up your lathe, clean your lathe. Do you want to get all of the corrosion inhibitor, gunk or spray that they put on these machines. Sometimes it’s more of a grease others. It’s almost like a spray that’s more like varnish than anything else. It is no good for lubrication or sliding. Now do whatever braking procedure the manufacture says to do. Get your Gibbs adjusted. Get you to post set up and start making simple turnings.

Once your machine is broken in warmed up, and all the little odds and ends are in check. I would also go through the entire machine and check every nut bolt and screw and make sure they’re tight. And then just start making some parts and as you get comfortable with the machine and you start wanting better tolerances the machine will start to show its face and then you can go and Chase alignment after that.

You’ll spend a lot of time chasing alignment on the machine if you haven’t run it through its paces for a little while as things settle down, warm up, wear in, etc. etc.

Since my lathe is well used and it’s not really a good leave so Mid90s Smithy 1220. Are use the down and dirty method of lining the tailstock. I put the dead center in the headstock taper. Am I live center in my tail stock and then I put a credit card in between the two tips. I was able to align it pretty well that way for what I need my lady to do. I still need to shim my tail stock just a little bit because it nose dives. Just a touch.

Again for what I’m doing it’s not a huge issue. But I’m one of those guys that that stuff just bothers me when I know it exists.

 

[Larry$]

Heads up, @Rufustoad- that type of carriage stop only stops the carriage when you're traversing with the handwheel! If you power feed into the carriage stop, you're going to break the weakest link in the drive system very quickly. Feed until you're close, then throw open the half nuts and walk the carriage up to your set stop with the handwheel. Power feed stops that you can run right into are more complicated affairs.

Edit- okay, I looked that lathe up, it has a clutched feed stop. It's not a cutout stop, but it's advertised as okay to run up against.

Caution!! My lathe came with the same system, BUT the system was so far off that the clutching didn't work. To make matters worse the shear pin that was supposed to be brass had a steel roll pin in it's place. There was a spring loaded ball detent on my lathe. If the ball can travel too far into the non-spring side it won't slide back into the spring side when it should.

 

[mac1911]

I've been looking for great tutorials for our 'beginner tutorials' section. PM me if you find one also.


Here's how I've done it for over 40 years:

When you are setting up the lathe you need to first get the ways *approximately* in a single plane. I call this alignment - but a more common term is leveling. That is because the easiest way to get the ways ready for setting up the lathe is to use a machinist's level. But any level that is sensitive to .005 (or even .010) per foot will do.

You can then align the headstock. That is done by turning a short piece of easily cut material - aluminum, soft steel, whatever you have, that is 1" in diameter or greater. You check that the *headstock only* is cutting a perfect cylinder, accurate to you best measuring device.

You then need to align your tailstock. I use a 'dial test indicator' to do this. but you are free to explore alternatives. I chuck my DTI in the 3 jaw chuck. Then I position the carriage, DTI and tailstock barrel so that I can sweep the inside of the tailstock taper with the tailstock barrel just contacting the tool post. My DTI holder is long enough to do this, but you might have to fashion an extension.

Now comes the magic. Once you have proven that the retracted barrel of the tailstock is on centre, you then crank out the barrel, which is held by the tool post. This causes the tailstock to move outwards from the chuck and DTI. You then adjust the tailstock so it reads true again. You might have to go back and forth a few times, depending on the design of your tail stock.

Then and only then, can you do the 2 collar test, which gets you to under tenths of a thousand of an inch on tapers. I've never need to do this step.

I am a beginer and all I can say.
There are tons of videos on youtube. Mr pete, blondiehacks, joe pie just to name a few.
Heres one at random

I have a head stock to ways alignment issue . I have come to the conclusion that the gear box to ways mounting is some how bent and the gearbox is just not sitting square to the ways. No amount of shimming has helped.
I dont have any ambition to tear down the head stock and I have improved it to the point where it will have little impact on what I am making and my skills at the moment.

 

[Larry$]

No amount of shimming has helped.

I did a headstock to ways alignment of my PM lathe. There were instructions in the manual that came with the lathe. 4 bolts hold the two parts together near each corner. Use one as a pivot. On the change gear side, there are set screws that allow pushing the head stock from side to side & therefore pivoting about the one corner bolt. Instructions called for a 2" x12" steel bar to do test turnings on. Tail stock is not used. I managed to get very close to a true cylinder. After the head has been aligned to the bed you can align the tailstock to the head. I don't think some up/down difference matters much since all tools are cutting from the side not top or bottom. If it matters to you shim or scrape between the upper and lower parts of the tailstock.

 

[mac1911]

I did a headstock to ways alignment of my PM lathe. There were instructions in the manual that came with the lathe. 4 bolts hold the two parts together near each corner. Use one as a pivot. On the change gear side, there are set screws that allow pushing the head stock from side to side & therefore pivoting about the one corner bolt. Instructions called for a 2" x12" steel bar to do test turnings on. Tail stock is not used. I managed to get very close to a true cylinder. After the head has been aligned to the bed you can align the tailstock to the head. I don't think some up/down difference matters much since all tools are cutting from the side not top or bottom. If it matters to you shim or scrape between the upper and lower parts of the tailstock.

Basically on my smithy the headstock/gear head slides on like a tailstock and locked down with set screws much like a crossslide lock.
I was able to loosen one and tighten the other to get some adjustment.
Im having trouble getting parts so this lathe might be short lived for me.

 

[B2]

sounds very interesting although doesn't that become an issue to have to start again to take another pass or do you just use this as a final pass set up?

@Rufustoad
Looks like you have plenty of suggestions on aligning. So...

With respect to the above on threading, I suspect that if you use the mechanical clutch to shut down the motion that the threading phase maybe lost or at lease offset. The proximity sensor system does not loose the threading phase.

My VFD design allows the jog function to still work after the proximity sensor has tripped the safety latch OFF which causes the motor (spindle and tool motion) to stop. I designed the VFD conversion in a way just to address the issue you are addressing. You do not have to change anything or trip any other switches. The Steps are: Thread or feed until the proximity sensor is tripped to stop the motion (automatic feed or by hand). Motor has shut off. 2) DO NOT disengage the feed or lead screw so you DO NOT loose the threading phase. 3) Back the tool out from the thread. 4) Reverse Jog away moving away from the proximity sensor, i.e move the saddle away from the spindle. This causes the proximity sensor to no longer being active. 5) Move the lathe run switch lever to the neutral position to enable the safety Latch to activate ON. This then allows you to put the run into Run. 6) Put the lathe run in reverse until you get to near where the thread or cut starts. 7) Jog to the exact location you want to start the next cut. 8) Put the tool point to the depth you wish to cut. 9) Start your next cut. Repeat all until the final thread depth is cut. (If you do not demand high quality threads you probably can just run the tool backwards rather than backing it off during the return trip to the start position. It should be tracking the threads to within any backlash or debris...)

These steps are very fast and you do not have to worry about the thread phase. So no mistakes doing so.

If I recall, the Jog function causes my motor run at 6 Hz. So 1/10 that of 60 Hz so the travel rate is typically very slow, so it is even hard to make a mistake and go the wrong way very far ... unless you are totally non-observant!

You will find this written up in my VFD conversion posting at the link below or at: https://www.hobby-machinist.com/att...-vfddescript-links-dnl-l910_1440b-pdf.378083/

However that write up is more on how to build the system rather than on how to use it. Maybe I should fix that up .... if I ever revise the posting.

VFD conversion using solid state electronic components.

Dave L.

 

[mac1911]

I've been looking for great tutorials for our 'beginner tutorials' section. PM me if you find one also.


Here's how I've done it for over 40 years:

When you are setting up the lathe you need to first get the ways *approximately* in a single plane. I call this alignment - but a more common term is leveling. That is because the easiest way to get the ways ready for setting up the lathe is to use a machinist's level. But any level that is sensitive to .005 (or even .010) per foot will do.

You can then align the headstock. That is done by turning a short piece of easily cut material - aluminum, soft steel, whatever you have, that is 1" in diameter or greater. You check that the *headstock only* is cutting a perfect cylinder, accurate to you best measuring device.

You then need to align your tailstock. I use a 'dial test indicator' to do this. but you are free to explore alternatives. I chuck my DTI in the 3 jaw chuck. Then I position the carriage, DTI and tailstock barrel so that I can sweep the inside of the tailstock taper with the tailstock barrel just contacting the tool post. My DTI holder is long enough to do this, but you might have to fashion an extension.

Now comes the magic. Once you have proven that the retracted barrel of the tailstock is on centre, you then crank out the barrel, which is held by the tool post. This causes the tailstock to move outwards from the chuck and DTI. You then adjust the tailstock so it reads true again. You might have to go back and forth a few times, depending on the design of your tail stock.

Then and only then, can you do the 2 collar test, which gets you to under tenths of a thousand of an inch on tapers. I've never need to do this step.

I would like to see a really good video on Rollies Dads Method?

 

[pontiac428]

I would like to see a really good video on Rollies Dads Method?

How about the original .pdf instead?

 

[mac1911]

How about the original .pdf instead?

Im a very visual type . Love to see a well done video also