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Creativechipper

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#1
Hello all and thanks for the help to get me to this point.

I have a 1" round of aluminum to cut my test cuts for squareness in my setup.

I have measured the round bar in my 3 jaw and played with center to come up with a high and low of 2 thousnadths on either side of zero on my dial indicator. I measured close and far on the bar and seems consistent.
I know the round bar stock aluminum has some uneven spots as I have not trued it.

Whats the norm on plus or minus for truing something like this up?

Also have a couple open threaded holes on my lathe, are these for accessories?

Set up specs, tools to use, procedures to follow, would be great info.

I am watching the MIT videos and mrpete222 series of videos and learning a lot.
 

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RJSakowski

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#2
The amount of runout your'e willing to work with depends on how you intend to use the stock. I try to use oversized stock and complete all operations where runout is critical in a single setup. This insures concentricity without a lot of fuss.
If I need to do a second setup like reversing the part where concentricity is critical, then I will dial it in. My 3 jaw chuck has about .003" TIR. If I need better than that, I'll use my 4 jaw or 5C collet chuck. If you need to have near zero runout but need to remove the part mid-process for inspection, consider turning between centers.
Joe Pieczynski did a You Tube video on getting near zero runout with a 3 jaw chuck
 

Eddyde

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#3
That test bar is sticking out way to much to give an accurate reading.
 

Cadillac

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#4
Those extra holes are for the follow rest to be mounted.
 

Creativechipper

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#5
I was going for the rollie dad technique of measuring a 10-12" long rod to check for square and levelness.

I am interested in finding out how accurate the lathe is and also what I should expect as far as accuracy? I would like to do this before turning a project and then wondering is it me or the lathe that is off. As I am sure I will be off as I have no skills at this yet.

Follow rest, hmm wonder if that came with my lathe, I will google now and find out if it did and what it looks like.

From the dial indicator I see a difference of 4 thousandths from base to tip if I crank the slide while ridding on the top of the test bar, lower at the end higher at the base. I have no idea if this is to be expected with a pc of steel about 10" long and 1/4" across. Different than the one pictured.

Thanks
 
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T Bredehoft

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#6
If you attempt to turn that bar, put a center drill hole in the end and a live center in your tailstock to support it. You cannot get a reasonable cut with that much sticking out of the lathe. If you knew that, ignore this.
 

Creativechipper

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#7
No cutting yet, just trying to measure , see if my lathe is going to cut a taper vs cylinder shape.

I have never done this before and just trying to go off the info I have so far. I really don't want to attempt to make something and then find it wrong and not know if its the lathe being out of square or myself making a mistake in cutting or measuring.

What steps would you take next with this lathe before cutting?
 

P. Waller

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#8
Band it, put a center in the end and cut the part to .975" X .5" long at the tailstock end. Pull the tool out and return to the chuck end and take a .975" X .5 long cut, measure and compare. This will give you the amount of taper from tail stock to chuck, if a long part do the same in the center and this will tell you how much the part is deflecting. With a manual machine you may adjust the tail stock to remove the taper, the deflection at the center presents a different problem.
With a decent NC machine one can program the deflection and taper out of the part, you do not have this option.
 

Creativechipper

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#9
Will a dead center work assuming I drill a pilot hole? Also should I worry about facing the end of the bar prior to drilling a divot?

Assuming my bar stock is 1" round a .975" cut does not leave a whole lot of room for error, is this right?
 

T Bredehoft

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#10
Will your lathe swallow the 1" bar? Put the entire bar through the chuck with 1/4" sticking out. Face the end, skin cut, and ctr drill. A C enter Drill is a special tool that the center in the tailstock will fit into. If the center is properly done, .025 is lots of room.
 

Creativechipper

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#11
Yes I tried tonight , put the 1" through the chuck with only a small amount out. I thought small amount was 3" after having 10" out, will adjust to 1/4".
Yes on the center drills, just arrived today. A set of anytime tools 5 lathe center drills size 1-5 60 degree tip angle. Also picked up a 1/2" JT33 2MT drill chuck, arbor is threaded for draw bars.
Just measured stuff, no power on or cutting. Put my dial indicator so the cross slide pushed on it, nice to test the accuracy of my dials on the lathe vs the dial indicator.
Thinking about modding a direct measure of cross slide and feed with a couple gauges. Might be a lot easier to read as I work, plus my handles/dials are a bit sloppy.
Thanks for the tips!!
 

MozamPete

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#12
Surely, if you want to check the alignment of the headstock or twist/leveling in the lathe bed (both of which will cause a taper if wrong) you need to take the very light test cut, over a reasonable distance from the headstock, without supporting the piece with the tailstock - just as he was proposing. If you support the work with a tailstock center all you will be confirming is the tailstock alignment.

You want to do both as part of your initial setup - but you should start with the test piece unsupported.

I made up a steel bar with two aluminum collars locktighted on for just this purpose. The cut can then be a light as possible and cause the least impact on the result, while the steel bar remains a rigid as possible.

IMG_0613s.jpg
 

Eddyde

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#13
Surely, if you want to check the alignment of the headstock or twist/leveling in the lathe bed (both of which will cause a taper if wrong) you need to take the very light test cut, over a reasonable distance from the headstock, without supporting the piece with the tailstock - just as he was proposing. If you support the work with a tailstock center all you will be confirming is the tailstock alignment.

You want to do both as part of your initial setup - but you should start with the test piece unsupported.

I made up a steel bar with two aluminum collars locktighted on for just this purpose. The cut can then be a light as possible and cause the least impact on the result, while the steel bar remains a rigid as possible.
How do you determine what is out, it could be the headstock, it could be the bed twist or even the chuck?
 

MozamPete

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#14
How do you determine what is out, it could be the headstock, it could be the bed twist or even the chuck?
Typically you don't need to, you just adjust the leveling on the lathe bed until the combine effect is no taper.

From the Myford ML7 manual:

1532697379773.png
1532697431240.png
 

Creativechipper

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#15
Used a laser on my cross feed and marked where the dot was on my 3 jaw then spun the feed wheel so it traveled to the tail stock end of the lathe. Over the distance the dot moved 1/8" up and 1/8" to the right. Anyone else try to use a laser, kinda like bore sighting a gun?

Will continue and try to get a test pc cut, thanks for all the help.
 

jdedmon91

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#16
The amount of runout your'e willing to work with depends on how you intend to use the stock. I try to use oversized stock and complete all operations where runout is critical in a single setup. This insures concentricity without a lot of fuss.
If I need to do a second setup like reversing the part where concentricity is critical, then I will dial it in. My 3 jaw chuck has about .003" TIR. If I need better than that, I'll use my 4 jaw or 5C collet chuck. If you need to have near zero runout but need to remove the part mid-process for inspection, consider turning between centers.
Joe Pieczynski did a You Tube video on getting near zero runout with a 3 jaw chuck
Old trick I learned years ago. Mark #1 jaw on your 3 jaw. Then make an alignment mark on on the part in line with with the chuck mark on #1. This will give you runout corespondent with the chuck


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Creativechipper

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#17
I do not follow marking my chuck and my bar stock, what is the relation/where do you measure to see the run out? I already rotate the stock as I tighten and loosen the jaws to get the best fit by measuring with dial indicator, loosening and rotating a bit more repeating making note until I find the least run out.
 

jdedmon91

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#18
I do not follow marking my chuck and my bar stock, what is the relation/where do you measure to see the run out? I already rotate the stock as I tighten and loosen the jaws to get the best fit by measuring with dial indicator, loosening and rotating a bit more repeating making note until I find the least run out.
That is on a 3 jaw chuck only. Not a 4 jaw that you adjust.


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Creativechipper

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#19
I have a 3 jaw self centering chuck.
 

jdedmon91

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#20
I have a 3 jaw self centering chuck.
I was referring to an operation where you need to flip the part in the chuck. In response to a post about using a 4 jaw to indicate the part in.

To check your chuck runout you need to use a different method. If I was checking chuck runout I’d find a true shaft preferably a ground rod. The chuck it up close to the chuck and indicate the runout.

Example if your chuck has .002 runout. You machine the first part of your part, mark as I describe and align the marks in theory the part would have the same .002 runout. This is what I did when I made my fly cutter


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#21
Maybe you know this, but a 3 jaw self centering chuck is usually off a few thousands. It is not going to be perfectly centered so if you take the part out to turn it around and put it back in the chuck, if you mark it and the chuck first you can put it back lining up the marks so that it is closest to the center it can be in that same chuck and position.
 

Creativechipper

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#22
oh the confusion has set in and a bit overwhelmed at getting a method to check my set up is square.

Simply trying to make sure things are true before cutting as mentioned that the lathe needs to be square and level to avoid cutting a taper on all the crap I am going to make. Not trying to make this difficult, just never done it before and you all keep giving me a crap load of different things to adjust.

Whats the proper set up and checking procedure before making your first cuts on a brand new lathe?
 

RJSakowski

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#23
Old trick I learned years ago. Mark #1 jaw on your 3 jaw. Then make an alignment mark on on the part in line with with the chuck mark on #1. This will give you runout corespondent with the chuck


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It's c;lose but not perfect. I do that as well and also if I need to pull a part for checking fit.
 

Creativechipper

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#24
1st time lathe user, 1st set up and trying to find out what checks before 1st cuts and maybe a procedure on checking my 1st cuts to see that all is ok with the setup of the lathe.
 

jdedmon91

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#25
1st time lathe user, 1st set up and trying to find out what checks before 1st cuts and maybe a procedure on checking my 1st cuts to see that all is ok with the setup of the lathe.
In order. 1 clean up completely. 2 make sure you have the correct fluids in the machine headstock carriage and way oils 3 make sure everything is tight 4 level the machine especially across the bed to prevent twist 5 connect power to the machine and check the proper function of all controls. 6 center tools and make test cuts.

That is my recommendation. When you make the light test cuts that will show up any loose spindle bearings or such in a used machine.

Then if everything seems ok the you can check chuck runout and taper when turning between centers.

First of all you want to know if everything functions before seeing what you have in things like runout


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Creativechipper

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#26
Basically I have no adjustments for leveling the lathe, 2 holes at head stock and one hole at tail to bolt it down. It sits on a wooden bench with non adjustable legs. I thought I could shim with feeler gauges under the lathe but was advised to remove all shims under lathe.

Looks like a set of adjustable riser blocks would give me options on leveling but I dont know where to get some and have extremely limited tools to make stuff.

At this point I guess it will just have to be ok, I dont want to disassemble my engine hoist and return it until I know I dont have to jack the lathe up anymore. Big pain moving a hoist on tile through hallways and into my lathe room.
 

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#27
Hello Creativechipper,
Yes it can be a bit daunting at first but you are in the right place. As jdedmon91 suggested a good clean and inspection and familiarize your self with what does what. Before getting carried away start with just leveling the lathe. The bed has to be level in two planes, longitudinal and across the bed. The idea is to eliminate twist. Your lathe could be nailed to the wall and still cut straight if the bed is level. That carpenters level is not accurate enough,(I like your laser idea, that definitely needs further investigation),for the moment watch the video at this link:
Getting the lathe level should be all you need to do. The level does need to be checked occasionally as everything shifts with time.

Get it level, adjust as much backlash out as you can on the gibs and cross screw and start cutting. As you get familiar with the machine and find out more about its foibles you will be better able to make informed decisions about what if anything needs to be done/changed/modified.
 

Creativechipper

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#28
Thanks, will do. The more measuring and practice turning the wheels and seeing exactly what happens is helping.
I have a small 1/4" cutter and to center in my qctp I needed to shim, is using a allen key/wrench ok to do?
I do have some 1/2" hss cutters that look much beefier than the indexable carbide 1/4" cutters. But being I am only taking a tiny cut to test should I use the carbide 1/4" or the hss 1/2"?
 

mikey

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#29
Hone the HSS tool, get it dead on center and do your tests. Trying to take micro-cuts with an inserted carbide tool and expecting accurate results is a lesson in frustration. The reason is quite simple; the nose radius will cause deflection at small depths of cut and you will not know how much is due to deflection and how much is your lathe level being off. Use the HSS tool.
 

GunsOfNavarone

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#30
CreativeChipper, I am where you are as well. I have spent the last 10 or so days, getting the right fluids, breaking in everything, oil change, leveling and leveling a bit more. Switching out tool post to a QCTP, checking that is correctly aligned after making t-nut. I went out and bought some 2.25" sq aluminum (by 4' as I have other projects) I AM NOW READY FOR THIS TEST SHAPE....FINALLY!! Researching what i need to do, I found This thread. So 10 plus days and a lot of checking and poking around, I'm ready (I also read "How to Run a Lathe") it has been a butt full of stuff to do and I have felt like an idiot, doesn't help i have a short attention span! you just want to make sure you're ready for the next step, if not you'll waste time and materials. Listen to these guys, the combined knowledge is staggering. I have found even after multiple questions and I am still confused (maybe even more than when I started) this group is patient and will work you through it.
do you have a machinist level, I believe it is a must have though I have seen overly complicated rigged up equipment to do the same. Watch that leveling video that Norton Dommi posted, it will clear some things up.
 
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