# Tramming the nod



## Aukai (Dec 17, 2017)

Learning about tramming on my G0755 mill. My X-Y  axis is/seems square at the table, and with the vice. If I put a stubby drill bit in the chuck upside down, and bring it into the vice jaws I can see that the nod is definitely off. I have used the dual dial indicators for the table, and a DTI when doing the vice. I did see the machinist square used, but read here that method was not in high favor, so do I need a cylindrical square? I have seen different opinions on shimming as well, and on what to use for that purpose. This is for garage personal use. Operator error may be in play here as well, but I think I'm getting better. I did read posts from here, and tried to go online also. Now I do not remember if I lock down the screws for the dove tail, so I have to go back, and recheck. Thank you


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## EmilioG (Dec 17, 2017)

Having you tried tramming in the vise or work surface instead of the table, with a .0005" res. DTI?
Don't know anything about Grizzly drill/mill. Maybe someone here has one?

RE:  https://www.manualslib.com/manual/513140/Grizzly-G0755.html?page=40


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## Aukai (Dec 17, 2017)

4ssss said:


> Ok, so you're eyeballs are more accurate than an indicator?


I hope I'm not giving that impression, but I may be making rookie mistakes. When I bring the spindal down I can see a light shadow between the vice, and the butt of the drill bit, It just does not look right. Now I'm looking for the right way to check the nod. Thank you


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## Tony Wells (Dec 17, 2017)

Use an indicator, just like the -X- axis. Just remember, if you are having to shim the foot, you might throw off the -X- axis, so check it along the way as you go to minimize the error. Otherwise you might end up just chasing the out of square surface and end up with many more shims than needed. 

Disclaimer: I have not looked at your machine to give more specific advice.


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## Aukai (Dec 17, 2017)

EmilioG said:


> Having you tried tramming in the vise or work surface instead of the table, with a .0005" res. DTI?
> Don't know anything about Grizzly drill/mill. Maybe someone here has one?
> 
> RE:  https://www.manualslib.com/manual/513140/Grizzly-G0755.html?page=40


On the X axis the vice is right on, on the Y vice axis it's a very short run, and looks to be very close to right on. I will have to go back, and write numbers down.


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## dlane (Dec 18, 2017)

Tram work area, whet ever it is


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## EmilioG (Dec 18, 2017)

Are you halving the numbers when you lightly tap the head up with your palm? Do you have a .0005" DTI?
Do you have precision 1 2 3 blocks/parallels? to use instead of the table surface?


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## Aukai (Dec 18, 2017)

EmilioG said:


> Are you halving the numbers when you lightly tap the head up with your palm? Do you have a .0005" DTI?
> Do you have precision 1 2 3 blocks/parallels? to use instead of the table surface?


I have not tried to manipulate the head while doing this, other than the X axis, yes on the blocks, and the DTI.


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## EmilioG (Dec 18, 2017)

See:   https://www.manualslib.com/manual/513140/Grizzly-G0755.html?page=41#manual


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## Aukai (Dec 18, 2017)

EmilioG said:


> See:   https://www.manualslib.com/manual/513140/Grizzly-G0755.html?page=41#manual


Thank you, I do have the X at 0.0 on the standing jaw face of the vice, I did not run it on the blocks though. I forget now if I indicated the top of the jaw. Yes I did, don't remember the run out.....


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## Silverbullet (Dec 18, 2017)

If the mill has the nod option then adjust it on the table in front to back and side to side. With the arc of the indicator to the edge front to back . If your mill doesn't have the nod then you'll need shims and have to shim the back of the mill mount to the base . It's tricky can be done. Stefan Gottswinter, on YouTube used an epoxy to cure his mill problems . He's very very good as a machinist .


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## Aukai (Dec 18, 2017)

Silverbullet said:


> If the mill has the nod option then adjust it on the table in front to back and side to side. With the arc of the indicator to the edge front to back . If your mill doesn't have the nod then you'll need shims and have to shim the back of the mill mount to the base . It's tricky can be done. Stefan Gottswinter, on YouTube used an epoxy to cure his mill problems . He's very very good as a machinist .


The mill column is bolted down, no adjustment. I saw him use shim stock, but not the epoxy, unless he did it after the X axis on the video I watched..


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## Billh50 (Dec 18, 2017)

If you tram the table and it is good. Then tram the vice and it is not good. Then the vice is what is out of square with the spindle and not the spindle. You may have to rework the vice to make it square. If you shim the nod to the vice that is out of square you will then be out of square if you need to use just the table without the vice.


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## TomS (Dec 18, 2017)

There are a couple of things to check for nod when it comes to dovetail column mills.  One is spindle to table and the other is spindle to column.  The following Hoss Machine link shows how to check the column to spindle nod.  G0704 Tramming Part 1.wmv

The best I could get my PM-932 was .002" over 8" in "Y" which is not too bad.  Keep in mind you have to have some gib clearance or the head won't move up and down.  If snugging up the gib doesn't correct the nod problem then scraping or machining of the head to column slide may be necessary.  Let us know what you find when running the Hoss Machine test.   

Or as Billh50 said what you are describing could be a vise problem.


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## Aukai (Dec 18, 2017)

Thank you everyone. I will go back and recheck. I may have let a damaged box during the vice shipping go by, and should not have. There was a forklift hole in the end of the box, but no real physical damage that I could tell. OH BOY...


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## Cobra (Dec 18, 2017)

Aukai said:


> The mill column is bolted down, no adjustment. I saw him use shim stock, but not the epoxy, unless he did it after the X axis on the video I watched..


I have a G0755 and had to shim the base of the column When I set it up.  Have not needed to adjust again (touch wood!)
When you are checking the tram you need to ensure that the locks on the column are done up.


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## ch2co (Dec 18, 2017)

Don't have your mill, but like it has been mentioned above, IF your column is perfectly straight  I would check the tightness of the ribs, there are probably several adjusting screws long their length.  You don't want them too tight so as to put too much friction on the movement of the head.
Checking the squarely of your presumedly square vice is also suspect. Lock the column before measuring. 
Good luck.

CHuck the grumpy old guy


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## Scruffy (Dec 18, 2017)

My old mill dosen’t Even have nod?  A little shim stock under the vise and a dial indicator in the spindle and all’s well. After a few minutes.
Thanks ron


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## Ray C (Dec 18, 2017)

Are you using a drill chuck to hold an indicator tool?   If so, that's probably your problem.   I don't know of too many drill chucks that hold better than a few thou runout at the jaws.   When clamping an indicator to a mill, use an appropriate holder that grabs onto the outside of the spindle.

I have an 8" diameter bearing race.  They tend to be highly precision ground.  Lay it flat on the table and adjust the indicator probe such that it circumscribes exactly on the flat edge of the bearing race.   The indicator must be affixed to the rotating part of the spindle.   From the top side of the mill head, turn the drawbar shaft with your fingers while you watch the indicator.   Adjust mill accordingly. 

Once the table is flat, check the back jaw of your vise.  Adjust vise accordingly (or buy a very expensive vise).

Regards

Ray C.


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## Ray C (Dec 18, 2017)

Oh, one other thing...  If you're adjusting nod by shimming the column (which is how I do it) use a torque wrench and the same bolt sequence when you tighten the bolts.


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## Aukai (Dec 18, 2017)

Ray C said:


> Oh, one other thing...  If you're adjusting nod by shimming the column (which is how I do it) use a torque wrench and the same bolt sequence when you tighten the bolts.


Thank you, That is interesting(both posts) I am using a collet for the dual dial indicators, but ran the DTI with the Noga, and the drill chuck. Note to self,  follow the same procedures....
My Noga is a collett mount, is the collar mount better?


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## Ray C (Dec 19, 2017)

A collet should be fine assuming you have no reason to believe it's been spun-out or otherwise inaccurate.  Also, make sure the stem of your holder naturally fits the diameter of the chosen collet.   I use collets on the lathe a lot and when the piece is on the small side of the collet's range, it can throw things off by many thou if you don't seat it properly. 

I don't necessarily think a collar mount is better.  I can see pros/cons to each way of doing it so, I'll back-pedal on my strongly worded advisement of doing it that way.   What I was really trying to convey is you should not use a drill chuck.  Most drill chuck jaws are off a good amount and/or are not repeatable. FWIW, the possible down-side of an external holder is that the bore of the spindle is not perfectly centered with the outside diameter.  That really should not be the case but, you never know until you test and find-out.

What I'm talking about is splitting hairs and may draw criticism.   I've learned the hard way...  you have to see all possible factors at play then, learn and know your equipment so you can refine your techniques. 

Indeed, use a trusted and properly sized collet or, an external spindle mount and tram your heart out.  

Regards

Ray C.


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## Billh50 (Dec 19, 2017)

It shouldn't matter how your holder is mounted as long as it is solid. The indicator, or indicators, will still spin on the spindle axis and thus also be perpendicular to the spindle axis. Much the same as it does not matter what angle a flycutter tool is at the tip still spins perpendicular to the axis of the spindle.


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## higgite (Dec 19, 2017)

Billh50 said:


> It shouldn't matter how your holder is mounted as long as it is solid. The indicator, or indicators, will still spin on the spindle axis and thus also be perpendicular to the spindle axis. Much the same as it does not matter what angle a flycutter tool is at the tip still spins perpendicular to the axis of the spindle.


Thank you, Bill. Exactly what I have been trying to put into words that someone besides me can decipher it. If a drill chuck has even as much as .010" TIR, as long as it doesn't move up and down, what difference does it make if you're sweeping a 10.000" circle or a 10.010" circle with your tramming setup?

Tom


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## Aukai (Dec 19, 2017)

Thank you gentelmen your assistance is greatly appreciated.


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## Ray C (Dec 19, 2017)

Billh50 said:


> It shouldn't matter how your holder is mounted as long as it is solid. The indicator, or indicators, will still spin on the spindle axis and thus also be perpendicular to the spindle axis. Much the same as it does not matter what angle a flycutter tool is at the tip still spins perpendicular to the axis of the spindle.



Bill is absolutely right here.  As long as the indicator is firmly affixed to any part of the spindle or chuck or collet etc, it should be good to go.  My thinking was off track due to a problem with a drill press I bought some time ago.  I happened to notice that drill bits did not appear to be spinning true and in fact, it was wobbling a good amount.  ...Took the chuck out, replaced it with a a different MT/JT mounted chuck...  Same problem.   Finally, I looked inside the spindle bore and there was a piece of the foam peanut packaging preventing the MT shaft from seating all the way.  From that point on, my brain was in the mode of thinking the rotation was off.   Rotation was fine.  Alignment wasn't. 

Thanks to Bill for setting it straight in my head.

Regards

Ray C.


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## Aukai (Dec 22, 2017)

OK let's see if I did this right. For the nod I used both a 0.001 dial indicator, and a 0.0005 DTI. I set the depth of the .001 DI, and zeroed on the outside edge, and swept it to the inside edge. There is a 0.003 runout. with the 0.0005 DTI same procedure it was 0.0025. Would this be accurate, and worth fixing?


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## Ray C (Dec 22, 2017)

Aukai said:


> OK let's see if I did this right. For the nod I used both a 0.001 dial indicator, and a 0.0005 DTI. I set the depth of the .001 DI, and zeroed on the outside edge, and swept it to the inside edge. There is a 0.003 runout. with the 0.0005 DTI same procedure it was 0.0025. Would this be accurate, and worth fixing?



Technically speaking, in my view of things, that's too far out; but.... for now, you might want to consider other things.   I'm going to assume you do most of your work using a vise.   Mount your vice and get a 6" long, 1/2" thick parallel known to be in good condition.  Stand it up vertically in the vise.  Use a piece of copper wire or tig rod etc between the parallel and front jaw and snug the vise so the parallel is kept flat against the rear jaw of the vise.  (Let us know if this is not making sense).  Now, use your indicator and check the up/down (Z) travel runout by cranking the head up/down (don't use the spindle crank).  Check an up/down distance of about 3-4 inches.

Ideally, the table should be flat and your vise's rear jaw should be perpendicular to the table.  If your vise is out a little and so is your table, you need to check error stack-up.  It could be that, for most of the working distances you operate at, the errors collectively cancel out, or, they combine and make things much worse off.

Once again, it's *best *if everything can be perfect (both table and vise) but, we don't always have what we want.  I'm also mentioning this so you understand all the different factors at play.

FWIW, I try to get my table within +/- 0.0005" over an 8" circle.  When I do the vertical test, it's also within +/- 0.0005".   Last but not least, my PM45 has only needed adjustment twice in the 7-8 years I've had it.  The first time was when I made an adjustment using a piece of junk vise.  The second adjustment was made when I purchased a half-decent vise.   Other than that, once nod is properly adjusted, it's pretty hard to knock it out of whack.

Regards

Ray C.


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## Billh50 (Dec 22, 2017)

The table should be Trammed without the Vice first. Get it as close to ZERO as possible. Then mount the vice the Vice and check that. If the vice is off then the vice needs to be repaired or replaced. Moving the quill up and down is not the proper way to Tram a machine!


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## TomS (Dec 22, 2017)

I agree with Billh50.  Tram the spindle to the table.  Once you've got that where you want it you can then check the spindle to the column using the Rollie's Dad's Method described in the Hoss Machine video link I posted above.  If your readings show the spindle isn't true to the column you can machine or scrape the head to column interface or live with it.  Now you can check your vise to spindle.  If the vise jaws are out then fix or replace the vise.


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## ddickey (Dec 22, 2017)

Billh50 said:


> The table should be Trammed without the Vice first. Get it as close to ZERO as possible. Then mount the vice the Vice and check that. If the vice is off then the vice needs to be repaired or replaced. Moving the quill up and down is not the proper way to Tram a machine!


Can you then shim the vice? Or just tram the vise if you are not milling on the table?


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## Billh50 (Dec 22, 2017)

If you tram the back jaw of the vise using the spindle. Then tap a part down on parallels. You can be drilling and milling out of square with the bottom of the part if the vice jaw is not square with the bottom of the vice or with the table.
By tramming the table first then the vice by using the spindle Z you can detect either a problem with the vice back jaw being out of square or wear in the spindle.
On a knee mill make sure the knee is locked and the spindle lightly locked when tramming the table. I know many people tram their machines differently. But the way some do does not show problems that may arise when accuracy is important. For hobby use where a few thoussandths does not matter it is ok to tram any way you think is best for your situation.
I am a bit anal when it comes to tramming my machines as I only use a tenths indicator for everything. I don't even own an indicator in .0005 or .001 divisions.


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## Aukai (Dec 22, 2017)

Thank you gentlemen, off for my 48 hr shift so it will be a couple of days. I can induce 0.0005 rock on the Y plane of the head, and 0.001-2 on the X with everything locked down. Total run out  0 on the outside, and sweeping to the inside is of the table is 0.003. From the center at 0 to the inside is 0.0015 to the outside is 0.001. I'll check back in a bit leaving for work. This is only off of the table.


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