# Tramming my mill/drill



## mickri (Feb 7, 2017)

Getting my Excel mill/drill set up.  So today I tried my hand at tramming the mill.  I have read numerous threads on how to do this and think that I did it right.  Because there is some play in the quill I discovered that I got different readings if I changed the direction of rotation.  And that I had to be very careful when rotating the quill or I would get different readings.  It was a real PIA to catch the indicator tip when it passed over the T slots in the table.  Is this normal? 
After much trial and error and carefully rotating the quill counterclockwise I was able to get consistent, repeatable readings. I went all the way around several times and watched how the readings changed as I went around a complete circle.  Front to back the back was -.001, maybe -.0015 compared to the front.  Side to side had the same readings maybe -.0005 compared to the front.  I was not able to determine accurate readings on a 45 degree axis to fore and aft, side to side.    My dial indicator has a pretty small dial and reads to .001 so it was hard to accurately determine the reading between the marks.
I think that I am good to go here.  I doubt that I will ever develop the skill to be able to machine even close to this level of accuracy.
What do you guys think?


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## willthedancer (Feb 7, 2017)

Don't sell yourself short.

I used large radiused points on my indicator to get past the t-slot issue. I also looked to not engage the indicator very far so that it wouldn't drop into the slots. If you're within a couple thou in 6" sweep, you probably won't notice any alignment related heeling by your cutter.


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## mikey (Feb 8, 2017)

Tramming a mill drill ain't for sissies, that's for sure. I have an RF-31 and went/am still going through the same thing. One thing I found is that if the spindle is loose then tramming is difficult to do, simply because the anchor for the indicator is moving around. This is one of the reasons I changed the bearings in the spindle and drive sleeve and it helped. I was able to tram well enough to get tram within 0.0005" in both 45 degree directions. HOWEVER, when I fly cut something it is clear to me the tram is still not close enough so I'm making an adapter to put my Starrett back plunger indicator with a big button tip (like Will said) on a Noga arm so I can get it out about 8-9" from the spindle in X and will attempt to get the tram closer.

Anyway, what the above will do is get the mill trammed at one specific elevation of the head, about mid-point in the travel of the head where I do most of my work. I have to see how off it gets when I move the head. I bought a Precision Brand shim pack assortment and also have onion skin so I am hoping I'll get it near zero in the near future. The question is whether or not zero tram in one elevation will translate into acceptable tram at other elevations. I'll try to document what I'm doing and post it sometime, in case its of interest to other mill drill owners.

Fun, isn't it?


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## jim18655 (Feb 8, 2017)

Try using a new disk brake rotor clamped down through the center hole. Measure the thickness of the rotor at several spots and determine if it's within your margin of acceptable error. Your well-used table might not be any flatter than the error of the rotor and it would average out the nicks and bumps in a larger piece of metal clamped to the table.


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## ddickey (Feb 8, 2017)

I talked my to an old friend the other day who is a tool and die maker. I asked him about tramming the mill. He said he never trammed the table only the vice. He has a round, ground piece of stock that he lays on the vice bed or  ways of the vise. Not sure if this is good idea or not. Sounded interesting though.


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## mickri (Feb 8, 2017)

In the future I will probably put a .001 shim under the back side of the column.  For right now I am just going to leave it the way it is.  I should receive my handwheel and crank within a day or so and will have my mill/drill ready to use by this weekend.  I have several projects lined up and will start new threads for guidance on my projects.  Thanks for your comments and suggestions.
Chuck


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## AGCB97 (Feb 8, 2017)

I too have found doing this as you explain not difficult but tedious and time consuming. Therefor I made one of these






I got 2 inexpensive indicators

http://www.ebay.com/itm/301598218762?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

from EBAY for $10.95 each and made the rest from scrap. Didn't do all the fancy stuff in the video, just a basic tool that works great! and a box to store it in. Now I won't hesitate to angle the head whenever I want

Aaron


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## mikey (Feb 8, 2017)

ddickey said:


> I talked my to an old friend the other day who is a tool and die maker. I asked him about tramming the mill. He said he never trammed the table only the vice. He has a round, ground piece of stock that he lays on the vice bed or  ways of the vise. Not sure if this is good idea or not. Sounded interesting though.



I would say that your friend is in the minority of mill users if he doesn't tram the mill head. I know a lot of mill drill owners tram the vise though, because the tram changes whenever you move the head on the stupid round column. Maybe your friend uses a round column mill? It is definitely easier to tram the vise than to tram the column.


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## ddickey (Feb 8, 2017)

mikey said:


> I would say that your friend is in the minority of mill users if he doesn't tram the mill head. I know a lot of mill drill owners tram the vise though, because the tram changes whenever you move the head on the stupid round column. Maybe your friend uses a round column mill? It is definitely easier to tram the vise than to tram the column.


 I don't know Mikey. I doubt he uses a mill much at all. If you tram the head to your vise isn't that all you need? Your vise hold your work, no? I'm not arguing I just want to understand why the bed of the mill is more important than the vise.


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## ddickey (Feb 8, 2017)

AGCB97 said:


> I too have found doing this as you explain not difficult but tedious and time consuming. Therefor I made one of these
> 
> 
> 
> ...


I just finished making one of those but I made the mistake of recessing the dial indicators into rectangle piece. Press fitting the rod into the center, meaning it is offset. Now when I rotate the opposite indicator is not on the same spot. Will probably have to make a new one.


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## mikey (Feb 8, 2017)

ddickey said:


> I don't know Mikey. I doubt he uses a mill much at all. If you tram the head to your vise isn't that all you need? Your vise hold your work, no? I'm not arguing I just want to understand why the bed of the mill is more important than the vise.



I think its a matter of convenience. If you tram only the vise, then you also have to tram your rotary table or any part you bolt to the table and that gets tedious because you have to tram it in both X and Y. Easier to tram the head so it is square; then anything that sits on the table is theoretically square.


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## ddickey (Feb 8, 2017)

Good point. So we can assume our rotary table and vise are flat? I'd like to believe my Kurt is, not sure about the rotary table though.


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## mikey (Feb 8, 2017)

Assume nothing. Best to check and verify.


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## AGCB97 (Feb 9, 2017)

ddickey said:


> I just finished making one of those but I made the mistake of recessing the dial indicators into rectangle piece. Press fitting the rod into the center, meaning it is offset. Now when I rotate the opposite indicator is not on the same spot. Will probably have to make a new one.



I don't understand what you mean by "recessing the dial indicators into rectangle piece". This does not have to be built perfectly square to work because you zero the indicators on a common point before tramming.

I put the indicators in a pinch hole so they can be made to look relatively the same (lets say zero on top). Then each indicator is zeroed one at a time on a block at the front edge of the table (so you can see them w/o using a mirror). Recheck a couple times and it's now ready to use being* perfectly* square.

Even if you can't move the indicators in their holes, it only results in the faces not being symmetrical but it still works once each one is zeroed

Hope this helps and you don't throw away the time you spent so far.


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## ddickey (Feb 9, 2017)

Like this.
	

		
			
		

		
	



	

		
			
		

		
	
 It works but is not proper as the opposite indicator never hits the spot you calibrated the first one after turning 180°. The indicators are offset from the axis of rotation.


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## MozamPete (Feb 9, 2017)

When I tram the head of my mill I normally just put my largest end mill in (25mm dia.) and take light cuts on a scrap aluminum block, overlapping them slightly (i.e. almost the full width of the cutter between passes).  If I cant feel a step where they overlap I consider it good enough and go on and do the other axis the same.  No need for a indicator.
May not be the best method but I find it simple and I'm checking the result I'm actually after - that if I take multiple overlapping cut I will end up with a flat surface.


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