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Tramming a mill

I like to use the indicol brand of indicator holders.

http://www.penntoolco.com/catalog/products/products.cfm?categoryID=583

If you adjust one axis at a time, you will probably be more likely to figure out how to do it fairly quickly. Leave a bit of snugness on the bolts so the head does not flop around, but not too much where it is difficult to move. After you think that you have it, tighten and re-check. Depending on the machine, some move when you tighten the bolts and some don't.
 
some people will say I don't know what I'm doing but I have been getting good results with my coax (at least my excuse is that my test indicator is busted)
 
Your choice..

You can leave the head about .0005" low on the left side so when you flycut the cutter's back side doesn't drag accross the work.

Tram the head the way you are going to use it the most. .. Spindle about 2" down, knee locked or unlocked?

Everything makes a difference.

If you want the "Y" axis handle in your tummy all the time then center the ram. If you want to stand close to the table while working, then move the head+ram over to the right a bit.

In other words make the machine comfortable for yourself. It does of course depend on the type of work you will be doing.

Regards,

Stan-
 
How about the 2 dial indicators. Is that worth the money? Also this looks like a big race are they worth the money? Thanks again. Home shop setup.
 
Dave is that way better than putting it in the collect? Alan

I think so. You get a wider reach and therefore the indicator is easier to read. It helps if you have an indicator that has at least .06 travel. I have an Interrapid that I bought about 20 years ago. It set me back $150 or so, but I still have it, and it still works like a new one. I use it almost every day. They make cheap knockoffs of both the Indicol and the Interrapid indicators, but you get what you pay for. If this is only a hobby for you, you might try the cheapo ones until you decide that the better tools are worth the investment.
 
How about the 2 dial indicators. Is that worth the money? Also this looks like a big race are they worth the money? Thanks again. Home shop setup.

I have to admit that I have never used the 2 indicator system. I have seen them in catalogs, but I like the Indicol and the Interrapid indicator. (A lot of this is personal preference. You might buy the 2 indicator deal and discover that you like it, and it works well for you.)
 
I have used the "two indicator" device and it works beautifully. Very easy to read and use. Very fast and accurate.

But, probably not worth the $ if not used often. So, if you will not be tilting the head with regularity, it may not be cost effective. Using an indicator that you already have it pretty darn cost effective.

A great way to easily and quickly get within the range of the indicator is to stick a piece of bent welding rod or coathanger in the chuck or a collet and swing it around against the table. Your eye can easily see .030-.060". Then use your indicator to nail it.

John.
 
I have two of the 2-dial indicators, one that I built a number of years ago and a commercial one that I bought.

They are MUCH faster than any other method I've used, and I've been tramming Bridgeports for 43 years.

- Leigh
 
Run the quill down, place a right angle plate on the table next to the quill, adjust either the X or the y axis by sight using the quill against the right angle plate, do the other axis next, then bring out the indicators. It'll get you in the ballpark quickly.
 
seems like there's always tramming gimmicks, maybe some save a little time....some may introduce error, none are necessary or worth shelling out hard earned dollars for, imo. once you're onto it with a simple homemade arm as shown in the photo and a good indicator, its a quick job. that and you need a little stealth in pilfering the wife's makeup mirror. I use a tenths indicator, not that it has to be trammed to tenths, but I always use a tenths as it exaggerates things, ie a lot easier to get with 1/2 a thou with a tenths than a .001" indicator. build an arm like in the pic and you wont need anything else

trammingmill.jpg
 
Actually, if the vise surface is not parallel to the table or the jaws perpendicular to the table it should be machined so it is. Leaving the vise or any accessory out of "0" on any flat surface is a mistake.
 
1/4 inch diameter bar out of a 1/4 inch collett. I bent the bar to about 75 degrees to create a tramming arm, and use an indicator holder on the bar to hold my indicator. Surface ground 4 A2 blocks to use as gauge blocks for tramming, tested them to assure equal heights with the small CMM.

I do the X axis first to get in the ball park easy, then the Y axis second to get it in the ballpark, then swing the whole circle as wide as the table in the Y and also touching the X axis to assure getting to better than .0005 error TIR.

I keep hearing about the .0005 "lead" for the flycutter, but try to avoid this as I do not always cut in the same direction. Probably no harm in doing this though.
 
I think you are supposed to tram to the table travel. If you don't the fly cutter will drag because the circle it makes will not be parallel to the milling motion. If the vise is off then fix the vise.

Regards,

Stan-
 
You can leave the head about .0005" low on the left side so when you flycut the cutter's back side doesn't drag accross the work.
Regards,

Stan-

I see this a lot, but no body seems to mention at what diameter?

.0005" tilt at 2" diameter is way different that .0005" tilt at 10" diameter!

Just pointing that out to some that may not realize that Stan, not critisizing you:)

Glenn
 
Here is what I used when I first trammed my Bridgeport.
Nice and simple........

RAW15001_1429.jpg


Then I wanted a better arm that was adjustable to find centers of holes, so I got the Nogaflex arm. Now I like to use it to tram the mill rather than my using original hardware because it sets up so quickly. And that Noga arm does not flex at all.......
RAW08ABC_2130.jpg

pg


 
I unscrew the rod from my cheapo mag base and lay a 6" or so diameter ball bearing race on the table. That's about as flat an object as you are likely to come across and it is also round. Sweep the indicator around, adjust either X or Y first, makes no difference, but do one and then the other. You'll chase your tail, otherwise.

I just tram it flat. If I were to tram it slightly to one side to prevent the flycutter dragging, I'd need to cut from the other direction on the first setup, lol.
 








 
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