Tramming a mill drill

Discussion on all milling machines vertical & horizontal, including but not limited to Bridgeports, Hardinge, South Bend, Clausing, Van Norman, including imports.

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Lewayne
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Tramming a mill drill

Post by Lewayne » Fri Mar 20, 2020 2:50 pm

CF6A02DA-F53E-466C-8056-44A7EF7223EC.jpeg
I have the mill rework almost finished now. The last job, I think, is tramming the column to the table. It came from China with a few tiny shims under the corners. So my question is, the mill head swivels side to side. Does it make any difference if the column is perfectly perpendicular side to side. Tram can be achieved by adjusting the swivel on the head, right? Am I thinking right?
Then I would only shim for tram on the column/ quill in the front to back direction, where the head itself isn’t adjustable. Just need to know if my thinking is correct before I move from regard?
Thanks.
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Lewayne
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Re: Tramming a mill drill

Post by Lewayne » Fri Mar 20, 2020 2:54 pm

Last sentence was supposed to read “before I move forward”
I hate my phone sometimes.

spro
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Re: Tramming a mill drill

Post by spro » Fri Mar 20, 2020 4:03 pm

Good answers first. Yours has the column base which is inset. It allows more travel in "Y" direction. It appears tilting gearhead and many wanted that. Mine is the old style everyone hated. Heavy solid iron with no tilt but you have to have register. I disassembled mine to get it down the stairs. I saved the shims but not the putty. It is funny about these and it should be so simple. Column base alighnment is one thing. Your actual base and table should be running on flat nice ways and surfaces. It has to be right before a person does this. Sort of right because there will be flex. Aligning everything to perfection is not what that machine sees under load.
I just happen to be in the mood to talk about this. You think the head is heavy, Read a dial indicator to the table when depressing the quill. I couldn't make sense about the shims. I tried other ways and shims until realizing it was set for work and not static. There Was a bias towards drilling and for milling. End mills etc rh drive pressure against the work surface flattened things that no static measurement could. Since yours has a swivel head, there are more angles to deal with. There is a happy medium between, which is the work area that you are comfortable with.

Harold_V
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Re: Tramming a mill drill

Post by Harold_V » Fri Mar 20, 2020 4:04 pm

Lewayne wrote:
Fri Mar 20, 2020 2:50 pm
CF6A02DA-F53E-466C-8056-44A7EF7223EC.jpeg
Does it make any difference if the column is perfectly perpendicular side to side. Tram can be achieved by adjusting the swivel on the head, right? Am I thinking right?
No, you aren't.
Then I would only shim for tram on the column/ quill in the front to back direction, where the head itself isn’t adjustable. Just need to know if my thinking is correct before I move from regard?
Thanks.
Here's the problem, although it is important to mill/drills with ways, not those with a cylindrical column.

When you dial the head true when the column is not dead perpendicular, if you move the head, you lose registration, albeit only by a portion of the amount the column is not perpendicular.

For a round column machine, where registration is lost if the head is moved, it makes little difference.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

spro
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Re: Tramming a mill drill

Post by spro » Fri Mar 20, 2020 4:23 pm

Without .. anyway these machines have had purposes. Dang. Simple little things like shims go opposite the intended use. I Did mine a certain way after noting the flex when drilling. We do get used to these machines and thank you for understanding the challenges.
That doesn't mean it is the end but we learned stuff.
Built quite a few parts and repairs with them back 25 years ago. Remember when you were 10 years old and didn't even have a drill press. When I became older, I wired the basement and got him a serious drill press.

Lewayne
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Re: Tramming a mill drill

Post by Lewayne » Fri Mar 20, 2020 7:34 pm

Okay, if the head rotates, ( as it does) then how do you even get the column square to the table. How would I even check that? How could I tell if the column was out or just the head out of adjustment. I hadn’t given this much thought till right now when I started preparing to do it. If I’m not looking for it to be correct when static. Do I just lock it down and use it, then check parts and shim it later as I think I need to. I’m not building any rocket parts here.

spro
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Re: Tramming a mill drill

Post by spro » Fri Mar 20, 2020 9:30 pm

Okay. I don't want to drop a load on you. We are talking two different machines. Very different round column machines. Static is good but check where it goes under pressure for drilling isn't the same as milling. Heck. Align it right and go from there. You will find in different ways than mine. One important thing is the shims to column base to table base. Don't crank tight on those ears when it looks out of tram. It is cast iron and goes from stable to a cracked ear in a second. I had shims tapered shims but the main thing was the base mating the table base. So the closer you get to that, the better. Sure, perpendicular seems right for the other angles to deal with. How else ? You can tweak it later but not too far.
Mine was old style with a honkin 2 hp single phase motor at the rear. I have 3 clamps to secure the head to the column. It was a balancing act to fix it tight and not flex much. I didn't drop the rebar and cement into the column like others did.
Get it aligned right and go from there, with minor tweaks. These are way above a drill press. The tables and heads of them are flexing every which way while drilling but still drill accurate holes. The good ones achieved a balance to where the drills were pulling the chips while the downward pressure. Cool stuff really. and coolant.

Harold_V
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Re: Tramming a mill drill

Post by Harold_V » Sat Mar 21, 2020 1:16 am

It's a little tricky dialing in a round column. What you can do is sweep the table and get the reading identical. Front to back will be a true representation of the column as it relates to the spindle, but the sides can be made to read the same because the head rotates. The difference, front to back, will be the amount that must be shimmed at the base, assuming you sweep a circle that is the same length as the bolt centers, front to back.

Side to side is a totally different matter, as you can make the spindle true to the table, but that may or may not (and most likely is not) true to the column. So what you can do is use that as a reference. Get the spindle true, then place an indicator (mounted on the quill) with the tip on either side of the column. Stroke the spindle full length, or as far as you can, and measure that distance so it will help you to determine how much shimming will be required. The reading of the indicator will tell you how far off the spindle is as it relates to the column. Keep in mind, the reading won't represent the proper amount of shim, as that is determined by the length of the stroke as it relates to the bolt centers of the column. A little math will be required.

Once you've shimmed the base, you're going to find that the head is no longer true, so you start over, dialing in the head once again, so you can repeat the process until you find the same reading (less than .0005") when you sweep the table and then the column. That's when the column is erect, and the head properly dialed in with the table.

I highly recommend you get the column quite close. While your round column will be subject to losing registration when you move the head, it's nice to know you can rely on the machine being properly set up. And, remember, unless you dismantle the machine for some reason, you only have to go through this once. Get it right and it's right forever. Leave it off and it's off forever. That's my logic, and I'd pursue good alignment, with less than a half thou over the length of stroke of the quill, or closer.

I hope this helps you. It may sound overwhelming, but don't get discouraged. This is an excellent exercise for you to help gain skill and understanding.

H

Edit: A little tip. As you won't be able to install full length shims (because each bolt will require its own thickness), you can make U shaped shims, wide enough to support properly, and easily installed by simply loosening the bolts. No need to remove the bolts or to lift the column. Just rock it to the needed position with all bolts in place so it can't get away from you. Bolts should be loose enough for the base to tilt slightly, but tightened fully when you do any inspections, so they represent the real condition of the column. By placing them as I suggested, it won't be easy to break an ear, either. Keep the shims under the bolts, not to either side.
Wise people talk because they have something to say. Fools talk because they have to say something.

elewayne
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Re: Tramming a mill drill

Post by elewayne » Sat Mar 21, 2020 1:24 pm

Okay, thanks to both of you for responding.
Harold, you write very well, I get you're saying. I really had no idea how to check the column side to side. Now I do. As soon as I get the time( I have a paying woodworking project going) I'll start truing it up. Looks like it may take a while anyway. But I'm patient and have the time. I'll get it done. I'm learning all kinds of things just trying to get this machine set up and usable. I know where it came from and also knew it would have issues. Maybe that should have scared me but I guess it didn't. I knew I had you guys, so thanks again.

pete
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Re: Tramming a mill drill

Post by pete » Sun Mar 22, 2020 12:32 am

If the column isn't as true as possible then it's obviously going to be tilted to some degree. That can be in a single axis or even a combination in both X and Y. Not to go too far OT from the original question, but compounding the issue is the column is going to deflect differently depending on where on the column the full head weight happens to be. All machine tools deflect, some more than others. But it's an inescapable fact of using them. The Moore Tools book Foundations of Mechanical Accuracy shows the best example I know of about how the way's in a machine tool or in your case the vertical column could be out in multiple combinations. If the column has a tilt to it and depending on which direction it's out, the spindle C/L can move (from the operators perspective) towards or away from you, or left/right, or that combination of both as the head is moved up or down the column. Since your spindle center line position is lost on these round column mills anytime the head is moved and you have to re-find that each time, then probably perfection for the column's exact perpendicularity is of a bit less importance than it might be on those knee mills. Since your head can tilt then only the Y axis would still need to be correct to tram the spindle to the table and ensure as straight as possible drilled or bored deeper holes.There are various tricks and work arounds for these round column mills to maintain that spindle C/L while moving the head. So if you expect to use any of those in the future and I expect you will, then yes a column as true as possible in both directions is a definite advantage.

Not to dissuade you from doing this since it is worthwhile. But getting these round column mills properly aligned is a great deal of time consuming and sometimes frustrating work before the jobs done. And given the head and column weight some type of lifting equipment isn't really optional to make the job as easy as possible. Your going to need to move and replace different shim combinations many times before you get it as close as possible. With the length of the column even a variation in bolt torque will shift the vertical orientation of that column around a bit.Depending on the strength of the rack and pinion that moves the head up and down, it might? be just possible to use it and some wooden blocking on the table to lift the head and column enough to remove or insert those shims each time. I'm not real comfortable about using parts on a machine tool to do something they weren't properly designed to do. Unfortunately there's no real way to tell if they are or aren't built heavy enough unless you do or don't break parts. So I'm definitely not recommending you try it. I've found in the past that getting lazy or cutting some corners I shouldn't have can be quite costly if you get a bit unlucky.

Harold_V
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Re: Tramming a mill drill

Post by Harold_V » Sun Mar 22, 2020 4:37 am

One thing I should have mentioned in regards to proper alignment of the column. It relates to the notion that side to side isn't critical, but in reality, it is. Here's why. If need arises to rotate the head to either side, because the head was dialed true in a given position, when the head is rotated, error is introduced (because the column leans), so you lose not only registration, but perpendicularity, too. That's why I encourage you to get the column as near to perfect as you can.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

RSG
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Re: Tramming a mill drill

Post by RSG » Sun Mar 22, 2020 7:52 am

Excellent explanations and advice given here, but I'd like to make a special note about Harolds writing! It's clear, concise and very "to the point"! Detailed advice like this takes time to write and not many are able to do it so I just wanted to commend him!

Pete, you're another one who takes the time to write in detail as well.

it's appreciated guys!
Vision is not seeing things as they are, but as they will be.

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