Problem/questions about Tramming and Squaring

[ranchak]

I have a Rong Fu RF45 mill that I need to tram and square. I started by trying to square the column, but I am having no luck. What I have done is attached a ground angle block squared to the table. On that to provide a longer smooth surface is a parallel. All of this is in this picture:

If I raise the head to the top of the parallel and reset the dial indicator to 0, when I lower the head I have more than .025 difference between the top and bottom. I have shimmed the left side of the column to try to compensate for this, but I can't seem to gain any progress. I have already added .075 of shims to the left side. Am I doing this right? Should I have started somewhere different?

[MichaelHenry]

Tram is usually indicated by placing the indicator tip on the table and rotating the spindle by hand. I like to use a 1-2-3 block between the table and the indicator tip so the tip doesn't bump when it passes over the T-slots. Take note of the indicator readings at 12, 3, 6, and 9 o'clock positions and shim accordingly.

Mike

[Lexx0001]

I've got a similiar problem. What's a good shim material? Then, I suppose, where can I find it? The shim stock I am familiar with comes in sheets of various thickness. I don't think I would need that much.

[maxboostbusa]

feeler guages work good for me

[ranchak]

Should you square before tramming, or is tramming enough?

[ranchak]

You can also buy brass that is about 1/2" wide at hobby shops. I bought some and I think it was less than $1.00 a piece.

[davo727]

I have a wttools 7045 mill. On the rf45, 7045 mills regardless of mfg. It takes some fine tuning of the bottom of the column to get it to sit square. I highly reccomend doing what I did - Drill and tap the bottom column flange for 4 , 1/2-13 thread capscrews, they will be used to move the column left, right or front and back for testing purposes with the main bolts loosened. You will not use them for final adjustment because if you did they would just punch into the cast iron base when you torque the main mount bolts. THEY ARE FOR TESTING ONLY!!! Next after you have the column back on top of the base leave the column mount bolts just slightly loosened. Now you can use a dial indicator mounted to your spindle or side of your gearbox and run the indicator needle on the side and then on the rear edge your right angle block as you crank the Z up and down. It will only take a few adjustments of the capscrews for you to see which corner of the bottom of the column is higher than the others. Adjust the capscrews to make the indicator run perfect. make note of which corner of the column is jacked up higher than the others. The corner that is flat against the base is the one that is high and needs to be ground down. Next take your engine hoist and pick up your column assy and use a 4.5 inch grinder carefully or a right angle sander and take a little off that corner of the bottom of the column- like .020 or so. Re assemble torque the main mount bolts down while the capscrews are retracted and re test. Repeat until you can run that indicator up and down the side and back of that right angle plate with no deviation. Took me a couple times with the grinder and then once with a hand sanding block on the column bottom to get it perfect. Dave

[davo727]

Trying to shim it just sucks, believe me I tried and its just futile. My method takes a little work but you can get it perfect and dont be afraid of a little careful grinding or sanding on that column bottom. Its not a table way, its a rough machined surface. Edit- actually its a sawed surface from the factory and just needs a little TLC.

[ranchak]

WOW!!!!!!!!!!!! I am an idiot. I just removed my column and discovered that my column and base is machined. Now comes the idiot part..... I bolted the column to the base, reattached the angle block and parallel. Then it hit me, if you look at how I the the indicator mounted you'll see that the indicator is not set in the correct plane! So I have corrected this problem and I have about .006-.008 of movement in about 5". I noticed that if I lower the head and then raise the head about a quarter of a crank on the handle the indicator will move back and then I will have about .003-.004 of movement. Would this be considered "backlash"? How do I go about removing this so I get a consistant reading?

[davo727]

I think your gib strip in your Z slide might be way too loose. This would let the z slide rock some when you move your crank up and down. The gib strip is shaped like a wedge and has adjuster screws on the top and bottom surface of the Z slide which pushes the gib up and down. The little lever operated screws on the side of the Z slide are just for locking the slide into a certain position and not for adjusting play in the dovetail. Sounds like your column is better than mine was but will prob still need a little work if you want it perfect.

[ranchak]

I'll remove the gib strip tonight and make sure that there aren't any burrs or heavy grease restricting the z movement. Hopefully this will help, if not I will pull the head of off the column and clean the ways.

[MrWild]

Originally Posted by davo727 Next take your engine hoist and pick up your column assy and use a 4.5 inch grinder carefully or a right angle sander and take a little off that corner of the bottom of the column- like .020 or so. Re assemble torque the main mount bolts down while the capscrews are retracted and re test. Repeat until you can run that indicator up and down the side and back of that right angle plate with no deviation. Took me a couple times with the grinder and then once with a hand sanding block on the column bottom to get it perfect. Dave

You had my attention until you started writing a horror novel. A 4-1./2" right angle grinder? Remove .020"??????? When I read something like this, I think of the phrase, "Put the tool down and back away from the grinder."

A big problem is lack of cleanliness when assembing. Sure, take the column off, but then use a flat mill fill to dress any burrs (YOU AREN'T FILING THE BASE OR COLUMN!), then use a large stone on the mating surfaces. CLEAN said surfaces well with a lint free cloth and reassemble. Now tram again. If you have run out, don't kid yourself that a angle grinder will do a precision job. Get the proper shims and shim the base accordingly. If it takes .004 shim in one corner, realize you will want to use thinner shims between the high corner and low corner of the mating surfaces, or you end up with the chance of stresses that could crack your mounting/mating surfaces.

Be warned that dirt will mess up the mating surfaces and give you tram problems. CLEAN these surfaces EVERY time you dissasemble or you will put problems in as you work to take them out. Cleanliness is god.