Hoping maybe someone out there can offer some guidance… but honestly at this point I don’t think this machine has significant rigidity to be able to accurately tram it, especially if your hanging the weight of an 80mm ATC spindle on it.
I have the 1F Elite Foreman with the stiffy bar. I have spent hours using a dial indicator to try and tram it accurately and it just doesn’t seem possible. My spoil board is freshly flattened, and I have checked for coplanarity and it’s perfect. Left to right is not a problem. But tramming front to back seems impossible. I can get it to within 1.5 thousandths on the far left X axis travel and far right. Then, when I move it to the center it’s out 25 thousandths over 20" front to back. If I tram it perfectly front to back in the center, it’s out at least 15 thousandths to the far left and far right. I think the weight of the spindle is flexing or ‘twisting’ the X axis rail assembly as it moves towards the center and loses the support of the X rail carriages. Or, perhaps, one of my rails is not perfectly straight? Not even sure how I would check that.
I think you are going to have to go for a compromise between the two limits. To be .020" out over 20" would only be .001" over 1" so unless you will be using a 3" fly cutter you will not likely ever notice it. You may be able to see the step but never be able to feel it. That’s how my machine is and it does not affect flattening at all. I use a 1.375" flattening bit.
Im not sure how you are trammung. I trammed my Journeyman with kitchen foil shims on the z frame. Work for me and flattened an mdf wasteboard with a 1.5inch cutter without ridges - that’s my test ( i dont have dials).
I trammed mine into about .002 on a 12" radius, oddly enough my front to back was good, just a little side to side which I expected but I did not check the sag from the left or right side to the middle, I am surprised you have .025 and am going to see how much I have, I have the Woodworker and the stiffy with a 2.2 KW spindle, not ATC, I imagine the ATC does add some significant weight.
Without taking your machine apart and verifying all 7 tubes on a giant granite table with v blocks and indicators…um…maybe if you rotate the top tubes and stiffy 180 degrees, one at a time. See if you get the same result on the opposite side. I wouldn’t bet a lot of money that all 7 tubes are perfectly straight better than a few thousandths or more. Also while making a cut in the X direction with your biggest bit, push on it a little several times in the Y direction to get a feel for how much force it takes to show up in your cut quality. You can tram all day long but you’re still not reproducing the forces you have while the machine is cutting. Sometimes good enough has to be good enough.
Thanks Chris! You’ve talked me off the ledge… LOL. After reading your post, I realize I was looking at the mechanics of tramming all wrong. I’m thinking the .025 out means the bit is going to be .025 lower, for example, in the front then it is in the back. But the tram is not representing the height of the bit off the spoil board, it is representing the angle of the bit to the spoil board, at the spindle’s current location. Obviously, the further out you go on the tram arm, the more pronounced that is going to be. I probably don’t need a 10" tram arm… and you’re right that’s only .00125 over an inch. If I find the happy medium it will be about as close to dead nuts accurate as it’s gonna get and it will be plenty accurate enough for wood carving.
Yea I had already trammed without dials, using some soda can tin shims on the Z carriage itself. I had then flattened the spoil board with a 1.25" bit and had what looked like ridges but you couldn’t really feel them. I probably should have left well enough alone!
Pat,
Yes the ATC spindle is somewhat heavier… but at the end of the day they’re both pretty darn heavy. I think I may have overreacted to the .025… if you read Chris’s response, he points out that if you do the math that’s only .00125 over and inch because I was using a 10" tram arm, so it’s 20" front to back.
John,
Thank you for the response. You’re right… if I can get close to only .001 over an inch, then that is absolutely good enough. Good idea on the rotating the tubes… I had thought of that but after Chris talked me off the ledge, I have decided not to mess with it. The micro tramming screws on the 1F work great… it’s just that with the weight of that ATC spindle, I don’t care how accurate you get it up against each Y rail, it’s not going to hold that accuracy out in the middle of the X rail. I read another post on some forum somewhere where someone pointed out that if your machine didn’t need a forklift to unload it, it’s not going to have that kind of rigidity. I thought that was an excellent point. LOL.