Re: z axis alignment
Posted: Tue Apr 14, 2015 5:07 pm
It WORKED!
You might have read my post above where I mentioned getting a new spindle, 80mm diameter, needing to cut an aluminum mount plate, but having to use the existing router which isn't aligned in Z....
Well, over the last couple days I've been getting the spindle in it's more-permanent mounting form. On first install, the large tubes of liquid coolant were hanging from the ceiling, and I could tell the z-axis was moving as I took more or less of the weight off those tubes. Well, now I have a much better cooling-tube routing.
And, the results are in: it freakin' worked! I took the skewed aluminum plate, flipped it over, and mounted the spindle in that. put a readout indicator on a magnetic base, and measure out-of-position along the spindle body. Over about 5 inches in Z, the spindle body was less than 0.0025" (yup, 2.5 mils). That includes a 30-mil thick strip of skived PTFE (Teflon) tape under the lower two bolts that hold the plastic to the metal Z-mount plate.
So, I'm going to say that it's a huge improvement. Before, I could actually SEE the router bit wasn't perpendicular, and it was clear. Over a 1" thick piece of material, the top and bottom were out by 20-30 mills, depending on direction.
The absolute-Z of the bearing rails is still there, but hopefully diminished a tiny bit by me mounting the chip-blowing air, wires, and coolant spindle tubes and valves on backside of the gantry plate. The sag from that was previously around 2.5mils over about 12" in the Y (along the bed; very likely your X unless you swapped axes).
Thus, I will recommend it. Take your router just as you have it now, get some aluminum or HDPE, and using that router, cut out the new bracket. Make sure that the orientation of the new plate is "the same" on the bed as the plate being used to make the new one. Then, flip that sucka over and use it in place of a the stock mount.
(Yes, before you all start flaming, I do know that the two (front and rear) walls of the router opening won't be precisely parallel. But at least in my case, that doesn't seem to affect clamping effectiveness or positioning.)
Regards, and hope the update is useful.
Thom
You might have read my post above where I mentioned getting a new spindle, 80mm diameter, needing to cut an aluminum mount plate, but having to use the existing router which isn't aligned in Z....
Well, over the last couple days I've been getting the spindle in it's more-permanent mounting form. On first install, the large tubes of liquid coolant were hanging from the ceiling, and I could tell the z-axis was moving as I took more or less of the weight off those tubes. Well, now I have a much better cooling-tube routing.
And, the results are in: it freakin' worked! I took the skewed aluminum plate, flipped it over, and mounted the spindle in that. put a readout indicator on a magnetic base, and measure out-of-position along the spindle body. Over about 5 inches in Z, the spindle body was less than 0.0025" (yup, 2.5 mils). That includes a 30-mil thick strip of skived PTFE (Teflon) tape under the lower two bolts that hold the plastic to the metal Z-mount plate.
So, I'm going to say that it's a huge improvement. Before, I could actually SEE the router bit wasn't perpendicular, and it was clear. Over a 1" thick piece of material, the top and bottom were out by 20-30 mills, depending on direction.
The absolute-Z of the bearing rails is still there, but hopefully diminished a tiny bit by me mounting the chip-blowing air, wires, and coolant spindle tubes and valves on backside of the gantry plate. The sag from that was previously around 2.5mils over about 12" in the Y (along the bed; very likely your X unless you swapped axes).
Thus, I will recommend it. Take your router just as you have it now, get some aluminum or HDPE, and using that router, cut out the new bracket. Make sure that the orientation of the new plate is "the same" on the bed as the plate being used to make the new one. Then, flip that sucka over and use it in place of a the stock mount.
(Yes, before you all start flaming, I do know that the two (front and rear) walls of the router opening won't be precisely parallel. But at least in my case, that doesn't seem to affect clamping effectiveness or positioning.)
Regards, and hope the update is useful.
Thom
