I’m in the process of tramming my spindle and have run into a problem. I recently purchased an Edge Technologies dual dial indicator, and a piece of glass, thinking these would be helpful in making the tramming process more accurate. I trammed the spindle, front to back, to approx. 1/10,000 of an inch (according to the indicators). I then used a 2 1/2" diameter insert surfacing bit, and ran the bit side to side across a piece of flattened maple, to check the results. Unfortunately, I ended up with the dreaded witness lines! I then decided to shim the carriage, strictly through trial and error, until there was relatively no witness lines. It took a while, and a lot of elbow grease, but the witness lines were just about invisible. It seems obvious that there is a problem with the tool, but I thought I would ask if there is something I’m missing here. So, is my thinking faulty here?
How did you set the glass to be coplanar to the X/Y plane of the spindle? Did you surface the table and then lay it on top?
Did you surface the maple stock - to dial in the tram - by milling in both the X and Y direction?
You may done tings in the wrong order. You need to flatten the bed first (both directions as above) and then do the Tramming, either to the ridges or the dips (one or the other) or the glass sheet.
The table had been surfaced previously BUT not after I started tramming this go around. I was actually re-tramming for more accuracy. I simply laid the glass on the on the table, inserted the tool in the chuck, and went from there. Additionally, I was only trying to tram front-to-back because I find it relatively easier than side-to-side. I figured I would tackle that afterwards.
Assuming the glass was flat and co-planer on both surfaces, wouldn’t the outside surface of the glass be parallel to the surface of the table? Therefore, wouldn’t the spindle that was trammed to the glass also be trammed to the table surface?
Wouldn’t the same logic apply to the piece of maple, assuming both surfaces of the maple were flat and co-planar?
In terms of the witness lines: I made a single pass with the cutter, pencil-marked the length of the far edge of the “wall” and “trough” the cutter created, jogged the cutter away from myself in the y-direction only so the near cutter insert overlapped the first witness line by about 1/4" (for a total of a 2 1/4" wide pass), and made another pass. I figured if the cutter removed the pencil mark without creating any witness line, and the junction was smooth, both cuts were in the same plane.
the Mitz Pellicciotta method, which is a method that works the better the larger the bit diameter is, because it looks at the direction of the patterns such a bit makes when it is not perpendicular to wasteboard surface, works only as third step after you ensured your machine is
IMPORTANT NOTE: Surfacing the wasteboard does help nothing if the machine is not accurately rectangular (“squared”) and coplanar (not twisted)! Not at all! All your workpieces including the wasteboard will remain a parallelogram and be twisted if you don’t ensured steps 1 and 2 accurately.
I believe the answer to both your questions is ‘yes’. I just wanted to make sure that is what you had done.
I have trammed a few times as I have been modifying my build over time. I also started by trying fine tune the nod, using the tramming screws on the X axis gantry blocks - in the end I needed to add metal shims behind the z assembly. Adjusting for tilt took a little back and forth but in the end I got it to where I was satisfied. Although I originally used a granite block and tramming tool, I found that fine tuning/re-tramming with a wide surfacing bit to work well in the end.
It is possible that depending on your table construction, the results of tramming may change over time with expansion/contraction of substrates, etc. This can impact the two critical areas of measure that @Aiph5u has highlighted.
I just checked my machine for squareness and coplanarity.
In terms of squareness, the diagonals were within approx. 1/32 of each other. Because the machine is the Foreman, I’d like to assume that is acceptable. However, if you think I should try to make them exact, please be sure to let me know.
However, the machine was about 1/4" out of coplanarity. So, I guess I know what I’ll be doing this weekend!
While reviewing the information posted in your various links, I landed on a page that describes ensuring the vertical alignment of the two x-axis rails using winding sticks. How should one proceed if you have the “stiffy” mounted as well?
Erik
Aiph5u
(Aiph5u (not affiliated with Onefinity))
11
Hey Erik,
here I made this drawing the other day. It shows one winding stick, but of course you need two.
Generally, tramming by adjusting the front/rear tilt on three rails is difficult. You could remove the third “stiffy” rail and adjust the lower two rails, and then try to adjust the third “stiffy” rail.
To be sincere, I think that if you have a third “stiffy” rail, the middle rail is rather useless and can only slow the machine down if not properly in line with the others. The gain in stiffness by adding the third “stiffy” rail is in my opinion not caused by augmenting the number of rails, but by the greater distance between the third and the lowest rail.
I plan to test the rigidity of my X-50 Journeyman with the middle rail removed, so that you have two rails again, but with the greater distance that should make rigidity better, but at the moment I have serious health problems and cannot work in my workshop. Since on X-50, the third “stiffy” rail is attached with only one bolt on each side(!)(why did they design it with attachment by only one bolt?), I would have to first develop a method to attach it more firmly to the X axis aluminium extrusion profile ends before I can really get rid of the middle rail.
So it’s a bit difficult to answer the question. I think you would need to remove the third “stiffy” rail to use the winding sticks one the lower two rails. If you have them trimmed, then I would set the third “stiffy” rail loosely on top of the X axis without attaching the bolts and adjust the two ends of this third rail with their tramming grub screws so that the rail is in line with the others by checking if the aluminium extrusion profiles at each end sit flush where they belong on top of the X axis aluminium extrusion profile ends, and fix the bolts only then.
Note that on X-50 rails (unlike on X-35 rails), the third “stiffy” rail is not in line with the two others, as to be seen here.
On X-35 rails, the third “stiffy” rail is in line with the others.