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NYCCNC has numerous videos on the Tormach. Here is one that starts the tramming process: <http://www.youtube.com/watch?v=lle-k_ccFAA>
As I recall, it doesn't complete the process, but I think all of the necessities are there.
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Hello all, isnt there a video somewhere showing the correct way to true in the mill by way of setting tram. I thought I saw a video somewhere but cant find it anywhere. Thanks
NYCCNC has numerous videos on the Tormach. Here is one that starts the tramming process: <http://www.youtube.com/watch?v=lle-k_ccFAA>
As I recall, it doesn't complete the process, but I think all of the necessities are there.
Beware, as the video notes what is depicted is not the correct way to tram a mill. All it does is demonstrates that how you support the mill can influence the tram.
Sweeping the table with an indicator only has the capability to show how close the spindle is to being perpendicular to the table surface, it tells you nothing about the relationship of the column ways to the table, which is equally important. What procedure you use depends on where the error is.
Example: If you are indicating off a table surface that isn’t flat why would you believe that shimming the column is going to correct it.
Example: if your spindle is indicating as not being square to the table surface, is it the spindle to the column that is not correct, or is it the column to the base, or is it both.
Phil
Phil, please do provide a link to the correct way to tram a mill. The subject has come up here several times previously, but I haven't been able to find a good, documented, reliable method that corresponds to, say, Rollie's Dad's Method of Lathe Alignment.
Thanks,
Randy
I posted a while back about re-tramming my pcnc1100 column by shimming between the column and base. I'd experienced a crash that put me further out of tram than the base-shimming method could fix, so I pulled my column and inserted carefully-designed brass shims that covered the whole column-to-base interface area to compensate for the measured column lean. It worked really well, but was rather involved.
Here is my original write-up:
http://www.cnczone.com/forums/tormac...00_column.html
I have shim drawings and pictures I took of the process of lifting the column if anybody is interested. In fact, I may launch into another re-shim after yet another z crash added another bit of lean to my column last month. If so, I'll post more detailed pictures and diagrams of the process I use.
The only real trick is in constructing two precision shims (one for each side of the column) from brass sheet stock. I'd rather use a compound sine plate on a real surface grinder with proper flat stock to make the shims, but alas I have no such gear as yet. If anybody else does have such gear and wants to produce custom shims, I'll craft a parameterized solidworks part to generate shim designs given measured X and Y lean angles in exchange for a set of finished shims
It'll be nice when I learn how to reliably not crash my machine. Just when I think such rookie moves are a thing of the past, I find myself humbled once again...
Randy, unfortunately I don't know of link to a good procedure. There are many different understandings of what tramming a mill actually means, so there are many different procedures out there.
I guess the basic definition is: to check and adjust the machine such that the spindle rotational axis is (and moves) perpendicular to the plane of the table surface (or is it more important to use the plane of the table movement), within the envelope of the x, y and z-axis travel. The precision of the adjustment will always be subject to the best compromise that is achievable within the precision errors that you cannot or do not intend to correct. A bowed column could be one such error and a table that deflects under its own weight when at the extreme of the x axis travel might be another. There are several more, all of which I am not sure I could identify.
Providing you accept all these subsystem errors then the two basic steps would be:
1) To ensure that the z axis ways are perpendicular to the table surface in both x and y planes.
2) To ensure the spindle rotational axis is parallel to the column ways in both x and y-planes.
If you use an indicator sweeping the table to check and adjust at step 2) you cannot do it before you have performed step 1).
Many people will perform step 2) without considering step one. This will potentially introduce a second error when trying to incorrectly adjust the original error.
How you perform the checks in 1) and 2) depends to some extent on what tools and measuring equipment you have available.
The proper method of correction would be to scrape the base of the column for step 1) and to scrape the head/saddle interface for step 2) The HSM’er fix would be to shim either as necessary. On the Tormach you may have to leave out the two head alignment taper pins.
PS: Not wishing to start another discussion but Rollie Dad’s method for lathes is only good for correcting an otherwise good lathe that has a twisted bed. For example it cannot differentiate between a misaligned head-stock and a twisted bed. So again you could introduce a second error when trying to incorrectly adjust the original error.
Phil
Originally Posted by zephyr9900
I think it is unlikely that a crash would result in a movement of the column relative to the bed, at least not one that would result in a change in vertical alignment of the spindle. The most likely source would be movement of the head on the saddle, against the taper pins, especially if the taper pins had worked lose, which they do.
Phil
Phil, thanks for your answer. Yes, I mentioned Rollie's Dad's method specifically because it is for setting up a well-performing lathe again after a move. And because it doens't use a lot of expensive test fixturing...I'd really like to find a corresponding technique starting from zero with the mill.
I was satisfied with my Tormach's performance in California but need to commission it properly after the move to Texas. When I first set up the mill, I had use of a long-base precision level, laboratory-grade Mitutoyo squares, etc. but probably just got lucky setting it up in the first place. It hasn't suffered any specific traumatic events during or after the move.
I have an early Series I machine, with the roughly-welded stand with the rubber pads between it and the machine base. It is sitting on a non-level or straight garage floor in an area where the ground is prone to movement if we don't soak the perimeter of the foundation every day. The machine is tight (I can interpolate short bearing bores to at least .001" size and roundness) but my flycutter shows obvious non-orthogonality of the spindle to table.
Bobeson, thank you also. I have read your thread, fairly recently in fact, but I'm wondering if I don't need to take a big step back from there. I don't even know if the stand pads are coplanar, since they weren't faced after welding as the later stands have been. So even if I would use the stand-leveling feet or shims under the machine base corners I don't have a stable connection between stand and mill. If I could borrow a precision level again and ensure the Y ways don't have any twist, how stable might that adjustment be, especially as a "foundation" for subsequent tramming steps?
Randy
Hi Phil,I think it is unlikely that a crash would result in a movement of the column relative to the bed, at least not one that would result in a change in vertical alignment of the spindle. The most likely source would be movement of the head on the saddle, against the taper pins, especially if the taper pins had worked lose, which they do.
Phil
It does seem unlikely, yet my measurements seemed to conclude column lean as opposed to head tilt. Specifically, I used a 4"x12" cylindrical square held vertically on the table, and measured deflection in both X (mostly) and Y (slightly) during movement of the Z axis. If the head was tilted, there would be no relative change during Z movement, only during a sweep of a spindle-mounted indicator across the table. Instead, I measured consistent angular deviation results using both the vertical-motion-with-square test and also during the spindle-mounted indicator sweep. After inserting my shims, the tram was nearly perfect, both during sweeping and Z traverse.
I'd be interested to know if you have a different interpretation, given this information. I was pretty shocked to think that a crash could deform the column, yet that's what the measurements seemed to show.
-Bob
I'm not entirely sure I follow your question, so pardon me if I'm answering the wrong thing
As for stability, although they seem pretty cheesy, I don't see why a properly constructed and positioned shim wouldn't have perfectly acceptable long-term stability. It's not like this is part of a highly dynamic motion assembly - it's clamped solidly between two hunks of cast iron that don't move. Once you get the distances correct, I don't see what there is to change, unless you go and bend your column again.
-Bob
Bob, it sounds to me like you've got it pretty much covered.
Phil
Randy, My method for setting the mill on a roughly welded stand was as follows:.
- Put adjusting feet on each leg of the stand.
- Sit the mill on the stand
- Adjust the feet so they are all touching the floor.
- Lightly bolt the mill to the table on three corners.
- Fully shim the fourth corner. Shims should have resistance in the gap but not forced.
- Bolt all four corners of the mill base down onto stand.
- Check for none twist of the base (and the stand) by undoing each hold-down bolt in turn and check for lift of the base from the stand with a thin shim. Re-shim as necessary)
- Adjust the four legs of the stand until the table surface is level.
You might get lucky and a table sweep with an indicator shows everything as OK, don't expect perfection (look at the test certificate for the acceptable tolerance). If the sweep is not good then you can check as Bob did, with a cylinder square or alternatively with an angle-plate to determine if you have column lean or head lean. The only problem with the angle plate method is you have to move it lots of times and the math can get a little confusing. (warning: cheap angle plates may not be square, however you can compensate for this by repeating each test with the angle plate rotated 180 degrees, lots more checks and the maths/geometry will make your brain ache).
I don't think that attempting to twist the base to correct a lean of the column as in the video is a good idea as it will not only impact the column but also potentially the Y-axis ways.
Which way does the fly-cutter indicate the lean, front to back or side to side, or both.
Phil
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