Hi all,

I have a (about 1989) YCI supermax-1 rebel and the head is about 8-9 thou out of tram in the Y direction (tilted forward) and another 3 or so in X. This is measured by swinging an indicator on a 5" dia plate we use for tramming the bridgeports....


Machine has box ways. 6 leveling pads, 4 under the table and 2 at the back of the column. I've taken all the tension off the rear column pads, hoping the machine would flex back with zero result.

Is there any way to adjust the head on something like this? Machine rattles terribly in some not so heavy cuts.

Any advice would be appreciated.

Have you tried leaving the casting sit for a few days on only the two center screws. If not give it a try. The casting sometimes gets a memory built into it. This often times happens when people buy used machines that are sitting on wood blocks for some time.

Well I discovered that I could move the head if I shoved it hard enough, it would tilt about .030" to almost level. I tried adjusting the gibs, drove them down until about a half inch was past the screw on the bottom, and it was better, but no way to lock the gib in place. Pulled the gib from one side out the top, and half the turcite it gone

Hi site administrator and fellow colleage, if that is true concerning castings having somewhat of a memory (and I have no reson to doubt) that would explain a few leveling encounters Iv'e had. But in this case of extreme I believe it is somthing else.
Thanks for the input, Bob

Hi GM&M & Dourk,
I have actually noticed this casting memory even on new machines that I have installed coming from Japan. Usually sitting over night is enough for the new machines, this seemed to occur more often on verticals then horizontals. I believe its because horizontals usually have thicker and larger castings I have seen fewer problems on new horizontal machines and more with machines that have been in production for long periods of time. Whether it’s because of wearing turcite, casting memory, or other stress factors that is unknown. But this will help you either way to square up the machine if it is a casting memory problem or some minor wear in the turcite. Most cases that I recall I have seen castings settle into .002-.005/foot.

You are right in extreme cases as this may be for this machine it could be worn turcite. Which I should have mentioned as well. In this case the part that rides on the top of the way or the capture plate that holds the Z-axis to the ways, which could cause the head to tilt forward could be the problem. It’s also possible that there is wear on the box ways for X and Y axis which may also cause the table to tilt. If you ran out of room to turn in the gibs on Z-axis then there is definitely some wear. This wear may also be a sign of a lubrication problem. Check that there is oil dripping out of the bottom side on top of the ways.

Beyond a turcite problem there is nothing else that could cause the head to tilt that far forward. I will admit 8 or 9 thousands is a bit excessive. The only other thing it could be is either the casting has the memory from over time or someone took a cut on the table. Also if the machine is anchored some people do not know how to level a machine and will actually distort the casting into shapes it was not meant to be in. Which I have witnessed once on a big used machine installation, that a maintenance guy decided to do one day to try to get ahead. Needless to say we had to redo it and leave it sit over the weekend before we could continue. Turcite is cheap however the labor involved is a lot and a quick fix by no means.

So first check that all the ways are getting lube and might not be a bad idea to mount an indicator on the spindle head and place it across the table and move in Y direction to get an idea if it’s possible that the turcite is worn under the table. First place a precision level on the table and run the table in 6 positions and get that absolutely perfect before running your indicator checks. Do not worry too much about the tram at this point. Once there is no twist in any X or Y axis movement or is even on both sides. Then run your indicators. This should tell you if the table top is parallel with the Y axis ways.



Kind of hard to explain in writing but hope some of this information helps

Petro

Have you checked the keepers on the backside of the Z guidways to be sure they're ok?
I agree 100% on the casting could be the root of your proble. Be sure to use a machine level and check both direction while keeping the table centered on the Y axis. Move from one travel limit to the other and stop in the middle of travel as well and adjust your pads to maintain the level bubble is centered in the X axis as well as the Y axis. You can amplify the pitch, roll and yaw thats in every machine if the pads are out of adjustment. I used to use a 90 degree magnetic level on the Z axis guideways after the able was level to adjust the pads. Place it on the side of the guideway and the front as well, and adjust the leveling pads on the column. Be sure to use quality machine levels to do all of this with.
I suspect that the excessive wear on the gibbs and probably the keepers as well will need to be addressed as well. New turcite and properly scraped in.

Good luck!