Lathe Alignment is a challenging task, requiring specialized equipment and knowledgeable personnel. With the Easy Laser Alignment system, Lathe Alignment is made fast, easy and accurate. Read below for a recent case study on a successful Lathe Alignment.
In June 2015, I&E Central (along with a service partner) performed alignment on an automatic lathe similar to the photo above. The lathe is fed 20’ sections of tube stock which are supported alternately by V-rollers, and then clamped by “steady rests” while being machined. The objective of this alignment was to have the stock in perfect alignment with the rotational center of the collet when supported by either V-rollers or the steady-rests. I addition, there is a pusher system that advances the stock into the collet. The movement of the pusher needed also to be aligned with the rotational center.
This photo shows one of the steady rests in the open position, and one of the V-rollers, also in a retracted position.
A laser transmitter was mounted in the spindle with its beam directed through the collet. The laser was aimed to follow the rotational center, then the spindle was turned at 100 RPM for measurement. In this way the beam precisely marked the rotational center along the entire length of the machine.
The first measurement was the location of the center or each steady rest. A laser detector was mounted on a 12” x 2” piece of stock, which was locked in each steady rest for measurement. A center of circle straightness measurement was used to determine the position of each steady rest. Once that was complete, each steady rest was measured again, and adjusted live so that the stock was held co-linear with the center of rotation. The measurement and adjustment process was completed in under 3 hours.
Once completed, pk-pk deviation in the vertical plane was 0.0095”, in the horizontal plane it was 0.020”, well within the customer’s desired specifications.
The next step was measuring the straightness of travel of the pusher arm relative to the rotational center of the lathe. This was accomplished by grasping the same piece of stock with the jaws of the pusher, then measuring its true position at 4 locations along its travel.
It was found that the initial path of travel was downward relative to the center-line, so 0.250” of shims were removed from the rear feet of the support structure. After adjustment, pk-pk deviation of the pusher in the vertical plane was 0.064”, and in the horizontal plane was 0.145. Further adjustment was possible, however this was well within the customer expectations.
The final adjustment on this end of the machine involved adjusting the V-rolls to support the tube stock in line with the center of rotation. This adjustment was actually done without the laser. Now that the pusher was aligned with the rotational center of the collet, a full length piece of stock was secured in the collet with the other end supported by the pusher. Each V-roll in turn was activated, and then adjusted with shims so that it supported the stock precisely on the center-line. Once adjustment was complete, the stock could be freely rolled into the collet without touching on any side, and when grabbed with the steady rests, showed no discernible movement (and this is a “violent” hydraulic grab).