Here is an idea that you can incorporate with the rollers. All you need to do is make a round disc with a square cut out the size of your stock. Position the rollers under the wheel about 8 " off center. Move the router to the center mark of the stock and mill the stock round. One blade width will be fine. Next mill both ends the same diameter. Now remove the guide wheel with the square hole and reposition the wheels under the section that you milled round. Now you will be able to mill the entire length without interference. One word of caution though. the tendency is to snug up the middle rollers. if you do, you will make the center tapered and both ends will be larger. Use the center cut and both end cuts as a guide to insure that you are cutting parallel. Clear as mud right? An easy guide is a combination square dropped over the side of the carriage to touch each of the 3 point milled round. If you measured them as all being the same diameter, they should all touch the square the same.
Mike OK