Funnily enough, I got my first instances of wheels going like swashplates today, even when I was taking care to press them on square. I was experimenting with the amount of interference on the push fit and had increased it by lessening the penetration of the taper reamer. That must have been caused by the resin releasing some stresses after the push fit. I think there is a reaction to the push fit since there is a combination of displacement and cutting by the square edge of the axle. If I get another set of axles made I think I might investigate getting the corner of the axle end rounded so that the push fit only displaces. I did get over today's problem by restoring the previous depth of penetration of the reamer and I also increased the diameters in the printed hole in the printed centres to cut down the amount of material removed by the reamer. Jim.