got some multi ply that is very stiff i think it is 3/8 and made a steady jig along with some roller blade skate wheels
used wing nuts on the bolts to secure it to the bed and then made a small wrench out of wood or course
not sure how i got by without but i found anything over 13 or 14 inches depending on the species was not producing good results and this jig really makes a big difference
had not thought much about the speed of the wheels and it turns out that it did not matter as the wheels are going slower than when they were on the skates