Truck issue primo

just finished printing the primo trucks, with my machine dialed in… the bolts slide it the holes with very little effort, but the bearings don’t all make contact with emt conduit, seems it sits and rolls on the 2 back bearings but the 3 on the front, no go, there’s actually a gap between the pipe and the 3 bearings i’m hoping that there is some trick to getting it to work, there doesn’t seem to be any way to adjust tension on the 3 bearings.

To get the 3 side bearings to touch, you tighten the top bearing bolts, squeezing it a bit. A little goes a long way

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how does that make the three bearings make contact with the emt?

The top bolts are how you adjust the bearing tensions and for squaring. Usually a small amount will cause the flex in the truck to allow contact. It will compress the sides a bit

Refer to: 3-Trucks - V1 Engineering Documentation

Truck Tension Header

What size printed parts STL’s did you use? And what size tubiing do you have?

ok hoping that tightening those two tension bolts takes the slop out, as right now with the three bearing bolts tight and the tension bolts loose theres slop

The “lower” bolts do not move in their holes. When I assembled my first one, I tightened the lower bolt bearings to 7 in/lbs (firm but not over tight), then tighten the 2 top bolts until they allow the truck to slightly move when they were on the tubing held at 45 degrees, and not just slide off fast. If the gap is more than say the thickness of 2 sheets of paper, you may have undersize tubing

i could see fair bit of light between bearing and pipe but i tightened everything up and its ok now just very finicky to tighten up to the correct amount, who knew it would take the much slop out :slight_smile:

just just barely slide good down the pipe at 45 degrees


They can be a bit finicky.