[KonradyTom]

I am looking for suggestions on how to make a split bushing. The material is non-ferrous--nylon. The OD is 6" and the ID is 4" with the length being 3 1/8 The split is along the length. Thanks.

[HuFlungDung]

Do the halves have to be interchangeable? In other words, do you need perfect symmetry, because the tricky part is getting the part line exactly on center.

[KonradyTom]

Yes. they have to be Symmetrical

[One of Many]

Yes. they have to be Symmetrical

So turn 2 and mill each half to the centerline?

Or, Bolt 2 plates together at the rear portion, mill a round on one end enough to grip, then lathe turn both halves at the same time. Much harder to get the split on center though functional.

P.S. Sure, this same approach would work with "Ferrous" Nylon too!

DC

[HuFlungDung]

One method would be to begin with rectangular blocks. Face them to the same overall height, lets say 3.125 x 6.03 x 3.015", the latter dimension being along the parting line.

Now set the pair of them up in a 4 jaw chuck in your lathe. Use a dial indicator to indicate the flat zones and adjust the jaws until all opposing readings are exactly the same deflection. I would set the indicator up on a mag base on the carriage of the lathe, and simply traverse clear of the part, while rotating the chuck 1/4 turn to access the next indication point. By rocking the chuck back and forth, you can easily find the minimum deflection point of the indicator travel.

Once this square 6.03 x 6.03 is perfectly centered, then bore the hole to finish.

Because the stock has a fairly decent length for this project, you should also be able to turn at least one half of the length of it on the OD without disturbing the chucking at all.

Now, take about a 4" length of 4" pipe with the OD accurately turned, and the end squared off, to fit the ID of the split bushing. Turn the pieces end for end in the 4 jaw and recenter to finish turning the other OD end. Use an indicator on the squared end of the pipe to ensure that the part is chucked squarely to the axis of the lathe. Adjustments in this plane are always made with a hammer or with prybars and jacks. Then, center the jaws.