I have to make a ferrule out of existing rods to join a piece to a butt section. Both are graphite but the butt has less graphite and has a thicker wall with od of 14mm. I drilled it to make an id of 11mm to be the female and have sanded it as best I can. This means that the top section needs to be the male and have an od of 11mm. Right now the od is 11.5mm. I'm hand sanding at the moment but looking for any suggestions as to how to get it to 11mm and remain round so that it will fit into the female snugly as a ferrule should. 0.5mm doesn't sound much but it'll still take a while by hand. I'm wary of using electric as can easily take off too much in one spot and ferrule will no longer be round but oval.

An over-sleeve on the tip most section out of glass would have been the preferred method. From where you're at now, you're making a tip-into-but ferrule which are generally problematic and not at all self-adjusting for wear.

However, being this is where you are and if you want to continue, then turning the top section on a lathe is about the only way to keep it concentric. Even then you can't simply allow the sandpaper to float on the surface, but need to back it with a block and then allow the sanding block to contact the blank surface while resting in place on the tool rest. At first it may only remove material from one side, eventually as the blank becomes concentric it will begin removing material around the entire circumference.

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Thanks Tom. Don't have a lathe so hand sanded. Not evenly concentric but I went slow and measured as I went along. Got some high and low spots but should even out just a little as it wears. To ensure that there is enough strength I'm going to oversleeve the butt which is the female and undersleeve the male ferrule. Let you all know how it fishes after I'm finished.

Strength may not be as much of an issue as flex is. If you make the area too stiff/strong, stress can/will occur at the ends of the section and can then result in further breakage.

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Hmmm, stiffness ought to be ok as the ferrule is going into the foregrip and being a medium taper all bending should be finished by then which is why I was thinking of reinforcing both male and female. So far I've reinforced the female by covering the remainder of the butt with eva and glued a winding check at the end. The winding check ought to hold any likely splits. Not too worried about wear as it'll be a long time before that happens and I can always sand male to fit.



Edited 1 time(s). Last edit at 03/07/2016 06:54PM by ken khoo.