Ferrule Shrinking

On May 7 I made a post about electroplating of nickel. This can be a protective finish for reel parts, but it can also be used to increase the diameter of a male rod ferrule that is loose. I was discussing this with C. Bogart at the recent Grayrock meeting, and he pointed out that the nickel goes on in a soft condition, so the fix may be temporary. He referred me to J.E. (Jed) Dempsey, who said that a better approach is to shrink the female ferrule with a roller device, similar to a tubing cutter.

I wanted to know if this really worked, so I made such a device, shown below. It uses 3 ball bearings as rollers.
IMG_4526
Also in the picture is a scrapped ferrule set donated by RKP. I re-sized the ferrule set for a loose fit, and then worked on it with the roller device for about 20 minutes.

The fit was indeed tightened. I suspect the the female was reduced by a few tenths of 0.001 inch.
IMG_4527
The rollers also raised a small welt on the female, seen here on the right side of the picture (two decorative grooves were already on both sides of this ferrule set). The welt can be rolled down by further work with the device, and then sanded away.

As I sit here finalizing this post, I realize that this ferrule set may be plated brass rather than nickel silver. That is why the copper color is showing through. So this still needs a trial with 18% nickel silver.

Update 19 July 2014: Yesterday I got the chance to use this device on a female ferrule of high quality, hard drawn nickel silver tubing. It worked; the ferrule fit changed from loose to perhaps a little too tight. I was surprised how little effort/time was involved, compared to the brass ferrule.

Update 15 July 2015: I have had a batch of tools made and am selling them. Contact me for details.
IMG_4900
Here is the prototype (left rear) and three tools from the batch.

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2 Responses to Ferrule Shrinking

  1. Keenan says:

    I am curious if the raised ring was caused by a poorly machined radius on the edge of the roller bearing, though it could be related to misalignment of the movable bearing. The effect appears more significant on the one side. Maybe putting a slight crown on the bearings would prevent this as well as allow you to walk it up and down the section you are shrinking.

  2. dave49 says:

    Keenan,
    I don’t see any flaws on the bearing outer races; corner radii look good. I don’t know how I would crown them. Since this ferrule appears to be plated brass, it may be much softer than hard drawn nickle silver. This may contribute to welt formation.
    I put the rollers over the welt and ironed it out nicely, but fine sanding would be needed for cosmetic perfection.
    Notice that there are two adjuster screws, one on each end of the bearing pin. It is possible to get more pressure at one end of the roller.
    Dave

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