Ferrule Tool Alignment

I have made more than 200 of the ferrule shrinking tools and have had only positive feedback on their performance, until recently. Paul had borrowed a tool from me and was able to tighten the ferrule fit on several rods. He returned the tool and then later bought one. But the tool he bought did not work as well as the borrowed tool. His description is that the ferrules were “unevenly swedged”. I can accept this description since he has successfully used the borrowed tool.

So I went through the 8 tools in my inventory and checked the roller alignment by squeezing a strip of pressure indicating film between the rollers (outer races of ball bearings). In the photo below you can see such a strip. On one of the inventory tools, the pressure was not even across the roller faces, see the two left side marks on the strip. The strip here is a Fujifilm product called “Prescale”. You can get a similar image using a strip cut from your checkbook, from the sheet that makes a copy of what you write on a check.
My recommended procedure for realigning your tool if you feel that it is not correct or if you have dropped it:
1. Loosen the two radial screws. Loosen the 3 screws that clamp the two sides together. This only needs to be a quarter turn or so. Tap the edge of one plate with a mallet to be sure that it is not adhering to the spacers.
2. Tighten the two radial screws, bringing the moveable roller into contact with the two fixed rollers. Bring both screws into contact with the bearing pin before tightening either.
3. Re-tighten the 3 clamp screws.
In the photo, the right side of the film strip is the impression made by the rollers after realignment. The two impressions are more uniform.

Paul is off on an extended fishing trip in our western states, so I will not hear further from him until November. I am hoping that this procedure cures his ferrule tool.

Update 4 Oct 2019: Sometime during 2019, I received a new batch of 10-32 axial clamp screws (7/8″ length). Screw dimensions have tolerances, and these had a slightly larger head diameter than those used previously. They would bind when driven into the countersink of the side plate when the countersink was not perfectly concentric with the screw hole. This, I believe, caused roller misalignment and is the problem with Paul’s tool.
Checking my stock (8 units) of tools, I find another one which will not come into alignment even with the procedure outlined in this post. If you bought a tool and suspect that it is not right, contact me and I will arrange an exchange. If you have been able to successfully shrink a ferrule with your tool, then it is OK.

Update 22 Nov 2019: Paul returned from his Grand Tour of Western Rivers, and sent back the troublesome tool. It seemed to me to be OK, so I disassembled and found:
The outer race of one bearing had been dragging on a side plate, but had worked itself free by the time I saw it. I may need to add some washer shims to the design.
After working with the pressure indicating film for a while, I realize that it is not very useful. I have been clamping down on a gage pin (or just bearing to bearing). But when a thin walled tube (i.e., a female ferrule) is clamped, the compliance is much greater and the pressure is much more uniform.

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