05-24-2018, 10:18 PM
Mr. Mark accusingly blurted, "I can't believe those guys are withholding information! That's not the spirit, right Mr. Ken?" 
OK, Mr. Mark, here's what I did.
The reason that I did not post this is because I am almost totally bereft of any vestige of spirit!
(Just kidding). The real reason is because there is some question as to if modifying the TMF may influence the readings due to a difference in the length of the threaded media. This can be seen the the 20% reading variance of the test clips, however the test clip media length is much shorter and over-tensioned. Slightly de-tensioning the media in the test clip is claimed to return the test clip results to be equal, or close to the same as the TMF.
I'm sure Mr. EOU will correct if I labor under delusion, but it is my understanding that the length of the threaded media is more or less determined by where the media goes over the edges/sides of the TMF.
As you will see, my mod shortens the length of the threaded media by about 1/4", because I clamp the media at the edge rather than a little way down the side of the TMF. It is my understanding that test media has very little stretch, so I would think that the difference in length of my mod would be of little consequence because it clamps the test media at the edge where it would normally be. If indeed threaded media length is determined by where the media passes over the edges and media stretch is not really a contributing factor I would think that my mod would have marginal, if any, impact on readings.
Moreover, I have not done razor blade testing since I did this mod. It would be a crude test verify that my mod had no impact on readings.
As I understand it, the gods of BESS certification are a picky and demanding lot. I get the idea that if you stare really hard at your TMF and even think about modification, your TMF would lose certification. Now..., that is a good thing and completely necessary for a reliable standard.
That said, before continuing to read, please check the following box to confirm that you have read and understand the Terms of Use Agreement.
OK, I'm done babbling.
The reason I did the mod was because I found it a bit fussy and slow to get the media under the screw on the side of the TMF. When the media is pinched in the finger, it tends to hold the media off the side of the TMF and catch on the side of the screw rather than go under it. This mod totally eliminates that, and reduces the process to a very smooth and fast operation of literally one or two seconds.
I drilled a 45° hole in the TMF and stuck a stud in. I made the little knob on the lathe from a chunk of 1/4" aluminum rod then drilled and threaded it. The 45° knob is a lot easier to grab the the fussy little screw on the side of the original unit. The bottom of the knob is just wide enough to cover the slot in the TMF so it can pinch the media at the out edge of the slot.
The top edge of the TMF is rounded and polished for two reasons. One, it provides a flat spot for the bottom of the knob to grip the media at the edge of the slot and two, because it is so smooth all I have to do is get the media anywhere on side of the TMF, pull toward the knob and it effortlessly, automagically, drops into the slot. (The new nickel plated TMF units may accomplish the same smoothness without the need for additional rounding and polishing of the edge. I did this on an original non-nickel plated unit.)
Putting the knob on a stud rather than having a screw that threads into the TMF, eliminates the problem of having the media getting additionally tensioned, pulled into and becoming stuck in the hole because with a screw, rather than a stud, the screw threads grab the media and pull it into the hole as it is tightened. Another way around that problem is to counter drill a slightly larger bore at the top of the thread bore for the screw which is what is done on the standard TMF. But that is another step which is eliminated by using a stud rather than a threaded bore in the TMF.
OK, Mr. Mark, here's what I did.
The reason that I did not post this is because I am almost totally bereft of any vestige of spirit!
(Just kidding). The real reason is because there is some question as to if modifying the TMF may influence the readings due to a difference in the length of the threaded media. This can be seen the the 20% reading variance of the test clips, however the test clip media length is much shorter and over-tensioned. Slightly de-tensioning the media in the test clip is claimed to return the test clip results to be equal, or close to the same as the TMF.
I'm sure Mr. EOU will correct if I labor under delusion, but it is my understanding that the length of the threaded media is more or less determined by where the media goes over the edges/sides of the TMF.
As you will see, my mod shortens the length of the threaded media by about 1/4", because I clamp the media at the edge rather than a little way down the side of the TMF. It is my understanding that test media has very little stretch, so I would think that the difference in length of my mod would be of little consequence because it clamps the test media at the edge where it would normally be. If indeed threaded media length is determined by where the media passes over the edges and media stretch is not really a contributing factor I would think that my mod would have marginal, if any, impact on readings.
Moreover, I have not done razor blade testing since I did this mod. It would be a crude test verify that my mod had no impact on readings.
As I understand it, the gods of BESS certification are a picky and demanding lot. I get the idea that if you stare really hard at your TMF and even think about modification, your TMF would lose certification. Now..., that is a good thing and completely necessary for a reliable standard.
That said, before continuing to read, please check the following box to confirm that you have read and understand the Terms of Use Agreement.
OK, I'm done babbling.
The reason I did the mod was because I found it a bit fussy and slow to get the media under the screw on the side of the TMF. When the media is pinched in the finger, it tends to hold the media off the side of the TMF and catch on the side of the screw rather than go under it. This mod totally eliminates that, and reduces the process to a very smooth and fast operation of literally one or two seconds.
I drilled a 45° hole in the TMF and stuck a stud in. I made the little knob on the lathe from a chunk of 1/4" aluminum rod then drilled and threaded it. The 45° knob is a lot easier to grab the the fussy little screw on the side of the original unit. The bottom of the knob is just wide enough to cover the slot in the TMF so it can pinch the media at the out edge of the slot.
The top edge of the TMF is rounded and polished for two reasons. One, it provides a flat spot for the bottom of the knob to grip the media at the edge of the slot and two, because it is so smooth all I have to do is get the media anywhere on side of the TMF, pull toward the knob and it effortlessly, automagically, drops into the slot. (The new nickel plated TMF units may accomplish the same smoothness without the need for additional rounding and polishing of the edge. I did this on an original non-nickel plated unit.)
Putting the knob on a stud rather than having a screw that threads into the TMF, eliminates the problem of having the media getting additionally tensioned, pulled into and becoming stuck in the hole because with a screw, rather than a stud, the screw threads grab the media and pull it into the hole as it is tightened. Another way around that problem is to counter drill a slightly larger bore at the top of the thread bore for the screw which is what is done on the standard TMF. But that is another step which is eliminated by using a stud rather than a threaded bore in the TMF.