Apparently this is a drop weight machine, but you do not have to get the drop weight bar to horizontal. Can anybody explain to me how it works? I can understand the concept of other drop weights, the gravitational pull on the weight is equal to the tension that you set when the bar reaches horizontal. But with the Laserfibre MS200 ECO, you just let the bar go and whereever it rests as long as it is not bottoming out on the table top or floor, you apparently have the correct tension. How does that work? Is there something more than gravitation at work here? Perhaps some sort of spring mechanism? And if there is, does this mean that the machine must be calibrated, unlike other drop weights.
Laserfibre MS200 ECO, no need to go horizontal, how does it work?
- Thread starter spirit
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fantom
Hall of Fame
Here's a link that shows how the Laserfibre (Stringway) drop weights work:
http://www.stringway.com/dwm.htm
They do not need calibrated.
http://www.stringway.com/dwm.htm
They do not need calibrated.
fantom said:
Very Clever. Must be patented. If I understand the illustration correctly, it looks like it involves a counter weight system. Because the arm does not need to be at a specific angle (horizontal or 180 degress), it should lead to more accurate and consistent stringing. For that reason, if one were to go drop weight, Laserfibre is the way to go. Any counter opinions on that issue?
SW Stringer
Semi-Pro
In a standard drop weight machine the geometry (length) of the drum "lever arm" (L1) is fixed, while the geometry (or length) of the sliding weigh lever arm (L2) is variable. The tensioning force applied to the string is the ratio of the two effective lever arm lengths multiplied by the weight of the system - sliding weight plus weight of the arm - or (L2 times cos(theta)/L1) times W. If the angle (theta) is horizontal, or zero degrees, cos(theta) equals 1. That's why you want to be horizontal to get the PERFECT pull, but any angle within plus or minus 10 degrees still gets a pull at 98.5% of desired tension.
In the Stringway system, the geometry of L1 is also variable and theoretically should exactly compensate for the effective shortening of L2 at angles that vary from the horizontal. For example if the arm is at 20 degrees (cos 20= .94) then the L1 distance would be increased by 6% over the horizontal condition by changing the pivot point. Now obviously if the arm is at plus or minus 90 degrees from the horizontal, it won't work, and Stringway doesn't say what the ACTUAL range of angles that the mechanism is accurate, but it does offer the convenience of (mostly) one pull tensioning.
In the Stringway system, the geometry of L1 is also variable and theoretically should exactly compensate for the effective shortening of L2 at angles that vary from the horizontal. For example if the arm is at 20 degrees (cos 20= .94) then the L1 distance would be increased by 6% over the horizontal condition by changing the pivot point. Now obviously if the arm is at plus or minus 90 degrees from the horizontal, it won't work, and Stringway doesn't say what the ACTUAL range of angles that the mechanism is accurate, but it does offer the convenience of (mostly) one pull tensioning.
fantom
Hall of Fame
There have been MANY discussions on this in the past.
I don't think you'll find anybody who tells you that the Laserfibre machines aren't really nicely built and easy to use.
People have had problems with dealing with Laserfibre from a tech support standpoint. There's basically only one point of contact (Tim) and he's not always the easiest guy to get in touch with.
Lastly, the Laserfibre machines are more expensive than other drop-weight systems. For example, the ECO w/ flying probes is only a few $$ than the Gamma with fixed probes.
For more information, do a few searches on these boards for "ECO". You'll find some very lengthy (and heated) duscussions on what I'm talking about.
I don't think you'll find anybody who tells you that the Laserfibre machines aren't really nicely built and easy to use.
People have had problems with dealing with Laserfibre from a tech support standpoint. There's basically only one point of contact (Tim) and he's not always the easiest guy to get in touch with.
Lastly, the Laserfibre machines are more expensive than other drop-weight systems. For example, the ECO w/ flying probes is only a few $$ than the Gamma with fixed probes.
For more information, do a few searches on these boards for "ECO". You'll find some very lengthy (and heated) duscussions on what I'm talking about.
SW Stringer said:
Thanks for the explanation. I'll do a little work with the formula to convince myself I fully understand it. Nice to know how things work. But it does seem that it is a better system in that it takes out the variance that can creep in from not getting the drop weight arm at the same spot at the horizontal on each pull. Isn't that correct? I have never strung a racquet so I may not be interpreting all this accurately.
Gaines Hillix
Hall of Fame
SW Stringer said:
This is just a SWAG, but my guess is that the pivot point of the arm has a cam built into it that allows L1 to vary in proportion to the length of L2. ??
SW Stringer
Semi-Pro
spirit says: "But it does seem that it is a better system in that it takes out the variance that can creep in from not getting the drop weight arm at the same spot at the horizontal on each pull. Isn't that correct?"
In THEORY that is correct. But in practice we just don't know. It would be nice to flip to the back of the owners manual to the Specifications page and read what the limitations of the tensioning mechanism were ( much like frequency response specs for audio equipment) so you could make comparisons. But the manufacturers of stringing machines don't disclose this information.
I've been intrigued by the Stringway/Laserfibre tensioning system since first reading about it. So if there's an owner in the DFW, Houston, or Denver area who'd be willing to put his machine to the test (digital electronic scale and angle meter) maybe we can publish some specs for the tensioning system.
In THEORY that is correct. But in practice we just don't know. It would be nice to flip to the back of the owners manual to the Specifications page and read what the limitations of the tensioning mechanism were ( much like frequency response specs for audio equipment) so you could make comparisons. But the manufacturers of stringing machines don't disclose this information.
I've been intrigued by the Stringway/Laserfibre tensioning system since first reading about it. So if there's an owner in the DFW, Houston, or Denver area who'd be willing to put his machine to the test (digital electronic scale and angle meter) maybe we can publish some specs for the tensioning system.
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