Re: ShopTalk: Frequency meters and deflection boards

[John Kaufman]

Hi Al,   First of all are you asking for data on raw shafts or gripped clubs? Secondly 30 to 75 pounds is extremely light clamping pressure. When the shaft is clamped you shouldn't be able to pull it out of the clamp. When I ran the tests I mentioned on raw shafts I probably ran the force from less than 50 pounds to probably over a thousand. I only got 6 cpm for steel and 2 cpm for graphite. As best as I can measure my Club Scout clamp puts about 200 to 300 pounds of force on the shaft. I have a pneumatic clamp with which I can vary the clamping pressure in a known amount very precisely. If I get ambitious I'll try to run some data. I'll have a booth at the PCS Expo and I'm pretty busty trying to get ready for it   As I mentioned in my email I found very little difference in various analyzers assuming the clamping length was the same. Cheers, John K ----- Original Message ----- From: Al Taylor To: [EMAIL PROTECTED] Sent: Wednesday, February 05, 2003 3:36 PM Subject: Re: ShopTalk: Frequency meters and deflection boards John, Only if you have the data handy, I would be curious what frequency variations you got by varying the clamp pressure around a given pressure of say 50 Lbs.  Or something that would be considered a normal FA clamp pressure.  Or say the differences from 30 Lbs to 75 Lbs.  Just looking for some idea of what the various FA's would demonstrate given their "normal" clamp pressure differences.  I suspect that the differences would not be significant or at least not in the range of a "flex". If my assumptions about clamp pressure are close, and given that the electronics either work or don't work, I would surmise that at the working level of most club makers, the differences in frequency readings between most analyzers would be minimal.  Just a semi techy question from a wannabe. Al  At 09:56 AM 2/5/2003, you wrote: Hi Folks Again,   One comment I forgot make is regarding grips. I do all my measurement on ungripped shafts.  Grips always add damping and will always lower the frequency. A Soft-Tee (sp?) can lower the frequency by as much as 10cpm. The effect of the grip damping can be minimized by added clamping pressure so if Sheets was using gripped shafts then  variations in clamping pressure  might have resulted in the differences he saw.   Cheers, John K ----- Original Message ----- From: Royce Engler To: [EMAIL PROTECTED] Sent: Wednesday, February 05, 2003 7:50 AM Subject: RE: ShopTalk: Frequency meters and deflection boards I've had a Brunswick freq analyzer for several years...one of the early things I learned was the effect of clamping on frequency.  When I bought it, I also bought a calibration shaft, and it turns out that what you actually do to calibrate the machine is change the clamping location.  Sooooo  as it turns out, the correct clamp length for my **system** (and I'll elaborate on that a little more in a minute) turns out to be about 4".   I mentioned the clamping "system"....here's what that includes:  The base of the machine has a v shaped slot that the grip is clamped into (you have to measure shafts with grips on them...I have a whole drawer full of split grips).  The shaft is clamped by a plate with one end resting on the base, and the other has a v-shaped slot that matches the one on the base.  The clamping force is applied by a screw type mechanism with a slip arrangement that allows the handle to slip when it reaches a certain torque (I have no idea what that quantity is, but the instructions say to turn it until you get three clicks.  This is similar to the clamp knobs on the Golfsmith FA.   One day I noticed that the clamp arrangement was squeaking, and like any good engineer, I took it apart and greased it.  Lo and behold, suddenly my frequencies jumped.  I "recalibrated" and found that I needed to shorten the clamping length to get the same frequency.  What had happened was that by lubricating the clamp, I enabled it to get tighter before the torque limiters started slipping, thus the clamp pressure had increased, resulting in an increase in measured frequency.   Enter the PCS Equalizer...The way the Equalizer works is that it measures a shaft against an arbitrary standard and assigns a frequency to it.  You then measure the frequency of that shaft in your machine, and compare the measured frequency with the standard frequency to get a conversion factor.  That conversion factor then generates a set of curves similar to the FM precision curves, but calibrated to your freq analyzer, clamping system, and all.  Soooo.....   The bottom line is that if I wanted to, I could make a shaft read in a wide range of frequencies, all of which would be correct for the configuration of clamping length, pressure, and grip.  The key is to get a good comparison standard and try to be as consistent as possible in how you clamp the shaft.   Having said that, I do notice that sometimes the electronics get fooled by a dark colored shaft.  I noticed that sometimes a black graphite shaft would read quite a bit lower than others.  What I figured out was that the electric eye that counts the times the shaft goes by it couldn't always "see" the shaft and missed counts, which leads to a lower indicated frequency.  Solution is to keep some strips of lead tape handy and wrap the shaft where it is in the path of the sensor.  Also helps to have a good strong light behind you pointing toward the sensor.  Steel shafts reflect light better, so they don't seem to suffer from the problem.   Sorry for the long note, but hopefully it is useful to someone.   Royce -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, February 04, 2003 11:13 PM To: [EMAIL PROTECTED] Subject: Re: ShopTalk: Frequency meters and deflection boards Dave   You are correct. That was a very good test. It opened my eyes. The clamping mechanism is more important than the electronic side because it is where all the variable seems to lie. The electronics are pretty well governed by design and components used while the clamping mechanism as well as the bench and its stability are where most of the deviations seem to lie between machines. I for one liked your home made unit because yours broke the CPMs down to less than one. I would like to have one that breaks it down to tenths which I think is overkill but that is just me.  Charlie B