PC based frequency meter

[MarkinTN1]

I'm looking to build a frequency meter used to measure golf club shafts. I was thinking I might be able to interface it to a pc, I know pretty much zero about electronics or pc's for that matter, but I figure it can be done.
The method I want to use is to mount a light source and phototransistor pointed at one another. The vibrating shaft passes between the two and interrupts the beam sending a pulse each time to the timing circuitry in the pc, and then the pc converts it to cpms and displays the number, in some program, possibly excel or some existing software that I have.
Here's a link to plans for a do-it-yourself frequency meter, but it does not interface to or use a pc, plans include a readout.

https://www.tutelman.com/golf/measure/fmeter.php?ref=

Here's a link from a manufacturer of freq meters who sells the machines and his tech notes;

https://csfa.com/techframe.htm

And here's a link to a page where an engineer did make one to link to a pc by using wave studio software that came with his pc and a microphone

**broken link removed**

I already have a clamping device I built for another machine.

Any golfers on the board? I'd love to work out some barter for some help on this project.

Thanks guys for putting up with me.

I'll check back for replies, also my email is mark681137@aol.com

 

[Sceadwian]

Exactly what are you trying to measure? When the club head hits the ball, or when the shaft passes a certain point? More detail on exactly what you're trying to measure would lead to some useful suggestions, you're asking far too generic a question right now. You could measure when the shaft passes a certain point, the head, shaft length, angular deflection. We haven't a clue! =)

 

[MarkinTN1]

"The cycles per minute (cpm) of a golf shaft, to precisely measure the time it takes for the shaft to make a fixed number of vibrations. The grip end of the club is held in a vise, the other end is "twanged" (pulled to one side and released, causing the shaft to move back and forth), the shaft breaks a beam put out by the sensor and the count is timed and translated into cpm's.
The method I would like to pursue is to use a light source on one side of the shaft and a photo transistor on the other side pointed at each other, the vibrating shaft passes between the two and interrupts the beam sending a pulse each time to the timing circuitry, which would use a microprocessor to actually perform the division to convert the time to cpm and display the value. I assume use a crystal controlled clock to time the oscillations."
I copied that from one of the tech notes pages I cited in the first post.

Thank you taking the time to read and post and for helping me get started.

 

[Sceadwian]

In a quite environment attach a small microphone near the head and you'll be able to pick up the frequency. The problem with using a break beam frequency measure is you have to absolutely guarantee that the beam is broken with each phase of vibration, which you can't as it will be limited by the thickness of the shaft itself and the exact position of the sensors will have to be calculated to a very high degree. How about something like an electric guitar pickup? Graphite shafts conduct electricity, a guitar pickup may be able to non contact sense the vibration. I'm not sure how electric guitar pickups work though, I thought it was a static magnet used to induce a current in the string which was picked up but the pickup.

Other users with more of a musical background may be able to clarify my intent. You have to be VERY careful about where you try to measure the vibration from as various vibration modes along the shaft will cause certain points to not move at all while points nearby are going through full phase to phase deflection. You have to exactly quantify the reason for trying to measure the clubs resonant frequency.

Human hands/arms/body move and are part of the vibrational analysis of a golf club strike. Measuring the static vibration in a vice will provide you with no real world usable information as in no real world situation will a golf club be struck as if it were being held in a vice.

 

[AllVol]

OP is measuring the flex of the club shaft, according to manufacturer's ratings of "stiff, regular, ladies and senior", apparently.

My two wood measures ~7 mm at the hostel, which should provide enough shadow to break beam for measurement. We're not talking a lot of hz here, perhaps in the tens of cycles.

 

[Sceadwian]

It'll give you basic information about the elasticity of the shaft but it still won't represent what happens when a real person swings the club, from the fingertips to the shoulders become part of how the shaft will vibrate on a real swing.

 

[MarkinTN1]

True Sceadwian, but this is used in clubmaking, I guess you would call it a static measurement as opposed to dynamic.
These machines are manufactured and sold. I built another clubmaking tool and a part of that tool was the vise assembly, it turned out really well, when I got through I realized I have halfway to having a golfclub frequency meter, the vise being a major component (and not as simple a task to achieve as it may seem). The part I was lacking was a sensing unit (infrared emitter and sensor) and the processing part (to count the breaks and convert that number to cycles per minute) and the display (an led readout). There was an existing plan on the internet for one, a home project type, but upon closer inspection most of the parts were obsolete and hard to find, it used EPROM.
https://www.tutelman.com/golf/measure/fmeter.php?ref=
However on another board there was a reference to using a pc to be an fm, via the soundcard and soundcard software.
**broken link removed**
A friend of mine familiar with the application suggested using a microcontroller, but that would require in his estimate 50 to 100 hours of programming.
I could purchase the completed unit of the pieces I need for about $180.
https://csfa.com/default.htm
However, funding for play toys is at an all time low right now and the $50 range was much in my budget.
I did find an EPROM at an arcade part dealer, and in his description he offers to program it for an additional $3, he asks for an image, I do have some downloaded files from the original plan (DaveT's), I not sure if thats what he would need or not. Outside of that, there are several other obsolete parts from the plan and I not sure how other substitutions would fit.
Thats about where I am on it right now, its taken several hours of researching and thinking to even be able to discuss it this clearly, if I am even being clear.
I have zero electrical background, other than don't touch the two wires together, but I like to think that I have the average intellect, but as of this point I'm beginning to wonder. Hence my offer to barter for assistance.
Now Sceadwian I could discuss the dynamics of the golf swing with much more intelligence than I do electronics.