MOI Matching

[Richie3Jack]

Has anybody ever done this?

I kinda get the overall concept, but I'm curious as to what the MOI measuring machine actually measures and how it works.






3JACK

[pavaveda]

I made an attempt at this once using the orange juice box, cut CD, kitchen scale, and lead tape approach. It took quite a bit of work as far as calculating went, but it was a fun project. I eventually removed all the lead tape though, and went back to a single swing weight.

Several references:
www.tutelman.com/golf/clubs/MOImatchRecent.php
www.logitekinfo.com/id/golfinfo/
www.leaderboard.com/SWINGWEIGHT (use mm and grams for the best measurement)

[woodbury]

The above method works for a sloped swingweight to approximate MOI matching, correct? to measure MOI, I believe you can just set up the club as a pendulum, measure the period, T, and solve for I (MOI). I dont remember the equation, but Im sure the Wishon message board has it somewhere in its archives. I have some excel spreadsheets with MOI equations, but its fairly basic and I wouldnt trust the numbers. Arent the MOI measuring machines just period counters?

[Richie3Jack]

The C-Taper seems stable in the demo 555M 6-iron with the shim installed. I measured the MOI and it came out to.....2,775. That's pretty heavy. The heaviest iron in my bag measured in at 2,700 when I first did it. The average was probably around 2,670 or so.

Looked at the club some more.

I saw that I made the demo 6-iron a tad bit too long. About the size of the cap of the Iomic grip too long. Which is about 3/16"

Cut that off. Measured the MOI.

2,715.

So about 60 kg.cm2 was trimmed just by cutting 3/16" of the shaft.

VERY sensitive piece of equipment.








3JACK

[ericpaul2]

Deleting...I just found the thread discussing this in detail.

[Richie3Jack]

Jan 9, 2012 9:52:51 GMT -5 ericpaul2 said:

With another opinion, suddenly the validity starts looking a little more believable. How close were your results to the photos posted?

Welcome aboard.

In the 'before' photo, my results were not as scattered. The 'before' mostly had shots in one area and most of the mis-hits were slightly towards the toe, but a couple of shots were more towards the heel.

The after, with the 7-iron...every shot was in the same exact place. In fact, it tore thru the impact tape. The impact was slightly towards the toe, so the 7-iron had to be bent 1-degree upright...probably due to shaft droop. However, after I matched the rest of the set, I then did each club to check for lie angles and my PW and 7-iron needed to go about 1-degree upright. However, my 3-iron thru 5-iron needed to be about 1-degree flat (3-iron had to be 2-degrees flat).

With the irons, I can be much more precise. As I get into longer clubs, I will not be as precise. Still, the dispersion is key and so is the ball flight.

With the hybrid, I was right on the money. I only had to add 1-gram of lead tape to the hybrid.

With the 3-wood, there was a bit more dispersion, but I still got it pretty good.

With the driver, the impact dispersion was the largest, but that's expected with a driver. Still, the ball flight improved dramatically. I couldn't get that driver very high when I started and then added about 4 grams of weight and the ball flight improved dramatically.

One other question...I understand the theory behind making the entire iron set match MOI based on one club, but does this hold up in reality? In other words, have you used the impact tape to confirm that the results you got for the 7 iron held throughout the set? I'm just wondering if the fitting process should be done for each club, or of that's a waste of time. I'm guessing that the difference between ideal MOI between adjacent clubs might be miniscule, but the difference between a 4 iron and a 9 iron might actually be measurable.

Doing it for each iron is a waste of time.

I recommend doing the MOI fitting and then afterwards, going thru each iron in the bag with impact tape (or spray) just to check your lie angles.

What should happen once you are fitted for MOI is that your impact dispersion should be the tightest it can be for your skill level. However, the impact may be towards the toe or the heel, even if it is all in the same spot. You then just need to adjust the lie angle and what's probably throwing off those lie angles is shaft droop in the swing.

For hybrids, fairway woods and driver, fit those separately. But, if you have more than one hybrid, then you just need to fit one hybrid and match the other. Same with fairway woods and even the driver.







3JACK

[ericpaul2]

Thanks for the reply.

So, I fitted myself for my 7 iron as described and had the same results you did as far as face dispersion. Really incredible. Starts to make sense why so many of the Pros have lead tape all over their clubs.

Totally worth it if only to discover that stock swingweights are just too head light for me, and I wouldn't consider myself especially strong.

What shocked me was not just the face dispersion improvement, but also the face angle consistency. I'm sure they're related, but the spray angle reduced signficantly.

However, I have a follow up question. I don't have one of the machines and will probably find a clubmaker locally that does and have them match the rest of the irons and then work on the driver/woods/hybrids separately. However, out of interest...I grabbed the swingweight spreadsheet from myostrich.com and added the MOI equation from Tutelman's site (understanding that it's an estimate). Using what information I could find on my component weights and his guide of 1.3 SW points for each inch of shaft, I wanted to get a rough idea of how much weight would need to be added to each club. Definitely just an estimate (particularly since clubhead weight could be off by a gram or two in either direction as we change clubs), but it showed a problem.

I'm running out of "room" at the 4 iron due to the heavy DG shafts (I'm happy with my trajectory with these, so I've never bothered to fool around with the shafts like I did with my driver). I would actually need to remove weight to stay "on slope" and match the MOI. Obviously, I may need to swap out the shaft for that club to something lighter.

I seem to recall you mentioning that issue somewhere, but I can't find it. What shafts did you use to get the initial MOI low enough to be able to come up to the fitted MOI with all clubs?

[Richie3Jack]

Wishon heads are lighter than just about every OEM's heads. The reason is so one can just add weight to the head and MOI match. If they are too heavy, you'll have to find a way to lighten the club, either with a lighter shaft or doing some grinding to the head which is really tricky.

I'm pretty sure KBS Tour and Tour 90 shafts are the same characteristics, just the Tour 90 is much lighter. I believe I will run into the same problem with the club being way too heavy when I get my Hogan's re-chromed. So I am thinking about using a Tour 90 shaft instead. I just need to see how much kg/cm^2 it takes off the club.





3JACK

[ericpaul2]

That's what I figured. I also have to say its nice that his head weights are actually published. I had to back calculate mine based on claimed swingweight. Another reason it's just an estimate and no substitute for actually measuring the MOI.

The interesting thing about MOI matching is that its starting to make a lot of other things make sense. For example, I have an old set of Mizuno MP-33s, but the 4 iron got damaged. A few months back I picked up a replacement 4 iron on ebay, but it had an old TT Dynalite Gold (discontinued) shaft that didn't match the DGs in the rest of my set. I figured I would get it replaced at some point, but didn't get around to it yet. However, I did take it out to the range for giggles and discovered that I hit it with great consistent contact. Made me start toying with the idea of getting all my iron shafts switched out to something lighter. Now from my MOI estimate, I see that it's MOI is a lot closer to the 7 iron I just fit than my other 4 irons. Good thing I didn't do it.

Another fitting question. Before I started fitting the 7 iron, I was worried about the small sample size. I figured I would go up by 1 gram increments, but I was concerned that I might just have a couple bad shots and miss the fit. However, when I actually did it I found that my face dispersion improved incrementally as I went up by 1 gram steps until suddenly it went completely haywire again. Backed off 1 gram and then added 0.5 gram, and voila...bang on impact. Did you have a similar experience? Trying to figure out what to expect with the hybrids and woods.

[Richie3Jack]

Yes, that was the experience I had. I used 1-gram increments as well. 1-gram will affect the MOI by about 10 points or so. You want everything within +/- 5 from your base MOI. Anyway, when I did it the dispersion got better then I found the MOI for me and I actually hit so many shots on the same spot that it tore a hole thru the impact tape after 7 shots. Then I added some more weight and the dispersion got larger again.





3JACK

[Richie3Jack]

I had a few problems with my MOI matching using the dry assembly method. This method is where you 'dry assemble' the club and put it on the Auditor MOI machine and get the MOI reading.

Typically, it's fairly easy to figure out as 1 gram of weight to the head will equal about 10 kg/cm^2. I was also told that when you add the epoxy and the ferrule on, it wil add about another 10 kg/cm^2.

I was having some issues is I would dry assemble the club and then get anywhere from 10 to 40 kg/cm^2 when I actually assemlbed the club with epoxy.

I've been told that it appears I'm using way too much epoxy. It does go to show how sensitive the machine is and how sensitive MOI is to your clubs.

Anyway, I was told a few things:

1. shafting beads/granulated sugar should only be used when necessary. The club should stay in pretty centered and the problem with beads/sugar is that it actually causes the epoxy to become weaker. This is what happened to me early on when using Tour Van Epoxy. Tour Van cures super quickly, but it doesn't have the greatest sheer strength. Combine that with using granulated sugar, it just made it too weak and that's why I was having issues with some of the clubs.

2. I was told that you don't have to use a lot of epoxy. In fact, I was told to use a thin layer on the shaft and the ferrule and that I should not coat the inside of the hosel. Instead, when installing the head, just install it with a circular motion and that will coat the hosel properly.

Last night I installed a Aldila RIP Beta shaft. I made it 45.25" long and the MOI was at 2,790 kg/cm^2. I didn't install any hosel weights because I didn't have any 2 gram weights on me. Plus, I want to see if I do this right. If I do, it should go to 2,800 and then I can simply add 2 grams of lead tape around the hosel. Won't be pretty, but it will still look alright and performance is really what matters.







3JACK

[laflamablanca]

Richie,

Is it the case that if you get dialed in for an MOI on say a Wishon set, you can then take that same MOI number and apply it to another set of irons?

[Richie3Jack]

Welcome aboard, laflamablanca!

Yes, if you get dialed in for MOI, you can use it with any club.

The problem is that the OEM's typically make the clubhead weights heavier. I've seen up to 20 grams heavier (rare case).

Wishon makes lighter heads so the golfer can just have weight added to the clubhead either via lead tape or a hosel weight. If you're fitted for 2,700 MOI, but your 6-iron is 2,750 MOI, you would have to find a way to remove the weight, either with a lighter shaft or grinding the head.

I think if you require extra length added to the clubs, you will probably have a difficult time not getting at least one club that is over your MOI unless you use Wishon's lighter heads. I used +1/2" and Wishon comes out well below my MOI with no weight added. But, my Titleist 690MB's which are +1/2" are almost all above the MOI I use (2,725).

I do offer a service where I will simply measure the MOI of the golfer's set of clubs. I charge $30 for a set (13 clubs) and the customer pays for the shipping back and forth.

I also offer the MOI fitting with a golfer's non-Wishon clubs and I can then match the MOI using lead tape. The cost is $50 per iron set (customer pays for shipping).







3JACK

[laflamablanca]

Thanks Richie. I will be reaching out to you via email about getting a quote on a set of 575s. Can you tell me the specs on a standard L/L/L for the 575 7i? NM, found the data on the Wishon web site.