Designing a Putter - Hosel/COG

[opmet]

Hi,

 

I've wanted to design my own putter for a few months now, and eventually got around to it. My reason is simply just to have the perfect looking putter for me, hopefully the feel will be good too. I looked at several putters for inspiration and then began on Soiidworks with my design.

 

After about a weeks on and off work I have this design.

 

The face grooving isn't completely finished, and the centre of gravity is fairly in line with the centre line, so after its complete there will be some minor weight movement to be done.

 

I just have a few questions, and some help would be much appreciated.

 

-I suppose that the centre of gravity should be in the middle, in this case thats on the sight line, which is where it is very close too. Where should it be in terms of the direction of the sight line? As in, should it be on the face of the putter, or behind, and how far behind etc...

 

-When making the circular part of the hosel, where the shaft connects, whats the radius/diameter of the hole? I know this depends on the shaft used, but I have read so many different conflicting things its gotten very confusing.

 

 

Thanks,

 

 

Opmet.

[keitha37]

For the center of graity ou will want it as far back as you can get it. Think abut the 2 balls and other larger mallets like the spiders, etc. They all have a goal of moving the cg to the back of the putter or away from the face.

Not sure what to say about shaft diameter...maybe just buy the shaft and take a few measurements with a caliper?

[opmet]

keitha37, thanks for the reply.

Makes sense about the mallet style putters - you have clarified that for me!

Yes thats probably the best, buy the shaft, trim it down to the correct length and then adjust the hosel.


Thanks for the help.

[indyvai]

Standard shaft tip diameter is .370" and shaft bores that they sell to enlarge holes are. 375". The shaft fits a bit loosely in the .375" hole, so if you shoot for .373" you should be good. Remember that a plated finish will decrease the hole if not plugged... so take that into account...

[hebron1427]

i thought .355 was the standard? seems that that's what cameron is using more often than not.

[indyvai]

I buy all my shafts from Golfworks, almost all true temper are. 370... there are few options @ .355

Good point though... I just looked and straight shafts are equally available in both, and maybe in hosel plumbers neck makes more sense @ .355"

I guess use either comfortably and add. 003" +/-

[moocherpix]

Bore your hosel to .370, it will save you some serious "Slop-Time". The majority of replacement putter shafts are indeed .370, but Cameron and Byron use .355 in most of their putters, especially plumbers necks. Some builders like the .370 due to the ability to fine tune the feel by tipping it. You cannot tip a .355 taper in the same manner, it gets bigger from the very tip.
The .370 shafts, after you prep the tip will allow for a snug fit in a .370 bore, but would be sloppier than you think in a .373 or .375.
I believe that a "U" drill bit is .368 and that might be a better option, if you have access.
Nick

[opmet]

Thanks for the info everyone!

[dci762]

I've been told that the CG should be in the center if the face vertically from the ground and of course aligned with your sight line. This started making more sense to me when you consider the weight of the neck which will raise the CG.

The other issue that you should consider is the balance that you are aiming for, face balanced, degrees of toe hang etc.

[hebron1427]

weight of hte neck will move the COG up and to the heel. as such, the heel weight pad should be smaller than the toe weight pad, unless you're cool with a putter who has a sight line or dot that's not in the center of the cavity (which is fine), or if you don't mind putting with a putter whose sweet spot isn't in the middle of the face where one would expect. Since you're doing all of this in cad, you should be able to tell where the COG is pretty accurately. seems like one problem a lot of designers miss on is they put the COG too low. at or a little above impact is ideal. putting in about 1 degree of high toe will help with moving the COG up a bit.

[hebron1427]

one more quick question--how exactly are you going to mill those grooves? the way they're designed, you're going to have a lot of issues with broken end mills.

[finalist]

[quote name='keitha37' timestamp='1344117647' post='5407280']
For the center of graity ou will want it as far back as you can get it. Think abut the 2 balls and other larger mallets like the spiders, etc. They all have a goal of moving the cg to the back of the putter or away from the face.

[/quote]

CG placed way back is for a specific stroke rotational requirement... The OP may not want that.

You have to decide what type of MOI you want. High MOI doesn't always equal forgiveness. Some need more rotation, some less.

[opmet]

Thanks for all the info Hebron on this topic and the sole draft, really made sense. As it is in the picture - with the hosel incomplete - the COG is very close to the sight line (which is central in the cavity), and about two fifths vertically up the face - so hopefully it will be easy to adjust into place with minor weight changes. As for the milling of the face grooves - I have changed them from what is in the pictures - they are now shallower and narrower, and the ellipses are still there. I have contacted several companies to mill it on their high end CNC machines from 303.