X10 FOC with Stainless Steel v Tungsten

[buzz lite beer]

Just done a little experiment to show the small amount of FOC change when using Tungsten points rather than Stainless Steel

1st image shows full X10 Shaft fitted with a 120gn tungsten point on DIY balance clip



2nd image shows shaft (now reduced in length by 14mm to get same arrow length) with a 120gn Stainless point fitted on the DIY balance clip



3rd image shows the overall FOC difference of 1/4" (6.53mm)



Not going to be really noticible to most archers!!

 

[Timid Toad]

Shortened off the front or back?

 

[Vagabond]

Hi,


I did a slightly different experiment:
* Balance the X10 with 120gr tungsten point.
* Replace with 120gr steel point.


i.e. no other change, so same shaft length.


Result?
The arrow balanced in exactly the same place - to within the thickness of a pencil line.
So the centre-of-gravity is exactly the same distance from the nock groove.


Arguably, the FOC had improved slightly.
The tungsten point is shorter so the centre-of-gravity is now closer to the tip of the point.


Here's another interesting experiment:
Measure how the centre-of-gravity is affected by arrow-wrap (i.e. arrow cresting).
No need to actually fit the arrow-wrap 'cos you can just tack it gently into position for this experiment.


Result?
The c-of-g moved back ~5mm.
Not much, but I decided not to pay good money to make my arrows worse.


Ho-hum!


V

 

[buzz lite beer]

Shortened off the front or back?

just from the front as is standard with cutting down arrow shafts

 

[Timid Toad]

just from the front as is standard with cutting down arrow shafts

I'm surprised you say that. Lots of recurve archers cut off the back too. Compounders have done that for years, of course. I've got about 8 sets of second hand X10s, all the same spine, but some cut from the front, some from that back and some both. All purchased from known archers, including GB Squad members. That's why I was asking. It might be recommended to take off the front for recurves, but that's not reality at this point in time.

 

[buzz lite beer]

Hi,


I did a slightly different experiment:
* Balance the X10 with 120gr tungsten point.
* Replace with 120gr steel point.


i.e. no other change, so same shaft length.


Result?
The arrow balanced in exactly the same place - to within the thickness of a pencil line.
So the centre-of-gravity is exactly the same distance from the nock groove.


Arguably, the FOC had improved slightly.
The tungsten point is shorter so the centre-of-gravity is now closer to the tip of the point.


Here's another interesting experiment:
Measure how the centre-of-gravity is affected by arrow-wrap (i.e. arrow cresting).
No need to actually fit the arrow-wrap 'cos you can just tack it gently into position for this experiment.


Result?
The c-of-g moved back ~5mm.
Not much, but I decided not to pay good money to make my arrows worse.


Ho-hum!


V

Yes if you leave shafts uncut both points will balance closer still but arrows will need to be 14mm longer to get same FOC

 

[KidCurry]

Just done a little experiment to show the small amount of FOC change when using Tungsten points rather than Stainless Steel
1st image shows full X10 Shaft fitted with a 120gn tungsten point on DIY balance clip
2nd image shows shaft (now reduced in length by 14mm to get same arrow length) with a 120gn Stainless point fitted on the DIY balance clip

I don't usually include the point length when using the AMO FOC calculation. My gut feeling is the extra long point will compensate for the extra long shaft inside the arrow.

Yes if you leave shafts uncut both points will balance closer still but arrows will need to be 14mm longer to get same FOC

Probably an issue for recurve shooting a clicker.

 

[buzz lite beer]

I'm surprised you say that. Lots of recurve archers cut off the back too. Compounders have done that for years, of course. I've got about 8 sets of second hand X10s, all the same spine, but some cut from the front, some from that back and some both. All purchased from known archers, including GB Squad members. That's why I was asking. It might be recommended to take off the front for recurves, but that's not reality at this point in time.

Whilst I've been cutting from the back of X10s on my own arrows since around 2003 it's not really relevant for the point of the topic of FOC if you cut off either end FOC won't be affected the 14mm off cut will weigh about 3 grains from either end. dynamic spine however will be affected, and it's also still not a recommended/approved practice by Easton, this example was mainly driven toward recurve archers who tend to have there arrows all the same length when possible to do away with moving clicker positions rather than following the AMO arrow length method, and to show that the claims that you get huge increase in FOC if you use tungsten are infact a myth (I've shot with arrows cut to obtain the same overall length arrows with tungsten and stainless points in them shot them from my bow randomly and get almost identical POI with both options despite the 1/4" difference in FOC