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Xeno Full Roller Layout P1

Posted: February 10th, 2017, 3:49 pm
by Dustin
Drilled a Xeno with the standard full roller layout (R.H. bowler) in it and it seems to be a little bit jumpy of the spot. Where would a person locate the P1 hole to slow it down a little bit. In my head would the P1 should be located left of the thumb hole and left of the pin? I tried a small balance hole here and the spin time decreased :shock: , what am I not understanding? Should I have just drilled the thumb hole deeper?

Re: Xeno Full Roller Layout P1

Posted: February 10th, 2017, 5:11 pm
by EricHartwell
Sounds like your P1 location succeeded in reducing the reaction.

Good question about the thumb hole. That would be aakin to drilling the fingers deeper to reduce flare on a standard layout. Though a P1 would have greater effect.

Was the reaction affected enough with the P1?
You could drill the thumb deeper and see if it reduces the spin time even more.

Re: Xeno Full Roller Layout P1

Posted: February 10th, 2017, 5:28 pm
by Dustin
Let me be more clear spin time before was ~5.3 sec. and after drilling it was ~4.9 sec. Not what I was shooting for with the added hole.

Re: Xeno Full Roller Layout P1

Posted: February 10th, 2017, 6:03 pm
by snick
Just curious: Why not drill the hole on the PAP?

Re: Xeno Full Roller Layout P1

Posted: February 10th, 2017, 6:09 pm
by Dustin
Good question. I was following the general rules for x-hole int a asym. ball. Hole on PAP would be ideal on a sym. ball but thought a hole closer to the of low rg axis would cause the ball to transition slower. Maybe if I made the hole deeper it would bring it back, just looking for some extra thought on this before I continue. Wish I had the ball with me so I could add the size and depth for added information but it's not in my possession.

Re: Xeno Full Roller Layout P1

Posted: February 10th, 2017, 8:21 pm
by JohnP
I don't think the gradient line applies to a full roller layout, and I doubt any research has been done. I'm going to guess and say to draw an arc 6 3/4" from the MB to where it intersects with the VAL extended on the backside of the ball. This should be fairly close to the NAP. You may have a problem using a large enough hole without being illegal on statics. I've made this guess based on a mental image & it may be totally wrong. This is really a problem for MathIsTruth to analyze. -- JohnP

Re: Xeno Full Roller Layout P1

Posted: February 10th, 2017, 10:21 pm
by EricHartwell
Dustin wrote:Let me be more clear spin time before was ~5.3 sec. and after drilling it was ~4.9 sec. Not what I was shooting for with the added hole.
Sorry I completely comprehended that one backwards. I feel silly now after re-reading your original post.

This is an interesting dilemma, Do keep us informed on how this one turns out.

Re: Xeno Full Roller Layout P1

Posted: February 13th, 2017, 4:37 pm
by Arkansas
Remember, spin time relates to diff ratio. What is diff ratio? Int Diff / Total Diff. So let's take a look at the Xeno.

Undrilled numbers are as follows:
Total Diff = .050
Int Diff = .017
Diff Ratio = .34

Drilled numbers are a guess so let's just use the published numbers for the Morich Mania that was used in the full roller study by MathIsTruth. http://wiki.bowlingchat.net/wiki/index. ... ymmetrical" onclick="window.open(this.href);return false;

Undrilled numbers are as follows:
Total Diff = .052
Int Diff = .013
Diff Ratio = .24

Drilled numbers (no balance hole):
Total Diff = .048
Int Diff = .019
Diff Ratio = .40

So let's think about what the hole near the pin did. By locating the hole near the low RG axis we know you raised the RG about that area. So we know that total diff would have decreased. The next question would be, did the balance hole affect the Intermediate Diff? We know that Int Diff = High RG - Int RG. I would tend to think that a hole about the Low RG would not affect either one of these axes.

Those two things together would lead me to believe that you decreased total diff while maintain int diff, leading to a higher diff ratio. Using the Mania numbers we could speculate that you may have taken the total diff from .048 to .043 or something, while maintaining the int diff. That would look like this:
Total Diff = .043
Int Diff = .019
Diff Ratio = .44

The higher Diff Ratio will lead to a lower spin time.

Now one might think, but isn't that increasing the ball's reaction? Not really. The decrease is total diff is going to make the ball reach the first transition later. It will however make the hook phase shorter, which will lead to a sharper breakpoint. I've experienced this myself when I drill a balance hole in a ball for a customer to try and tame it down. It was a Brunswick Slingshot drilled with a 3/4" pin to PAP with the CG on the midline towards the grip center. Something like 180 x 3/4 x 90. I drilled the pin out, raising the RG of the PAP and lowering the total diff. The result was the ball was sharper off the breakpoint and the customer was not happy. Lesson learned.

Re: Xeno Full Roller Layout P1

Posted: February 13th, 2017, 6:18 pm
by Dustin
Great feed back James! Now the question is still where could I place a hole to smooth out the reaction.

Re: Xeno Full Roller Layout P1

Posted: February 14th, 2017, 4:01 am
by EricHartwell
What surface is the ball?
Have you considered taking it to a lower grit?

Re: Xeno Full Roller Layout P1

Posted: February 15th, 2017, 3:12 am
by Dustin
Yes, have tried more surface and less.

Re: Xeno Full Roller Layout P1

Posted: February 26th, 2017, 4:07 pm
by MathIsTruth

First of all, my sincerest apologies to Dustin for not replying earlier than now.

I am going to model the layout in Solidworks and place a few different balance holes to see how the mass properties change. Could you post a picture of the Xeno please? Do you remember the pin distance that you used?

I should be able to work on this during the week.

Steve




Re: Xeno Full Roller Layout P1

Posted: February 26th, 2017, 10:14 pm
by Dustin
No apologies needed. Thank you for responding. I should be able to get the ball from him on Tuesday. I will try to get it sooner.

Re: Xeno Full Roller Layout P1

Posted: March 3rd, 2017, 1:25 pm
by Dustin
Sorry for the delay, he has a shoulder has started to bother him a lot and took this week off. One of his teammates said he may miss the rest of the season. I'm still working on getting his ball from him though.

Re: Xeno Full Roller Layout P1 (pic added 3/7/17)

Posted: March 7th, 2017, 8:20 pm
by Dustin
MF span 4 3/4", 0 For/Rev 5/16" L.H., 27/32" insert
RF span 4 13/16", 0 For/Rev 9/16" R.H. 53/64" insert
Finger depth 2 1/4"
Thumb 3/16" Rev., 1/8" R.H., 63/64" slug 1 1/4" O.S. dia.
Depth 2 1/2"
Pin 3 3/8" from center grip, 30* from mid grip, PSA 1 7/8" Right of grip center line
If you need anything else let me know, thank you again.

Re: Xeno Full Roller Layout P1

Posted: June 5th, 2017, 3:13 pm
by Arkansas
Hey Dustin,

I guess MathIsTruth got busy and hasn't had time to model this yet. I came back to it and was giving it some thought. Here's what I came up with. Let me know what you think.

We need to increase spin time, therefore we need to decrease the diff ratio. As stated above, diff ratio equals Int Diff/Total Diff. So we have to either decrease Int Diff or increase Total Diff in order to lower the diff ratio. My first thought was, let's increase total diff because that's easy. But I checked the charts and just increasing total diff by placing a hole near the high rg also had a corresponding increase in Int Diff and Diff Ratio.

So how can we decrease Int Diff? We know Int Diff equals High RG - Int Rg, so we can raise Int Rg to lower the Int Diff. So I think a hole on the Intermediate RG is what you're looking for here. The problem here is you have to make sure it is flare safe and the statics will work. You also need to not use too big of a hole. I'm linking to an old thread I remembered and looked up. In post #6 MathIsTruth models a hole on the Int RG. You can see it has the ability to kill the diff ratio. One HUGE word of caution. Using a large hole on the Int RG resulted in flipping the axis on the Morich Frenzy in Math's study. 3/4" 3" deep seemed sufficient however and did not flip the axis. Also, the PSA on your customers Xeno should have been enhanced by placing it near the finger holes. So I would think it'd be harder for you to flip the Int RG and the High RG than in Math's study.

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Re: Xeno Full Roller Layout P1

Posted: September 18th, 2017, 12:13 am
by MathIsTruth
Well, I owe Dustin another public apology for not getting this done after I said I would.... I have been working on this project and wanted to share some results. I am not finished but wanted to share something. I placed balance holes left of the pin/thumb and another in the PSA for a comparison. I have been reluctant to place a balance hole in the intermediate axes since they would not be flare safe.

Radical Xeno with 3.5" Pin to CG
Undrilled...............................15.25#, Low RG 2.482, Diffs 0.018/0.054, Diff Ratio 0.33
Standard Full Roller Layout.......15.00#, Low RG 2.490, Diffs 0.026/0.053, Diff Ratio 0.48
BAL Hole Left of Pin.................14.84#, Low RG 2.502, Diffs 0.026/0.040, Diff Ratio 0.64
BAL Hole on PSA.....................14.86#, Low RG 2.488, Diffs 0.038/0.066, Diff Ratio 0.58

I believe the spin time decreased due to the decrease of total diff along with the int diff not changing. Notice the increase in diff ratio. However, the loss of total diff should have caused less flare in the ball. I do not recall reading any analysis of the ball being thrown after the balance hole was placed in the ball.

I know the spin time decreased but did you have a chance to watch the ball after you added the balance hole Dustin?

I discussed this with Mo and he recommended that a shorter Pin to CG ball could have been used so the pin would be closer to the center of grip which means the original PSA location would be further from the fingers. He also gave me another suggestion to try that uses a slight change to the layout specs. I will report back when I have finished with his suggestions.

I included a picture of the ball below. I have marked the Low and High RG axes after each step so you can see where the axes shifted. The ball with NO Bal Hole is marked with red points, BAL hole left of thumb/pin is marked with Blue points and the ball with Balance hole on PSA is marked with purple points.

John P... Do you think your suggestion would be flare safe?



Re: Xeno Full Roller Layout P1

Posted: September 18th, 2017, 1:52 pm
by Dustin
The wait is always worth it, no apologies needed. If my memory serves me it seemed to be more angular off the spot. He was having some shoulder issues at the time and since went under the knife I believe, I will see him this next week and see how things are going. Thank you again.

Re: Xeno Full Roller Layout P1

Posted: September 18th, 2017, 3:42 pm
by JohnP
John P... Do you think your suggestion would be flare safe?
I have no idea. Remember, I did a lot of guessing. -- JohnP