Oval holes

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gbabione
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Oval holes

Post by gbabione » March 20th, 2021, 6:51 pm

I have a Brunswick 61-100000. How would I go about making oval thumbholes? First, where do I find 6" long end mills? Second, if I mark the oval angle before drilling pilot hole, can I then after drilling pilot hole, rotate ball and just use 1 axis to make cuts? Or will that change the pitch?

gbabione
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Re: Oval holes

Post by gbabione » March 22nd, 2021, 3:53 pm

This is a benchtop press. I am thinking that by rotating the ball, the pitches would change. I use to have use of a Litchco Ovalmatic jig. It's been a long time but I think that's all that does.

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Re: Oval holes

Post by MineralitePaul » March 22nd, 2021, 6:34 pm

You can find the end mills at Innovativebowling.com. I used to drill ovals on an old AMF press back in the 80’s. I had so much radial play in the spindle, that I would take an oak 2x2 (that some old bowler gave me for seating the morse tapper bits) and get it between the press’s column and spindle and push on it, adding more force with each plunge. A caliper would measure between each until the desired oval was attained. It would always be a tad less so all the grooves could be sanded out. It was primitive but it worked

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Re: Oval holes

Post by gbabione » March 24th, 2021, 8:03 pm

All I see there are full sets which I don't need. They are out of stock and would be $940.

gbabione
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Re: Oval holes

Post by gbabione » March 25th, 2021, 4:29 pm

Any thoughts on the pitches?

gbabione
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Re: Oval holes

Post by gbabione » March 30th, 2021, 1:04 pm

I just found this post viewtopic.php?f=7&t=14847. This is exactly the information I was looking for. I am surprised nobody answered my question or pointed me to that post. Since I have an old press, I will mark the centerline and thumb angle, drill the pilot hole, then measure pitches off of the thumb angle line and adjust drill press to match to cut my oval. Now I just need a 6" long milling bit or maybe I just need drill bit sharpened.

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bowl1820
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Re: Oval holes

Post by bowl1820 » March 30th, 2021, 1:26 pm

gbabione wrote:
March 30th, 2021, 1:04 pm
I just found this post viewtopic.php?f=7&t=14847. This is exactly the information I was looking for. I am surprised nobody answered my question or pointed me to that post. Since I have an old press, I will mark the centerline and thumb angle, drill the pilot hole, then measure pitches off of the thumb angle line and adjust drill press to match to cut my oval. Now I just need a 6" long milling bit or maybe I just need drill bit sharpened.
Question How does the thread you linked too:
Does the type of ball/core matter when measuring PAP?
viewtopic.php?f=7&t=14847
answer your question about making a Oval hole thumbholes?

Nothing in that thread appears to have anything to do with drilling ovals. So I can see why no one pointed you to that post.
"REMEMBER, it isn't how much the ball hooks, it's where."

gbabione
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Re: Oval holes

Post by gbabione » April 3rd, 2021, 1:53 am

Somehow it inserted the wrong post. I have never been on that post and I copied the link right from the address bar so I don't know how it did that. I'll have to search my history for correct post.

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Re: Oval holes

Post by gbabione » April 3rd, 2021, 2:21 am

I think this was the correct link. viewtopic.php?f=7&t=7805&p=116046#p116046

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