I Created a Smooth Bore With a Tap
- SteveHGraham
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- Location: Florida
I Created a Smooth Bore With a Tap
I decided to be a man and redo the wheels on my wood vise. I bought some cast wheels from Enco, and I found a great deal on a 3/4-6 Acme tap on Ebay.
Today I bored a wheel out to about 0.590", which is correct, and I put the wheel in my drill press vise. I did not have a tap wrench big enough for the tap, so I used a socket wrench extension held in the drill press chuck.
I applied a little tapping oil, because I read somewhere that it's a good idea with cast iron. Then I applied pressure with the press while cranking the chuck manually.
I ended up with a smooth bore with the exact same profile as the tap. It cleaned out the wheel without making threads.
Explain. Immediately.
Today I bored a wheel out to about 0.590", which is correct, and I put the wheel in my drill press vise. I did not have a tap wrench big enough for the tap, so I used a socket wrench extension held in the drill press chuck.
I applied a little tapping oil, because I read somewhere that it's a good idea with cast iron. Then I applied pressure with the press while cranking the chuck manually.
I ended up with a smooth bore with the exact same profile as the tap. It cleaned out the wheel without making threads.
Explain. Immediately.
Last edited by SteveHGraham on Sun Apr 03, 2016 11:43 am, edited 1 time in total.
Every hard-fried egg began life sunny-side up.
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- SteveHGraham
- Posts: 7788
- Joined: Sat Jan 17, 2009 7:55 pm
- Location: Florida
Re: I Created a Smooth Bore With a Tap
For diagnostic purposes or just so you can laugh?
Every hard-fried egg began life sunny-side up.
- SteveHGraham
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- Joined: Sat Jan 17, 2009 7:55 pm
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Re: I Created a Smooth Bore With a Tap
This is really all I have.
This is after I took the socket thing out. The tap wasn't wobbling, so I put a pointy thing in the drill chuck and inserted in the center hole on the tap, and then I cranked with a wrench while pushing down on the tap with the drill press.
This is after I took the socket thing out. The tap wasn't wobbling, so I put a pointy thing in the drill chuck and inserted in the center hole on the tap, and then I cranked with a wrench while pushing down on the tap with the drill press.
Every hard-fried egg began life sunny-side up.
Re: I Created a Smooth Bore With a Tap
Too much pressure with the press while turning.
Glenn
Operating machines is perfectly safe......until you forget how dangerous it really is!
Operating machines is perfectly safe......until you forget how dangerous it really is!
- SteveHGraham
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Re: I Created a Smooth Bore With a Tap
You're kidding. I was thinking the opposite. Are you sure? It felt like it was never going to bite.
Every hard-fried egg began life sunny-side up.
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Re: I Created a Smooth Bore With a Tap
That depends on how much and when.SteveHGraham wrote:You're kidding. I was thinking the opposite.
If it didn't bite, it may very well have bored the hole while turning due to not pulling itself along with the helix.
If forced too hard the leading edges of the tap "teeth" could have cut faster than the natural helix action when being turned.
Glenn
Operating machines is perfectly safe......until you forget how dangerous it really is!
Operating machines is perfectly safe......until you forget how dangerous it really is!
- SteveHGraham
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- Location: Florida
Re: I Created a Smooth Bore With a Tap
Slap John for me.
I'm not sure what to do with the next one now. I guess I'll try it with less pressure. Wheels are cheap.
I'm not sure what to do with the next one now. I guess I'll try it with less pressure. Wheels are cheap.
Every hard-fried egg began life sunny-side up.
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Re: I Created a Smooth Bore With a Tap
If your tap doesn't bite then the hole may be undersize, even if it's to spec it can still be too tight for the tap and the conditions under which you're using it,
- Nick
- Nick
- SteveHGraham
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Re: I Created a Smooth Bore With a Tap
The tap seems really tight in the hole, but it measures 0.590" by calipers and telescoping gage, so you would think it was okay.
Every hard-fried egg began life sunny-side up.
Re: I Created a Smooth Bore With a Tap
Steve,
Well, there goes your hundred attaboys!
Apparently the tap acted like a succession of square ended single tools rather than a helical cutter. The basic bore seems to be adequate, maybe even a little large according to the general table. Perhaps the tap did not have sufficient taper at the start (bottoming), or was dull. I don't have a lot of experience with Acme, but it is an awful lot of cut to make from scratch.
Why not try a boring bar with suitable tool and positive feed to make gradual cuts to rough this out and then finish with the tap. Cast iron should have ehough graphite for lubrication, and will not retain the crumbly chips like a fluid.
Hope this helps.
Bill Walck
Well, there goes your hundred attaboys!
Apparently the tap acted like a succession of square ended single tools rather than a helical cutter. The basic bore seems to be adequate, maybe even a little large according to the general table. Perhaps the tap did not have sufficient taper at the start (bottoming), or was dull. I don't have a lot of experience with Acme, but it is an awful lot of cut to make from scratch.
Why not try a boring bar with suitable tool and positive feed to make gradual cuts to rough this out and then finish with the tap. Cast iron should have ehough graphite for lubrication, and will not retain the crumbly chips like a fluid.
Hope this helps.
Bill Walck