boring bar usage question
- Thread starter alinwa
- Start date
C
Crow99
Guest
Outstroke.... i.e. feeding from left to right. Final cleanup whatever.... Check a couple of times with indicator to make sure the bore's not running out. With a reasonably stiff boring tool the bore should clean up and con-centrize (??) in one or two cuts.
inward
Sounds good in theory but in actual practice I find myself starting all boring cuts from the outside and boring inward, mainly so that I can see everything that is happening, confirm cut depth, feed direction, feed rate, etc.............stop boring if anything does not look correct..................Don
Sounds good in theory but in actual practice I find myself starting all boring cuts from the outside and boring inward, mainly so that I can see everything that is happening, confirm cut depth, feed direction, feed rate, etc.............stop boring if anything does not look correct..................Don
Butch Lambert
Active member
I bore toward the headstock. If you are worried us an indicator or in my case I have a Trav A Dial. Use solid carbide boring bars and you will have very little deflection.
Butch
Butch
Jay Cutright
New member
I'm boring inward with a solid carbide bar & for the same reasons as Bob, I also do a couple clean-up runs. I thought the in to out method would make since because it would drag some of the cuttings out with it instead of piling them up ahead of the tool in the end of the chamber but I never liked it that way.
BTW:I always run the tool in to the same depth as the drill & mark the dial on my saddle so I know when to disengage the feed.
BTW:I always run the tool in to the same depth as the drill & mark the dial on my saddle so I know when to disengage the feed.
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thanx guys.... I've been boring outward because I haven't had a good way to stop, no DRO. Soooooo, I go in to feel the shoulder and find my start point with the machine off and then start 'er up and feel my cut (confirming with dial) and kick her on to "out."
It's worked well. Kinda weird to get the grind right for "out" feed but got 'er good now with few fuzzies.... and it's real safe for this guy who's re-learning the moves after almost 30yrs hiatus.
Tonight I bought a 16" digital caliper off Craigslist and am going to fasten it to a gadget on the tailstock for a cheapy dro readout. We'll see, I might be able to go both ways now with ease
Altho going IN I'm sure that sooner or later I WILL give the dial a spin and WREEEEKK!! minor trainwreck........
juuuust when ya's gets comfertable.....
al
It's worked well. Kinda weird to get the grind right for "out" feed but got 'er good now with few fuzzies.... and it's real safe for this guy who's re-learning the moves after almost 30yrs hiatus.
Tonight I bought a 16" digital caliper off Craigslist and am going to fasten it to a gadget on the tailstock for a cheapy dro readout. We'll see, I might be able to go both ways now with ease
Altho going IN I'm sure that sooner or later I WILL give the dial a spin and WREEEEKK!! minor trainwreck........
juuuust when ya's gets comfertable.....
al
Niccolo M.
Member
Greetings,
You want to be feeding the boring bar toward the head stock, the lead angle and rake of the tool is set up for using it in that manner. Look at the cutting insert, or how the solid boring bar is ground and you will see the logic. The boring bar will be much stiffer under compression than under tension resulting in less chance of chatter, again look at the boring bar, the way it's made and how it's ground. If concerned about swarf use a shot of cutting oil to float out the chips or use boring bars drilled for flood coolant. When chambering a barrel blow any chips that might have migrated into the bore out by applying air through the muzzle. Then hook up your muzzle flushing system and you will be golden. Use a dial indicator to gauge when to stop the carriage at the right depth by disengaging the feed. Don’t waste your half nuts on boring save them for threading, their designed purpose. If your lathe does not have a carriage feed other than by the use of your half nut, feed by hand.
Individual results may vary,
Nic.
You want to be feeding the boring bar toward the head stock, the lead angle and rake of the tool is set up for using it in that manner. Look at the cutting insert, or how the solid boring bar is ground and you will see the logic. The boring bar will be much stiffer under compression than under tension resulting in less chance of chatter, again look at the boring bar, the way it's made and how it's ground. If concerned about swarf use a shot of cutting oil to float out the chips or use boring bars drilled for flood coolant. When chambering a barrel blow any chips that might have migrated into the bore out by applying air through the muzzle. Then hook up your muzzle flushing system and you will be golden. Use a dial indicator to gauge when to stop the carriage at the right depth by disengaging the feed. Don’t waste your half nuts on boring save them for threading, their designed purpose. If your lathe does not have a carriage feed other than by the use of your half nut, feed by hand.
Individual results may vary,
Nic.
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The proper use of boring bars was discussed at the Home Machinist web site. The discussion initially was on boring bar angles then other comments were made on the subject.
Many individuals there are professional machinist who give advice to amateurs like me. I found the information useful. The advice given by the pros was that you bore towards the headstock.
http://bbs.homeshopmachinist.net/showthread.php?t=40758
Many individuals there are professional machinist who give advice to amateurs like me. I found the information useful. The advice given by the pros was that you bore towards the headstock.
http://bbs.homeshopmachinist.net/showthread.php?t=40758
pbike
New member
I have the criterion (? spelling) boring bars sets and a couple of insert tooled boring bars (Iscar and Sanvik), In all cases, the ones I bought have the geometery set up so that boring towards the headstock is the proper method. In the mill those same criterion bars would be used to bore on the down stroke.
Paul
Paul