# What is the purpose of left hand cut router bits?



## TopamaxSurvivor (May 2, 2008)

What is the purpose of left hand cut router bits? Are there reversible routers?


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## ajosephg (Aug 25, 2008)

Looks like they are used in production machines like this CNC door edge mortising machine. It has two motors, one right handed rotation and one left hand. "The computer automatically selects the proper motor to cut into the door to eliminate chipout and then switches to the second motor, if necessary, to prevent chipout at the other end of the cut."

I didn't know this until you asked and got my curiosity going. So, I learned something today.


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## CharlieM1958 (Nov 7, 2006)

From the Tyler Tool website:

Left hand cutters are used in routers that can run in reverse for special applications. Left hand cutters are most often used in industrial applications. Requires left arbors.


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## Dez (Mar 28, 2007)

I've never seen one although they could be used in a shaper, most are reversible.


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## JuniorJoiner (Dec 24, 2008)

the use I can think of is if you have a combo jointer planer machine that has the horizontal morticing attachment, the drive is off the jointer head, thus would be cutting opposite of a normal router.


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## degoose (Mar 20, 2009)

You are all wrong …. they are for use down under….


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## TopamaxSurvivor (May 2, 2008)

Sheesh!! I should have known that


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## patron (Apr 2, 2009)

*larry*
so at the equator
they can't use routers
as the bits don't cut in either direction ?


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## tierraverde (Dec 1, 2009)

your all wrong. They're for putting the wood back on.


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## DanLyke (Feb 8, 2007)

david, at the equator they're reduced to just using planes.


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## tyskkvinna (Mar 23, 2010)

I use left-hand router bits on my CNC router fairly often.


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## rogerw (Jan 14, 2011)

larry- the blades are straight out for use on the equator. lol.

I have often pondered on the question about toilets on the equator. the northern hemisphere the water goes ccw and down under it goes cw. Does it just go straight down on the equator???

I once worked with a girl that went to australia on vacation for two weeks. i asked her when she got back about the toilets. she said she never paid any attention. *WHAT !?* That would have been the first thing i would have done when i got off the airplane! go find the bathroom!


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## Justin1110 (Apr 9, 2010)

I know with line boring machines there is a left and a right hand bits (orange and black bits)Line Boring Bits but i never had any experience with left handed router bits or slot mortising bits.


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## ND2ELK (Jan 25, 2008)

My Shaper can use router bits and has a forward and reverse motor. Sometimes running a piece of wood in a different direction might prevent tear out, and a smoother/safer feeding of a piece.


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## oluf (Jan 29, 2010)

Don't forget the Dewalt radial arm saws that used a router bit adaptor on the motor shaft for overhead routing.


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## TopamaxSurvivor (May 2, 2008)

I don't think i have ever heard of a small router with a reverse. Has anyone else? They must be just for CNC and other larger machinery, eh?


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## PurpLev (May 30, 2008)

to avoid tearing out the grain when routing parts with certain curves that call routing in the reversed direction you'd want to route the 'other way' which is where the left hand cutters come to play

... or if you are left handed… that also works


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## TopamaxSurvivor (May 2, 2008)

Yeah but…... where ya gonna find a left handed router?


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## rogerw (Jan 14, 2011)

Top- the left-handed routers are in the section with all the other left-handed tools like left-handed screwdrivers and such. 

Bently- i think you need to open a window lol


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## b2rtch (Jan 20, 2010)

Yeah but…… where ya gonna find a left handed router?

TopamaxSurvivorm just reverse the plug, it will then turn the other way!!!!!!!!!!!!!!

I TRULY LIKE THE IDEA OF THE BIT WHICH PUT THE WOOD BACK , THIS SOME TIME WOULD SAVE MY BUT


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## ChrisForthofer (Jan 1, 2010)

Often times they are used when "mirroring" a part on a CNC machine. When cutting the original part, you'll program the machine to climb cut, but when you mirror that same program and run the opposite hand part the cutter path becomes a conventional cut because of the mirroing. The solution to this is running a left hand cutter and reversing the spindle direction. Now your mirrored part is being climb cut.

Chris.


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## TopamaxSurvivor (May 2, 2008)

I think those tools have been put over by the nails with the heads on the wrong end. Somebody is going to ship them to China to get them fixed ;-))


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## Magnum (Feb 5, 2010)

*Hey! take it easy on us Lefties …LOL…* Which brings up the Skill Saw. I cut with it using my Left Hand. I get a Clear View of the Blade, Line and the Cut I'm Making. I Picked up a Left handed Skill Saw with my Left hand in HD one night. I have to Peek through a Hole/Cut Out to see the Blade. I couldn't use it! Is that what Righties (or Wrongies…LOL) have to do? I can use my Mitre saw with either hand without missing a Finger.

Reminds of My Partner when we first had our company. First time Nailing Drywall in a Hallway, he kept throwing some of the nails over his shoulder. "OKAY! Why the hell do you keep throwing those nails over your shoulder." He says. " They're pointing the other way so there meant for the wall behind us."

I'm not even gonna tell you about the First Time he got me to mix QUICK SET Plaster Of Paris. Other than. "Make sure it's mixed good!" HUMMMMMM???? Wa Happened?


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