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View Full Version : OK, Fess up! How tight is your throat???



Brian Hale
03-22-2008, 10:31 PM
I'm hot rodding a double Hocked WWII 4 1/2 and getting the throat closed up tight is a real bugger since there is no adjustment screw. It's pretty tight now but i think i want it a bit closer which means more of the slide/tap/tap/tighten the screws etc. Problem is with the chip breaker set real close to the cutting edge the chip breaker actually closes the throat up and not the cutting edge so i'm considering filing the opening on an angle to allow the chips to pass but i hate to do that to a near mint plane.

So the big question is, how tight do you get the throat on your best smoother?
Ever file the mouth on an angle?
Am i going overboard?


TIA!
Brian :)

Steve Rozmiarek
03-22-2008, 10:58 PM
These two are not sooped up Hock hot rods, but I use a 603 at .018" and a 604 1/2 at .026". Both work fantastically. Seems to me that filing the mouth at an angle would work, but I wonder if it is really nessecary? Have you tried it with the chip breaker backed up a bit? Lots of great cutting wooden planes out there that don't even have chipbreakers.

Mark Stutz
03-22-2008, 11:02 PM
Brian,
How does it work? If you're making nice .001 shavings, I would call it good for now. If you ever come across a piece of stack that you can't smooth, then play with it a little more, but personally, I wouldn't file the mouth.

Mark

Johnny Kleso
03-23-2008, 12:26 AM
On the near mint plane..
I asked Patrick Leach which of two T15 bench plane with varaitions in bed lettering is more rare and which should I keep when I was green..

He reply was, "There is NO Rare Bench Planes other than a T1 or T2 and IMHO T3"

There are about 100 bench planes sold evey week at eBay, so make you plane the best user you can, as long as you dont trash the thing it will not really hurt the value... Ready to Use planes sell higher than most any other..

I try to set my smoothers and shoulder planes at .008 if I can, read my set up page on filing the mouth at 15º to make cap iron clearance..
www.rexmill.com (http://www.rexmill.com)

On planes with out a bed adjuster I used strips of masking tape on the front side of the blade with out a cap iron to set gap ..
A sheet of paper is .003 and I guess with glue makes it a little thicker, so I shoot for three strips which should be a fat .009

This is ultra fine and .015 is 1/64 and is a more reasonable smoother setting for a Heavy cutting Smother ..

My jacks I set at about .020 if I have an extra thick blade and have to file the mouth open to fit.. I use LN for LN blade which are .140 and most Baileys of the SW era will just fit a .125 blade and NO room for chips.. They need to be files a little to let shavings pass..

I file the mouth about 1/64" (.015) more open, at the same time I square the mouth to a scribed line with a square rom the side, and a 15º back bevel to the front if the mouth as my friend David Charlesworth says in his great tune up article from FWW..

I also break any sharp edge on the back of the mouth at sole so a stray nail or knot will not chip the back of the mouth with a sharp bevel, just a few strokes of a smal file adds a very small chamfer..

Newer that T17 era planes up have wider throats in general that older planes.

The back bevel on front adds room for the cap iron to be set close up to the front edge and have room for shavings to pass through the throat..

These are what I shoot for and are a little over the topto be truthful..

PS:
I set my Baileys with the frog and blade resting on the back slope of the mouth..
This added the most support and helps stop vibration..

Some like to set the mouth tighter than choose extra support..
Now I am really giving you a hard choice to make .. :)

Jim Koepke
03-23-2008, 3:50 AM
Well, I was going to say on the planes where I set the mouth tight, I mark the side with a pencil at 15° put it in a vice and use a thin file across the front of the mouth.

Then, I read Johnny's post and don't have to. I think it was from his site that this idea came to me.

It does help, but I have not measured my mouth settings. Maybe in the morning. Oh, it is morning. I need to go to bed soon.

jim

Brian Hale
03-23-2008, 9:53 AM
Right now It's cutting almost as good as my LV BUS so i'm not quite where I want to be but i'll keep it as is for now. The BUS works very very well but the 4 1/2 just feels right in my hand so i've been "collecting" them for awhile and decided it was time to hot rod a few. Filing the mouth seemed logical and i may do that but not yet. Not too worried about the value of the plane as i have no plans to sell it. At least not in the next 30 years or so ;)

Brian :)

Robert Rozaieski
03-24-2008, 8:09 AM
On my #4 (type 9 I think, pre-frog adjusting screw) with Hock iron and Clifton chipbreaker, I put blue painters tape on the face of the iron, installed the frog snug but loose enough to move with a little thumb pressure, put the iron assembly in, advanced it so it was through the throat and moved the frog forward until the iron touched the front of the mouth. Then lock the frog in place, remove the tape from the iron and you have a perfectly adjusted mouth opening without worrying about measuring. The mouth is tight and square to the frog & iron. Takes mere seconds to do.

Tim Sgrazzutti
03-24-2008, 10:06 AM
I'd play with setting the chipbreaker farther away from the cutting edge before considering filing the mouth. I've got a double hocked #4 that works fantastically with around 1/32 of camber, the chipbreaker about 1/16 to 3/32 away from the middle of the edge, and a very small throat opening, about 0.008" - 0.010". The small throat opening will do more to minimize tearout than a close chipbreaker, and if they're both finely set, my plane will choke on the shavings. The extra space with the chipbreaker set back also makes it much easier to clear the throat when needed, without having to remove the iron. YMMV