Jack plane 8" radius blade

[Elijah A.]

Hey y'all, today I took an extra blade and put an 8" radius on it to use for hogging off heavy material with my stanley no 5. I'm a bit confused because I have another iron that I use in my no 5 jack that is a straight iron with a slight camber. I have no problem getting nice shavings and seem to have enough room within the mouth. When I stick the 8" radius blade in the jack plane, it barely gets through the mouth opening and there is definitely not enough room for even a thin shaving much less a thick one. I have pushed my frog all the way to the back. I know I probably need to file the mouth but before I take that step, I want to make sure that it is necessary. I'm not crazy about filing on my 1920 plane but I want to do what I need to do to be able to remove heavy material quickly. I'm just not understanding the difference with the mouth opening when both blades are the same with the exception of the radius. Any help would be appreciated!

[bandit571]

Hey y'all, today I took an extra blade and put an 8" radius on it to use for hogging off heavy material with my stanley no 5. I'm a bit confused because I have another iron that I use in my no 5 jack that is a straight iron with a slight camber. I have no problem getting nice shavings and seem to have enough room within the mouth. When I stick the 8" radius blade in the jack plane, it barely gets through the mouth opening and there is definitely not enough room for even a thin shaving much less a thick one. I have pushed my frog all the way to the back. I know I probably need to file the mouth but before I take that step, I want to make sure that it is necessary. I'm not crazy about filing on my 1920 plane but I want to do what I need to do to be able to remove heavy material quickly. I'm just not understanding the difference with the mouth opening when both blades are the same with the exception of the radius. Any help would be appreciated!

A  bit confused as well....are the irons the same thickness?    That would be about the only way this would happen....OEM irons?   I run an 8" radius on one of my Jack planes, and a Stanley type 16 barely has any,  maybe just at the corners....a Millers Falls jack plane is straight....I don't change irons...I change planes....The 8" frog is set the normal distance, iron has plenty of room for thick shavings....I use it as a scrub-jack.    The Stanley more as a fore plane, and the No. 14 more of a long smoother.  

Would need a couple photos, to see what you have going on....is the chipbreaker getting in the way?

[Derek Cohen]

Hey y'all, today I took an extra blade and put an 8" radius on it to use for hogging off heavy material with my stanley no 5. I'm a bit confused because I have another iron that I use in my no 5 jack that is a straight iron with a slight camber. I have no problem getting nice shavings and seem to have enough room within the mouth. When I stick the 8" radius blade in the jack plane, it barely gets through the mouth opening and there is definitely not enough room for even a thin shaving much less a thick one. I have pushed my frog all the way to the back. I know I probably need to file the mouth but before I take that step, I want to make sure that it is necessary. I'm not crazy about filing on my 1920 plane but I want to do what I need to do to be able to remove heavy material quickly. I'm just not understanding the difference with the mouth opening when both blades are the same with the exception of the radius. Any help would be appreciated!

Elijah, you should be able to use the blade without opening the mouth (which I would not do!) - just pull the frog back. 

If the radiused blade is not going through, check the length under the slot - it may be too short. And are you using the same chipbreaker - the adjusting slot may be at a different position. If so, switch back to the original chipbreaker.

Regards from Perth

Derek

[Elijah A.]

Irons appear to be the same thickness but I think they are slightly different because when i take the 8" radius iron out and replace it with the original straight iron, I have to tighten the lever cap screw about a turn and 1/2 to get it to feel right. I really don't want to file on the plane. This was just an old blade that I had and it may have been for a no 4. I may just try to put a little more camber in my straight blade and open the mouth as wide as possible. I would love to get an 8/10" radius blade into the plane but not necessarily at the cost of filing on the plane.

[Elijah A.]

Btw, I am using the same chip breaker and they are both old Stanley irons.

[Elijah A.]

Maybe the answer is to put the 8" radius on the original blade that fits well. I have a smoother and a jointer so the jack will simply be for heavy removal.

[Elijah A.]

I just ran a test and when I put the straight blade in the jack plane and back the frog up, I am getting very nice thick shavings. I think I'm going to start by slightly clambering that blade with my diamond stones, it may be all I need. I would like to add the radius but I don't have a great grinder setup. For now, the shavings seem thick enough with a straight blade so with a slight camber, I will probably be able to push it even farther. Thanks for y'alls help!

[Steve Friedman]

Elijah,

I have a #5 size blade with a 5" or 6" radius camber and have no issues.  In fact, it's a Hock blade.  No need to open the mouth of an old Stanley even with that severe camber.  Works like a charm.


Maybe I'm not understanding, but I don't get why the amount of camber would make a difference.  I could be wrong, but I think it may be the placement of the cap iron.  When I decided to have a blade with that much camber, I also decided that the cap iron should match the shape of the blade.  Otherwise I couldn't get the cap iron close enough to the edge without having the corners protrude.  I really have no idea if it would help, but thought I would suggest it.

Others with more experience may have a better idea, but I just went out and played with a plane to test this out.  I made it extreme, but moving the cap iron back really far from the edge made it impossible to get the blade back into the plane. I wonder if the camber on the blade is causing you to pull the cap iron  back too far from the edge.  Cambering the front edge of the cap iron would let you keep it in the right place.

Just my $0.02

Steve

[Elijah A.]

Can I put a hock blade in with the existing chip breaker or do I have to put a Hock chip breaker as well?

[Steve Friedman]

Can I put a hock blade in with the existing chip breaker or do I have to put a Hock chip breaker as well?

I have the Hock chip breakers with my Hock blades, but I'm pretty sure that most others just use the plain Stanley ones without issue.  In fact, the thinner Stanley blade might make the Hock blade fit better.

I have to admit that Ron Hock cambered my blade and chip breaker for me when I bought them.  My grinder skills are lacking and I didn't have the patience or willingness to do it by hand.

I can check the radius of my blade, but pretty sure it's less than 8".  I think scrub blades are 3" and I wanted something in between that and 8".  I use my scrub plane, but use the cambered #5 much more often.  It's much easier on my joints.  

I always wondered about a cambered low angle jack blade, but abandoned the idea after reading Derek's pictorial on how much more steel you have to remove from a BU plane.


Steve