How to fix a skewed block plane

[Daniel Rode]

I have a stanley 12-920 block plane. It's the $35 model with the adjustable mouth. The sole is flat and smooth and the iron is sharp and cut square. However, I can't get the blade adjusted straight in the mouth. If I move the adjustment lever over as far as it will go I can almost get both edges to cut a shaving the same thickness. Almost.

I never really noticed it before because I'd only ever used it to cut chamfers. I totally disassembled it. Nothing looks out of sorts but I still can't get the iron straight. Looking at the sole, it's easy to see that the cutting edge is not parallel to the mouth. Maybe it was just poorly cast?

I'm not going to put a ton of time or money into a $35 plane but It's so close that it seems like some small tweak might save it from the junk heap. I thought that the issue might be that the frog is slightly angled but I'm not really sure what to work on or how. In addition, there's not much room to maneuver a tool in there.

Any suggestions? Do I just cut my losses and move on or can it be saved?

[Jeff Heath]

Dan

This is a common problem with cheaply made planes. The reason why planemakers who make quality planes charge as much as they do is because of all the time taken to ensure that the plane actually functions when it arrives at your door.

Without having the plane in my hands, it's difficult to say exactly what you need to do.....but in general, you need to true the mating surfaces between the frog and bed of the plane, and also true the sole of the plane. Often, this can be done with sandpaper taped to a true surface like plate glass or a granite machinists plate. Even a regular piece of granite scrap from a countertop manufacturer will work great for this. Go at it slow, checking frequently until you have removed enough metal to get the cutting iron and the sole to be co-planar. You may decide to cut your losses and purchase a better quality plane that works correctly......these cost more than $35. Think Lie Nielsen.....Lee Valley.....etc......for metal versions.

I make wood planes for sale, and I spend more time tuning the planes to work perfectly than I spend actually making the planes.

[Derek Cohen]

Hi Dan

BU beds are difficult to machine perfectly.

You have a choice: either lower one side of the blade by filing the bed to be parallel, or build up the other side with epoxy. The latter is easier - spread a thin layer of 5-minute epoxy on the bed, wax the blade so that epoxy does not stick to it, then place the blade on the bed and adjust it until square and parallel. Hold it in place until the epoxy dries. Clean up any squeeze out.

Regards from Perth

Derek

[Dave Cullen]

I know this just sounds wrong, but if you ground the iron slightly off square would the plane work?

[David Weaver]

I have a stanley 12-920 block plane. It's the $35 model with the adjustable mouth. The sole is flat and smooth and the iron is sharp and cut square. However, I can't get the blade adjusted straight in the mouth. If I move the adjustment lever over as far as it will go I can almost get both edges to cut a shaving the same thickness. Almost.

I never really noticed it before because I'd only ever used it to cut chamfers. I totally disassembled it. Nothing looks out of sorts but I still can't get the iron straight. Looking at the sole, it's easy to see that the cutting edge is not parallel to the mouth. Maybe it was just poorly cast?

I'm not going to put a ton of time or money into a $35 plane but It's so close that it seems like some small tweak might save it from the junk heap. I thought that the issue might be that the frog is slightly angled but I'm not really sure what to work on or how. In addition, there's not much room to maneuver a tool in there.

Any suggestions? Do I just cut my losses and move on or can it be saved?

I had one of those once when I got a replacement iron and needed plane for it (the iron was free). It may be the casting or it may be the adjuster mechanism. Take your iron and hold the front of the iron against the bed with the plane upside down and without the lever cap on. If the iron seems to project evenly without the lever cap on, but the influence of the cap on the adjuster brings it out of alignment, it may actually be the adjuster mechanism that needs to be worked. That was the case with mine. I can't remember what I did about it, though, it was years ago but I did fix it and use the plane for a while.

[Jim Koepke]

Here is a post of mine that may be of help:

http://www.sawmillcreek.org/showthre...05#post1246005

jtk

[Dave Anderson NH]

Another possibility that I have run across in a number of Stanley planes from a wide variety of eras is parallelism. Check the width of the blade (iron) at both the top and the bottom. Quite often there s a difference of up to .062". If the sides aren't parallel and you tried to square up the cutting edge off of the "wrong" long side it is a miserable task to try and get the cutter squared in the mouth. This leaves you with the option of either grinding the long side parallel or regrinding the bevel to fit the mouth squarely.

[Daniel Rode]

Wow. That's a lot of information. I need to get home, take another look at the plane and process it all. I don't want to spend too much time on it. Ultimately, I want replace it with a low angle. A Stanley sweetheart LA runs about $75.

I can't afford it but I really like the LN rabbit block plane. It seems like it would be so useful for so many little fitting jobs.

[david charlesworth]

If as I suspect, this is Azimuth error it is easy to fix.

The bed is twisted relative to the sole. You will need to grind and hone the blade out of square.

Once a nice even shaving is set, file the edge of the sliding front sole, to match the blade edge. i.e. out of square.

Everything will now work fine.

Best wishes,

David Cha\rlesworth.

[Daniel Rode]

If as I suspect, this is Azimuth error it is easy to fix.

The bed is twisted relative to the sole. You will need to grind and hone the blade out of square.

Once a nice even shaving is set, file the edge of the sliding front sole, to match the blade edge. i.e. out of square.

Everything will now work fine.

Best wishes,

David Cha\rlesworth.

Thanks David, I will give it a try.

We've had quite a number of posts from well known names today. I didn't expect my newbie question to garner any attention

[Jim Koepke]

I didn't expect my newbie question to garner any attention

Most of us have learned from the experience of others. It is only right we help the newbies.

jtk

[Moriz Klonner]

If as I suspect, this is Azimuth error it is easy to fix.

The bed is twisted relative to the sole. You will need to grind and hone the blade out of square.

Once a nice even shaving is set, file the edge of the sliding front sole, to match the blade edge. i.e. out of square.

Everything will now work fine.

Best wishes,

David Cha\rlesworth.

I think my block plane might have the same issue, the blade is not parallel to the mouth when I get nice and even shavings. Wouldn't it be a more proper fix to file the bed of the plane parallel to the sole? Or is this impossible by hand?

Thank you for your help!

Moriz

[Winton Applegate]

Time for another of my infamous paper weight posts:

but I will do the unheard of and hold off and TRY to be helpful first.
As a friend of mine says “There is no try”.

Here’s whacha do . . . take a thin strip of foil say three eighths wide by about an inch long. What was I thinking ? Foil is probably too thin use strip from pop can or thin paper. Can cut pop can with scissors ; won't hurt scissors/cuts easily. Put this strip between the blade and the blade seat. If the problem gets worse try it on the opposite side. The idea is to compensate . . .
TEMPORARILY
to see if maybe the blade seat face is milled out of proper orientation with the sole of the plane.
Once you determine this is the case (of course taking as 100% true your blade is square) or even if you don’t then . . .
Run . . . don’t walk . . . to your computer and order one of these and save the $35 job for a nice paper weight for your desk.

PS: you have gone Bevel Up so that means there is hope for you yet

[Winton Applegate]

OK . . .
sigh
You are taking this Stanley block thing seriously. I feared as much.
Here is the end all and be all article on that plane.

Join FWW for a one month period for a very fair and nominal fee and read that article.
By the way you will learn a whole lot from it. Seriously. It is a great article.

Then once you get your Stanley cutting perfectly . . .
then
Buy the Varitas.

[Winton Applegate]

Most of us have learned from the experience of others. It is only right we help the newbies.

Ha, ha you are right of course but
I am a mechanic and people ask me where they can go to learn what I am doing for them. Often what I am doing for them they should already be doing for themselves if they are asking the question they are asking. Like . . . I was probably doing this when I was twelve.
So I just say : "There is no where. One must be born knowing it."
Ha, ha, I love the look that elicits Some people call it "The dog look" or the "Whaaaaaaaaaa ? ? ? ?t look".

This all comes from many questionable and flabbergasting experiences I have had actually teaching classes in what they are asking to learn.
Ha, ha, ha, ahhhhh
The student signs up, takes the class, gets lots of one on one in a small class, two instructors for six people
(Two highly experienced and highly motivated very friendly and life time dedicated to their one and only full time lively hood instructors)

. . . the students complete the tasks and perform well in class AT THE TIME.
A few months or years later here they are at the counter paying me to do the simple thing for them.
I am now miming the motion young teenage girls used to do to express the way they are feeling at the moment . . .
taking the edge of my flattened hand across the inside of my wrist.