LV LA Jack Plane Setup

[sawdust_tom]

I just received my new LV LA Jack. I'm having a problem with setup. I thought I'd ask this group because this is the smartest handtool group on the web.

I took the blade as delivered and did a quick hone on the 8000 stone. I checked the edge with my best engineer's square and it's right on 90 degrees to the blade edge. I installed the blade and went on to setting the cutting depth. I sighted down the sole and discovered I had to significantly skew the blade in order to get a constant cutting edge projection through the mouth. The skewing is significant - looking through the mouth it is obvious that the cutting edge is way off of parallel to mouth. This makes it impossible to achieve a tight mouth.

What am I doing wrong?

 

[Anonymous]

Hi Tom

I don't won that specific plane but if it were me I would check the blade to make the sure the bevel is square to the side. If that is close

THe only thing I can think of is the bed for the blade is skewed (higher on one side compared to the other) and therefore the blade always cuts on one side

Cheers
Dan Clermont

 

[MikeW]

Hi Tom,

Other than the bed being lower/higher on one side or the other, check the following.

1) Make sure the blade is really in full contact to the bed itself. Sometimes the adjuster might not be fully engaged into the blade, or upon taking the blade out the adjuster is itself not fully reseated in its hole.

2) Also, it is possible the blade is hanging up on the set screws that prevent sideways movement. So, make sure to loosen the set screws on the sides of the planes, make sure the blade is fully seated on the bed, put the cap back in place and see if the blade is now square to the mouth.

If so, and once it is square, lightly tighten the set screws against the blade. Key is lightly else you will have problems upon removing the blade and putting it back.

Take care, Mike

 

[engineer one]

tom i am not a proper expert, but first thought is to look at the top of the plane, not the bottom. can you see whether the blade is off centre, as mike says can you check whether the blade sits flat and properly on
the bed. loosen off the set screws and see whether that helps, then try adjusting the blade.

lets hope rob can offer an answer too!! :wink:

 

[Philly]

HI Tom
Hmm...The blade is square when you check with it out of the plane. Yet when you fit it into the plane, tighen it down and set it to cut the blade has to be skewed to give an even projection? How much skew? Full adjustment on the lever? And you have got the beveled side of the iron facing up, haven't you?
Make sure there's no chips of wood or rubbish on the bed of the plane before fitting the iron. If its all clear and the rest is true then you must have a faulty plane. Any chance of posting a picture of the plane and mouth?
Cheers
Philly

 

[Chris Knight]

Tom,

I had the same problem with a Veritas bevel up smoother (BUS). Brimarc exchanged it without any problems as I wasn't happy. The problem (once you have eliminated other causes) is most likely that the blade bed is tilted with respect to the sole.

I talked with Rob Lee about this at Tools 2005 and he agreed that the amount of gap I had at one end (around 1.5mm) when the other end was closed) was excessive but noted that there is a tolerance on parallelism that may mean the blade is not exactly square to the mouth opening. Apparently there is a number (five I think he said) of separate machining operations where the relative tilt can creep in and it is a difficult parameter to control. A one thou tilt apparently translates to a five thou out-of-parallel to achieve equal blade protrusion.

My replacement plane is not perfectly parallel but it works very well nonetheless and I am happy. Rob says that they will change any plane with such problems and furthermore that he far prefers customers to complain rather than remaining silent as this provides valuable feedback for their manufacturing/quality control etc.

 

[ike]

I would suspect the set screws simply need adjusting either side of the blade. One may be fully screwed in and one out which can perhaps (I'm guessing) skew the blade beyond the range of the angle adjuster.

cheers

Ike

 

[Alf]

Assuming all set screw/bedding etc suggestions don't cure it, it sounds like the same issue I had with the L-N skew block. From all Rob said, it does seem to be an extremely sensitive operation to get right; any little bit of swarf in the wrong place and it can go pear-shaped. If it's just a tad out of parallel, it's nothing to worry about; if it's a lot, then one's slipped through the net by the sounds of it. Either way I imagine we'd put our mortgages on L-V replacing it without a murmur. :wink:

Cheers, Alf

 

[bugbear]

<i> A one thou tilt apparently translates to a five thou out-of-parallel to achieve equal blade protrusion. </i>

Yes - the lower the bedding angle the greater the magnification of bed error into blade error.

As long as the error isn't HUGE, I'd just (gradually) alter the edge angle on the blade (by simply leaning on one edge during normal sharpening).

Correcting this sort of small problem is why a lateral adjuster is fitted; it'd be a shame not to use it

BugBear

 

[Rob Lee]

I just received my new LV LA Jack. I'm having a problem with setup. I thought I'd ask this group because this is the smartest handtool group on the web.

I took the blade as delivered and did a quick hone on the 8000 stone. I checked the edge with my best engineer's square and it's right on 90 degrees to the blade edge. I installed the blade and went on to setting the cutting depth. I sighted down the sole and discovered I had to significantly skew the blade in order to get a constant cutting edge projection through the mouth. The skewing is significant - looking through the mouth it is obvious that the cutting edge is way off of parallel to mouth. This makes it impossible to achieve a tight mouth.

What am I doing wrong?

Hi Tom -

Various posts above mine tell the story.... it's a question of some amount of skew to the bed. With a low angle plane, the slope of the the blade bed is such that a .001" yaw in the bed (from the long the axis of the plane) will result in the blade edge having to be skewed .005" to compensate. No effect on cut - but the mouth opening will then not be parallel to the blade edge.

Contrary to what most people believe - this is the most difficult aspect of plane manufacture - not squareness, or sole flatness. With a standard frog angle, the rise/run ratio is 1:1 (LA is 1:5) - so while a bevel down plane may have the same error - it gets magnified by a factor of 5 in the bevel-up orientation.

Since this effect is part of the plane geometry, how you sharpen the blade (square or not) will have no effect on addressing the blade edge/mouth edge parallelism. It can only be addressed by fettling the throat plate... something we don't do. Other than deburring edges - we don't do any hand adjustments to any fit....our choice is always to swap a plane out (which of course, we'd be glad to do for you too).

Our yaw spec across the 2 1/4" bed is +- .001" from flat.... at the extreme limits, that could be .002" total difference from one side to another...and that's lower than it was 6 months ago. There are a number of factors at work on this tolerance - milling a surface inside a cavity (bit deflection is a factor), and repositioning the casting in different orientations between finishing operations.

As I said - glad to swap for you if you like, just contact me by email, and I'll be glad to set it up.

Cheers -

Rob

 

[sawdust_tom]

Wow!

I'm impressed (and very grateful) for all the responses. I certainly appreciate Rob's offer to swap out the plane. I'm going to try some of the things suggested below first to make sure I don't waste LV's time and resources. I've got 4 LV handplanes and they are all excellent. I've got a bunch of things to check out and I'll do this in the next few days and let everyone know what the result is.

1. I'll check the bed to make certain it's clean and I'll also check the blade back as well. I can see where a small amount of debris could throw off the blade projection. I had no idea that a .001 bed error will cause a .005 error in edge to mouth parallelism. Machining these planes has got to be a real challenge.

2. I'll also check the adjusting screws and make certain the blade is not binding on them.

3. Bugbear suggested that it might be possible to correct the problem by intentionally putting a slight skew into the blade edge. Rob has suggested that this might not work. I think I'll hold off on trying this for now.

4. I'll take some before and after pictures and post them this weekend. I'll see if I can measure the amount of skew that results from setting an even blade projection.

Thanks again to everyone for taking the time to respond.

 

[bugbear]

Bugbear suggested that it might be possible to correct the problem by intentionally putting a slight skew into the blade edge. Rob has suggested that this might not work. I think I'll hold off on trying this for now.

Agreed. My suggestion merely allows the blade to "sit straight" in the plane body, with a central lateral adjust. It does not (at all) help edge-mouth parallelism.

I have used this approach on slightly skew bedded shoulder planes where there is no (scope for...) lateral adjust; if you want an even shaving you HAVE to skew the blade edge, and a parallel (and tight) blade/mouth is not an option.

BugBear

 

[gidon]

Tom
I have the same plane and notice the same issue (and was pleased to hear Rob's explanation for this at his Tools 2005 talk). But it's never caused a problem for me - saying that it's not as far out as Chris's was. It just means you can't close the mouth as fine as would otherwise be possible. I had a similiar problem with a LN LA Jack - but because there is no lateral adjustment possible at all with that plane I had to return it (and swapped it for the LV).
A good indication of how bad it is on your model may be to try what Chris did with his: with a squarely honed blade, set it for a fine uniform cut and then close the mouth as far as is possible. If you let us know the mouth gap the other side we may be able to help you in your decision whether to return it.
Cheers
Gidon

 

[bugbear]

3. Bugbear suggested that it might be possible to correct the problem by intentionally putting a slight skew into the blade edge. Rob has suggested that this might not work. I think I'll hold off on trying this for now.

Sorry. My suggestion would fix depth of cut even-ness, but not mouth-blade parallelism.

My suggestion is merely a substitute/supplement to your use of the lateral adjust.

I have been forced to do this on a shoulder plane, which doesn't (really) have much scope for lateral adjust.

BugBear

 

[Derek Cohen (Perth Oz)]

Hi Tom

I have used several bevel up LV planes and have only experienced this on one plane.

In my sample, the mouth was out of square by about 0.5mm. I checked the blade for squareness - nope, that was not the problem. Finally I decided that the bed was ever-so-slightly out of square, and decided to fettle this myself. It took about one hour of careful, slow filing, but the end result was a perfectly square bevel-mouth relationship.

It is really quite a simple matter - determine which side of the bed needs to be lowered, then paint the whole bed in Engineers Blue (or scribble with a pencil) to keep track of what you are doing. Then just file carefully, making sure that once you take the one side down, that you file across the bed to level it off. Keep reapplying the Blue. File a little. Test the fit. File a little more.

Regards from Perth

Derek

 

[Anonymous]

I believe this problem is probably caused by trying to square up both sides to the sole. Very tricky work for any plane manufacturer.

If it were me I would send the plane back providing the side screws/ blade sides are not out of square and get a replacement.

If you are bent on keeping this plane possibly rounding the corners will prevent plane tracks but not provide a blade which will remove shavings from the center of the blade with a tight mouth.

Derek's method might work for him but I would be concerned about rounding over the blade bed or creating a non-flat surface for the blade to ride and may cause lotsa problems down the road. It is also allot harder to return a plane if you have milled the bed with a file.

MOre time spent QC'ing these planes may prevent them from getting out in the field.

Cheers
Dan Clermont

 

[MikeW]

... Finally I decided that the bed was ever-so-slightly out of square, and decided to fettle this myself. It took about one hour of careful, slow filing, but the end result was a perfectly square bevel-mouth relationship.

It is really quite a simple matter - determine which side of the bed needs to be lowered, then paint the whole bed in Engineers Blue (or scribble with a pencil) to keep track of what you are doing. Then just file carefully, making sure that once you take the one side down, that you file across the bed to level it off. Keep reapplying the Blue. File a little. Test the fit. File a little more.

Regards from Perth

Derek

Yep, that's what I did on my original LV LA smoother. I had it for at least a year before I realized it. Rob and Company gladly offered a replacement. Upon thinking about it, I decided to just file it myself and save both of us any trouble.

Worked out fine, as Derek's experience.

But it was reassuring to know I could have just swaped it with LV and they would have done so with a smile--and mean it.

Take care, Mike

 

[sawdust_tom]

I apologize to the forum for my delayed response - too much stuff going on with the Thanksgiving holiday.

I did check the blade bed for debris and the lateral adjustment screws - they didn't seem to be the problem. Phillly requested a picture so here it is.

The picture makes it a bit hard to see the extent of the skew.

I decided to try and check to make certain I was actually setting the blade to a constant depth across the mouth. I must admit to being something of a measurement geek. This picture shows the setup I tried to use.

This wasn't very effective but it was fun trying :lol:

I've decided to keep the plane - it works quite well as is. I'm going to try the method Derek C. suggested (fettling the bed). I've done this before on a cheap #4 smoother I got years ago and now it's a really good plane.

I appreciate everyone's input and support.

 

[MikeW]

Let's try this to get the album:

Photo Album

Mike

 

[Philly]

Tom
Thanks for the pics. Looking at yours reminds me of something. MINE! :lol:
My blade has a similar (small) amount of this- skew the blade to make the blade parallel and you have uneven blade projection.
In use the slightly uneven mouth has had little effect (I use high angle blades).
Glad you like your plane,
Philly