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Skew block query

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Alf

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Spent an hour or so adjusting the skew angle on the blade of my new #140 so it'd give an even cut across its width (minimal pressure from the lever cap, before you ask). Seems the bedding angle is out a bit, 'cos now the blade projection is even, the front edge of the mouth isn't parallel with the blade edge. #-o So long since I actually bought a plane :oops:, I can't decide whether I should be asking for a replacement or not... What d'you think? Or does this effect a lot of L-N #140's so I should stop worrying anyway?

Cheers, Alf
 

Chris Knight

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Alf,
I shouldn't worry about it - mine's the same and it doesn't seem to hamper performance. The mouth opening is quite large in any case (at least 1mm) but I can still take fine enough shavings for the jobs I use the thing for.
 

Shady

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Alf, mine's the same. Not the most adjustable of planes - there's a degree of suck it and see with this thing. I have to say, it's not mymost favourite of the L_N offerings - interested to see what you think of it in due course.
 

Alf

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Thanks, chaps. Rest, mind at. :D I'm beginning to understand why Rob doesn't rush to fill our requests for skewed anythings, btw... :lol: My thoughts on it will take up unnecessarily large amounts of bandwidth in the fullness of time.

Cheers, Alf
 

bugbear

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Any left-right angular error in the bed is massively magnified by the low up-down ("bedding") angle.

BugBear
 

Alf

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Derek,

Yep, I remember it well - thanks. I was just wondering whether I should justifiably have to do it for the L-N. Seems "yes". Funny though, 'cos I could have sworn the thing the LNs win on every time there's any comparison done is the fact you don't need to do anything to them. I suppose the answer here is there's no similar alternative to purchase instead, so we just lump it. :(

Cheers, Alf
 

Shady

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Yup: the epoxy tip will fix mouth tightness, but my personal frustration with this one is the inherent flex at the unsupported side: the slightest 'non-uniformity' in the stuff being planed leads to unpredictable and unforgiving deepening of the cut, as the blade 'digs in' a little. I love it for dovetail marking out (a la Cosman), and also use it for removing finish to the precise width of carcass pieces with the fence, but I would like to see a redesigned one with the unsupported edge not leading, but trailing, relative to the direction of cut - I think this would reduce the flex problem...
 

MikeW

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Shady":ezanh734 said:
... but I would like to see a redesigned one with the unsupported edge not leading, but trailing, relative to the direction of cut - I think this would reduce the flex problem...
This would defeat the purpose of the plane. Having the side removable is only useful if the leading edge can be brought slightly proud of the side.

And one would still have the issue of flex and hence having to bring the blade/mouth out of true to each other anyway.

With that said, I have often wanted a skew block plane without a removable side for general use.

just my 2 cents...
 

MikeW

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Hi Alf,

Observations of my LN 140.

As the LN web site says, the skew angle of mine is 18 deg.

Also from the site (which is also in the product sheet incl. w/ the tool):

Blade Adjustment: Hold the tool in one hand with your fingers supporting the sole of your thumb on the cap iron just in front of the screw. Loosen the spinwheel, and with your thumb still holding the blade and cap, adjust the blade. Tighten the spinwheel. Do not overtighten (you should be able to adjust the blade after loosening the spinwheel about 1/4 turn).

Because of the unsupported right side, there is some flex inherent in that thin metal edge when the cap is tensioned on the blade.

This will produce a slightly tapered shaving which will normally not present a problem, but if on occasion it does, adjust the blade slightly out of parallel with the sole to produce a shaving of uniform (not tapered) thickness.
I seperated the paragraph and added the bold for ease of reading.

The tension on the blade is truly important. It will distort the bed if it is too tight. It needs to be just snug enough to keep the cap from falling off. Well, a little tighter than that, but not much.

With that said, however, I measured mine. The mouth/blade is in as near a perfect relationship as these old eyes can measure. The blade projection is even across the sole and at the same angle as the mouth using the protractor head on my old Tumico combination square. It takes an even shaving thickness--at least even enough according to two different dial calipers.

The mouth/blade gap is between .5 and 1mm. I didn't care to measure exactly.

However, imho, a skew block plane such as the 140 does not need a tight mouth. The shavings one sees in Derek's Wood Central post from cross grain cutting are obtainable from a chisel--I pare tenons often with a chisel. You probably have as well. So the mouth/blade gap is mostly a non-issue and certainly not something to get too worked up over.

In fact, it *only* gets more important as one closes the mouth in a tighter relationship to the blade edge. What is important is to produce even shaving thickness. Or uses the 140 for long grain cutting--which I also do quite often, and it cuts just fine with moderate hardwoods (like cherry) to less than friendly hardwoods (like say bubinga or cocobolo).

Do also realize that as you adjust the blade projection, that the blade can and does often twist (even slightly). This is an inherent design flaw that I wish LN would have addressed more than simply lowering the blade bed angle.

I do gring the blade geometry to match the mouth--and btw, skews are one blade type that I do use jigs for consistently. Once the blade is back on the plane, the cap adjusted to hold the blade so adjustment is still easy, I slide the blade so that the right edge is against the removable fence. That puts me either where I do not need to adjust it or where I need to only move the back of the blade a little. It will pivot against the cap iron screw.

I either sight down the sole to see the blade projection or use my finger tips and feel the projection. This is a plane that demonstrates how important it is when adjusting blade projection to always back off and tighten the adjusting nut to bring the blade forward. If it ends up too deep, back off and come forward again. With the spinwheel as loose as it should be the backlash has to be accounted for.

Why don't you send LN an email with your concerns. They'll address them.
 

MikeW

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Oh gosh, yet another response...somebody stop him...I promise to go do work and leave y'all alone for a while :lol: .

Alf, I got to thinking more about this and looked at some other LN planes I have.

The LN 95 (bronze edge plane) pair I have also have about the same mouth/blade gap as the 140 and "suffers" from the same issue of getting the blade to take an even shaving. However, it still is capable of fine shavings both cross and long grain. It can also be over tightened. But here all it does is affect ease of adjustment.

The LN Rabbet Block Plane (based on the Sargent 507) can also (just like the 140) have the spinwheel over tight, causing it to distort the sole. Less of an issue as it is square to the sole. It does have a little less of a mouth/blade gap than the 140, though.

Also from the LN site:

However, because the sides are open at the mouth, the frog may flex under the blade as pressure is applied to the cap iron via the spinwheel. Very little pressure is necessary to hold the blade, so if you wish to minimize the flex, back the spinwheel off a bit.
fwiw, I have had 2 planes that did need the bed filed/leveled. Both are LV planes. I did decide to do something about both of them (LA block and LA smoother) as their purpose, with their adjustable mouths, did need to have as perfect of a mouth/blade gap as I was capable of making them.

In both cases I corresponded with LV and both times their immediate response was an offer to immediately ship me new ones. As I am always one for a little adventure I was the one to decline their offer and fix them myself. They still offered to replace them should my efforts prove futile. Aside from their products, it is their customer service people that keeps me going back.

As I wrote in my first post to you about this, if there is an issue do contact LN. But also see if it does do the job it is designed for as well and make sure the spinwheel is not too tight.

Take care and have fun...
 

Alf

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MikeW":28xunrfk said:
The tension on the blade is truly important. It will distort the bed if it is too tight. It needs to be just snug enough to keep the cap from falling off. Well, a little tighter than that, but not much.
Yep, I was fully aware of that before I even bought it - been down this road with the Veritas medium shoulder plane and hope I've learnt something! :roll:

MikeW":28xunrfk said:
With that said, however, I measured mine. The mouth/blade is in as near a perfect relationship as these old eyes can measure.
Not like this then:



MikeW":28xunrfk said:
The blade projection is even across the sole and at the same angle as the mouth using the protractor head on my old Tumico combination square. It takes an even shaving thickness--at least even enough according to two different dial calipers.
Even with just enough pressure from the lever cap to just stop it dropping off, I had a noticable difference in projection, and not enough leeway to compensate via lateral adjustment. Believe me, I tried...

MikeW":28xunrfk said:
However, imho, a skew block plane such as the 140 does not need a tight mouth.
My opinion too, but having spent a reasonable wad of cash on it, which I'm not in a position to do nearly as often as I wish, I find myself slightly irritated by the fact it's out of parallel. I could have got that for a tenth of the price. :lol:

MikeW":28xunrfk said:
Do also realize that as you adjust the blade projection, that the blade can and does often twist (even slightly). This is an inherent design flaw that I wish LN would have addressed more than simply lowering the blade bed angle.
Yeah, I noticed that. Feeling rather nostalgic for set screws and lateral adjusters at the mo'... :roll:

MikeW":28xunrfk said:
...I slide the blade so that the right edge is against the removable fence...
Er....? :? Explain that again, slowly. Don't get it - sorry.

MikeW":28xunrfk said:
I either sight down the sole to see the blade projection or use my finger tips and feel the projection. This is a plane that demonstrates how important it is when adjusting blade projection to always back off and tighten the adjusting nut to bring the blade forward. If it ends up too deep, back off and come forward again. With the spinwheel as loose as it should be the backlash has to be accounted for.
Okay, I have the sucked eggs now - what should I do with 'em...? :wink: (Sorry, couldn't resist. :D )

MikeW":28xunrfk said:
Why don't you send LN an email with your concerns. They'll address them.
Well as it seems to be the norm, and I don't believe I can be the first to have wondered, it seems a bit pointless to tread a path already travelled. The best they can reasonably say is return it, and that simply leaves me back in a skew block-less state. :(

Thanks anyway, Mike.

Cheers, Alf
 

Derek Cohen (Perth Oz)

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Alf

Your orignal post here has been nagging at me. Basically, I can imagine that a blade from LN might be ground slightly out of alignment with the mouth (my LN "Stanley Replacement Blade" was), but I cannot accept that LN would consider that an out-of-square bed to be a normal part of a tuning regime with regards their planes. One might accept this of a vintage Stanley, but not LN. I suggest that you contact LN, who I am sure will replace the plane.

Regards from Perth

Derek
 

Shady

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This would defeat the purpose of the plane. Having the side removable is only useful if the leading edge can be brought slightly proud of the side.

And one would still have the issue of flex and hence having to bring the blade/mouth out of true to each other anyway.
Err - probably down to my poor explanation, but not the way I envisage it, it wouldn't. Whole concept's exactly the same, except the skew trails to the removable edge instead of leads to it... You can do all the same cuts (in my imaginary 'reverse-skew' world - how sad is this?? :roll: ) as you can with the current design, and choose to 'come proud of the side' if you so wish (although I don't actually understand what you mean by this - mine works fine, and I don't muck around sticking it out beyond the side...). Yes it would still flex, but a heck of a lot less, in exactly the same way as a Japanese saw flexes a lot less than a Western saw, because the design works with the material instead of against it.
 

Alf

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Derek, I'm now so totally befuddled as to be useless. Humour me, please. [-o< If the blade is ground so that the projection of said blade is now even across the sole of the plane, but the front edge of the mouth is not equidistant to the blade edge, does that mean the bedding is at fault? I thought it did, but now I have my customary crisis of confidence in what I thought I thought. :oops: Or is it the mouth? Putting it another way, could it be the blade and not the plane? No, that can't be... Aaaargh, wish I'd never bought the bloomin' thing now! :lol: Someone? Please? In small words, if you would. :roll:

Shady, if the skew goes the other way it'd tend to pull the plane away from the rebate/fence, wouldn't it? At least I think so...

Cheers, Alf
 

Shady

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Alf: yes, you're right, that's the only downside I can see to my magnificent patent pending 'shady-skew' plane - you'd have to positively hold it in, and that's probably the reason it simply never happened.

As to all the bedding, I'm also now confused. Have you also noticed that, when viewed from behind, the bed is also 'canted' across the sole of the plane? I actually had an e-mail correspondence with Tom L-N about this - thought I'd got some sort of reject or something, but apparently it's the design geometry... Doesn't help when trying to calculate skew settings...

(edit, having read Chris's post below: yup, mines exactly the same...)
 

Chris Knight

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Alf,

My blade/mouth gap is exactly like yours so if you do decide to return it, I shall be interested to see what response you get. I use mine for relatively few tasks and it does these very well but the plane doesn't give me the same frisson of pleasure when I pick it up that I get from some of my other LNs - the 102 for example. That's a plane I'd take to a desert island - even if a scrub would be more sensible. :)
 

Alf

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Shady":1x9y9k36 said:
As to all the bedding, I'm also now confused.
Thank goodness - company. :D

I've just had another measure of the mouth angle in comparison with the blade angle I now have (using a plastic protractor ruler thingy, so hardly the most accurate I dare say, but at least it'll be consistantly inaccurate between the two) and the difference appears to be - wait for it - one degree. Hmm, I think BB may have a point here... Is it reasonable to beef about one degree of error? Discuss. :roll:

Chris, I don't recall you saying these sensible things when I was busy trying to resist being pushed down The Slope back in March...

Cheers, Alf
 

Chris Knight

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Alf,
I'm constantly apologising these days,:oops: . Trouble is, even though I need glasses to see the tapered mouth, I have 20/20 hindsight! Plus, of course, as I get older, I get wiser, as you will too Grasshopper.
 

Derek Cohen (Perth Oz)

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If the blade is ground so that the projection of said blade is now even across the sole of the plane, but the front edge of the mouth is not equidistant to the blade edge, does that mean the bedding is at fault?
Alf, the answer is ... yes. Yes, I think the bed is skewed. It is in cases like this that epoxy is helpful - but you should not do this, and instead send it back to LN. (I used epoxy on my Stanley to close the mouth as much as square the bed - I would have sent it back to them, but the warrantee had run out :( ).

Regards from Perth

Derek
 
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