Luban chip breaker/advancement knob issues

I have a Luban no4. I notice that the adjustment knob grinds on the depth adjustment level - this isnt normal is it? It sits really high within the knob's cutout for the lever which is why I think its grinds. I notice though, when the wheel is screwed in more, it sets better - see photos:

20230125_125804.jpg - Google Drive

vs

20230125_125723.jpg - Google Drive


However, to get the blade advanced enough to use I cant have the wheel that far in, the wheel needs to be way out there.

I would like to have the frog further back but it means the wheel is even more out causing more grinding.

I have resorted to opening the plane's mouth with a file which means it works fine now, but have people experienced this with their luban no4?

ie the level grinds against wheel at a usable cutting depth when you have an open mouth (and using the chip breaker) and have put a microbevel into the chip breaker (making it shorter)

Qu, I'm having trouble understanding your terminology & what, exactly is "grinding" & what is "level"?

However, looking at your pics, I can see that the thumbwheel is back near the end of its travel on the stud when you have your blade exposed enough to cut (it's a left-hand thread if it's a full copy of the Bailey so turning the thunbwheel to the right to advance the blade actually backs the wheel off) When the wheel is at the extreme of its travel like this it rotates the cam on the end of adjuster yoke more than it normally needs to, which can cause the cam to bind on the edges of the slot. I suspect that's the source of the 'grinding' you describe. You also lose mechanical advantage when the thumbwheel is at the extremes of its travel & the wheel tends to become stiffer to turn.

My immediate diagnosis is that this is the result of taking a bit too much off the end of your chipbreaker and setting it ultra-close. The distance from the edge of the CB to the cam slot is critical with the Bailey adjusters, you've got about 1mm max of tolerance. Some years ago, another member got into this same pickle with his Lie-Nielsen....

Cheers,

Attachment 521932

the blue circles is where it rubs

the red bit - tiny bits of brass comes off every time I turn the wheel

by putting the frog more forward I can have the blade at a usable cutting depth and the advancement knob a little more towards the middle of the thread where the advancement lever sits better within the knob. this has resulted in a closed mouth, so ive had to grind the mouth wider.

Kinda sucks that the luban chip breaker isnt make a bit longer, because even stock im pretty sure the advancement knob is pretty far back already - anyone else have this problem?

Try grinding a new "hole" for the adjuster in the chipbreaker. This will permit it more forward movement. Alternately, get a new/different chipbreaker.

Regards from Perth

Derek

Quote:

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Originally Posted by qwertyu

Attachment 521932

the blue circles is where it rubs

the red bit - tiny bits of brass comes off every time I turn the wheel

by putting the frog more forward I can have the blade at a usable cutting depth and the advancement knob a little more towards the middle of the thread where the advancement lever sits better within the knob. this has resulted in a closed mouth, so ive had to grind the mouth wider.

Kinda sucks that the luban chip breaker isnt make a bit longer, because even stock im pretty sure the advancement knob is pretty far back already - anyone else have this problem?

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OK, I see what you mean - but part of the reason the yoke is grinding on the thumbwheel is that it's being pushed to the max, it looks way too far back to me.

I just realised that the fact the blade setting changes when the frog is moved tells me your plane uses the "Bedrock" frog - is that correct" The original Bailey frog moves parallel to the sole, and moving the frog fore & aft will not alter the depth setting (or shouldn't). But the bedrock frog moves down as well as forward when you close the mouth, so that makes sense.

But it's still the distance from toe to slot in the chipbreaker that determines where the thumbwheel will be in its "central" position (i.e. with the blade just on the point of exposre), so that's the problem to correct. Making the chip-breaker longer would have allowed you to take off a bit more without causing the blade exposure problem, but if they made it longer it could cause the opposite problem, you wouldn't be able to retract the blade enough for a fine shaving. As I said, the slot-to toe distance is critical with the Bailey adjuster (the adjuster works exactly the same on both bedrock & original Bailey frogs), & so you need to be very careful if you change it, you have very little leeway, altering the distance by as little as 0.5mm can cause trouble, damhik!

You've probably spoiled your chance of a refund/replacement by taking a file to the mouth, but that might have been the preferred "cure"...
:)
Cheers,

Quote:

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Originally Posted by derekcohen

Try grinding a new "hole" for the adjuster in the chipbreaker. This will permit it more forward movement. Alternately, get a new/different chipbreaker....

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Derek, I think option 2 is the more viable. To make a new cam slot in the chipbreaker would need it to be moved up or down from the existing slot by far too much, you'd need at least a couple of mm or so of metal for the cam to push against or the force would simply bend it. Moving the slot by that much would throw the thing so far out of whack, it could not work at all.

If it were me, I'd simply make a new chipbreaker but I suppose not everyone has the means or desire to do that....

Chrers,
Ian

This is mine. It seems like the pivot pin on mine is positioned further away from the bend transition at the fork.

Attachment 521935
Attachment 521936

I don't know how to rotate the photos, so you'll have to tilt your heads 🤣

Oh, the geometry in yours is completely different! I bought mine from mcjing and noticed that I had beech handles + no 'luban' logo on the lever cap. The receipt had quangsheng but online they had it advertised as luban. Its kind of annoying learning this now years later, I thought the 2 were the same functionally....

Can replacement yokes be bought?

Quote:

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Originally Posted by qwertyu

Can replacement yokes be bought?

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Almost certainly, BUT be careful - the geometry and dimensions of the yoke are pretty critical & if the yoke you replace the current one with isn't a proper match, you will be in more trouble than you are in now. The length of the arms & the angle of the bend in the yoke is dependent on the placement of the stud and pivot point and different makers are likely to have those in slightly different places. It won't take much variance to throw the whole thing off.

Really, the easiest solution, imo, is to attack the problem at its source, i.e., the shortened chipbreaker...
Cheers,

How long have you owned it, I would be seeking a replacement.

I bought a luban 4 from Mcjing in store ,the adjustment wheel was very stiff and tight after a year or so i decided it was a lemon, contacted McJing, i had receipt,they happily took it back,full refund,an option, Ross