Thread: Hand Plane fettlers should read this

Originally Posted by Virgil

Ok, so does this twisting, and the uneven wear that it may cause over time become the "fingerprint" of the plane? Do we unconsciously compensate for this as we are working, in the way that we hold the plane, the places we apply pressure? Does the plane then wear into us a bit like a pair of shoes? Would this twist manifest itself differently if I were to use a plane that wasn't mine, but had been in use by another woodworker for many years? Is this all rather esoteric and off topic?

All very interesting!

Cheers,
Virg.

Hi Virg,
Don't know about a plane wearing into us, but it sounds very warm and fuzzy. So the twist may introduce troubles when planing a thin shaving, I hadn't really thought of that possibility until it came up in this thread, what I was more interested in was the presence of twist when the maximum wear on the sole was occurring, ie when lapping...

CHeers
Michael

Originally Posted by Brobdingnagian

Not at all, I recon there would be a difference between a surface ground sole and a scraped one. I can add another possible reason; a scraped sole would have little wax lubrication pockets which would make using it much smoother/easier (ie the same as flaking does for machine tools with oil lubrication).

The laser beam width has very little to with the measurement but rather the relative distance the laser travels after it goes through a beam splitter. I would not be trying to measuring the straightness or flatness of the sole but rather the angular deflection perpendicular to the main axis of the sole with a fixed torque. The kind of error your talking about can be minimized if the beam splitter is place one the sole of the plane and then reset before the application of torque. But then again that is only one idea, there are quite a few different setup that could work well. I will try to be as scientific as possible.

I just tried on a couple of the planes behind my shoulder as I'm typing this to see how much force it takes to introduce a visible twist; the answer a lot less than I thought. :S even the relative stout LN#2 will move visibly with moderate sideways pressure (about 0.5kg), and RayG's infill is MUCH more rigid.

Just be careful that the clamping pressure for grinding doesn't introduce a distortion into the plane then... if you go for the surface grind...

Originally Posted by Virgil

Ok, so does this twisting, and the uneven wear that it may cause over time become the "fingerprint" of the plane? Do we unconsciously compensate for this as we are working, in the way that we hold the plane, the places we apply pressure? Does the plane then wear into us a bit like a pair of shoes? Would this twist manifest itself differently if I were to use a plane that wasn't mine, but had been in use by another woodworker for many years? Is this all rather esoteric and off topic?

All very interesting!

Cheers,
Virg.

Quite possibly, this is subjective but I know I can get better results with my LN#4 than when I use RayG's infill. *insert old friend analogy*.

Another small point - Mic mentions the effect of twist in lapping would be cumulative ... but it is in the nature of people to be inconsistent I would suggest ... especially at the sub-thou inch level.

When you consider possible (micro) rocking, changing grip from totes to grabbing the middle, hands and arms getting tired, lapping forward only vs forward and back, changing from heel forward to toe forward, skewing the plane, etc etc - I wouldn't expect one predictable outcome - like many human operations

You could go through a lapping process, taking time out to spot on the granite plate to chart the 'progress' ... which would be interesting ... but I suspect most people would be looking for taking 'a little bit of a mongrel' to 'pretty well darn flat' via lapping

But please keep investigating!

Thanks,
Paul

Originally Posted by mic-d

off you go then!

yup, i'll give it a go, i need to get some more blue stuff by the looks, couldnt find any here...Ian would have a point though wouldnt he, its possible that directed pressure disperses the blue in a pattern to suit, i remember when i do occasionally use the granite and blue stuff that i get different readings depending on how thick the blue is applied (obviously), so its usually important to get it as thin as possible but enough to give a spotting pattern.

i'm not confident of getting the cliftons to twist though, been trying and i cant imagine they will just yet, they are about 33% thicker (base and sides) than stanley and still much thicker than LN, if you count the extra webbing (strut type things) thats on many of the clifton planes, obviously their arranged to add strength, it appears to effectively make the sole even thicker, about 10mm or so thick without measuring it but my eye is close enough, i cant see my self twisting that! but i'll give it an experimental go


cheers
chippy

Originally Posted by ch!ppy

..Ian would have a point though wouldnt he, its possible that directed pressure disperses the blue in a pattern to suit, i remember when i do occasionally use the granite and blue stuff that i get different readings depending on how thick the blue is applied (obviously), so its usually important to get it as thin as possible but enough to give a spotting pattern.

i'm not confident of getting the cliftons to twist though, been trying and i cant imagine they will just yet, they are about 33% thicker (base and sides) than stanley and still much thicker than LN, if you count the extra webbing (strut type things) thats on many of the clifton planes, obviously their arranged to add strength, it appears to effectively make the sole even thicker, about 10mm or so thick without measuring it but my eye is close enough, i cant see my self twisting that! but i'll give it an experimental go


cheers
chippy

Personally I don't reckon he does . For one thing the blue is very very thin, for two I apply the twisting force before placing it on the granite, then lower it ever so gently onto the plate and spot just as gently as a 'normal' spotting, I apply virtually no downward force just do a small wiggle once the plane has settled onto the plate.

Don't break the tote on your Clifton!

Ok I have finished off the plane blades time to get to some science!

I need to make a jig to two for the setup. check back a bit latter.

I have a #5 BAILEY clamped at the heel with a grinding vice mounted to a compound sine table. I then have a 605mm 165g aluminum SHS clamped to the toe of the plane and at one end a 455g weight.I have also temporarily set up some gauges to see what kind twist is going on so that i can calculate what I should read on the interferometer (I'm still very new to the the whole laser metrology thing so I need some sanity checks to make sure I'm measuring what I think I am measuring) I getting very little deflection at the heel which is what I want but I needed to check less than 0.002mm. and a total 0.19mm on one side and 0.11mm on the other at the toe with a ~50mm spacing between them. And I work that out to be ~330 arcseconds of twist or almost a 10th of a degree. This method with the gauges has lots of error in it, but according to my math the inferemoter should be good down to 1 arcsecond, but I think I will aim for +- 10 arcseconds, so that will be the next test on the Bailey.

Hi All,

While Josh is busy doing twisting measurements on various plane bodies, I get to document the experimental setup,

The aim of this experiment is to measure angular twist versus applied torque on a few typical plane bodies, in other words how rigid is a typical plane body when twisting forces are taken into account.

Plane Body Twisting Measurements - YouTube

Josh will be along later with the results....

Regards
Ray

Please excuse me while I sound ignorant ...

How is the tote end held, please? I can't make it out from the photo.
... ok ... got it from the video ...

The twist is being applied at the toe ... do you think it will be a different result from twisting at the heel?

And ... (deep breath) ...

Regarding the angular rotation ... assuming it is a linear rotation across the width of the toe ... can I see if I have it correctly ...
One side has gone up (or down) 0.19mm ... the other side down (or up) 0.11mm?

Then would that mean an effective centre of rotation that is 'x' mm from one edge and (19/11)*'x' mm from the other edge?

If that is correct then the 50mm width represents (30/11)*'x' => x=18.333mm (and the other side (19/11)x = 31.666mm)

Again, if I'm not off-track down a bumpy dirt road ...
The rotation could be approximated by a RH triangle 18.333mm base, 0.11mm height
-> rotation angle of 0.344 degrees

I'm only approximating with the RH triangle, but it's quite off from Josh's 0.1 degree ...

Am I out of my tree here?

Thanks,
Paul

Originally Posted by pmcgee

Please excuse me while I sound ignorant ...

How is the tote end held, please? I can't make it out from the photo.

The twist is being applied at the toe ... do you think it will be a different result from twisting at the heel?

And ... (deep breath) ...

Regarding the angular rotation ... assuming it is a linear rotation across the width of the toe ... can I see if I have it correctly ...
One side has gone up (or down) 0.19mm ... the other side down (or up) 0.11mm?

Then would that mean an effective centre of rotation that is 'x' mm from one edge and (19/11)*'x' mm from the other edge?

If that is correct then the 50mm width represents (30/11)*'x' => x=18.333mm (and the other side (19/11)x = 31.666mm)

Again, if I'm not off-track down a bumpy dirt road ...
The rotation could be approximated by a RH triangle 18.333mm base, 0.11mm height
-> rotation angle of 0.344 degrees

I'm only approximating with the RH triangle, but it's quite off from Josh's 0.1 degree ...

Am I out of my tree here?

Thanks,
Paul

Paul,
The heel is mounted in a grinding vice. (I would have preferred to have only one side of it fixed but i could not imagine a way to keep the holding point consistent across different planes other than clamping across the heel.)
The error here is that you don't divide the 19 and 11 it is a subtraction the to get the tilt in other word the short side if the hypothetical triangle is 0.08mm. the rest is dip not the twist. if you know what i mean.

Just dropping in from the metal work forum because this is an interesting discussion (to me anyway)

To pick up on a point that Greg Q suggested in post 22, the plane sole will heat up from use but if the work being planed is narrower than the blade of the plane then the heat will be applied in a strip along the sole. As the sole is not a uniform section but varies with ribs, bosses and even the frog being bolted on, the plane will distort anyway.
Even if the work is wider than the plan so that the whole plane is in contact with the work with a 'uniform' friction heating effect, the varying section thickness will ensure non-uniform distortion. Of course, as soon as that happens there will be more pressure in some areas so the frictional heating becomes non-uniform...

From an engineering point of view it's sounding like a thick uniform section is needed with a temperature control mechanism built in (eg chilled water circulation) if you want to get (and stay) flat to a micron level.

Michael

It appears that the relationship between torque and twist seems linear as does the distance from the fixed point (vice holding the plane).
I tested at fixed points along the sole of the plane body with three different torques so that we might have a way to compare plane bodys from various makers as well as different sizes (LN#4 vs Bailey#5). Since the relationship seem to be linear for the most part it should be possible to put a number to a plane body for its twist resistance. Ie arc seconds/ per Nm /per mm.

any way here is the chart for the Bailey #5 (sorry no error bars yet)

The smallest plane I can test, any narrower and the retro reflector mount is not stable