Low VS standard angle planes

[Phil Pascoe]

How about this for a revolutionary idea - use the plane that suits you best for the job in hand, ignoring everything anyone else says. It really doesn't matter much.

 

[Jacob]

....

Custard is fairly homogenous, but I would prefer to push a snooker ball through it than a ping pong ball.

Excuse the perverse metaphor here, but I think it conveys the point.

Nope. I see no point.

Momentum will overcome friction as wall as cutting resistance.

Yes but to get the momentum you need to exert more force. And how would you submerge the ping-pong balls? :shock:
Ask yourself - does it work with stewed prunes? They help to get things moving apparently.

So this is where you learned your physics; playing with your pudding? I would never have guessed!

 

[clivethecarpenter]

....

Custard is fairly homogenous, but I would prefer to push a snooker ball through it than a ping pong ball.

Excuse the perverse metaphor here, but I think it conveys the point.

Nope. I see no point.

Momentum will overcome friction as wall as cutting resistance.

Yes but to get the momentum you need to exert more force. And how would you submerge the ping-pong balls? :shock:
Ask yourself - does it work with stewed prunes? They help to get things moving apparently.

So this is where you learned your physics; playing with your pudding? I would never have guessed!

:lol: giggle

 

[woodbrains]

So, putting sandbags in the boot of the car helps to save on fuel? You have invented the perpetum mobile, congratulations.

Which brings me to the second one. Moving a heavier weight from a to b (and back) takes more energy. I suppose everyone agrees about that.

So, that leaves irregularities in the wood. And yes more weight helps but it comes at a cost: more energy.

There are other ways to deal with irregularities. In the first place a sharp blade. "Sharp cures everything".
You can skew the plane, you can plane across the grain in a heavy cut, you can choose your stock wisely, you can wax the bottom. You can even lean on the plane to alter the weight dynamically when you need it.

It's all a matter of perception too. Someone who paid a lot for an extra heavy plane feels more difference them someone who got it for free. That's human nature, not physics.

Where did I ever say there is an energy saving? This is what annoys the living daylights out of me, someone always writes something I never said and then tells me I'm wrong. So people here don't understand momentum; well I tried.

It seems the folk here would prefer to believe that psychology makes their planes work rather than mechanics and they have the front to chastise me for playing with my food. Never mind.

Incidentally, custard is a non-Newtonian fluid. Ping pong balls will stay submerged..
Mike.

 

[Corneel]

The custard example is fundamentaly flawed, you'd have to acknowledge that.

I think where you are going wrong is comparing planing with a swinging action, like hammering. Planing is a pushing action, where the circumstances are different. When you try to push a nail into the wood it doesn't matter if the hammer is 50 grams or 5 kg.

And don't take it too personally, it's just a discussion on a forum, not a matter of life and death.

 

[iNewbie]

I always use a Bevel-up spoon with Bird's custard.

 

[Phil Pascoe]

Fine, but doesn't the muck off your water stone get the custard dirty?

 

[Jacob]

This one could run and run!

 

[woodbrains]

The custard example is fundamentaly flawed, you'd have to acknowledge that.

I think where you are going wrong is comparing planing with a swinging action, like hammering. Planing is a pushing action, where the circumstances are different. When you try to push a nail into the wood it doesn't matter if the hammer is 50 grams or 5 kg.

And don't take it too personally, it's just a discussion on a forum, not a matter of life and death.

I know I'm going to regret this, and you must realise that the custard was said more out of facetiousness than anything, but why is the example flawed? If this doesn't illustrate why something with more momentum will move against an opposing force easier than something with less, then why?

I don't take these things personally, but it is is irksome to be argued against with things I have not said. The hammer thing or flywheels were nothing I said, but here I am having the the comments attributed to me. Now there is sand bags in cars! I have said on more than one occasion, that I own use and like wooden planes. I have said I do not want to change anyone's working methods. I was only trying to explain, a least in part, why many people find a heavy plane an advantage. The soles can be waxed just the same the blades can be equally sharp, they can be skewed through the cut just the same. They can be as cheap as chips and rough as bears behinds, so not instil any sense of awe and wonderment like a premium tool can (apparently?) But there is a perceivable difference that can only be explained by mass providing more momentum. And no amount of flawed mechanics as counter arguments will disprove the fact. You might not like heavy planes, but don't try to prove it by disproving Newton. Enjoy your wooded because of why ever it is you do. In fact tell us, it would make good reading here. I can tell Lyon why I like mine, but has nothing to do with poor physics.

Mike.

 

[iNewbie]

Fine, but doesn't the muck off your water stone get the custard dirty?

Just a trifle.

 

[MIGNAL]

What you said Woodbrains is that 'light Planes offer no advantage'. I suppose you implied that they don't cut the custard.
My experience tells me that they do offer advantages in certain situations. They are light and therefore less tiring.

 

[Corneel]

Dear Mike,

You still don't understand this fundamental physical thing, energy doesn't appear from nowhere. The momentum doesn't push the plane. You are pushing.

When you push something at a constant velocity against a constant resistance, you have to deliver energy constantly. If you stop pushing the plane it will stall to a complete stop. The heavier plane will move a little further then the lighter one because YOU have put more energy into pushing it until that point. The same goes for the ball through the custard. If the momentum would do any pushing you would have created a perpetuum mobile and the plane would take of from itself. That is fundamentally impossible.

Hope you now understand what I am trying to explain. When pushing the plane you store some energy into the momentum, so it will continue a liitle further after you stop pushing. But the momentum itself doesn't create energy to push the plane. The momentum doesn't push.

If you don't understand this I'm afraid i can't explain it more clearly.

Wishing you all the best, corneel.

PS, I don't remember exactly who said what, but the custard example and the hammer example came from you.

 

[woodbrains]

Please also note that a knot, or any other imperfection that might slow the plane, will impart a given return force. This force will slow a plane with more momentum by a lesser amount than a plane with less momentum, true. However, the force required to accelerate the plane back to full speed will be equal to the force imparted by the imperfection in the first place.
Thus, weight and momentum, while making a plane seem smoother in a push, actually do not save any energy at all.

Fraser

Hello,.... I'm afraid your logic above s wrong....

Hello....No it isn't.
You need to do a bit of physics revision woodbrains.
There may well be advantages in heavier planes on some occasions but it's certainly not a general rule.
Compare axes and hammers - they work by imposing all the momentum gained in the swing on to a brief contact with the target. You couldn't get the same effect by just pushing at nail or an axe head even with the same amount of energy invested - it's the short sharp blow which does it.

Like I said, it was Jacob who introduced hammers and axes. Someone ele fly wheels.

Dear Mike,

You still don't understand this fundamental physical thing, energy doesn't appear from nowhere. The momentum doesn't push the plane. You are pushing.

When you push something at a constant velocity against a constant resistance, you have to deliver energy constantly. If you stop pushing the plane it will stall to a complete stop. The heavier plane will move a little further then the lighter one because YOU have put more energy into pushing it until that point. The same goes for the ball through the custard. If the momentum would do any pushing you would have created a perpetuum mobile and the plane would take of from itself. That is fundamentally impossible.

Hope you now understand what I am trying to explain. When pushing the plane you store some energy into the momentum, so it will continue a liitle further after you stop pushing. But the momentum itself doesn't create energy to push the plane. The momentum doesn't push.

If you don't understand this I'm afraid i can't explain it more clearly.

Wishing you all the best, corneel.

PS, I don't remember exactly who said what, but the custard example and the hammer example came from you.

And kinetic energy also has a mass component. Like I said, it is feasible to push a plane of 2 times the mass but less so increase speed significantly because cutting resistance and physical limitations of the human body limit this.

The phenomenon that people have noted in massive planes could be down to magic, I suppose.


Mike.

 

[Corneel]

So you do agree with me?

Kinetic energy is mass x velocity. When you accelerate the plane you store kinetic energy in the plane. The heavier the plane, the more energy you must deliver to reach the desired speed. When you have reached that speed, the kinetic energy remains constant, because the mass and the velocity remain constant. In other words, no energy goes in or out as long as the speed remains constant. You only have to continue delevering energy to overcome the friction in order to keep the speed constant.

Then half way the board you may decide to stop planing and let go of the plane. At that point the energy balance is disturbed. The friction remains the same, so the plane decelerates. Because it decelerates the kinetic energy is released.

In other words, as long as the speed is constant, the kinetic energy doesn't help you. Only when the plane decelerates (because of an irregularity in the wood) wil the stored kinetic energy help you to overcome that irregularity. And of course the kinetic energy is first delivered by you in accelerating the plane at the start of the planing stroke.

So, the weight of the plane doesn't help you to push it.

The rest is personal preference, when and where you want to deliver energy.

 

[woodbrains]

Cornell,

Momentum is mass times velocity, KE is (mass times velocity squared ) divided by 2. And the KE is not released on decelleration either. Neither have I ever said that you do not put more energy into the system with higher mass, but twice you have accused (attributed) me of inventing momentum perpetua. Neither is accellerating a plane storing kinetic energy in it. It HAS kinetic energy because It is moving, the more massive plane having more kinetic energy it has for a given speed. We need energy transferred from the plane through the blade to make the cut. (kinetic energy from the plane to potential energy in the blade back to kinetic, heat and sound energy lifting the shaving.) And yes, on more than two or three occasions I have said it is personal preference, and I wasn't trying to change anyone's working methods. I am merely trying to explore why heavier planes are preferred by many. All things being equal, blade sharpness, low friction soles etc. both systems can be equal. So the only differentiator is weight. If people observe this helps them push through the work better, it must be, in part, down to increased momentum, there is nothing left to attribute it to. It will take more energy from the user to push the plane as I keep saying, but if I can use a heavy plane all day, then I can still only use a light one all day, so there is no real disadvantage. But, if the energy in a light system is not enough to move the plane through a cut then the only solution is to reduce the depth of cut and make more passes. It is horses for courses.

And as I have said, I still live my wooden planes, I'm not getting at anyone.

Mike.

 

[Jacob]

If you aren't dazed and confused already what about these questions:
1 Why can't you play ping pong with snooker balls?
2 Vice versa?
3 Cricket with shuttlecock?
4 Would it help if you were in a vacuum? (nb not a hoover)
5 Why can't you just throw bullets at a target, they are only little after all, compared to say the effectiveness of throwing a cricket ball.
6 What would happen if you dropped each of these into very deep custard?

 

[Corneel]

Yes, the planes has kinetic energy because it is moving. And why is it moving? Because YOU accelerated the plane, YOU have put energy into it.

For the weight to help the planeuser overcome the resistance, it must release energy. And I allready explained that during the phase of the constant speed, the kinetic energy remains constant, so no release of energy. I'm afraid I have to "accuse" you of trying to invent momentum perpetua once again.

You are right about the correct formula for kinetic energy, i got them mixed up after a couple of beers. It doesn't change my proof though. As long as weight and velocity remain constant, the kinetic energy remains constant and no help is given to overcome the resistance in planing. BTW, at the end of the board when the blade leaves the wood and the resistance disapears, the kinetic energy works against you and you must put effort in it to stop the movement.

Because kinetic energy is proportional to the velocity squared, speed has more influence the weight. Not many people are planing at the top of their anatomical abilities, a bit of increase in speed is almost always possible. So if you need more kinetic energy to overcome a knot, you can speed up the lighter plane. Increasing the speed of the heavier plane is more tiring again.

The total energy balance of the act of planing is always in favor of the lighter planes. Nobody can plane nonstop, a full day long. When you get tired you take a break. When the heavier plane tires you more you must take a break sooner.

Another advantage not yet mentioned, you can use longer planes without expending more energy when they are lighter. For example my 18" fore plane is still lighter then my 14" Stanley #5. This makes it easier to make a flat surface.

So, in fact there are many arguments in favor of lighter planes, and not much in favor of heavier planes.

 

[dj.]

Phew, I`m worn out reading that lot, #-o

Personally I like a woodie if I`m working away from a bench etc where the weight of the plane is not being supported by the piece of timber I`m planing.

6 What would happen if you dropped each of these into very deep custard?

Well first off you`d need a bloody big bowl & second you wouldn`t be putting it on my apple pie when you`ve finished with the custard :lol:


Regards.

dj.

 

[Phil Pascoe]

I have a perfectly good argument for heavier planes. I like heavier planes.

 

[Corneel]

I'm going to make it even more complex. We haven't yet thourougly discussed the influence of the bodyweight of the planer. Let us try to find some numbers about this.

When I put a scale on my bench I find it is not very difficult at all to press down with 20 kgs. This weight is also moving with the planing stroke but not at exactly the same speed, nor is it rigidly attached to the plane. But it does have an effect. When you encounter a knot, your moving body will try to continue on its path, and because you are pushing the plane with relatively rigid arms, some of that momentum will help the plane to move over the knot without slowing down.

Say only a quarter of the 20kg mentioned above plays a role in the momentum of the plane. That's still 5 kg. The difference between a beech smoother and a Stanley #4 is only 800 grams, a fraction of the 5kg. So in real life the difference in weight between the planes is only a small part of the total picture.

Personally I enjoyed this discussion. I learned more about planing dynamics, just thinking about it! Alas, no planing for me this weekend, because I have all kinds of other jobs around the house and garden.