Planing a straight edge

[Muina]

This thread (or the need for it) doesn't say much for the tuition/tutors, does it?

BugBear

Do you mean College?

 

[jimi43]

I've always seen it as a body weight/position issue.

(note I am left-handed so this talks of hand positions)

Standing at the back of a piece of stock in the vice both your elbows are tucked in naturally and are low. As you move forward they both rise up....then reach the apex of an arc midway along the stock and then the body balance leans forward, lowering them again.

The stance where you are compact and reach out to complete the shaving leads to an arc.

Moving the pressure on the plane as you progress through the cut (as in correct planing) counteracts this and prevents the near and far ends being rounded downwards.

At the beginning of the stroke, maintain downward pressure at the front of the plane and as the stroke passes the centre, slowly transfer the pressure to the rear of the plane.

The reason stopped shavings work (using multiple strokes along the board stopping at intervals), is because you are not over-extending reach and thus the error is not as accute.

On long boards try to get a slight concavity in the centre of the board so that when it is clamped in the centre it pulls this tight and progressively along the board joint right up to each end. This is a "sprung" joint as mentioned above.

Jim

 

[Dee J]

Planing is an interactive activity involving an error detecting feedback loop. Plane perfomance varies, human input varies and timber characteristics vary. The only real way to plane a straight edge on a length of timber is by frequent testing of the timber during the planing process - using a reference steel rule or similar, and adjusting plane useage to take off the high spots from the timber. The more proficient the practitioner, the less checking required.

The idea that one can apply 'plane number x for y strokes' and end up at a predictable outcome just does not work (unless one is highly experienced, working with a familiar plane on a relatively simple timber)

Just my 2d worth

Dee

 

[Jacob]

Planing is an interactive activity involving an error detecting feedback loop. Plane perfomance varies, human input varies and timber characteristics vary. The only real way to plane a straight edge on a length of timber is by frequent testing of the timber during the planing process - using a reference steel rule or similar, and adjusting plane useage to take off the high spots from the timber. The more proficient the practitioner, the less checking required.

The idea that one can apply 'plane number x for y strokes' and end up at a predictable outcome just does not work (unless one is highly experienced, working with a familiar plane on a relatively simple timber)

Just my 2d worth

Dee

Agree. You have to keep an eye on your progress and adjust your technique accordingly.

 

[Alf]

The reason stopped shavings work (using multiple strokes along the board stopping at intervals), is because you are not over-extending reach and thus the error is not as accute.

If I understand you right, jim, them's aren't stopped shavings. Paul is talking of starting a "full length" shaving (for a given, and inaccurate, value of "full length")) a little distance in from the end, and stopping it a little distance from the other. Do it a coupla times or so, then take a genuinely full length shaving right from stem to stern.

One of the most helpful bits of advice I had was simply to try like **** to plane a hollow. You won't do it (within reason, assuming you're using the correct tool for the job) but it will get you putting your weight in the right places at the right time.

Dee is quite correct; it's not an apply wood here, push, stop, all done scenario. That's machinery.

 

[woodbloke]

Planing is an interactive activity involving an error detecting feedback loop. Plane perfomance varies, human input varies and timber characteristics vary. The only real way to plane a straight edge on a length of timber is by frequent testing of the timber during the planing process - using a reference steel rule or similar, and adjusting plane useage to take off the high spots from the timber. The more proficient the practitioner, the less checking required.

The idea that one can apply 'plane number x for y strokes' and end up at a predictable outcome just does not work (unless one is highly experienced, working with a familiar plane on a relatively simple timber)

Just my 2d worth

Dee

What's been suggested elswhere is the following simple test to see the effect. Take two identical pieces of wood, say 15mm wide and 500mm long, reasonably straight and support them side by side together on the bench top. Then take around 10 - 20 properly applied, full length strokes with an appropriate plane...as if you were preparing the pieces for an edge/edge joint. After said number of strokes, upend one on top of the other...the convexity ought to be clear at each end and will be magnified accordingly - Rob

 

[Modernist]

Planing is an interactive activity involving an error detecting feedback loop. Plane perfomance varies, human input varies and timber characteristics vary. The only real way to plane a straight edge on a length of timber is by frequent testing of the timber during the planing process - using a reference steel rule or similar, and adjusting plane useage to take off the high spots from the timber. The more proficient the practitioner, the less checking required.

The idea that one can apply 'plane number x for y strokes' and end up at a predictable outcome just does not work (unless one is highly experienced, working with a familiar plane on a relatively simple timber)

Just my 2d worth

Dee

Agree. You have to keep an eye on your progress and adjust your technique accordingly.

I've never seen your "error detecting feedback loop" Jacob. Do Veritas make them?

 

[matthewwh]

I agree that it isn't a predictable process, which is why an observation of something consistent stands out like a sore thumb.

If the vast majority of people consistently get a convex edge from multiple through shavings, it is surely possible to eliminate all of the random stuff on the basis that random inputs don't produce consistent outputs.

The only consistent change of circumstances I can see that would influence the outcome of a full shaving is a change in reference surface halfway through the cut, when we switch from using the front sole (reverenced against the unplaned surface) to the rear sole (referanced against the planed surface).

 

[Dee J]

"I've never seen your "error detecting feedback loop" Jacob. Do Veritas make them? "
No these are generally homemade, usually by unskilled labour!

Dee

 

[jimi43]

The reason stopped shavings work (using multiple strokes along the board stopping at intervals), is because you are not over-extending reach and thus the error is not as accute.

If I understand you right, jim, them's aren't stopped shavings. Paul is talking of starting a "full length" shaving (for a given, and inaccurate, value of "full length")) a little distance in from the end, and stopping it a little distance from the other. Do it a coupla times or so, then take a genuinely full length shaving right from stem to stern.

One of the most helpful bits of advice I had was simply to try like **** to plane a hollow. You won't do it (within reason, assuming you're using the correct tool for the job) but it will get you putting your weight in the right places at the right time.

Dee is quite correct; it's not an apply wood here, push, stop, all done scenario. That's machinery.

Ah! I never interpreted it like that...you learn something new every day.

My experience with joining two halves for guitars...thin stock sometimes...over an inch other times depending on the job. I guess lots of shorter swipes and one or two full ones has the same effect ultimately but it's nice to know what the term actually means.

Your idea of "thinking and aiming" for a hollow makes a lot of sense!

Jim

 

[Jacob]

Planing is an interactive activity involving an error detecting feedback loop. Plane perfomance varies, human input varies and timber characteristics vary. The only real way to plane a straight edge on a length of timber is by frequent testing of the timber during the planing process - using a reference steel rule or similar, and adjusting plane useage to take off the high spots from the timber. The more proficient the practitioner, the less checking required.

The idea that one can apply 'plane number x for y strokes' and end up at a predictable outcome just does not work (unless one is highly experienced, working with a familiar plane on a relatively simple timber)

Just my 2d worth

Dee

Agree. You have to keep an eye on your progress and adjust your technique accordingly.

I've never seen your "error detecting feedback loop" Jacob. Do Veritas make them?

It's on top of my head, revolving slowly, 24/7 :shock:

 

[dunbarhamlin]

I'd keep that one under your cap, Jacob - you'll get weird looks from the ferrets and unwelcome advances from the other team if they see you've got a twirling garter on your pate

 

[bugbear]

One of the most helpful bits of advice I had was simply to try like **** to plane a hollow. You won't do it (within reason, assuming you're using the correct tool for the job) but it will get you putting your weight in the right places at the right time.

Ditto, seconded, etc.

BugBear

 

[GazPal]

perhaps the simplest guides for planing to true are (i) a solid or intermittant pencil line/fine chalk line, (ii) using the correct plane size for the job in hand, (iii) focus/concentration and (iv) sharp blades. Once you're capable of consistantly working to a drawn line you'll soon find your hand to eye co-ordination improving and problems with dips and delves tend to lessen.

Three simple guides to follow are

1. Dimensions (Including square).
2. Lines.
3. Levels (If moving on to construction).

Mark everything out first and work to the layout lines set.

Technique regarding stopped shavings, planing to hollow, etc., will soon become second nature, but you firstly need to practise planing to a straight line and square to face. Practise on scrap whenever possible.

 

[David C]

Planing the edge hollow is very good advice.

For edges up to about 2 times the length of the plane it goes like this.

Put pencil marks at either end. Take repeated long shavings (Stop shavings), starting and finishing as near the pencil as possible. (i.e. about 1/42 to 1/2" from the ends) Carry on till the plane stops cutting. The edge will now be hollow (unless you have the dreaded concave sole and there are many of these about).
After one or two or three full length though shavings the edge will be at it's straightest. A few more and convexity or bump will develop.

Long planes are beneficial as the work gets longer but for very long work a good straightedge is essential.

I was taught this about 35 years ago and have passed it on to many students.

David Charlesworth

BTW did we ever see an American dvd where a straightedge was used on the length??

 

[barkwindjammer]

OMG :shock:

 

[Muina]

I finally got a straight edge! After trying the stop shavings techniques many times I finally had one that I had a good feeling about

Just imagine it... very late at night in the garage with a piece of wood clamped in the vice, planing it down to nearly a matchstick, then... Eureka!!! I put the straight edge against it and there isn't even the tiniest bit of light showing!

Thank you for everyone's replies and tips, they've helped me so much!

Anthony

 

[CroppyBoy1798]

Just imagine it... very late at night in the garage with a piece of wood clamped in the vice, planing it down to nearly a matchstick.....

Dont have to imagine it, thats me, most nights =P~

Nice work! Interesting thread too!

 

[GazPal]

I finally got a straight edge! After trying the stop shavings techniques many times I finally had one that I had a good feeling about

Just imagine it... very late at night in the garage with a piece of wood clamped in the vice, planing it down to nearly a matchstick, then... Eureka!!! I put the straight edge against it and there isn't even the tiniest bit of light showing!

Thank you for everyone's replies and tips, they've helped me so much!

Anthony

Now you've had your eureka moment/broken past this particular plateau, your hand planing will become much easier as you become far more familiar with technique. Well done that man! :wink: Shy bairns get no broth and you did the right thing in asking and experimenting/practising.

 

[David C]

Well done!

Perhaps we should start talking about square edges next........

This is all stuff which I will be demonstrating at the Get Woodworking show Alexandra Palace.

David C