planner height 11

[tablesawtom]

I read the responses  of many and started watching the video in the other post but didn't finish and here is the reason why,

1. A datum is a line, surface, plain or feature assumed to be perfect. And in your case you are assuming that the cutter head is perfect. Knowing production practices I am fairly certain it is not. And I will go over to my shop tomorrow and take a picture of what I am talking about. We are having freezing rain today and nothing is moving.

2. The general practice is to run the wood over the jointer to make one surface flat and then send it through the planner. Now the thickness of the wood exiting the planner is controlled by the distance of the cutting edge of the knives and the planner bed, The thickness is not controlled by the cutter head. And the bed of the planner is the datum, not the cutter head. All dimensions  are referenced from a datum but a Datum doesn't carry a tolerance, it is assumed perfect. This is just an example but the cutter head could be in the machine at a 45 degree angle and the wood coming out would be at a 45 degree angle if the knives were set to the cutter head. But if the knives are set to the datum (planner table) even though the cutter head is at 45 degrees the cut would be parallel to the planner bed.

3. Using a jig to set the knives is a great starting place but relaying on spring pressure or a jacking screw against hand pressure is not reliable in the least. And there is the twisting action of the screw as the blade is tightened even though there is a clamp in between it and the blade.

The video showed an indicator being used and rightly so because the actual cutting edge of the knife can be measured. The relationship of all three cutters to the cutting plain can be measured in relationship to what ever datum is used, cutter head or my choice planner bed. The actual cutter head can also be measured to see if indeed it is parallel. If one blade is in at an angle the board coming out will be angled. if one knife is lower it will do all of the cutting and become dull the quickest. If one wants to argue that the other blades are still cutting, yes they are, but the lowest one will still recut the surface. The lowest blade will produce a rougher surface and as the ridges are knocked of during sanding the thickness changes  according to the difference in cutter height. and surface quality also gets worse as the blade dulls.

The same holds true for a jointer. The outfeed table is the datum not the cutter head. Since both the infeed and the out feed tables are adjustable and separated pieces that may or may not be a
parallel to the cutter head and asking even the outfeed table and the main tool body to be in perfect alignment is like expecting an elephant  to fly. Again magnets will not hold against the twisting force as the screws are tightened. The actual position of the cutting edge however be measured and if all cutters (3 or 4) can be brought into the same plane, I shoot for .002 total indicator runout (TIR), on the knives. then if xero is  set off the cutting edge the out feed table can be brought the zero. NO guess work, no assuming, or hopping, everything has been measured. Unless one wishes to get into discussing running load or static load on the bearings.

Also the outfeed table should be used to set the fence for square and not the infeed. I used the term square instead of the correct political term of perpendicular.

Now if one has a lunch box planner the cutter head has to be used because the bed us not machined and therefore not perfect. Dewalt uses pins to control setting knives and I tried to check but the planner bed made it unreliable at least. I have no other experience with lunch box planners. so I can't comment.

The same holds true to the jointer with an insert cutter head, the only adjustment is to the outfeed table and fence. Dealing with the cutter head is a moot point. On a note: the infeed table controls depth only not quality.


Tom

[JGrout]

I guess I need to go someplace and learn all this unimportant stuff. 

If the head of any cutting tool is parallel to the  beds of the machine than the knives by default will be parallel. 

Using a dial indicator is only an assurance that you did a good job. 

And you can learn that with a caliper and a piece of wood once the knives are set. 

IOW you can set knives with very basic jigs  and do just fine.

Joe

[tablesawtom]

But if the cutter head isn't parallel to the datum then your product is out. And after building, jigs, fixtures dies and special machinery for industry (50years worth) so they could produce a part I would suspect that the cutter head is not perfectly parallel sense my tolerances were up to ten times the production tolerances.

I wrote what I know to be true, if you wish to settle for mediocrity because you mind can't handle the truth go for it.

Poor workmanship in the beginning bleeds through in the finish, and it follows you all the rest of the way through the build. Speaking from experience. So if a person comes up with a better mouse trap why not use the information to your advantage? Why not do it right in the first place? Its effect are far reaching.

Tom

[Phil Thien]

Now if one has a lunch box planner the cutter head has to be used because the bed us not machined and therefore not perfect. Dewalt uses pins to control setting knives and I tried to check but the planner bed made it unreliable at least. I have no other experience with lunch box planners. so I can't comment.

So if my lunchbox planer, with all its faults (a bed that isn't machined, as you say) produces stock that is of uniform thickness across the width, why change technique on a stationary planer?

[tablesawtom]

So if my lunchbox planer, with all its faults (a bed that isn't machined, as you say) produces stock that is of uniform produces stock that is of uniform thickness across the width across the width, why change technique on a stationary planer?

Don't get me wrong, because lunch box planners are priced reasonably and do a very good job.  Saying uniform thickness across the width across the width is like saying plywood is flat and parallel and it isn't.  I am not knocking lunch box planners. For some it is the best they can afford. For others it is what their shop can afford to give up in terms of space, not to mention storage. I just mentioned them because I don't feel anything I wrote can improve the result of what they turn out. And I am happy for anyone who has one. I am not knocking them and having any planner is better than not having a planner period.

I am sorry I didn't make the title of the post more clear. Please except my apologies, my mind was racing ahead to the meat of my post.  It should read Planner Blade Height 11 because it is a continuation of someone else's post about setting the height of stationary planner blades. I posted 11 because I didn't want to send his post in a different direction or as they say steel the post. I also didn't want my replay to get lost on page 3 or 4 of his post.

Stationary planners and lunch box planners are different animals and this reply is for stationary planners. To answer the question, why change technique on a stationary planer? In regards to the actual post, Why not? Better results and longer run time on the knives is strong advantage. If you put, lets say, a 2 inch wide oak board through one side of the planner and then put another 2 inch wide oak board through the other side of the planner the results will be measurable, and more so down the road on wider boards. 

I have some pictures but photo bucket is not responding at the moment.

[JGrout]

But if the cutter head isn't parallel to the datum then your product is out. And after building, jigs, fixtures dies and special machinery for industry (50years worth) so they could produce a part I would suspect that the cutter head is not perfectly parallel sense my tolerances were up to ten times the production tolerances.

I wrote what I know to be true, if you wish to settle for mediocrity because you mind can't handle the truth go for it.

Poor workmanship in the beginning bleeds through in the finish, and it follows you all the rest of the way through the build. Speaking from experience. So if a person comes up with a better mouse trap why not use the information to your advantage? Why not do it right in the first place? Its effect are far reaching.

Tom

make the bed parallel to the head 

It is not rocket science; I can accomplish that in less than an hour with a simple feeler gauge and a block of wood. Then I never have to concern myself with the issue again 

My mousetraps are of the KISS style; the simpler the better as long as it is accurate. For instance while you are searching for all the measuring tools to shift a jointer knife to eliminate a nick I am back to work. That is the beauty of a simple jig made from a scrap stick. As long as it is straight it is very accurate 

Additionally you will not see mediocrity or poor workmanship in my efforts either for clients, myself, including the ones I help professionally or on this forum 

YMMV Obviously




There are far more critical things in life to concern myself with

[packerguy®]

Not sure where this is coming from? Seems there was maybe a previous thread?

My education was in mechanical design, and in fixtureing in a manufacturing setting. With that said, I think one HUGE thing is dealing with metal and wood are they are different mediums. Wood moves often with minimal change in atmosphere where most metal is pretty stable unless heated or cooled dramatically. You can plane wood dead nuts flat. Give it a few hours. It wont be.

Ever see a piece of furniture made in the 1700 or 1800's? Its amazing they made this stuff with hand tools only....and its still around based on how some folks get their tools dialed in to .0001 when in reality, like I said, wood is a living thing and it absorbs moisture and moves. 

Just like potters and glass blowers deal with their mediums differently. Or oil painters and watercolor painters. 

To each his own.

[Downwindtracker2]

What you say makes sense Tom. Now you got me itching to fix the  stationary project planer I picked up, a General 130 . I think the feedworks are worn out.

[tablesawtom]

Here are the pictures I said I would post.









I would like to note that the indicator has a 1/2 dia. tip on it. That way it can be moved around and the cutter can be rotated and the person can see the cutter come up to top dead center and also see when it falls of. The indicator is held in the perpendicular position Apart from tolerances  during manufacturing which is about .010 in one inch this type of indicator is direct reading And because it is perpendicular the cosign error that is operator error is a moot point. Yes I know that one can get better, more accurate indicators but I feel they are cost prohibiting for a home shop.

With that in mind here are some other uses ( reasons why I like this gage ) for this gage.

Back to datums which happens to be the table saw top. the height of the saw blade is set with this gage, remember the blade can be rotated back and forth to read set the height. The actual actual blade centerline changes on
 on a table saw it swings on an arc. 




Raise or lower router bit height. Yes I know all about set blocks and feeler gages and the dial on my my what ever is accurate and Bla, Bla, Bla  but once you try it you will never go back.



I know wood moves and I will address this in up comming posts for all who will listen. But so does metal, it also twists and goes bonkers so lets be carfull about hindering some one else. And personally I don't care if one uses this information or not, I wrote the truth. I wrote from a world most of you know nothing about, where 2 tenths of one thousandth make a difference and taking the time to set them the best way possible pays dividends down the road.

1. So my question is why be stuck in a rut?
2. Why introduce problems into your work when they can be avoided? 
3.And to feeler gages, why do anything half butt.


Tom

[tablesawtom]

I forgot a picture and I had trouble getting it in when editing so here it is.

 I use it to move my rip fence very small amounts when going for fits. The how much do I move it when in between lines on my fence and if I move to much how do I get back. Here the cosign error can come into play but it is such a small triangle  it is all but direct reading.