planer snipe

[Steve Maskery]

Does this suggest that no matter how good the setup, you will never get a glue up surface straight from the planer because on some magnification or other the surface cannot be fully flat?

No and yes in that order.
You have to define "flat". No surface is flat, if you take it to the extreme, but for our purposes we use 'flat' as shorthand for "flat enough".
Manifestly, a machine-planed surface can be glued, but a hand-planed surface will finish better. If you put a polish directly onto a machined surface you will see the machine marks (DAMHIKT!).

Any machine is donkey. It does the hard work. It's up to the skill of the craftsman to refine that.
S

 

[katellwood]

Does this suggest that no matter how good the setup, you will never get a glue up surface straight from the planer because on some magnification or other the surface cannot be fully flat?

No and yes in that order.
You have to define "flat". No surface is flat, if you take it to the extreme, but for our purposes we use 'flat' as shorthand for "flat enough".
Manifestly, a machine-planed surface can be glued, but a hand-planed surface will finish better. If you put a polish directly onto a machined surface you will see the machine marks (DAMHIKT!).

Any machine is donkey. It does the hard work. It's up to the skill of the craftsman to refine that.
S

One other thing to consider is that a machined surface will be more consistent if its power fed through the machine as opposed to hand fed (think surfacing as opposed to thicknessing).
For surfacing the feed speed will be dictated by the user and in some circumstances may be a bit erratic producing varied planer marks on the surface however if powerfed the marks will be consistent. I personally find this is more prominent on the spindle when taking big bites like rebates and moulds, my spindle power feed was one of my best purchases

 

[marcros]

I am definitely going to budget for the power feed when I get a spindle. In the meantime a number 8 for jointing is on my radar.

 

[custard]

My power feed will extend from the spindle over to the planer. It sounds useful but in practise I hardly ever use it because there's a very, very fine line between too much pressure (which artificially straightens out any bow or cup in the board) and too little pressure (which doesn't feed the board through). I can spend twenty minutes or more setting up the power feed so that it's just perfect, I don't begrudge that time on the spindle moulder because you can see the investment in the results. But for planing I'm not convinced the results are noticeably better.

IMO the real winner in terms of an "extra" for a planer thicknesser is a Tersa block or some kind of fast knife change system, as always in woodworking the most important thing is a sharp cutting edge, and to be able to change the planer knives in just a few minutes means there's no excuse for not having sharp planer knives all the time.

 

[katellwood]

Sorry if I've confused anyone I don't powerfeed on the planer just the spindle and I agree with the quick change knife systems. My current planer thicknesser is a four knife felder and changing the blades is a five minute operation. the only thing that confuses me is felder only sell them in sets of six when the block takes four, why I will never know??

 

[marcros]

I have spent this evening using the oneway multi gauge to set planer blades. Bearing in mind that this is the first time that I have used it, I can offer a few thoughts.

Steve mentioned that if you put some finish onto a planered surface, it would show up the marks as in the sketchup drawing. When I last set my blades, the surface was that bad you didn't need to- you could see the ripples. I had one knife set level with the outfeed and unbeknown to me, the others were about 10 thou low. This is only a quarter of a mm, so my excuse was that it was very difficult to see. I had used a wooden straight edge. The one way hasn't made it much quicker this evening, but it has allowed me to know exactly what is happening at each blade. IMHO, the gauge was worth very penny of the £85 + p and p. I ran a piece through after setting the blades 3 thou above the outfeed and the machine sings. The wood also shines when it comes off.

I don't doubt it is possible to make magnetic jigs and achieve accuracy and consistency. It is also perfectly possible, with experience to use scrap and achieve results. But, I am happier measuring it. I think next time it will be quicker. At least I know what I am aiming for. I may have tried for too much/unnecessary accuracy but I did discover that I cannot see or feel a single thou blade movement- and I found it difficult without the dial gauge to confirm TDC. This may both be lack of experience, but whatever the cause, both were an issue.

There are no Tersa blade options for my axi planer. There are only the manufacturers blades for it- nobody else does them in that size. When I upgrade- hopefully next year- I will definitely look at this type of system. In the meantime, with this gauge and a wixey angle gauge I can get accurate and repeatable setup of everything on the machine.

For anybody looking at knife setting jigs, although expensive I would give serious thought to this one. The quality of the casting, machining and parts, and the results are excellent. There are many ways to skin a cat- each to his own- but I like this one and will continue to use it.

 

[custard]

the only thing that confuses me is felder only sell them in sets of six when the block takes four, why I will never know??

Just a guess but maybe because there used to be a six knife option on their Format-4 range, which I believe many Format-4 buyers went for. But that's all being phased out now in favour of the spiral cutter blocks which Felder seem to think are the future...actually I agree with them, if I was speccing my machine today I'd probably go the spiral route.

Incidentally, I use the same four knife, quick change Felder block as you. And while knife changes are quick they're still not foolproof, I always check the knife heights with a Oneway Gauge after each changeover, and I'll often find one knife that hasn't seated quite properly and is three or four thou above the others. Having identified it, it only takes a moment to tamp it down with a hardwood block and then it'll register spot on. The way I look at it is that on a two knife block if one knife is proud you're running at 50% of the machine's potential, but on a four knife block having one proud knife means operating at only 25% of the machine's potential! Probably why industrial users are so committed to Tersa blocks or spirals, which are pretty much guaranteed to register correct within a thou without any faffing about.