Will helical cutter heads become the standard?

[transatlantic]

Do you guys think that helical cutter heads will become a standard thing on planers in the next few years or so? or do you think that straight cutters will always be standard on the sub £1k planer/thicknesser combos?

Obviously, no-one can tell what will happen, but what do you predict will happen?

 

[custard]

When Felder introduced their spiral cutter blocks they emphasised just how much complex (read expensive) engineering went into their manufacture. Maybe that was all just tosh, I'm not an engineer so I can't say. But if it's true it suggests that cheaper versions may never appear, or if they did then they may disappoint. Certainly, the spiral cutter blocks for spindle moulders seem to show a "quality gradient", the good ones offer the same benefits as spiral planer blocks, the poor ones just leave witness lines all over the workpiece.

The other thing to bear in mind is that not everyone prefers spiral blocks. The sense I get is that where furniture makers value the superb finish even in figured timbers, joiners aren't happy with the practical restrictions they put on depth of cut.

 

[PAC1]

It is hard to see them being any other than a high end offering in a specialist area. Yes furniture makers using difficult grain will be thankful. It is far harder to see any benefit for the average joiners shop which means it is not worth the expense.
Similarly in sales to the weekend warriors there will be a few who can afford them but far more who wonder what the point is.
Many of us might be far better buying a good drum sander or keep up the ability to sharpen and set a hand plane.
Manufacturers will not fit them as standard unless the demand is there. I am not sure where the demand will come.

 

[transatlantic]

Ah - I didn't know about a depth of cut restriction. I hadn't thought about a quality issue, I was thinking the majority of it would be down to the quality of the blades? but I assume you mean the quality of alignment of each cutter?

They just sound so appealing though.

- easy to replace
- 4 cutting edges
- last a long time (some people say they havent changed in years (hobbyist))
- cleaner finish
- quieter

I was kind of hoping it was one of those things where when they become produced in mass, the price will come down and then they'll be more common. Although maybe that doesn't apply to the hobby market as it is quite small.

 

[Doug71]

I think I remember it being discussed on here in the past and most joinery shops seemed to like the tersa disposable knife system.

I thought the helical cutter heads looked great but when I heard the arguments for the tersa system I remember thinking that is what I will go for on my next planer thicknesser.

 

[MattRoberts]

Whilst I agree that they won't be the standard, I certainly hope more aftermarket spiral block solutions come on the market.

There's an American company making a killing providing spiral blocks for the dewalt lunchbox thicknesser...

 

[transatlantic]

Whilst I agree that they won't be the standard, I certainly hope more aftermarket spiral block solutions come on the market.

There's an American company making a killing providing spiral blocks for the dewalt lunchbox thicknesser...

Yes, it was the Jay Bates video that spawned this thread. The Americans have it so good when it comes to wood working. I want to move.

 

[MattRoberts]

Same here. Imagine being able to buy American black walnut boards from B&Q...

 

[custard]

I'm not an expert on the American woodworking scene, but I have worked there and spent a fair amount of time with American woodworkers, both hobbyist and professional. I get the impression that US timber yards tend to be more locally orientated than British yards. Great if you live in California and want Claro Walnut, or live in Pennsylvania and want Curly Cherry, but otherwise the selection might not be so great. Also the distances there are so unimaginably vast that what we regard as "American" might as well be on the moon if you're in the wrong part of that continental sized country.

Where as if you live in, say Manchester, you're still only two hundred miles away from Capital Crispin and Timberline, you could visit them both in a day and still be home for dinner. I've met plenty of American woodworkers who would regard it as bliss having world class sources like those so close!

And for the woodworker prepared to show some industry and ingenuity Britain is an absolute goldmine for reclaimed CITES listed timbers and antique "breakers", they're available in far greater quantities here than they are there.

Just my view.

 

[johnnyb]

I think cnc machining in Taiwan has really brought these cutterheads down price wise. It's a bit like hss circular saw blades theyve passed out of the marketplace entirely. Not saying this will happen with planers as there nowhere near as common. But benefits are benefits and difficult to not want once experienced. Tersa knives will never go beyond the trade because European machines are not cheap enough to be mainstream. My hope is the finish will plateau at a level then stay like that for ages. It's definitely gotten worse since i swapped the knives. I've run hundreds of metres through though. The dust extraction benefits are still really impressive it must pack double into each bag.
I now reckon if i hone the knives Everytime i swap I'll never have to change them for new. How goods that. But not really the point i guess .

 

[no idea]

Having compared the two when changing the head on my planer thicknesser from the original 3-knife block to a helical head block, I don't think they will become mainstream purely due to the cost of machining the heads.

The standard block is a really simply machining exercise and any inaccuracies in depth of slot, diameter of head etc. can be made up for by correctly positioning the knives on assembly.

The helical head has no in-built adjustability and every insert position must be accurately machined in terms of both position and shape so that the inserts cut correctly and get located correctly on the head. Yes, CNC machining is cheap in relative terms, but the tolerance requirements increase the cost.

 

[doctor Bob]

As a business I prefer tersa blades

 

[johnnyb]

The CNC machining must have a greater cost everything being equal but everything isn't equal. Taiwan manufacturing is advanced and low cost. If they need to make a spiral block to sell a product they will at an appropriate cost. Its a bit like free range eggs if everyone want them the cost plummets because of competition. My guess is stateside is way ahead of us as far as trends go. Byrd shelix have great success selling replacement heads which makes good sense imagine a Sedgwick with a helical head. DeWalt thicknessers are routinely helicalled.

 

[johnnyb]

Tersa is a great system maybe better than helical overall but is a product of European manufacturing and as such destined to be top end.

 

[PAC1]

The advantage of a Teresa block is not the engineering of the block it is:
1. Speed of change of blade. It can sometimes take me as long as 5 minutes to change all three blades.
2. You can swap the blades to achieve different results. For example: hardwood, softwood and even a set for when the wood is reclaimed and you never know what you will find.
3. I sometimes swap to new edge just for the finish cut for a better finish and to avoid tear out.

 

[deema]

CNC machine costs can be the same the world over. A proper dedicated setup involves virtually no operator involvement so there is no real labour cost issues machining anywhere in the world. The only labour required is for the occasional load and unload of the finished parts and to change over the cutters in the sister tooling. Renishaw on tool measuring takes care of accuracy / tip wear.

I can’t see any real difference in the machining costs for any if the head variants, patent issues will run out at some point. Each I would envisage would involve a bar fed lathe to be turned and then probably auto loaded into a milling machine for feature to be added. The machining time will not be significantly different.

Commercially Tersa heads have massive advantages for users. The speed of change over coupled with almost guaranteed safety of them not coming out is almost certain to maintain them in demand.

Going forward however a robotic arm (with driven head and tooling stack) is IMO likely to replace almost all machines found in a commercial shop as prices drop and vision system become more advanced. Laser detectors to ensure that robots don’t move when operators are present now enable robots not to have the usual cages to keep people safe. Prices are such that a robot is as cost effective as a commercial flat bed router.