Thread: Which thicknesser?

Hendo,

About 18 months ago our Men's Shed bought the CT330X that Chief Tiff mentions above. It's tackled red gum, spotted gum, jarrah, merbau and all sorts of unidentifiable stuff. Been a fairly good machine but then I don't have any experience of other benchtops. Only issues have been:

1. We've replaced the ordinary steel spiral cutters with carbide ones.

2. This machine really does need some form of dust collection - not because of the volume of chips (although there are plenty of those). Even if we just let the chips spew out of the side of the machine onto the floor (not my favourite option), without some form of vacuum lots of chips don't get cleared from the cutter area and start to build up leading to reduced cut quality. I also suspect the heat generated from the clogging was a major factor in needing to replace the original cutters early. With some extraction attached it does a pretty good job - but again I can't offer any comparison.

Brian

Originally Posted by DaveVman

Also is the Dewalt in metric?

OK, I am an Imperial bloke as most of you know.
I have a Grizzly jointer / planer (Thicknesser) that was made in an ISO factory in Taiwan. (i.e. A metric factory) Metric threads everywhere.
I have owned a DW-733 and heavily used a DW-735. Both are superb machines. (What I have seen of other thicknessers, I have the impression that they would make better boat anchors than thicknessers.) Both DeWalts have Imperial threads on the thickness adjustment.

On either DeWalt I could easily adjust the thickness to within 1/64 of an inch or almost .4mm AND be accurate every time. On my Grizzly I had to add a digital gauge and I use that to adjust the thickness. Then I still use a vernier caliper to measure thickness to insure accuracy. Frequently I am re-adjusting just that little bit.

Here in lies the really big deal. You would think that an infinitely variable adjustment using either metric or imperial threads would be irrelevant. Well unfortunately it is not irrelevant and it is a very big deal. As I'm working and I need to take another 1/64 off it is 1/8 of a turn. You need to take a half millimeter off. Well that's more than 1/8 of a turn but less than 1/4 turn on the DeWalt. Or in other words, it's not exactly obvious. I run into the same type of problem on my Grizzly, it's not exactly obvious.

My advice is based upon the metric / imperial issue. If you can live with working metric on an imperial machine, find a DW-733 (Two knives) or DW-734 (Three knives) used. Either will serve you well until the funds become available for the DW-735. I had actually considered putting a different cutter head in my 733 before I bought the Grizzly. While the swap out would have been easy, the alignment would have been a nightmare. The cost was almost 1/3 of the Grizzly and the Grizzly had the spherical cutter head.

BTW - It is very simple to build a jig to sharpen knives for either 733 or 734. (They are the same cutter knife.)

I can +1 the Carbatec 13" spiral head. I was looking at the Dewalt 735 as well, but having to buy the unit + outfeed tables was pushing the budget out a bit - that and no one had the tables in stock locally. There is a Hafco unit that is similar to the Carbatec but weighs less and the fit and finish seems to be a bit lower in quality. The Carbatec has done a great job on spotted gum, pine, and vic ash for me. I've still got the original HSS teeth, I'll get carbide when I need a new set, which may be soon - when I get my garage unpacked I need to finish a spotted gum project. I've found the height adjustment easy enough to use and it holds position well. The depth of cut indicator is only at a point in the center of the thicknesser so while still useful, could be better. Snipe can be an issue, but it'll be an issue on all 'lunchbox' thicknessers. Easy enough to work around if you plan for it.

Originally Posted by Chief Tiff

Have a look at this one; Carbatec TH-BX330P
...
This isn't a true spiral or helical head...

What makes it not a spiral or helical head?
For that matter, isn't 'spiral' just another (albeit incorrect) name for helical?

(Not being a smartarse - just seeking to learn.)

Hendo.

In the spiral the cutters are mounted at an angle so they slice the timber in the other they are helically mounted square to the timber so they tend to gouge the timber.

The first one is quieter and produces less of a scallop effect but the cutters have to be sharpened on a curve to optimise performance.

A true helical head has the cutters mounted along a curved helix; a bit like the fluted on a drill bit. This gives a shearing cut that slices into the wood.

This model has its cutters mounted in straight lines; albeit staggered so as the head is rotating several cutters hit the wood at the same time and in the same plane but apart from each other. This gives a chopping cut, but in a small area and as the head rotates another set of cutters then hit the wood; and so on. If you watch it in slow motion you see the cut advancing across the timber width but each cutter is hitting the wood as a dead square chopping cut.

The shearing cut from a helical head copes much better on cranky grain; but these are very expensive.

Well, now I'm thoroughly confused.

Originally Posted by Bohdan

In the spiral the cutters are mounted at an angle so they slice the timber in the other they are helically mounted square to the timber so they tend to gouge the timber.
The first one is quieter and produces less of a scallop effect but the cutters have to be sharpened on a curve to optimise performance.

Originally Posted by Chief Tiff

A true helical head has the cutters mounted along a curved helix; a bit like the fluted on a drill bit. This gives a shearing cut that slices into the wood.

If I'm reading these right, Chief & Bohdan seem to be contradicting each other.

I asked this question of another well-regarded maker on YouTube & he said "... all heads that are a constant diameter are a helical head. I have never seen a spiral head in my life as a spiral increases in diameter. A helix remains constant in diameter whilst it has a rotating configuration." (This is correct in geometric terms - but maybe the term is applied differently when speaking of these machines?)

I've attached two pics - one with the cutting edges parallel to the axis of rotation, & another with the cutters oblique to the axis.
Please confirm for me which is which. (Again, in geometric terms these are both helical in design, but which one is generally called 'spiral'?)
Parallel cutters.pngOblique cutters.jpg

Thanks again,

Hendo.

Both cutters are helical in design but the head where the cutters are at an angle are the ones that are normally referred to as spiral.

We are getting into semantics here and because there is no definitive definition you have to read the advertising blurb very carefully to determine what is actually being sold.

The picture on the left is a spiral head as the cutters are mounted on a helix but the cutters are mounted parallel to the head axis and they enter the cut in a chopping motion.

The head on the right is a helical head as the cutters are mounted in a helix and aligned with the flutes so they enter the cut in a shearing motion.

This the head on the CT330X:




As you can see the cutters are held along a straight plane, but each revolution brings them in a different position along the width. They advertise it as a spiral head because the cutters still enter the wood in different positions along the width but not as elegantly as a "true" spiral head because you have considerably less cutters overall. My personal view is that this is more of a segmented head and nothing more. Still; for the price it works very well; better than all but the most expensive straight bladed heads.

Here is a link to a discussion on the same subject on fine woodworking .com, click here

Bohdan is absolutely correct in his statement that this really boils down to semantics and you should examine the goods to determine which blade layout you are buying; in order of superior finish they are: 1. helical, 2. spiral, then 3. segmented using my interpretation of the terminology.

My understanding of helical vs spiral is the same as Chief Tiff's as to which is which.
i tend to disagree with the overall conclusions of everyone though, because while helical is better then spiral is better then straight knives when all are equally sharp, I also know that a sharp straight knife is better then a blunt helical. So I like Tersa, and I suspect my thicknessers see more timber a week then most here handle a year. It's about horses for courses.

And I agree it's mostly irrelevant. Buy what you can afford, get a spare set of straight knives and change them when they get moderately blunt then get them sharpened as opposed to running them to dead blunt and tossing them.
You can buy an awful lot of sandpaper for the price of a helical head, and fitting a helical head to a tabletop planer is like sticking a Ferrari engine in a Hyundai Getz IMHO. Somehow we all managed before these upgrades were available, and while they're nice to have it's not essential

As others have said, don't get hung up on the words because the retailer's descriptions are confusing and misleading. Of the two pictures, the style on the right is superior to the one on the left (because of the shearing action) so that's what one would prefer. Of course, it's much more expensive than units like the CT330X which work like the picture on the left.

I had previously owned a Carbatec benchtop thicknesser which they no longer stock but which is basically the same as the Jet 12 inch benchtop. My thoughts on this are:
- snipe is a bit of an issue, but you can overcome that by just making boards slightly longer than you need
- Seriously loud
- Could only handle taking off a tiny shaving at a time (nothing like the advertised max 3mm).
- I had some trouble with the circuit breaker tripping when under very small load. I took it back to Carbatec who sent it away to be checked. They said it there was nothing wrong, it's just tripping because I'm overloading it. But sometimes it would trip and then would refuse to start even the next day. Anyway, I bought a replacement breaker and changed it myself - problem solved.
- Decent finish until you nick the blade. Then it's seriously expensive to replace. I made a little jig to sharpen blades myself, but it was really only good for honing, not removing a nick from the blade.

I got frustrated with the unit and eventually replaced it with H&F's version of the CT330X. My comments on this unit are:
- quieter, but still loud enough that I don't like to use it in the evenings.
- Can't be used without a dust extractor, although I wouldn't anyway.
- still some snipe issues, but I'm not too fussed.
- Can maybe take off slightly more at a time than the straight blade model, but still not much. Perhaps I just need to learn to be more patient.
- I get some ridges on the board when I run it through. This only happened after the first time I rotated the cutters. I then replaced them all with carbide ones from SJE. Seemed to fix the issue at first, but I'm starting to get a problem again. Not a massive issue as I can just sand them out, but rather annoying. Perhaps there is some dirt lodged in behind some of the cutters making them sit slightly out of place. I need to get hold of an air compressor to give them a good clean out.

To me the most significant advantage of the CT330X (or similar) over the simple straight blade model is the economy of just replacing (or rotating) the damaged/blunted cutter rather than the whole blade.

How does the noise from the CT330X compare to the dewalt with the standard three-blade cutter?

I'm looking at both of these options as I might be able to pick up a new Dewalt for the same price as the CT330X.

check out the sale section someone had a thicknesser with true spiral head for $600 can't go wrong at this price

I own the CT and it has performed well330x there is an issue with very faint tracking marks that are easily removed but shouldnt occur,i made a lot of laminated serving/ breadboard
/ kitchen boards which used the full width , generally little tearout and some of the timber was tough old cranky HW. Im able to carry the machine to an outside location and i dont use any dust extraction, reading these posts i realise that maybe i should , what would your recommendations be for the smallest unit possibly portable that would do the job. i Have the Aldi shop vac but only use it to blow the chips and dust away and blow out the cutters, thanks , Ross