helical cutter thicknessers

[scuffle]

Gday everyone,

Im in the market for a thicknesser (first one!) and I came across this one.
http://www.machineryhouse.com.au/W815

Main reason I was interested is because it has helical cutters opposed to straight blade cutters. I have heard great things about them but they are mostly from people that have been paid to do a good review Does anyone here have any real world experience with helical cutters in thicknessers? Any issues?

I guess i mostly want it for running figured woods through it as i dont have a drum sander. Apparently it doesnt tear the figuring like regular blades can.
I can get it for about $500 (through a friends staff discount) which seems like a pretty good deal

[Allen]

We have the jointer and thicknesser set up with helical cutter heads at the Cairns Woodworkers Guild. Both are large Carbatec units. Lots of cast iron and no vibration to speak of. Came with straight cutters that we retrofitted heads to several years afterwards.

They certainly give a better finish on most woods, and if you were using yourself rather than a club situation, then they should last a very long time before you will need to completely change the cutters.

I can't say I've tried putting anything really hard and figured through them, so can't say if they'd do what you're looking for as for finish.

[auscab]

Its a strange looking head for a helical . It's a bit hard to see what it is , not anything like the normal type Ive seen . I don't ,run any but have been checking them out for a while.

here are links to the real deal , with some good reading.

http://www.holbren.com/spiral-cutterhead/

http://www.byrdtool.com/

http://helixhead.com/

[scuffle]

yeh i dont think its a "spiral" cutter head like your thinking. it uses the same little cutting bits (dont know what to call them) but they are set out in a different fashion. I just watched a video about a thicknesser with the same type of cutter.
https://www.youtube.com/watch?v=C8JKQzPxZ2E
After watching this video i still have no idea if there are any benefits.

[auscab]

Yeah , that's not a Helical cutter . With none of the benefits of a Helical. It may be a quieter cut and that's all that would be different I would think.

[scuffle]

why would it be so much different do a helical cutter (im assuming you mean spiral cutter)? Its still staggered cutting bits so wouldn't it do the same job?

[curly]

We run a helical cutter Hammer/Felder buzzer thicknesser alongside several older straight blade type machines .
The quality of the finish is definitely superior though it's no cure all in figured woods . We use it as a preference on all cranky woods , though the older technology works perfectly well providing the blades are kept properly sharp and the feed speeds are slowed down . Like most poor cutting issues , sharp is the real key .
The helical machine is also significantly quieter though that's a bit hard to quantifty because the felder is spanking new and the others go back decades .
One of the things we most like with the individual cutters is that when a blade is nicked as is inevitable you simple release the grub screw , spin it 90 and lock it back down . The adjacent cutters which were not affected don't need to be touched , unlike the old technology where the knifes come right out for sharpening or replacement . That is a proper improvement on down time .

On getting the new machine I decided I'd best see what it was and wasn't capable of to plan our work around it . One of the sillier things I tried , which provided us with a pretty clear example of what not to do , was run some miss sawn sides material through it . Bandsaw wobbles on the big horizontal bandsaw had thrown some slices in fairly rough Qld Maple that went out to 7mm from the 4mm rough size they were meant to be . First pass at 5.5 mm was not too bad , acceptable anyways . Next pass at 4mm however converted thicknesser into woodchipper as the board exploded up the dust chute . Gone .
Other tests like running Gidgee and Supplejack fingerboards through it down to a half mm oversize worked perfectly with straight grained stock , and just as would be expected , a small amount of tearout on high curl stock which means staying a good mm over to be eaten by the sander .
I reckon the future is definitely with helical .
Pete

[jeffhigh]

Seems to still have High speed steel blades rather than the carbide on most helicals

[J.F. Custom]

Pete has pretty much covered it all in the above post so far as to the "why" or "pros" of helical cutter heads, so I won't double up.

As a side note however, I would caution you about comparing it to a thickness sander (or the lack thereof) for figured timber. Though the helical heads are advantageous to finishing figured material over a standard blade setup, I would not consider it for back and side thickness material, as Pete also alluded to.

These are two different machines, that cross over a little. A thicknesser is just that - it is designed to remove quantity of timber to your desired thickness in relatively rapid fashion. They work best with thicker, longer stock material of non figured stock. Another name for a thickness/drum sander is 'finish sander' and realistically, this is what they are designed for.

You don't want to be trying to reduce an 8mm board to 2.4mm for a side unless you have plenty of time to burn and are prepared to clean your paper religiously on a drum sander. By the same token, you don't want to use your thicknesser to attempt to take figured material down to 2.4mm at all. Not "impossible", but the risk is very high of irreparable tear out or shattering the piece, thereby ruining it. Ultimately you won't 'ruin' a piece through a thickness sander, though burning it is a consideration.

I had a thicknesser and it was useful for electric bodies etc, but due to very limited space and disuse, I sold it. I found that the combination of a well set up bandsaw and a drum sander proved much more useful for luthierie purposes, having first resawn to near dimensions then just finished on the sander. If you have the space, both would cover all bases but if I had to choose one over the other, for our purposes I'd go the sander every time.

Oh and with that particular setup, you are not getting the benefits of the 'shear' cutting action of the helical heads, which account for a lot of the benefits. On that machine, about the only advantage over standard blades is the opportunity to rotate a cutter should one get a nick in it.

Jeremy.

[scuffle]

great tips guys!
Jeremy:
I absolutely would never considering running back and sides through it i know it would never replace a thickness sander but as I build solid body electrics I dont find myself working with wood that thin anyway. I would LOVE one but they are not as necessary for electric builds (IMHO) also I cannot afford a drum sander. I have to buy a bandsaw before that
If i was building more acoustics i might ssave my pocket money for a drum sander but I cant see myself building that many.

i would be using it for (as it is made for) thicknessing stock. I figure if it gives a better finish than straight blades and then I am in the lead. If it is neater on figured woods im further in the lead As for quite operation that doesnt worry me. I already have a minor case if tinnitus so I ALWAYS wear hearing protection.

[Kim]

If your main interest is instrument making and you don't currently have a drum sander then IMHO 'that' should probably be your priority....I say this because in lutherie and many other pursuits, you will find endless uses for a drum sander. Probably not so much a thicknesser, nice to have and all but if the board has been properly resawn, then the results should be closer to finished size than would be necessary to justify such a machine.

Cheers

Kim

[auscab]

why would it be so much different do a helical cutter (im assuming you mean spiral cutter)? Its still staggered cutting bits so wouldn't it do the same job?

It looks to me that the blades come down and contact the timber the same way a long blade does . its just that they are smaller and stepped back from each other, so smaller bites spread out . I don't see anything helical about that head . helical / spiral , there is a difference but for what we are talking about its the same.

There are heads that have long runs of blades that look like they hit the wood the same as your one, and the blades are arranged in a helix , and these are called helical heads . but their not doing the helical cut.

From what I know, with one type, the blades can be ground straight but seated to give a helix type cut .
With the good ones the blades are ground with a curve and are seated at the right angle . the little shavings come off in a spiral form, from what I'm told.

[scuffle]

i appreciate that kim but i dont feel like a drum sander would be very efficient at milling rough lumber to the right size. I sometimes need to be taking off 5mm to 10mm to get to the right thickness.

[Kamusur]

Scuffle, I dressed a piece of Cassia, bark and all this afternoon on an old combination Casadei machine retrofitted with a spiral or if you will helical head this arvo. Now the good, the bad and the ugly truth .

Good..They really are that much quieter than 2 or 3 blade heads. You could have a conversation without hearing protection whilst passing a log across the heads- but don't. They are also quieter in startup mode and my suspicion is that the air is always continually funnelled out more efficiently from the coiled channels next to each row of cutter heads. the cutting heads are square so you get 4 changes of fresh blades. You could change just one cutting head if the all the edges were damaged.

Bad..The head was custom made and cost the best part of $2ks and took 10 months to get here. Warning, don't order from an agent go straight to the maker and cut out the middleman so you save bucks and it gets here quicker.

Ugly..Like straight knived heads they do leave some marks its just that they are different in patternation from their noisy cousins. As referred to previously its still about sharpness of the blade that will give quality finish. Straight or heli any timber that explodes when you are making a pass is a sphincter tightening moment to be avoided at all costs, i can promise the noise gets your attention like no other epiphany.

Like Kim said (as so much of our supply is already processed) if you can only afford 1 machine go the sander route, Like you said if you are processing timber/slabs n logs etc you'll need a combo $$? probably 3 phase $$?...

Steve

[rocket]

I don't have a thicknesser or a jointer [the powered type that is] if i had to choose out of those two i'd go the jointer with spiral head, as far as milling stuff down to size i simply stick it through the bandsaw and get it a mil or so oversize and then chuck it through the drum sander,,, hey presto, size!!
I'd love to have the room for all the machinery in the catalogue but sadly i just haven't, so i just use a bit more elbow grease .
Rod.

[scuffle]

hey rod im the same I have a jointer but everything else is done the old fashioned way. I figure i have a few ways to cut the body out (handsaw, coping saw, jigsaw etc.) but i have no way of thicknessing stock...hence why i want a thicknesser

[demonx]

I have a thicknesser and two drum sanders

For guitar building the thicknesser rarely gets used now that I have a good bandsaw.

For non guitar woodworking the thicknesser gets used often, for example I had to make eighteen plinth blocks for a skirting & architrave job I'm doing. The thicknesser came in very handy.

Straight vs spiral cutters - I have straight but wish I had spiral, however the drum sander/bandsaw method means I don't need the spiral cutters anyway.