How come nobody's ever manufactured a "skew planer"?

On 1/6/2012 1:52 PM, Steve Turner wrote:
> Yes, it's already been invented:
>
...

That's basically what the helical knives do...

One (out of many)...

<http://www.byrdtool.com/>
<http://www.byrdtool.com/journals.html>

I have seen some with solid curved knives years ago but afaik they've
gone the way of the dodo bird--they're nearly impossible to mount evenly
and are _very_ expensive to fabricate...

--

On 1/6/2012 3:02 PM, dpb wrote:
> On 1/6/2012 1:52 PM, Steve Turner wrote:
>> Yes, it's already been invented:
>>
> ...
>
> That's basically what the helical knives do...
>
> One (out of many)...
>
> <http://www.byrdtool.com/>
> <http://www.byrdtool.com/journals.html>
>
> I have seen some with solid curved knives years ago but afaik they've gone the
> way of the dodo bird--they're nearly impossible to mount evenly and are _very_
> expensive to fabricate...

Yeah, I've never used a planer with a spiral cutter head, but I can see how
they would do a much better job of managing tear-out, which is one of the
things I'd imagined a skewed cutter head would excel at. Do the spiral cutter
heads do anything at all to alleviate snipe? That's another problem that I'd
think a skewed cutter would help to solve.

Of course, having a skewed cutter begs the question of how you combine that
with feed rollers that keep the board moving in a straight line, especially
with my thought of being able to vary the angle of the cutter head...

--
See Nad. See Nad go. Go Nad!
To reply, eat the taco.
http://www.flickr.com/photos/bbqboyee/

On 1/6/2012 4:17 PM, Steve Turner wrote:
...

> spiral cutter heads do anything at all to alleviate snipe? That's
> another problem that I'd think a skewed cutter would help to solve.

Cutterhead itself has nothing really to do with snipe...that's a problem
of the feed rollers set improperly or too much clearance on a bottom
roller for planers that have them.

> Of course, having a skewed cutter begs the question of how you combine
> that with feed rollers that keep the board moving in a straight line,
> especially with my thought of being able to vary the angle of the cutter
> head...

Shouldn't really matter that much...

I should mention one can achieve the effect simply by feeding a board at
an angle--with all the planers I've used (and I will admit I've never
used one of the newer lunchbox or portables or open-frame of modern
popularity, I have now an old Rockwell/Delta Model 13 and have had PM
180s/240s and Delta 18 industrial machines in the past exclusively[+])
they don't really care; the material runs through driven by the feed
rollers past the knives and they really don't affect it's path much at
all. I can imagine in the lighter-weight machines that _might_ not be
true; somebody w/ experience with them can comment on that.

[+] And I've been kicking myself ever since I didn't keep the 180 when
moved back to the farm--thought I'd find the 13 enough. (It is, except
when it would be really really nice to have the extra width for glued up
panels, etc., since there's nobody locally w/ a large
thickness/finishing sander that had access to and got used to before I
wasn't clearly thinking about at the time was paring down...)

--

On 1/6/2012 4:32 PM, dpb wrote:
> On 1/6/2012 4:17 PM, Steve Turner wrote:
> ....
>
>> spiral cutter heads do anything at all to alleviate snipe? That's
>> another problem that I'd think a skewed cutter would help to solve.
>
> Cutterhead itself has nothing really to do with snipe...that's a problem
> of the feed rollers set improperly or too much clearance on a bottom
> roller for planers that have them.

Or not having support on the exit table is another favorite, of course...

--