Peter Sefton's Open Day - Last Saturday

[Eric The Viking]

Wot 'ee said really.

It was hot, there were enough people round each demo for it to be busy, and personally I didn't want to lug the kit round with me (or be annoying taking pics). The things I probably would have snapped especially were the furniture Peter and students have made (on his web site, I think), and the Hammer spiral cutter block - sad innit? The people would have been pretty much everyone, exhibitors and visitors alike.

I'll be back next year and will deffo take my SLR, if it's still functional by then (it's getting a bit old these days).

E.

 

[Big Gaz]

Picture courtsey of Paul McAnenny a 2012/13 student of Peter Sefton furniture school....

Garry Rowberry (me, in grey T shirt) is talking with a visitor and Paul our resident furniture school assistant and accomplished furniture restorer.

My table is the pentagon in the foreground and Paul McAnenny's table is the circle table.

 

[bugbear]

There's another thing I haven't heard mentioned - the block ought to put far less mechanical stress on the machine components and the motor and might even take less power in use. That's because it's not as percussive as the standard type, and is doing a narrow slicing cut rather than 'chopping' into the stock like the standard arrangement. The instantaneous force required to drive it becomes much less.

It may be of note than lawnmowers ALWAYS use spiral cutters, for at least some of those reasons.

BugBear

 

[Eric The Viking]

Good point - It's so many years since I last pushed one, I'd quite forgotten!

 

[Jelly]

There's another thing I haven't heard mentioned - the block ought to put far less mechanical stress on the machine components and the motor and might even take less power in use. That's because it's not as percussive as the standard type, and is doing a narrow slicing cut rather than 'chopping' into the stock like the standard arrangement. The instantaneous force required to drive it becomes much less.

It may be of note than lawnmowers ALWAYS use spiral cutters, for at least some of those reasons.

BugBear

Aye, Well...

If the felder/hammer blocks are set up like i think they are (i.e. like everyone elses spiral blocks) then you're not actually getting a spiral cutting edge, the edge remains perpendicular to the feed direction, the only real difference to a normal block setup is that you're only cutting a small portion of the full width of cut at any one time; no slicing action at all.



FWIW, (and noting that my experience is with 4 siders) I really don't rate that style of block, you can't joint them and the finish tends to be better using normal ones (20 knives will fit in the same space as 8 rows of spiral cutters after all).

We tend to use them as first bottom and first top (esentially for a roughing cut) as the carbide cutters can go a few days before being turned to the next edge meaning the blocks can stay in place, as opposed to the HSS ones where all the knives need reground every 8-12 hours or so...

Needless to say turning (or worse replacing) 100+ cutters is not a popular task in the toolroom, changing or grinding knives is much quicket.

 

[Eric The Viking]

I had a close look at the Felder/Hammer one: the cutters aren't square-on, quite. It takes a shearing cut with each 'knife' at around 7deg angle. I'm guessing the actual twist - I'm sure the Hammer rep would have told me if I'd asked.

On the big stuff, do you change the knives in situ, or swap the whole block out? I'm guessing the whole block...

What did you mean about jointing, too?

I can see the sense for low-duty-cycle machines (e.g. in a cabinetmaker's shop), as if you nick a blade you don't have to reset the whole machine, also if the stock is often less than the bed width, you only need change out the worn carbide cutters, but I can't see what you'd gain with big production machines. Is there any usage / wear monitoring built into the control system?

E.

 

[Peter Sefton]

Just a couple of photos from Saturday
Our web site guy has added some to the Open Day page http://www.peterseftonfurnitureschool.c ... an-update/
We will be adding a video of the event soon but it is still being worked on.
Cheers Peter