Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: kagliostro on September 02, 2012, 05:09:22 pm

Title: I need advice about a concave cutter for wood
Post by: kagliostro on September 02, 2012, 05:09:22 pm
I want to buy a concave cutter for wood and use it to mill cabinet borders

do you think 9.5mm radius is the right measure for a concave cutter to be used for that purpose ?

have you any council ?

(http://t3.gstatic.com/images?q=tbn:ANd9GcSJ3fmsR1HWYm4oficUjtj1pwcoSjBvrLeDeboRxw1duba-7s49&t=1)

K
Title: Re: I need advice about a concave cutter for wood
Post by: sluckey on September 02, 2012, 05:41:01 pm
I have three of those bits. 1/4", 3/8", and 1/2". Covers all roundovers I ever needed.
Title: Re: I need advice about a concave cutter for wood
Post by: kagliostro on September 03, 2012, 02:26:00 am
Thanks Sluckey

can you say if one is more frequently used ?

Franco
Title: Re: I need advice about a concave cutter for wood
Post by: G._Hoffman on September 03, 2012, 05:59:56 am
Make a zero clearance base for your router - it makes a world of difference in the quality of the cut.


Gabriel
Title: Re: I need advice about a concave cutter for wood
Post by: sluckey on September 03, 2012, 06:36:59 am
For a variety of woodworking projects, you really need all three. If all you will be doing is rounding over edges of guitar amp cabs, 3/8" is probably what you want. Hopefully some of the cab building guys will speak up.
Title: Re: I need advice about a concave cutter for wood
Post by: kagliostro on September 03, 2012, 06:51:38 am
@ Gabriel

That is a good idea, about that I've found lot of projects on the web

@ Sluckey

3/8 inch = 9.52500 millimeters

so you are confirming what I suppose

Thanks to both friends for answering

K
Title: Re: I need advice about a concave cutter for wood
Post by: Willabe on September 04, 2012, 08:01:30 am
When I use 3/4" stock for a cab I use 3/8" round over bit. So the round over is 1/2 of the total 3/4" stock.


                  Brad     :icon_biggrin:
Title: Re: I need advice about a concave cutter for wood
Post by: kagliostro on September 05, 2012, 05:44:08 am
Thanks also to you Brad

K
Title: Re: I need advice about a concave cutter for wood
Post by: PRR on September 07, 2012, 07:13:59 pm
I also have a 1/4", 3/8", and 1/2" set. Stores here don't like to sell one basic bit, they make you buy 3 for less than the price of 2 good single bits.

I use the 1/4" (~~6mm) to round rough lumber for hand-rails. Feels good. Seems like that's the only bit I use.

I like the idea of 3/8" round-over for 3/4" cabinet... "half". But the only "traditional guitar cabinet" in the house is the low-low-price junker made of 1/4" cardboard; I don't think I would like a 3/8" curve on that.

-AH!- Wait... I did a semi-circle of 3/4" to go over the fire-place, and I see that I did that with the 3/8" cutter.
Title: Re: I need advice about a concave cutter for wood
Post by: kagliostro on September 08, 2012, 12:28:32 pm
Hi PRR

Thanks for your contribute

K
Title: Re: I need advice about a concave cutter for wood
Post by: G._Hoffman on September 09, 2012, 01:05:45 am
I think I've got all the sizes from 1/16" to at least 1/2", by 1/8" increments.  Actually, the one I use the most is the 1/16" bit.  I use it whenever I cut something to break the edges, which keeps me from ripping my hand open on the sharp edges all the time.  You can't do that if it is going to be part of a joint, of course, but whenever possible, it saves a lot of wear and tear on my hands.  Also really great for working with aluminum.


Gabriel
Title: Re: I need advice about a concave cutter for wood
Post by: kagliostro on September 09, 2012, 04:19:30 am
Hi Gabriel

Quote
Actually, the one I use the most is the 1/16" bit.  I use it whenever I cut something to break the edges, which keeps me from ripping my hand open on the sharp edges all the time.


for that purpose I use a less professional tool than your's

like this one with sandpaper

(http://www.laferramentashop.it/img/1267432807110000.jpg)

K
Title: Re: I need advice about a concave cutter for wood
Post by: PRR on September 09, 2012, 11:00:12 pm
There is a thing of bent steel, like a beer-can opener (if you are old enough), with a slot through the bend. You drag it down a wood edge and it cuts a small radius.
Title: Re: I need advice about a concave cutter for wood
Post by: Willabe on September 09, 2012, 11:46:49 pm
PRR, I have a couple of those and they work well IMO. They come in a few small size radius, IIRC.

I have ripped my share of jamb stock for windows/doors/openings/pass throughs... and sometimes/most times that edge is as sharp as a knife. I think this is what Gabriel is referring to. It WILL cut you up pretty good, pretty quick too, but I have found these to work really well for knocking it down quickly.

Also it will help stop that sharp fine 90 deg. corner edge from so easily breaking off and tearing away. + nicer/easier to paint/finish, IMO.  

You can find them at big box stores for not much $$. I'll look through my tools and see if I can find them and post a pic.


            Brad     :icon_biggrin:
Title: Re: I need advice about a concave cutter for wood
Post by: kagliostro on September 09, 2012, 11:56:35 pm
Yes I'm old enough to remember this

(http://t2.gstatic.com/images?q=tbn:ANd9GcSNy-rqGfN5ymGJ7t22OdHmH0E_6lJnEU9ya9jLYW0Ed6Sed_wA)

and also this

(http://t3.gstatic.com/images?q=tbn:ANd9GcQGgVCIFa5WLkj36mhLcPyJ0Qc8T5rir1UmiOPzkzX9_tsDYg-p)

and this

(http://scappi.daonews.com/files/2011/12/lattina-apertura-a-chiavetta.jpg)

the tool you mean I think is similar to this but I' don't remember well as I haven't one

(http://t2.gstatic.com/images?q=tbn:ANd9GcQb8eowCHiWxV5sX_qh8mcbi0DuD965ogg6ovsy11hZkJp6ofqs_w)

K

p.s.:Knowing your motor passion I think this is your favorite Beer Bottle Opener

(http://t0.gstatic.com/images?q=tbn:ANd9GcSwvzjAO_aR2kznfTPP8csAqf8c524ul_aur8Fu0uaYKP_lF-Plug)
Title: Re: I need advice about a concave cutter for wood
Post by: Willabe on September 10, 2012, 12:06:47 am
NO K,     :l3:

For wood not beer.


               Brad      :laugh:
Title: Re: I need advice about a concave cutter for wood
Post by: kagliostro on September 10, 2012, 03:36:28 am
Hi Brad

quote from PRR
Quote
There is a thing of bent steel, like a beer-can opener (if you are old enough)

I was replaying to that  :icon_biggrin:

K
Title: Re: I need advice about a concave cutter for wood
Post by: G._Hoffman on September 10, 2012, 05:06:31 am
There is a thing of bent steel, like a beer-can opener (if you are old enough), with a slot through the bend. You drag it down a wood edge and it cuts a small radius.

Yeah, but that router is set up permanently (and woe to the person who messes with it! :cussing: :cussing: :cussing: :cussing: :cussing: :cussing: :cussing: :cussing: :cussing: :cussing:), and very precisely, so it is a LOT faster than any other tool.  Most of the time, it is already plugged in.  And really, I use it for just about anything that I've ripped, crosscut, jointed, planed, shaped or routed on the over-arm router.  Most of those edges are going to be rounded off even more before I finish it anyway, so a couple extra seconds is worth the effort.  Even with that, I typically have 2-3 bandages on my hands (right now it is only two, but it should be about 8! - I forgot to take the bit out of my CNC spindle while I was working on the dust collector, and even when they aren't spinning, those things are SHARP!!!!), and if I can cut down on that a bit, well, it's a good thing, so to speak.


Gabriel