"the_dawggie" <the_dawggie@[EMAIL PROTECTED]
> wrote in message
news:4f50dd00-f011-4ffa-8a56-5cf19d9b8ba3@[EMAIL PROTECTED]
> On May 11, 6:36 pm, "Trevor Wilson"
> <trevor@[EMAIL PROTECTED]
> wrote:
>> "the_dawggie" <the_dawg...@[EMAIL PROTECTED]
> wrote in message
>>
>>
news:03bf65f4-4893-42b1-8383-d2e923cb526c@[EMAIL PROTECTED]
>>
>>
>>
>> > On May 11, 5:02 pm, "Trevor Wilson"
>> > <trevor@[EMAIL PROTECTED]
> wrote:
>> >> I had to cut some 8mm steel yesterday and today. I dusted off my
>> >> trusty
>> >> 9"
>> >> angle grinder and set to work. I wore out one wheel (Flexovit)and
the
>> >> only
>> >> one I had available was an 8" Flexovit (Aussie made). I wore it out
in
>> >> short
>> >> order. It's cutting performance was what I would term
"satisfactory".
>> >> About
>> >> 2cm/minute (best guess). I toddled off to Bunnings this afternoon to
>> >> buy
>> >> some more wheels. Unfortunately, the Flexovit wheels had the wrong
>> >> size
>> >> mounting hole, so I purchased a 5 pack of Trojan (Chinese made)
>> >> branded
>> >> wheels. Hopeless cutting performance. I mean, REALLY BAD. It took
>> >> about 5
>> >> minutes to cut 2cm. The wheel didn't wear down and faster or slower
>> >> than
>> >> the
>> >> Flexovit. It just hardly cut the metal at all.
>>
>> >> What gives?
>>
>> >> The technology is hardly state of the art. All wheels are rated for
>> >> ferrous
>> >> metal cutting. Since most of my cutting is done with a 4" grinder,
>> >> this
>> >> is
>> >> not something I've experienced before. I've not experienced this
sort
>> >> of
>> >> poor performance when cutting concrete, bricks and stone. Are all
>> >> these
>> >> Chinese wheels bad, or did I get a bad batch?
>>
>> >> The Torjans are going back on Monday. I doubt that I'll buy them
>> >> again.
>>
>> > I've used a GMC drop saw with the appropriate very large
>> > discs and the kit to line stuff up - they tend to work.
>>
>> > Angle grinder is for a different purpose, sure can use it,
>> > however you would need to get the cut perfect. The metal
>> > cutting drop saw is essential for getting welds right.
>>
>> **I appreciate that. However, the cuts are not critical. I just need
>> clearance for the job. +/- a couple of cms is fine. Cosmetics don't
>> matter,
>> since it will be covered anyway.
>
> Structural strength might.
**Not so much. I'm cladding 4" X 3" bearers on three sides with 8mm steel
(using an 'L' beam and a flat bar). I need to eliminate one row of piers,
so
the span will be 3600mm, rather than 1800mm. Deflection under static and
dynamic load is less than 1mm at the centre (measured with lasers). Design
standards allow for 10mm deflection. My builder mate tells me to aim for
3mm
deflection. According to my calculations, I could have used 4mm steel and
still gotten excellent results. A builder mate popped in yesterday to take
a
look and was happy with the work. "Way overkill" were his words. Suits me.
I
need to cut the steel on the last two pieces, because the fabricator got
the
measurements wrong (well, he just used what he had lying around and
figured
it would be OK). Instead of a 'L' piece measuring 95mm X 95mm, he gave me
two pieces the correct size and two measuring 95mm X 125mm. I either have
to
cut notches in the joists, cut the extra 30mm along the 3600 length, or
cut
some notches in the steel. I figured that cutting the notches in the steel
would be the easiest, most structurally sound solution. I'm leaving most
of
the steel in place and just cutting notches for the joists.
It's all for my new workshop. It'll give me a total of 74 sq Metres of
workshop space.
Trevor Wilson
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