Lots of older (large/pro) tale saws needed DC brakes fitting to them to meet regs, even without a dado set. Inverters can do all that now.
AIUI since the HSE banned the use of dadoes, they did it by specifying the max length of arbor on new table saws on sale - not by banning the sale of dadoes.
You need to consider how the thing is loaded and what you are nothing. If you notch the top of a joist, and then fill it with a tight fitting cross member, you will not lose much strength.
+1
Did they actually ban dado sets though? or just specify a maximum stop time?
Does not seem to be a problem on my 1948 Unisaw ;-)
Did admit to being tempted with the large number of Wadkin saws on ebay ... incl the tilting table versions
I suppose you're still allowed to fit wobble washers. I've made my own in the past if I wanted a specific groove size. 47 mm is pushing it though!
Industrial woodworking machines have a maximum time for the blade to come to rest, and this applied retrospectively, hence many machines with DC braking retrofitted.
I think dadoes were also banned in industry (i.e. you had to discontinue using them), *and* a maximum length of arbor specified for all new machines sold.
I bought an old 3 phase Startrite bandsaw and fitted an inverter to run it off single phase. When I have a suitable location there'll be a Wadkin or similar mahoosive old-british table saw too.
I'm not sure maximum permitted stopping time improves safety that much on table saws.
As they say - it's stopped when you can count the teeth.
I think the problem was more spindle moulders (along with high background noise environments), where it isn't so difficult to put fingers into a more-or-less-invisible rotating cutter.
I'm surprised Elfin Safley has not tried to do something about Routers ...... hell of a speed, and no guard what so ever.
+2
Kerfing out is a good solution.
You may be able to buy dado sets, but you would find it hard to buy a table saw that they will fit.
"the blade must come to a standstill within 10 seconds of the machine being stopped".
Is the problem, the extra weight of a dado set causes it to over run.
Kerfing - that's the word I was looking for :-)
All traditional woodworking joints significantly weaken the wood due to the amount of timber that has to be cut away. Mortice/bridle/halving joints are the very worst for this. Dovetails are only slightly better. Gang/plate nails, hangers, timber connectors are a minimum of 50% stronger (in some cases 1000% stronger) and are faster to use. In most cases the joint is far stronger than the timber. Loads are better distributed in the timber hence the joints are much less likey to fail. There are other advantages too, eg joists need no longer penetrate the inner leaf making the house draught proof and protecting the timber from damp. In practice much less timber is needed hence the job is cheaper as well as quicker. They also lend themselves to machine shop assembly of factory made components (eg trusses) They just look like shit but where they are hidden, it matters not.
Anybody that doen't know this needs to get some education/training.
Yup I was aware of the time limitation, and also the short arbour problem. Just not sure if there was actually an industrial ban on dadoes as such. They don't strike me as particularly dangerous (compared to wobble blades say).
Not a problem with active braking on the saw though. Even my 12" SCMS has that to stop it in ten secs.
I think the HSE wanted to stop the practice of "dropping on" to form closed cuts.
I'm sure I've read all this in HSE information leaflets, but my memory of them is hazy.
Bollox again. If the joints are glued as the OP stated, the joints will be stronger than the timber.
Bollox. They are used because they are quick & require no great skill.
Education & training? Get some.
I have qualifications in woodwork and mechanical engineering thanks.
This stuff is all well known. Has been for years.
Have a read at this and start your education.
Yes I had a read of that and could find no mention of superiority of metal brackets to traditional joints. It appears to confirm that the main advantage of this jointing system is ease of use on and off site.
While their load bearing capacity may be adequate in one plain their ability to resist twist or stress in the non designed for planes would be less than the glued cross halving joint under discussion.
To me they always looked like a cheap alternative to doing the job right especially as the report raises concerns with incorrect site practices, (i.e.) using plaster board nails or not using enough nails
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