Throat plate required?

[pim42]

Hello,

I'm new to BT3central and woodworking in general. I recently got a 21829 table saw based on the advise from this forum and I'm really enjoying using it.

I bought the Delta 35-530 stacked dado set recently listed in the bargain forum. I'm actually really impressed by the set. The cuts are very clean and precise. I don't have a dado throat plate or a zero clearance throat plate to use with the dado set though. I ran a few test cuts using the dado set without a throat plate. Everything went fine. My questions are: Do I really need a throat plate? What does it buy me? Is it safe to use the saw without a throat plate? So far I'm very happy with the cuts I got without using a throat plate but I want to understand the side effects of using the saw without a the plate.

[gwyneth]

My questions are: Do I really need a throat plate? What does it buy me? Is it safe to use the saw without a throat plate?

People who know more than I do are probably about to give you a better explanation, but here are the answers:

Yes!!!!
Support for the wood up to the blade. Slightly less important for dado blades as the wood is theoretically staying intact, but if something went wrong, it would be very ugly. It buys you safety, precision, and a better quality cut.
No!!!!!

[Garasaki]

Well IMO it depends entirely on the cut you are preforming.

I think if you are performing a "non thru" cut, where the blade is buried in the wood the whole time, you would be ok. Like if you were putting a big sheet of plywood over the blade, say cutting a dado in a cabinet carcass, you could get away without the throat plate (if you really need to).

Or a situation where the wood is supported by somethign else, like if you build a sled you wouldn't need a throat plate (done this before myself).

But for a large majority of cuts, I think the throat plate is necessary for saftey reasons (support of the wood as mentioned before).

Furthermore, you don't GAIN anything by not using the throat plate, so there's really no reason not to use one (or buy one).

[LCHIEN]

I would surely get one.
It supports the wood. THis may not be very important if you are cutting or grooving a lot of 3/4" panels 24" x 24" which will be large and stiff enough to span the 10" long and 4" wide gap without prolems, but certainly as the material gets floppier and smaller at some point there will be problems, you don't want to be finding out what the number is the hard way, just get a proper sized plate if doesn't have to be zero clearance but 1/4 or 1/2" clearance is prefereable to several inches.

What can happen not using one is
cutoffs fall into the saw flying around the spinning blade may be jammed, may get ejected at high speed, etc.
The material will sag in to the hole, leading to deeper than intended cuts or worse, may catch on the trailing edge of the hole making you do dangerous things to get the wood moving again.

[jziegler]

YES!!!!!! You NEED the throat plate for safety.

And, the dado TP isn't good enough for some cuts (ie. small pieces of wood).

With the dado TP, I had a piece of wood thrown back at me when it didn't get enough support. I was following a plan that had me cut pieces of wood to a lenght of about 8-10", and then cut a dado in the edge 1/4" wide x 1/4" deep. There is a big enough gap around the dado blade for that so that the wood can easily fall down and make a real mess of things.

As said before, if you are cutting a large panel, using a sled, etc. then you can get by without one, otherwise use it.

Also, I discovered that for small stacks (like the 1/4" I mentioned) the stock non-dado TP works, just make sure that you check clearance before you run it, YMMV.

Jim

[jackellis]

Don't cut corners when it comes to safety. I friend of mine has run a woodworking school for ten years or so that always has a mix of folks who know what they're doing and beginners who have never used machinery before. He's obsessive about safety and has never had an injury. That should be your goal as well.

I don't know what your day job is but mine would be a lot tougher if I could not use all ten fingers to type.

[mschrank]

Besides the safety benefits, a zero-clearance throat plate will virtually eliminate tearout when making a dado in plywood.

[gwyneth]

After thinking about it for several days, and now that there are answers from more experienced w-workers, I'd add this to my answer:

It's the sort of thing that if you have to ask about it, you shouldn't be doing. It's good to ask, in a theoretical sense, to find out about what it does and how it works, but the difference between this question--"Can I...?"--and "Can it be done?" can be vast.

I don't mind being a beginner; I don't mind being considered a beginner. It's better to look pesky with my questions than asymmetric.

I put a sign on the wall: "Wood is cheaper than machines. Machines are cheaper than hands."

[Pappy]

Go out to your shop, unplug the saw, remove the troat plate, and mount a full stack dado blade set at 3/8" depth. Step back and look at the gapping hole that surrounds the blades. Now, double check that the saw is unpluged and stick you hand in the hole! If the saw were running and your hand was caught by the blade, how far down into the saw would your arm be pulled, and how much flesh and bone would the blades and chippers destroy?

Now go buy or make at least one throat plate for dado cutting!

[gwyneth]

pim42,

Here is a thread that addresses your question and describes a solution.

http://www.bt3central.com/showthread.php?t=27380

[JimD]

I do not know exactly what your throat plate opening consists of but learning to make wooden zero clearance throat plates is something that will benefit your woodworking. They minimize tearout on the underside of your workpiece and are particularly useful when cutting across the grain. The difference when cutting veneered plywood is particularly striking.

If you can make a zero clearance throat plate then you can use a blank one for a dado throat plate. Just raise the dado head slowly through the throat plate. Depending on what it is made of, you may need to apply backing to the throat plate (a good sized hunk of scrap). I use 3/8 laminated flooring for my BT3100 throat plates and they do not need to be backed. I made my first throat plate from a hunk of 2x4 scrap as a test of the BT3100 to rip 3 1/2 inches. I mention this just to say that you can make a throat plate of nearly any kind of scrap you have laying around that is big enough. You do not need anything special.

Smaller openings around blades are safer, as has been noted, and produce better results - also already noted. They are easy to achieve once you get the hang of it.

Jim

[eezlock]

throat plate required?

Most definately, on any cut using a saw no matter what kind or type of cut
being made. The throat plate is a safety factor that should always be in place
to protect the operator. You can take a stock throat plate to use as a
template to make your own throat plate, it will give you a good outline as
to the dimensions needed to start fitting it to the saw. If you make your own,
you can custom fit it around the dado blade at it's highest setting for your
intended cut and it will give all the clearance needed and give the most
protection needed for the operator. eezlock