BT3 throat plates

[reedand]

I've got the Ryobi BT3100 with standard throat plate as well as one that seemed to be the only dado blade plate that Ryobi had to offer. Turns out it's only a 6 1/8" opening -- too small to accomodate my 8" Freud Diablo dado stack. Dumb mistake, but I'm wondering what my solution could be.
Does anyone know about an 8" dado throat plate for the B3100?
And if not that, where can you get blanks that will fit the 3100 so I could try making my own zero clearance throat plates for the various stack widths?
Thanks!
Reed Anderson

[JR]

Reed, are you sure you need the bigger opening? How deep is the dado you want to cut?

I use an 8" dado set and have never found the standard dado throat plate to be a problem.

JR

[LCHIEN]

that's one reason Ryobi suggested a 6" dado for the saw.
There's a bunch of info on dados in the BT3 FAQ (see my sig line).
Might be good reading for you.

[steve-norrell]

Turns out it's only a 6 1/8" opening -- too small to accomodate my 8" Freud Diablo dado stack. Dumb mistake, but I'm wondering what my solution could be.

And if not that, where can you get blanks that will fit the 3100 so I could try making my own zero clearance throat plates for the various stack widths?
Thanks!
Reed Anderson

Its hard to imagine the circumstances that would require a larger opening in the dado throat plate. I use the 6" dado, but how high would you have to raise even the 8" blade to have a problem?

I have made throat plates out of UHMW plastic and several versions of "Sanotec" (which is called something different, like "Sanicell" by others). Ask for the plastic that they use to make cutting boards. The Sanotec is definately better than the UHMW because it does not flex as easily.

Lots of folks have posted information about using baltic birch and other plywoods and hardwoods. Also, some have even used Corion. You should be able to find lots of info on this site.

Good luck, Steve

[reedand]

Thanks for all good (and prompt!) advice. I'll have a try with the 6" throat plate -- I don't think I'll need such depth of cut that the 8" stack won't work. I'l just beginning to get familiar with this (incredible!) site, so I'll do some more reading here and start butchering in the shop. I'm a rank beginner, so all the advice is welcome!
Thanks to all.
Reed

[Gary L]

Hi Reed, When I bought my BT 3000 I purchased a pack of Zero clearance plates, # 4070333.
I have used one of these plates with my Freud Dado set for 3/4" W X 3/8" D dados and I can't imagine when I might need to go much wider or much deeper. I am pretty sure as you get to know and understand your saw and the use of the dado set you will be fine with the 6" plate or the ones I have that are blanks.
Keep an eye out here and on that auction site as I have seen them offered FS.

Gary

[JR]

Reed, I should note that using an 8" dado set is not without complications.

The teeth of the blades will want to slice up the interior of the BT unless you're careful with placement of spacers on the arbor. You have to move the dado set away from the motor to maintain sufficient clearance. It's totally doable, but something you'll want to watch for.

The result is that you can't make a 3/4" stack without to the outside blade resting on the threads of the arbor. This, in turn, may cause an uneven bottom in the dado.

JR

[Black wallnut]

Reed, I should note that using an 8" dado set is not without complications.

The teeth of the blades will want to slice up the interior of the BT unless you're careful with placement of spacers on the arbor. You have to move the dado set away from the motor to maintain sufficient clearance. It's totally doable, but something you'll want to watch for.

The result is that you can't make a 3/4" stack without to the outside blade resting on the threads of the arbor. This, in turn, may cause an uneven bottom in the dado.

JR

YMMV some users have had to remove a small amount of material from a boss in the saw to gain clearance. Yet others have not had any clearance issues what-so-ever with 8" dado sets. You'll have to check yours to see. I'll try to remember later to update this with a picture of the boss that may cause clearance issues. Even if you have to remove a little material for clearance there should be plenty of room otherwise for a full stack while keeping all blades and chippers off the threads of the arbor.

[Kristofor]

For the question about the maximum Dado depth when using an 8" dado in a 6" slot. I think the answer is ~1.35"

(not to scale)

4^2 - 3^2 = 7
7^0.5 = x = ~2.65"
4" - 2.65" = 1.35"

So, it may be an issue if you're half-lapping 12/4 material, but that would cover every need I've had so far.

[Black wallnut]

Left side of picture the boss that interferes with an 8" stack is indicated by the arrow.

[LCHIEN]

Left side of picture the boss that interferes with an 8" stack is indicated by the arrow.

I think there's two approaches. Leave the protrusion alone and leave a 1/4" spacer on the arbor. Or file/cut off the protrusion and you can put the 8" dado on w/o any spacers.

for the first, this will limit you to only about 9/16" dados, not 13/16 max of the stack or risk having uneven dados because the last plate is ont he threaded part of the arbor which is a little smaller and won't keep the plate centered.

For the second, well, yoiu have to cut into your saw.

I've been able to use the standard throat plate with an 8" and make cuts of reasonable depth. Just don't want to cut real deep. But the opening is really huge to the point of being unsafe - you might want to make a custom plate with a smaller opening.