I have another dumb question and was hoping you guys could set me straight.

If you recall from my earlier post about my fence (I'd link it but I'm too new to include links in posts), I need to cut notches in 1x4s. The notches are to be 3/4" wide by 1.75" deep. My router wasn't doing what I needed it to do so I decided to try a table saw and dado blades.

I've been looking at table saws and was thinking about buying the Makta 2705; the product description says, "The large cutting capacity (3-5/8 inches at 90 degrees . . . can use up to a 6 x 13/16-inch dado blade."

The description for a Freud 6" dado blade (SD-206) says, "This re-sharpenable set will produce grooves from 1/4" to 7/8".
You PM'ed me last night with this same question. Just got home.

First, the Makita says it's a 10" saw -- can I adjust so that a 6" dado blade will protrude enough from the table so as to make 1.75" cuts into wood? Will any 10" table saw (Ridgid 4510, Bosch 4100 -- the other two I'm looking at) have a similar blade-size reduction when a dado blade is used?

Second, if I have this right, the Makita will take a 6" dado blade, but that blade will only make notches up to 7/8" deep? Or does it mean 7/8" wide?

You PM'ed my late last night on this. Sorry I couldn't get to it sooner. Just got home.

The Frued item you mentioned is a stackable dado. It has 2 blades (each 1/8" wide), some chipping blades (Most 1/8" wide and one or two 1/16" wide) and some shims (usually 0.005", 0.010", 0.020", 0.025").

You usually stack the outside blades with the number of chippers inbetween them to get the thickness you need... Such as the 2 x 1/8" blades and 4 x 1/8" chippers would be 3/4". You would add an appropriate shim to that if that was too tight for your joint. On depth, Dados aren't usually very deep. For instance, you're only going 3/8" deep. What I notice between a 6" and 8" dado is that my 8" dado always comes out smoother than the 6" I have.

That model table saw could take up to 13/16 of a stack. That set has more (7/8), which means you just aren't going to use the whole set at once.

*** What you would need additional, that you didn't mention in this post nor in the private message to me- is a blade insert for that model Makita table saw. The original insert is too narrow, as it was made for a single 1/8" blade at 0 to 45 degrees bevel. Standard dado inserts come in 2 sizes, for a 6 inch dado and for aan eight inch dado. The slots are usually wide enough for a 7/8 dado plus room for a 45 degree bevel.

I make my own zero clearance inserts for single blades, blades with dampeners (different offset), dados. That way I don't get any to little tearout. I would not suggest this as someone starting out... And you're not doing cabinets, rather fence boards. But if you get too much tearout, something you can ask about later.

All 10" table saws would cut with a 6" blade to around 1.75"... Not all the lower priced table saws have an arbor long enough to take a 3/4" dado. (I have gone 3/8" on some of those saws.) Lowered price saws would not be able to do a 3/4" wide x 1.75" deep cut at one pass. The motor wouldn't handle that- the cut would have to be done in steps. Besides, that deep with a dado is something you might use on tenon joints, which doesn't apply with what you're doing.

Yes. Makita, Rigid, Dewalt and Bosch... the appropriate models would serve your purpose. As long as you check the spec's as it relates to dados.

Did that help with your questions?

 

Bill,

I don't think you will get more than 1.5 inches deep with a 6 inch dado. The 7/8" measurement is Max width of the dado.

How many of these do you need to cut? If you can describe the project further maybe there is another option

 

Bill, consider building the economy router table top that is a sticky thread in our table mounted routing section. You can clamp this to a bench or on saw horses for use. You will have no problems making the cut you described.

 

@MAFoElffen Thanks, I really appreciate your help. Figured you were @ work or similar; I have some local time pressure hence the forum posting, is all. After reading your advice, I realized that the radius of the blades is partly what was confusing me -- the 6" blade cuts 2" less than max table-saw spec. depth, and 8" cuts 1" less, yes? So I need to get on to the mfgrs. and confirm which models take an 8" dado blade so I can do 1.75" cuts.

Thanks also for the dado insert tip. I can see myself standing in my yard on Saturday evening or Sunday afternoon cursing for not having one!

Mike & @kp91 -- I really can't do it any other way, thanks though. I'm new to power tools and tested the idea with a Bosch 1617 and it worked fine. Then I primed the wood and put 2 coats of paint on it. Now the router binds on the coats of paint and won't do the job I need. I'll know better next time!

 

Check under the hood of the saw. On my Ridgid R4510 (same class of contractor saw) the latch for the riving knife extends into the path of an 8-inch dado when in the latched position and is dangerously loose IMO if not latched. The latch clears a standard blade to the side when the riving knife is secured. This in addition to the lower powered motor are the main reasons contractor saws in this class recommend a 6-inch dado.

GCG

 

How many total pieces?
Drill a 3/4 hole at the bottom of the the notch, cut the sides of the notch with the tablesaw and std blade, clean last bit of waste with chisle or router.

 

how many total pieces?

144

 

Bill, I might also add this...The only dumb question is the one you didn't ask. That's what we're here for.

 

Thanks again, guys.

FWIW;

Makita 2705 will not accept 8" dado blade, max is 6" (confirmed with Makita sales rep via telephone).

Ridgid 4510 ditto Makita (confirmed with Ridgid sales rep via phone).

Bosch 4100 will accept 8" dado blade (confirmed online chat with Bosch rep).

 

Yeah the Bosch has a 4 hp motor but that means more amps and you'll have to take that into account. The Ridgid is rated at 15 amps and would probably bog down at least a little on an 8-inch dado taking a big bite. I didn't check the HP rating of the Makita but would expect it to be the same or close. Check the breakers feeding the outlets you'll be using for the saw.

per the Engineering Toolbox website:

As a "rules of thumb" amps horsepower rating can be estimated as

115 Volts motor - single-phase : 14 amps/hp
230 Volts motor - single-phase : 7 amps/hp
230 Volts motor - 3-phase : 2.5 amps/hp
460 Volts motor - 3-phase : 1.25 amps/hp

That 4 hp motor will not play nice on a 15 or 20 amp breaker under a near full load.

GCG

 

4HP?! You're joking, right? Who has a 4HP tablesaw, other than a full on cabinet shop?
Who can afford one...
Is Bosch playing HP rating games?
Yes, they are.
4100-09 10" Worksite Table Saw with Gravity-Rise
They need to be smacked for this nonsense.
Here's the specs for an honest 3 HP, and 5 HP, saw...
General & General International 10" 3HP Left Tilt Cabin [GEN-650RT50M2M] - $2,799.99 : KMS Tools & Equipment from Vancouver BC, Selling quality tools at affordable prices all over Canada. Largest powertool, handtool and woodworking machinery retailer

 

4hp + table saws,you will see them all the time..

Grizzly.com

==

 

Exactly, Bob! The Bosch saw weighs in at 60lbs. A 4HP motor alone weighs at least 90lbs.
Amazon.com: 4 Hp Electric Motor 3450 RPM 240 Volt: Home Improvement
That particular motor is 15 amps @ 220V!

 

Those sneaky Germans. If you look at the spec's for the 4100 on the Home Depot site THEY have the rated current @ 15A. For a 115VAC single ph. 4hp motor?!? Whaaa?

SPECIFICATIONS

Amperage (amps) 15 A Assembled Depth (in.) 39.5 in
Assembled Height (in.) 29.75 in Assembled Width (in.) 21.5 in
Bench & Stationary Tool Type Table Saw Bench or Stationary Bench
Blade Diameter 10 in Blade Location Left
Blade Speed 3650 RPM Blade guard system Yes
CSA Listed Yes Color Family Blue
Cord Length (ft.) 10 Dust Collection Method 2 in. Dust Port
ETL Listed No Item Package Type Cardboard Container
Manufacturer Warranty 1 Year Maximum Cut Depth @ 45 Deg. 1.875 in
Maximum Cut Depth @ 90 Deg. 3.125 in Maximum Speed (rpm) 3650
No Tool Blade Change No Power Tool Product Type Bench & Stationary
Product Depth (in.) 37.95 in Product Height (in.) 30 in
Product Weight (lb.) 99 Product Width (in.) 20.9 in
Returnable 90-Day Rip Capacity - Left 12 in
Rip Capacity - Right 25 in Table Length (in.) 21
Table Width (in.) 29 UL Listed 1-UL Listed

Fishy.

GCG

 

hi

I have a Craftsman 3 hp table saw and it comes in at 50 lbs/ >>> the key thing it's rated at peak power..

===

 

No. I'm surprised you're defending the practice, Bob! the key thing is the numbers are fraudulent. An honestly rated 2HP motor will pop a 15 AMP breaker if you put any serious load on it, never mind the voltage drop on a 100' 12/3 power cord.
Rating a motor at the amperage it draws on stalling, then converting that back to HP is simply B.S.
I'm deeply disappointed in Bosch; I thought they were better than that.

 

Hi Dan

I don't like but that's the way it is,they all want to sell them and many just look at the HP rating/>>>
I have a belt sander with a real ( Baldor motor) 2HP and it will not pop the 15 amp. breaker and my dust system is a 2HP 110 volt system and the 3 1/2HP router runs on the same line all the time... and it's all plugged into a 15 amp. power bar on top of that...


===

 

I'd be seriously looking at the breaker, Bob.
You run the sander and the D.C. on the same 15AMP breaker at the same time?