Incra IBox -- Finger Joint Made Easy

[ChuckM]

Incra has a good reputation for precision and quality products, though I had no prior experience with any of them. I received as a gift a rarely used IBOX a couple months ago, and finally I found time today to try it. The instructions including the DVD are done well, though some areas can be improved for better clarity.

The jig is well built, and the first finger joint project of two sample boxes turned out really fine (shown as dry fit):

[attachimg=1]

I didn't like the dust spilling out from the opening on the back guard, so I duct-taped a dust shroud, which was connected to the SawStop's overarm dust collection tube.

[attachimg=2]

The essential parts to be installed to the saw before the IBox could be used:

[attachimg=3]

Last time I used finger joinery it was in 2010, made with a shop-made finger joint jig on a Ridgid contractor saw.

 

[jbarr]

Yes, the Incra I box is really good but not perfect. I found that if the fingers are 0.006" smaller than the slots then I do get perfect joints each time with the right gap for glue but I have to do this by trial and error using the micro adjust as the Ibox doesn't necessarily get me to the right spot. I followed this web site ....https://www.lumberjocks.com/threads...pass-a-foolproof-method.351121/#post-2264046. and I now get great results. Bottom line .... don't trust the automatic adjustments but you can start with them. I also use Freud's box joint blades which do a great job.

I hope this helps
John

 

[ChuckM]

Thanks, John, so much for the LJ's link. The use of a caliper  to check the finger against the notch makes good sense as it gives a definitive answer on whether the silver screw should be turned clockwise or counterclockwise.

 

[4nthony]

I got one last year but unfortunately it hasn't seem much use after my initial testing.

Mark Mueller from INCRA has a few videos on his YouTube channel on tuning the iBox jig.

=175s

 

[luvmytoolz]

That's a brilliant link thanks John!

 

[ChuckM]

snip.

Mark Mueller from INCRA has a few videos on his YouTube channel on tuning the iBox jig.


snip.

In his video, he turned the silver knob without holding the red knob, not the way that is given in the user manual. I wonder if that matters.

Setting up the dado stack takes a bit of work because of the finger-saving feature (which also requires checking/setting the cartridge distance), so next time, I'll try to find and use a flat grind 1/8" sawblade. Any source for a cheap flat grind/flat top full kerf blade out there for experimentation?  (My Mastercraft dado set from Canadian Tire cost me only $50 Cdn more than a decade ago.)

 

[jbarr]

In his video, he turned the silver knob without holding the red knob, not the way that is given in the user manual. I wonder if that matters.

I noticed that too but the red knob didn't turn when he turned the silver knob. That won't always happen. I would definitely follow the manual and hold the red knob while turning the silver

If you do a lot of these, as I do, I highly recommend the Freud box joint blades which give 1/4" and 3/8" cuts.

 

[ChuckM]

I did come across a Forrest flat grind blade set when looking for an economical flat top blade. I found a cheapo from a local vendor that has the right price, but unfortunately it's thin kerf:

[attachimg=1]

 

[ChuckM]

Snip.

If you do a lot of these, as I do, I highly recommend the Freud box joint blades which give 1/4" and 3/8" cuts.

Thanks for your suggestion. I'll consider this if I decide to make full use of the IBox (the Freud set has the anti-kickback design, not suitable for the SawStop):
https://www.amazon.ca/Oshlun-SBJ-08...7308368206&hydadcr=25614_9772717&keywords=box+joint+blade+set&qid=1681130356&sr=8-2

 

[jbarr]

According to my local woodwork supplier who sell Sawstop, these are fine. I asked that very question when I was in their store. In fact they showed me the Freud dado set that is marked as Sawstop compatible compared to the Ibox set and the difference in design was negligible in terms of how fast the brake would activate. I guess Sawstop are the only ones who can truly answer that question but I'm comfortable using that set with my Sawstop

 

[ChuckM]

SawStop has posted the answers to various questions regarding blades on its web site under FAQ. Both thin kerf blades and anti-kickback blades, among others, are not recommended:

"Further, blades with depth-limiting shoulders may take longer to stop in the event of an accident than standard blades, and you could receive a more serious injury. Therefore, SawStop recommends using blades without depth-limiting shoulders."
https://www.sawstop.com/why-sawstop/faqs/

I've seen many YouTubers using their SawStop with or recommending the Freud regular ripping blades that have the anti-kickback design, not realizing the official advice by SawStop.

 

[jbarr]

Fair enough! I can see your point.

I can always use my Dewalt dado set for box joints as it is recommended by Sawstop or go into bypass mode but I see minimum risk given the obvious blade path and where you grip the jig so I'll stick with the Freud set but all other cuts will be with recommended blades

 

[ChuckM]

Thanks to Jbarr's heads-up about the box joint blade set, I pulled the trigger for something similar:

[attachimg=1]

Incra Ibox jig: Free

Box joint blade: $120 Cdn

Finger Joint projects to be attempted: Priceless

 

[ChuckM]

Thanks to Jbarr's heads-up about the box joint blade set, I pulled the trigger for something similar:

[attachimg=1]

Incra Ibox jig: Free

Box joint blade: $120 Cdn

Finger Joint projects to be attempted: Priceless

First finger joint project completed: Tools trays (to replace plastic ones)

[attachimg=1]                [attachimg=2]

 

[jbarr]

Are they suitable for Sawstop Chuck?

John

 

[ChuckM]

John,

Are you referring to the Oshlun box joint blade set? I think so as it doesn't have the anti-kick back feature. But I still have to use the zci sold for the dado stack as well as the dado cartridge because the regular cartridge isn't wide enough.

 

[jbarr]

John,

Are you referring to the Oshlun box joint blade set? I think so as it doesn't have the anti-kick back feature. But I still have to use the zci sold for the dado stack as well as the dado cartridge because the regular cartridge isn't wide enough.

Yes the Oshlun's.

I always assumed you would change cartridge and throat plate.

 

[Crazyraceguy]

John,

Are you referring to the Oshlun box joint blade set? I think so as it doesn't have the anti-kick back feature. But I still have to use the zci sold for the dado stack as well as the dado cartridge because the regular cartridge isn't wide enough.

It's not really about width as much as it is diameter. The adjustment travel of the cartridge is pretty limited.
I have even seen 10" blades that are too small to allow the machine to function. If the cartridge is not close enough to the blade, the red flashing light will never go out.

As far as the depth limiting teeth being a problem, I'm sure it's a CYA thing for SawStop, same as thin-kerf. The cartridge will definitely stop them....and even if there was a micro-second of delay, the blade has already dropped below the table.
Over the last 10 years, we have had six of these machines, always at least 2 at a time. The current pair have literally been abused. One of them has been set-off so many times that I raised that question with their customer service guy. "Is there a limit to how many times this can occur without damage to the machine?" I was concerned with the cartridge mounting points and mechanism. He said "We haven't found that point yet"

 

[ChuckM]

I forgot to take a pic (may be next time). With the box joint blade installed, the standard cartridge covered only part of the blade, not its whole width. The diameter was fine.

About the anti-kick and thin-kerf advice, I follow it to a T as I think the manufacturer knows about its products and safety performance better than I.

 

[Crazyraceguy]

The blade in that pic definitely says 8", the standard cartridge would never work with it, nor would a dado cartridge work with a 10" blade.
The contact pad that fires into the blade is pretty wide (in comparison to the blade)
I don't have one right here in front of me, but it has to be close to 1/2"? and I've never seen one hit anywhere but dead in the middle of it.
Is your set one of those reversible ones that does 1/4" and 3/8"?