Router Table Box/Finger joint jig

[Moonsafari69]

Can anyone recommend a 'good' Box/Finger joint jig that they've used on a router table?

I've looked at the Incra I-Box and Rockler thus far, but before I make the call I'd like to hear some advice that's been tried and tested. I have a Kreg table if that helps any.

Or, if you think a shop made jig is better let me know.

Cheers.

 

[Glynne]

I've not used one (don't like finger joints) but Steve Maskery of this forum has a home made one on YouTube. Given that his DVDs on Bandsaws & Tablesaws are well thought of, you might want to have a look before you part with any cash.

 

[Moonsafari69]

Thanks for that Glynne, much appreciated. The video of the build on YouTube looks good but I see the DVD is £20 to get the full plans.

Question to all:
Has anyone on this forum built one that I could have a look at in the flesh? Thanks in advance if you can help.

 

[MattRoberts]

I built one as a prototype, but didn't like it personally. You need to hog out a lot of material with the router, and you need to use a sacrificial back board to avoid massive tear out. I found it a bit unforgiving in the precision department.

I have since downloaded the plans for John Heisz' advanced box joint jig from ibuildit.ca - as this can use the tablesaw to make multiple cuts rather than the router, and seems to be pretty precise by all accounts.

 

[Moonsafari69]

Hi Matt, interesting you say that. Here is the wrong reason for me looking at the router jig instead of a TS jig. Basically my router table set-up is better than my TS. This is a space limitation so unlikely to change to be honest. It could well be that I'm barking up the wrong tree I guess. I was hoping that there would be a resounding solution for the router set-up but it looks like I've got more thinking to do... Thanks :?

 

[MattRoberts]

Not sure why space is an issue - the jig for one is arguably much the same size as the other?

 

[Moonsafari69]

Not space for the jig itself, space in my workshop. I have a decent kreg router table, but a less good folding Axi table saw to save on floor space. As the router table is the better of the two I was initially looking for a jig for that.

 

[Glynne]

Lots of other (free) plans out there. Just search for Router Finger (or Box) Joint Jig.

Having said that I don't like finger joints, it's just occurred to me that I made a very simple finger joint jig to make wooden hinges for one of my jewellery boxes!
Mine is based on
http://www.routerforums.com/attachments ... eplans.pdf

 

[transatlantic]

Cutting finger joints on a table without a dado looks like a lot of work.

Probably a horrible idea but I wonder if you could tilt the jig so that you could cut wider slots with just a normal kerf blade?

 

[Moonsafari69]

Transatlantic, this is the issue. I bet if this box/finger joint question was asked in say USA the answer would be 'use a dado blade' 100% of the time. So, I'm fairly new to flat woodworking (predominantly lathe work previously) and I'm a little surprised there isn't a more definite answer to cutting box joints easily. I guess my question should be rephrased such as (other than cutting by hand) how does everyone cut box joints?

 

[MattRoberts]

Well you could use a grooving blade to achieve the same sort of result

 

[Eric The Viking]

Steve's jig works well, but...

I've had a torrid time doing box joints on the router table. To the extent that I'll be rebuilding my table saw ASAP just so I can do them that way instead

The worst problem, by far, is tearout. Don't even think about trying it in softwood - I was stupid enough to do that, and wasted a lot of time on it.

Frankly, if it's a one off, by the time you've made the jig and got it working, you could have made several boxes by hand - it's not that hard to do and a lot easier than dovetails.

 

[Moonsafari69]

Steve's jig works well, but...

Thanks for the heads-up Eric, this is exactly the type of feedback I'm after. One mans pain is another mans wisdom...

So, once you've rebuilt the TS, what jig will you be using on that for box joints?

Cheers.

 

[Eric The Viking]

I'll make one - something with a leadscrew on a sled, I think.

Metric studding is great, as 10mm has a 1mm pitch (I _think_ that's correct!), so it's easy to make something you can calibrate quickly.

I haven't had the saw running for a while, so don't know what the kerf is (and I have a couple of different thickness blades too).

But seriously: get a cheap Japanese saw with a rip-cutting blade and a fretsaw and a sharp chisel, and try it - it's pretty fast.

 

[monkeybiter]

10mm has a 1mm pitch (I _think_ that's correct

1.5mm

https://en.wikipedia.org/wiki/ISO_metric_screw_thread

Threaded bar leadscrew on table saw gets my vote too.

 

[Moonsafari69]

Thanks Eric
Thanks monkeybiter

So a Matthias Wandel type jig then?, preferably a simplified version in any case. With less gears at least. I suppose with a thread pitch of 1.5mm then just using a crank handle on the sled would work. I see my initial router table sled qstn has quite definitely turned into a table saw sled answer. Am glad now I didn't make a rash purchase as I was close to doing that yesterday. More googling to be done.....

 

[transatlantic]

So is the only problem with the router option the tear out? If thats the case, couldn't you just only make the cuts half way through, flip the board (or jig) and come through from the other side? Sure it'll be a pain, but it has to be quicker than using the tablesaw.

 

[wcndave]

I made one where you cut a slot on RT, then move that over a finger, and then move along. Worked ok but was a bit hit and miss at times. I now use a WoodRat for those joints, and it works perfectly, you don't even need to mark / measure. However it may be a bit pricey unless you're doing lots, or also doing dovetails etc. Maybe watch the video on it, interesting in its own right. https://vimeo.com/3598302

 

[Eric The Viking]

So is the only problem with the router option the tear out? If thats the case, couldn't you just only make the cuts half way through, flip the board (or jig) and come through from the other side? Sure it'll be a pain, but it has to be quicker than using the tablesaw.

In short, no, you can't. Or at least you won't solve the tearout problem that way.

Think about the cutter at various points during the slotting process:

• It enters the wood going sideways. If it doesn't have a razor-edged corner, it will scuff and tearout at the top of the notch. You can minimise this by "marking out" with a sharp blade, equivalent to the spurs on a plane, but that's extra work.
  
• When it's gone in one radius deep, one side is pulling fibres directly out of the stock (the "climb-cutting" side). and there's usually no 'backer board' at the front (although you could add one, I suppose).
  
• At the back, it emerges going sideways, and the non-climb-cutting side is always going to pull at the fibres until the cutter diameter goes past the end of the stock. You can mitigate this with the backer board of the jig, obviously, but after only a few notches, everything gets a bit looser and voila! Tearout.

Regarding flipping the jig: I made a jig to cut box-jointed octagons. It was a nightmare to do, and the results (admittedly in softwood) weren't pretty.

That was mirrored, so you cut one end normally (pushing right-to-left across the table), and the other end in reverse. BUT... you need the registration pins on the "fence" side of the table* at both ends.

On the "normal" end, the cutter is pushing the stock towards the pins... but on the cack-handed end, it's pushing the stock out of registration - a disaster! I ended up with a long 8mm bolt clamping the stock edgewise against the registration pin, and even then it was slow and awkward.

Frankly I could just have cut them by hand, and they wouldn't have been much worse for all that.

E.

PS: mods to that jig could havbe been made to improve it - I have a better design in my head - but I lost interest. Might resurrect it at some point in the future though.

*obviously no fence needed in this context. I mean the side furthest away from you.

 

[monkeybiter]

but it has to be quicker than using the tablesaw.

IMHO a table saw cuts much quicker. With the RT you can pick the cutter width to suit the slot width, but then you can also pick a groover for the same reason, so only one pass needed.

The finger joint jig will be essentially the same regardless of which machine you use.

With regard to jig type, one references each slot from the previous slot using a peg type insert on the jig [to match the saw kerf]. Steve Maskery's jig is very good in that the relative peg position is adjustable to remove any build error, but this type of jig still allows a compounding error which can throw the finger alignment out with longer runs.

The leadscrew type jig references all cuts from the same metal screw thread, you don't get alignment errors unless you use it incorrectly.