Faceframe Alignment w/Biscuits?

[Canuck]

I am working on a couple of shop cabinets and completed the carcass' and the glue up of the faceframe's today.

Question.......:icon_scra

I left the overall outside dimension of the faceframe about 1/16" proud of the carcass so I could followup with a trim router and flush things up with the carcass after the FF is attached.

Now,,,,,if I choose to align using biscuits and I reference from the outside edge of the FF and carcass; won't I be off by 1/16" on the FF slots? What is the trick? Do I place a shim on the face of the biscuit joiner fence to account for the 1/16" overhang?

Difficult question to put into words in a post, but I hope you can advise in spite my ramblings.

(I wouldn't see any issues if the outside dimension of the FF matched the carcass outside dim..)

Thanks

Wayne

 

[FredP]

not knowing what biskit joiner you have it's hard to say. with my lamello i can either adjust the cutter with the micro adjust or use the auxiliary fence and reset for the offset FF. you could also use shim stock but that adds another thing to keep in place while you cut.

 

[MarkE]

Here is what I do with my PC.

Use the fence to cut the slots in the carcase. Draw a line on the back side of the face frame to mark the offset 1/16". Index off of that line with out using the fence to cut the slots in the face frame.

If you had a little more than 1/16" to work with, you could clamp on a straight edge to index against.

Not sure if any of that made sense.

 

[Canuck]

not knowing what biskit joiner you have it's hard to say. with my lamello i can either adjust the cutter with the micro adjust or use the auxiliary fence and reset for the offset FF. you could also use shim stock but that adds another thing to keep in place while you cut.

Fred..... That Lamello is pretty slick, I notice that Norm uses one and never mentions the offset feature nor does he mention overhanging and trim of FF's :dontknow:.

Here is what I do with my PC.

Use the fence to cut the slots in the carcase. Draw a line on the back side of the face frame to mark the offset 1/16". Index off of that line with out using the fence to cut the slots in the face frame.

If you had a little more than 1/16" to work with, you could clamp on a straight edge to index against.

Not sure if any of that made sense.

Thanks guys.

I have been using a Dewalt (682) joiner. I have a straight edge ruler that is 1/16" thick and I think I will try double stick taping to the base of the joiner as a shim and give this a try - think I only need to do the FF. The carcass I should be able to use the standard butt reference for the cut.

I'll give it a shot in the A.M..

Thanks for your responses. :wsmile:

Wayne

 

[FredP]

Fred..... That Lamello is pretty slick, I notice that Norm uses one and never mentions the offset feature nor does he mention overhanging and trim of FF's :dontknow:.




Thanks guys.

I have been using a Dewalt (682) joiner. I have a straight edge ruler that is 1/16" thick and I think I will try double stick taping to the base of the joiner as a shim and give this a try - think I only need to do the FF. The carcass I should be able to use the standard butt reference for the cut.

I'll give it a shot in the A.M..

Thanks for your responses. :wsmile:

Wayne

I think you will find that using the shim on the carcass works better:wwink:

 

[ehpoole]

The good news is that the type of slot you'll be creating is pretty much the most difficult type of biscuit joinery, so once you master it you will have pretty much mastered biscuit joinery. Fortunately, if you take a little bit of time to lay things out and think out your references, it really isn't terriibly difficult, just a little nerve wracking for the first timer is all.

For this type of joinery you typically reference against the bottom of the biscuit joiner (rather than the fence like you do with edge joinery). THE MOST IMPORTANT POINT TO REMEMBER: THE OFFSET FROM THE BASE IS EXACTLY 3/8" ON CENTER! If your carcase is 3/4" thick, then this conveniently centers the biscuit for you. If it is at least 5/8" thick to around 1" thick, you can safely install the biscuits off center if you wish to simplify the layout. If your carcase is less than 5/8" or much more than 1" thick, then you will need to go to the extra effort to lay things out appropriately and calculate your positive or negative offsets and starting pionts.

To begin, match your faceframe to the carcase and clamp it, centered and aligned according to your specs or design. Take a pencil and trace the outline of the carcase on the backside of the faceframe (when you are done you can erase any excess pencil lead from the perimiter of the carcase, but make sure you leave a good, clean, solid line on the backside of the faceframe). You'll want this pencil line to be as narrow and sharp as possible (sharp pencil point, or a 0.5 to 0.7mm pencil). This line will show you the outline of your carcase on the faceframe providing you with a point of reference for calculating your offset (if needed) OR referencing the base of your biscuit joiner IF the 3/8" offset is compatible with your carcase as-is.

Just to confuse things a bit: If you are certain the offset is precisely 1/16" (and not just thereabouts) then you could use the fence like you are familiar with, centered for the carcase, then carefully adjusted 1/16" for the faceframes -- but only if the overhang is a perfect 1/16" all the way around. I'm not sitting in front of my PC biscuit joiner right now, but my guess is that 1-1/2 to 2 turns probably equals 1/16" (the threads are likely about 24-32 tpi) -- but test your offset before you go this route or you may encounter alignment issues.
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Once you have any necessary positive or negative offsets calculated, clamp or tape (with double-sided tape -- you could also use 23ga pins with minimal penetration into the carcase) edge guides in place, with the guide's edge aligned perfectly to the offset (or original line if 3/8" offset is perfect). You will then be able to register the bottom side of the biscuit joiner against this guide, press down firmly to keep in from shifting when you power it on, power it on, then press inward and you'll have your biscuit slot.

Like I said earlier, if the built-in 3/8" offset from the base works well for your glue-up then all the referencing and alignment is pretty much quick and trivial. If you need an offset of more or less than 3/8" then you simply need to take the time to calculate the needed positive or negative offset, clamp your edge guide to match this offset, then make your cuts. Take a breath, take a minute or two to double-check your math and think things through and you should have no problems.

If you have a Woodcraft nearby, they have these wonderful plastic shim sets that include 10ea of 1/32", 1/16", 1/8", and 1/4" shims. They are quite accurate and absoulutely wonderful for offsets in increments of 1/32" (you can stack shims to create any offset in even 1/32" increments). I use them to offset jigs, to gently step my router table fence in difficult woods, etc. and they are wonderful for these sorts of tasks. Use a little double-sided tape and stick them to the bottom of your biscuit joiner (or edge guide, depending on which needs offsetting) and you can establish a fixed offset for whatever offset your math suggests is optimal.

I hope this helps answer you question. It really is not a difficult biscuit joint to make, just a little bit nervewracking if you have never used your biscuit joiner in this manner.

 

[woodlaker2]

This is useful info.. Has it been placed in the NCWW Library of helpful hints??

Thanks for posting.

 

[Bas]

Excellent info Ethan. A couple of practical tips to complement the setup info:

I cut all the slots on the carcass first centered in the material, then cut all the slots on one stile of the face frame. Next, I cut ONE slot on the opposing stile somewhere other than the end, and see if it fits. If the slot in the face frame isn't perfectly aligned, adjust the shims or fence as apprpriate, then recut the same slot until it's perfect. Now cut the other slots. This is much better than cutting ALL the slots, discovering they're off by 1/64", filling all the slots, and then recutting them. Don't ask me how I know this I usually don't even bother fixing the test slot, one loose biscuit isn't going to matter.

Another thing to remember is that if you do any kind of measuring, then measure from the side that has the overhang. So, if you want the face frame to overhang the carcass by 1/16" on the _outside_, then measure _and cut_ from the outside of the carcass (and face frame). Plywood is never 3/4" exactly, so if you cut the slot at 3/8" from the outer edge it will usually be around 11/32 from the other edge.It is much easier to calculate a 1/16" offset from 3/8 than 11/32".

 

[lwhughes149]

Ethan, thanks for the helpful information. Please add this to the library of information. I plan to come back to it often. Lorraine

 

[ehpoole]

My goodness, aren't we getting greedy -- one tutorial for the month just isn't enough for you all! :rotflm:

I'll think about writing up a tutorial. In my opinion, the standards for a tutorial are much higher than for a forum post. So, if I go the route of a tutorial I'll have to build a mock carcase/faceframe to demonstrate and photograph -- I just don't have any actual projects going on right now that lend themselves to biscuit joinery.

That said, it probably would be useful to provide first timers with a tutorial on biscuit joinery since there aren't really that many good examples out there -- like many tools they largely assume you know what you are doing if you purchase a biscuit joiner. They are wonderful tools once you master them, though, allowing rapid assembly of common joints with minimal time and fuss.

I'm grateful you found the post helpful.

 

[Canuck]

Well, I am done!

Thanks so much to Ethan and everyone else submitting the great biscuit joiner ideas.

(I like to reference off of the base of joiner whenever possible - just personal preference, I guess.)

I wanted a 1/16" overhang all way round the FF so I built it 1/8" taller and wider that the outside dimensions of the carcass. To get the required offset, I found an old ruler (1/16" thick ) that I used as a shim taped to the base of the joiner.

I then marked and cut all of the FF biscuit slots using this setup...

(With the narrow ruler, I had to be a little careful, I didn't tip the base to the rear. Wider shims next time!)

All cut and ready for glue....

And just like magic, I ended up with a 1/16" reveal all the way around the carcass!

After the glue dried this afternoon, I trimmed the FF nice and flush to the carcass.:wsmile: Two cabinets done and on to the doors.

Thanks again everyone for all of your help! Sure made this chore easy peazie.:icon_thum:icon_thum:icon_thum

Wayne

 

[Bas]

Thanks for posting the pictures Wayne. Of course, when working with biscuits, a large mallet and strong clamping action goes a long way too

 

[Canuck]

..... Of course, when working with biscuits, a large mallet and strong clamping action goes a long way too

You are right on there, Bas!!

I have had these #20 biscuits for some time and they have swollen a wee bit. I few persuasive taps with mallet and they were home.

(Just noticed in the last picture, my "little ticky" witness marks for the dowel reference faces. Obviously have quite a bit of sanding left to do!:eusa_doh

Wayne

 

[MarkE]

If you have any more of those swollen biscuits, just squeeze them in a vice for a couple of seconds. Flattens 'em right out.