"Swingman" wrote in message
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"SonomaProducts.com" wrote \

I am wondering if you have any experience with deep mortising. I am
considering how I would do through mortises with the MR. I want
squared corners, even though I have seen through mortises with rounded
tenons. I could cut square tennons easily enough with the MR but would
need to under cut the through mortises slightly and square them by
hand.

In the past, I've used my hollow chisel mortiser for squaring rounded,
through mortises cut on the M-R.

My concern is I'd likely need to go a full 2" deep or more. Have
you found end mills long enough enough for that and do you think it
would be stable enough on the cuts if you were careful?

A 2" cutting depth has never been a problem with any size end mill I'ved
used in oak, thus far

That said, with square, through tenons that are deeper, I usually route
the
mortises from each side, both on the M-R, and then a squaring pass on each
side with the mortising machine, deep as I can to get a good reference
edge
for the chisel cut.

The only caveat with the M-R is that you really need to measure your stock
thickness carefully so that the formula:

(bit diameter + stock thickness)/2

... works to allow you to position your cutter at the exact center of your
stock thickness ... you can't be too precise with this step, IME.

(apparently a lot of folks think 3/4" stock is 3/4", even when you milled
it
yourself, which we know is not always the case, thus drilling from the
opposite side, using the opposing face down on the M-R table for the
second
cut, won't guarantee the cuts meet precisely enough for the purposes of a
through tenon)

IOW, take the setup time, with some test cuts, to verify that both faces
of
your stock are equal as a "reference edge/face".

Once you have that dialed in, the M-R can easily cut through mortises in
some pretty wide/thick stock precisely from either face when making the
opposing through cut.

I haven't had any trouble using a 5/16 or 3/8", four flute, end mills for
boring deep on the MR ... a long 1/4" end mill may give you a bit of flex
in
some material at depth, but I've not really had any problem with routing
through tenons in 3/4" QSWO using a 1/4" end mill.

I buy mine from:

www.travers.com

PDF of their catalog online at:

https://www.travers.com/htdocs/catalogs.shtml


Thanks, this is great information.