Cutting casing miters w/ a TS-55

[mrFinpgh]

I'm going to be redoing an archway for a relative in a week or so and the new trim is going to be a very simple 6.5" wide mitered casing with veneered MDF.  I've been laying up 1/16th walnut veneers for the last week or so.  [smile]

Thinking about it a bit, I'm trying to determine whether it makes more sense to bring my TS-55 or my SCMS along with me to cut the miters.  My SCMS (a Makita LS-1019L) has never proven to be very reliable for furniture work, although 'good enough' for paint grade stuff. Despite my efforts to fine tune it, there always seems to be just a little bit of deviation from square.. the point where I just cut everything by hand and plan to shoot it before cutting joinery.

The TS-55 cuts a very good 90 (vertically) and with the GRS-16 my crosscuts are almost always dead on - narrow pieces occasionally do see a little deviation.  However, a 45 is going to be something I'd have to cut by eye and that could probably lead to some very small imprecision.

Is there a good way to construct a miter jig for the TS-55 without getting into an MFT situation? Or should I just bring the SCMS and plan to spend some time tweaking the joints?  Is there another way of thinking about this? 

 

[woodferret]

TSO MTR-X.  A little more than the angle adapter from Festool but I'd say more useful in and out of shop.

But truth be told, casing is more sliding t-bevel gauge territory if you're set up right next to it anyways.  But that might just have been me with a really old house that I don't think has ever seen a 90 deg.

 

[Packard]

Pre-mitered and then trimmed is the exact way I used my Lion miter trimmer when I started out in picture framing.  I had a wooden miter box and a hand saw.

After which I took minute skim trims on the miters.  Those miter trimmers used to be very pricey, as I recall I spent about $250.00 on mine in the early 1970s (about $1,830.00 in 2023 dollars).

Lion is out of business now, driven out by high quality imports which are still about $250.00:


Oops.  Forget this.  I just checked.  Mine will only trim about 4” on the diagonal and about 6” at 90 degrees.  This is either going to just work, or it will be too small.

 

[woodferret]

On reflection, I figured I'd expand on my bevel answer and add this video on bisecting to be clearer.


Once you have that bisected angle, stick it on the bevel again, and use that bevel as your miter fence for lining up the track to the front edge.

 

[peter halle]

Bring your SCMS.  That is what it is designed to do. 

Peter

 

[mrFinpgh]

Thanks all.

[member=72072]woodferret[/member]  The current archway is a bit out of square, but I'm planning to rectify that by laminating over the existing jamb, putting shims and blocking behind it as needed.  The casing is going to be about 2.5" wider than the current stuff, and there's beadboard wainscoting on one side of the archway, so this way I get to square things up and also avoid messing with the beadboard.

Giving this some more thought .. I was inclined to go with what [member=1674]Peter Halle[/member] recommended except it means 1. my known out of square Makita becomes critical to the work and 2. I need some kind of miter saw stand, since I'm cutting 8' long MDF board.

I think the squareness issue is one I can mostly rectify before I head out, though I've developed major trust issues with that saw.  Hopefully if it's not quite right, it's a question of some painters tape shimming and nothing more involved.

My other thought at this point was either the MTR-X or the (award winning) Parf Guide Mk2 and making a grid to establish a 45.  The upside of those is that I can use my tracksaw for all my cuts and it travels a little better than the miter saw. It looks like I have a couple weeks (another delay due to scheduling issues).  I don't know if those would be more accurate than a miter saw, or if I'm making this more complicated than it needs to be (I tend to do that).

 

[mrFinpgh]

I've spent the last couple hours inspecting my Makita LS1019 and found the following:

[list type=decimal]
[*]The fence is out of plane by about .010 inches, with a low spot on the outside.  I don't see a way to actually adjust the fence.
[*] The table is mostly flat..  if i put some paper under a straightedge and try to pull it out, I have resistance everywhere except for on the left side of the blade closest to the kerf.  A piece of wax paper makes that difference go away, which isn't too bad.
[*]I cut a 7" x 20" piece of MDF into two 10" pieces, then flipped one end and cut it again referencing the same edge against the fence. My hope was to magnify any mis-calbration.When I butt those pieces together, there is a little bit of a gap between them. Oddly, flipping them over doesn't make the gap go away, which I would have thought would happen since any deviance should be complementary
[*]There seems to be a little bit of a curve in the length of the cut. Meaning, there is a more notable hollow in the center of the cut than at the edges.
[/list]

I don't think these things mattered very much when I was using the saw primarily to do baseboards and other painted stuff around the house. I've never found the saw to be accurate enough for furniture or cabinets and don't know if it would really be sufficient for wide mitered stain grade trimwork.

I'm going to reach out to the local Makita rep and see what he thinks. The LS1016 that I replaced with this saw did not have these kinds of issues - even though I knew a lot less back then, i could get accurate cuts without any significant effort.