How to make this cut

[MitreKnown]

I was wondering what people thought the easiest way to make the cut shown below. It's in a total length of >20m of timber (each piece about 2.4m). Dimensions in mm. My table saw can't cut 120mm, max 80mm I think, but it would be a difficult cut to make anyway as keeping the timber on its edge would be tricky. I guess I could clamp or screw an additional timber to it to give it a more stable footprint, but then I am still up against the 80mm maximum cut problem.

I don't fancy using a router as that will take a long time and create a huge amount of sawdust. I suppose if I use the table saw for 80mm worth of it, then the router only has to do the remaining 40mm.

Any bright ideas?

 

[Gordon Tarling]

It would take a while, but 8mm depth parallel cuts the length of the board until you've covered the 120mm width, then clean up with plane or chisel.

G.

 

[rogxwhit]

It would take a while, but 8mm depth parallel cuts the length of the board until you've covered the 120mm width, then clean up with plane or chisel.

On a 20m run - you must be joking!

I suppose if I use the table saw for 80mm worth of it, then the router only has to do the remaining 40mm.

I guess that's as good as it gets. Use a tall sub-fence to stabilise the work and have the saw cut close to the fence rather than away from it to limit blade exposure at the start & end of the cut. Also you'll need outfeed support.

I think I'd do the routing first (more support for the router base), and part off the waste with the saw last, but all the more need for a tall sub-fence that way.

Any bright ideas?

No :-(

 

[Jacob]

Plane off whole board 8mm and add on the 8x100mm upstand? Glue and a few pins.

 

[TRITON]

A 20m run of small sections of 220mm removing the above section will be very time consuming if you do it all by hand.
I suppose the standard would be cross cut at the 120mm mark, then using a rip tenon saw cut down to that make, and clean up the cuts with a chisel/plane(rebate and shoulder).

In all honesty it is a job for the router, mainly because it will give an accurate consistent cut/finish etc. So sort out extraction on your router and then the construction of the simplest of jigs will enable you to easily cut one after the other.

 

[Ttrees]

Why can't you the TS?
You could do a number of consecutive shallow cuts, but leaving the edge,
or perhaps just inside of it for support so you could plane off the strip afterwards

I do wonder how one would rig up the infeed and outfeed, that is the hurdle IMO.
Not something I would do, as I would never have doors open.
You need to make a jig for this kinda thing ideally something like this,
(thanks to Trevanion for this video)
I've timestamped the video to the bit where it's featured.

Good luck
Tom

 

[MitreKnown]

Thank you for the inputs

Plane off whole board 8mm and add on the 8x100mm upstand? Glue and a few pins.

My thicknesser only goes up to 200mm so that's no good. It would also create even more sawdust

Sounds like routing a 40mm wide groove near the middle of the work piece and then making an 80mm cut is the way to go, if potentially a tad hazardous.

 

[MitreKnown]

I had wondered if you could get something like the image below, but without the protrusion in the middle. It would allow me to use that and a circular saw to take off 20mm x 8mm strips at a time.

Looks a little dodgy though as I could imagine things going wrong quite rapidly if you went off vertical with the router.

 

[MitreKnown]

Plane off whole board 8mm and add on the 8x100mm upstand? Glue and a few pins.

I've a load of scaffolding boards I am trying to resist using

 

[TheUnicorn]

what is this cut for?

without a simple effective way of completing the cut is it worth exploring other options?

 

[akirk]

don't you simply want a router surfacing jig and bit - used for flattening slabs, so quite capable of large areas, and run it a couple of times to drop down the amount you want...
so a bit more like this:

 

[MitreKnown]

what is this cut for?

without a simple effective way of completing the cut is it worth exploring other options?

It's for a set of door frames. They are for heavy garage doors and I want the frame to span the cavity wall as the exterior leave of the wall isn't carrying much weight (~200kg) so isn't as well 'constrained' as the inner leaf which is carrying a floor load and roof load so has over 2t bearing on it, so shouldn't be going anywhere with a 60kg door hanging from it.

 

[MitreKnown]

don't you simply want a router surfacing jig and bit - used for flattening slabs, so quite capable of large areas, and run it a couple of times to drop down the amount you want...
so a bit more like this:

I guess I'd have to go pretty slowly with that.

Am I likely to be able to take it anywhere to have the cut made?

 

[Sgian Dubh]

Spindle moulder and 80 mm spiral planer head, a snip at just under £200 from Wealden. Board edge down, set head low, make first cut. Use an 8 mm spacer 50 - 70 mm wide which you attach to the bottom of the outfeed fence of the moulder to hold the profiled end of the board parallel to the fence to prevent digging in. For second cut set head at 120 mm height and make final cut.

All the above said somewhat tongue in cheek, but your local friendly joinery/furniture shop might be able to oblige for maybe something close to £100, and would save you a lot of work, dust, and potential hazards if you choose to use your own kit which may not be well suited to the task . Once the parts are machined, you simply fit them to the opening. Slainte.

 

[baldkev]

wot he said

 

[Linus]

Could this not be done with an electric planer using rebate fence? Most planers will rebate to about 9mm depth.

 

[Ttrees]

It seems the jig shown in Roy's video has gone out the window?
I'm going making one sometime, now I have the answer to why my fence has holes tapped into it.

 

[Doug71]

First choice would be cut rebate on spindle moulder, second choice would be cut rebate on an old planer thicknesser, most of the new planers are designed so you can't cut rebates on them (think you still can on new Sedgwicks though).

 

[D_W]

In the US, you would do this with a dado blade in short order.

This won't help you, but if I were going to do this myself, I'd plane a few steps to depth with a plow plane, check the depth and then plane the stuff out in the middle to that depth. What I'd do would also depend on whether or not it was OK for it to be off a hundredth or not OK.

Tracksaw would also be an option to establish depth marks.

I could think of a lot of ways to do it, but all of them would be physically demanding (by hand, but accurate and safe) or miserable (router).

if I had dado in a table saw in the US, I'd blast them right through - I hear you guys don't like those.

 

[Jacob]

It's for a set of door frames. They are for heavy garage doors and I want the frame to span the cavity wall as the exterior leave of the wall isn't carrying much weight (~200kg) so isn't as well 'constrained' as the inner leaf which is carrying a floor load and roof load so has over 2t bearing on it, so shouldn't be going anywhere with a 60kg door hanging from it.

In that case just use them as they are and add stops for the doors. Why go to all that trouble?