Router advice wanted

[andyv1]

I've got a Bosch POF 1200 AE router. So far I've only done minor bits of edge trim, but I want to trim down a table which is too big for my kitchen. This involves cutting the top to size, then rounding each corner to a 4.5 cm radius, then running all the way round with a moulding pattern.

It's how best to do the corners. I understand how to make a template and think I could do the job were it not for the 35mm thickness of the table top. Most of my bits are 1/4 inch shank, but I think it will take larger bits up to 5/8 inch, if there is such a size.

The largest bit I have has a 25 mm long cutter with a bottom bearing. Is there any way to use this perhaps with a double pass or alternatively can anybody recommend the correct sized bit from a reputable supplier? I'm a bit dubious about some of the ebay offerings from China.

 

[Diver Fred]

The size of the shank doesn't matter that much but most routers that have more power than yours have the capability of 1/2inch shank cutters.

Cutters come in many sizes and shank diameters (look at Trend and or Axeminster websites).

To shape the corners with your machine you will need to take at least 4 passes and probably more taking only a 1/4-/8inch cut per pass. To cut that depth you are going to need either a larger router with 1/2inch collet to take a 50mm long bit. To use that you will need to make a jig that takes the router base bush - I'd make the jig to be slotted rather just a one sided guide for safety reasons. Make the jig big enough to ensure you can clamp it to the workpeice securely.
Alternatively use a shorter bit, say 25mm long, with the jig then use a Top bearing cutter to complete cutting to the full depth.

With your router I'd only use a 1/2 cutter to prevent overloading the router.

 

[andyv1]

Many thanks. I don't think I can use 1/2" bits - I got that bit wrong, the max is 5/16". However just so I understand this, if I have a top bearing bit, is it feasible to make a partial depth cut, then reset the depth so the bearing is resting on the workpiece instead of the template, then keep going until I've gone all the way?

 

[Diver Fred]

Just had a look in the manual - it talks of up to 40mm bits.
regarding the Top Bearing bits, yes, exactly what you said.
just remember it is better with a low to medium power router to make several passes and not overload the tool.

 

[Ryler]

is it feasible to make a partial depth cut, then reset the depth so the bearing is resting on the workpiece instead of the template, then keep going until I've gone all the way?

 

[Deleted member 174758]

The router in question can use cutters up to 40mm in diameter and when fitted with an appropriate collet can acommodatecutters with shanks of 6mm, 1/4in (6.35mm) or 8mm (NOT 5/8in). 8mm shank cutters have the advantage of a 60% larger cross sectional area than 1/4in shank cutters, meaning that they can take a heavier cut with less chance of the cutter shank bending or breaking. On the flip side 1200 watts isn't really enough to drive many 1/2in shank cutters - 1/2in routers tend to start at about 1400 or 1500 watts with many trade models being 2000 watts and above these days.

The best way to deal with the corners is not to rout them, instead mark the radii and trim to within 5mm or so of the line using a jigsaw (with a new blade) or failing that if you have no jigsaw "threepenny bit" the corner by using a circular saw or even a hand saw to remove the majority of the waste by a series of straight cutters to get near to the line making a series of straight cuts (looking s bit like the edge of an old 3d coin). Hogging the waste away in this manner reduces the amount of work the cutter and router have to do making for a much easier job (and is a technique commonly used by pro woodworkers).

Have you decided about the cutter set up.you want to.use? The cheapest option would be to use a straight cutter with s guide bush fitted to the underside of the router, but you must be aware that there will be an offset between the jig and the cut line (because the cutter needs to be smaller than the guide bush in order to pass through it). The alternative is to use a cutter with a guide bush fitted (same diameter as the cutter) but this will probably not be available in lengths long enough to run the edged in one cut (and as a newbie I'd strongly avoid buying one of those super long Chinese cutters as they are easily bent if pushed too hard). On a straight cutter I think you should be looking for something like a 12 or 14mm diameter cutter - smaller diameter cutters are not only shorter, but can break more easily and are more prone to clogging and potentially kicking back on deep edge trimming tasks.

The problem with using a top bearing template trim bit is that you will need to make the first cut with the template fitted, then remove the template to make the second cut and if a third cut is needed the depth of plunge will necessarily be limited by the depth of cut of the router (so not very much)

A good source of 8mm shank cutters is Wealden Tool although you will need to install an 8mm collet

 

[mrrusty]

Your router will do what you want with good cutters, as long as you don't get too greedy. Taking shallow passes I think you would be fine with 1/4" cutters, although 8mm is preferable if you can get the collet easily.

You could get two cutters, so you don't have to make the template too thick. Start with a short one e.g. like this https://www.trenddirectuk.com/c121bx14tc and once you have gone as deep as you can swap over to a longer cutter https://www.trenddirectuk.com/c121dx1-4tc, however price comes in to it. As J&K says, cheapest way is just to use a guide bush and straight cutter and size the template to suit.

Note the comment about care to avoid breakage - take shallow passes, and do wear eye safety.

 

[^woody^]

Wouldn't the corners be rounded with a saw and some sandpaper?

 

[mrrusty]

Wouldn't the corners be rounded with a saw and some sandpaper?

Of course you could, but tricky to keep it all square on a 35mm thick table top. If you have a router, it's a bit of a no-brainer to use it.

@andyv1 - just a thought occurs - what is this top made of? if it isn't oak/pine/similar planks it may not be solid, even if it looks like it.... Are you confident it will take cutting down?

 

[^woody^]

Of course you could, but tricky to keep it all square on a 35mm thick table top. If you have a router, it's a bit of a no-brainer to use

No way. A router is probably the hardest, most long winded, messiest, costliest faff of way to do this task.

Block of wood on the top to guide the saw if it's not possible for someone to cut anywhere near 90°.

That's the problem nowadays, everyone looks for (and more people promote) the coolest way of doing things with the most drama. And if it means buying lots of gear, all the better.

 

[mrrusty]

Block of wood on the top to guide the saw if it's not possible for someone to cut anywhere near 90°.

So exactly which type of saw are you suggesting to cut the 45mm radiuses on 35mm thick material dead square to the edge?? - which is what we are talking about...

 

[^woody^]

If the OP has a standard Jack hand saw he can use that by cutting vertically and leaving a bit more space off the lines to sand the saw marks, otherwise a tenon.

Presumably he/you will know to cut a series of straight lines to rough out the line of the curve.

Then form the true line of the curve with sandpaper. If he has a rasp for initial smoothing all the better, otherwise some 60/80 grit will do.

 

[Deleted member 174758]

And what's the betting it will end up looking pants done that way? I use hand tools when appropriate, power tools likewise - but in this case the OP already has a router, and used correctly a router can produce a neat, acurate, consistent corner - so "what's not to like?"

 

[^woody^]

And what's the betting it will end up looking pants done that way? I use hand tools when appropriate, power tools likewise - but in this case the OP already has a router, and used correctly a router can produce a neat, acurate, consistent corner - so "what's not to like?"

How can it look pants?

Set out the radius, follow the lines, that is it.

Its not all 100% guaranteed perfect with a router after all the messing about, and things are just as likely to go wrong.

 

[andyv1]

Thanks folks, I've been experimenting today. I figured that if I'm going to make my own template starting with a jigsaw I might as well just jigsaw the corners of the table. I've tried it on a bit of scrap pine and reckon it's possible to do a decent cut then sand it down. I've got one of those thicker "precision" blades that doesn't wander too much and does a reasonable vertical cut. Then I can rout a pattern into the edge.

It needs a bit more practice though before I venture onto my kitchen table.