Cutting stopped groove with router table

[maznaz]

Hi there. I'm building a toy chest out of 2cm cherry and need to make stopped grooves in the frame. I've got a few options for making the grooves, but my preferred is a slot cutter bit on my router table, as the grooves need to be at the sides of the frame and I prefer to hold the wood flat to the table while cutting.

I'm fine with the regular grooves and they come out nicely on my test piece, but I've not had any joy with the plunge cut for the stopped groove. Both times I've tried to do this, the router bit has chunked and tried to rip the wood out of my grip. I'm using a very elaborate and safe push block so I'm not losing control, but it's a bit scary and makes a bit of a mess of the cut. It's also obviously tapering the groove the radius of the bit, which isn't ideal.

The stock is 2cm thick cherry. I also have a plunge router, a table saw (not keen on using this for the task) and chisels, although I have a lot of grooves to make so I don't want to hand cut them all.

Is there a way to safely and easily cut these stopped grooves with what I have, or do I need to purchase something else? Some kind of hand plane or a spiral upcut bit for my plunge router?

Cheers!

 

[MikeG.]

Stop blocks are your answer here, at both ends of the cut. They can be as simple as a piece of scrap clamped to the fence.

 

[clogs]

as above but dont cut the groove in one big hit......even if the slot is 25mm wide and or thick, 3 cuts should be quite poss.....
I only use a big 3hp Hitachi router for this kinda thing.....free hand with a guide and another router the same size in a decent router table....
all cutters for that kinda job are from Freud etc....nothing from Asia,,,,,just wont chance it...

 

[maznaz]

as above but dont cut the groove in one big hit......even if the slot is 25mm wide and or thick, 3 cuts should be quite poss.....
I only use a big 3hp Hitachi router for this kinda thing.....free hand with a guide and another router the same size in a decent router table....
all cutters for that kinda job are from Freud etc....nothing from Asia,,,,,just wont chance it...

Thanks. I should have said, i tried to take 3mm deep of a 1cm wide groove with the slot cutter. Is that too much at once?

 

[MikeG.]

.......i tried to take 3mm deep of a 1cm wide groove with the slot cutter. Is that too much at once?

Not at all. That should be child's play, assuming you have adequate dust extraction.

 

[maznaz]

Not at all. That should be child's play, assuming you have adequate dust extraction.

Once it was in the groove, the cut was absolutely fine, but it was the initial plunge that just tried to grab the workpiece and fire it away from me. It was slid in very gently and held firmly as well. I have good dust extraction. Is it possibly these cutters are just bad? They weren't the cheapest but they also weren't expensive. Never used previously so probably not blunt!

 

[MikeG.]

Fire it away from you?! Are you starting at the wrong end? It should try to fire it towards you. The stop block will resist that, and make the plunge simple....but you must offer the workpiece up at the correct end.

 

[maznaz]

Fire it away from you?! Are you starting at the wrong end? It should try to fire it towards you. The stop block will resist that, and make the plunge simple....but you must offer the workpiece up at the correct end.

Right, I see now. I plunged the front of the workpiece which is to the left of it, and then continued moving the workpiece from right to left. The grab as the bit entered will have tried to push the workpiece to my right, and a stop block would have helped anchor it and prevented that jolt and the subsequent damage to the cut. Is that correct?

If so, what kind of stop block would I want? The workpiece is going to have to be angled prior to the plunge, and some of them are actually quite long (90cm).

 

[MikeG.]

Well, it sounds like you are pushing things the right way.

If your workpieces overhang the table then you'll need to clamp on a batten to hold the stop blocks. It really is an ad hoc arrangement that simply stops the workpiece at both ends of the cut. Taking the work off the cutter at the end is usually more tricky than starting it. It helps to back the piece off the finish stop block, and then pull it away from the fence carefully.

 

[maznaz]

Well, it sounds like you are pushing things the right way.

If your workpieces overhang the table then you'll need to clamp on a batten to hold the stop blocks. It really is an ad hoc arrangement that simply stops the workpiece at both ends of the cut. Taking the work off the cutter at the end is usually more tricky than starting it. It helps to back the piece off the finish stop block, and then pull it away from the fence carefully.

Thank you, that's helpful. I must admit I'm not a huge fan of this approach to what I'm doing though. Is there a better method for cutting these kind of stopped grooves safely and securely that I may want to use in future? How do you folks approach it?

 

[MikeG.]

For repetitive work, this is the best way....so long as you use a winged cutter and not a straight cutter. For a slower pace but with more calm and satisfaction, use a plough plane or combination plane with a chisel and a mallet, or use a scratch-stock.

 

[Droogs]

You could pre drill the ends of the groove with a forstner bit or decent brad drill bit so as to avoid the initial plunge cut. Once in and started deepening the groove shouldn't be a problem for the router bit

 

[maznaz]

For a slower pace but with more calm and satisfaction, use a plough plane or combination plane with a chisel and a mallet, or use a scratch-stock.

I feel very strongly at the moment, that that's a direction I'd like to take! I'll have a look at plough planes for future projects. Thanks Mike and everyone for your tips.

 

[MikeG.]

You'll make a terrible hash of your first few grooves with a plough plane, and get deeply frustrated.....but at least your fingers and your hearing aren't at risk!!

 

[maznaz]

You'll make a terrible hash of your first few grooves with a plough plane, and get deeply frustrated.....but at least your fingers and your hearing aren't at risk!!

That's alright. I'll live long enough to get good at it without the minor heart attacks I get whenever a router kicks at me!

 

[MikeG.]

That is music to my ears. The Hand Tool forum is thataway --------->

 

[AndyT]

While I don't disagree that cutting grooves with hand tools is a lot less stressful and dusty once you leave out the electric router, there are a few more things to think about.

First off, in trad joinery or furniture construction, it's hardly ever necessary to cut a stopped groove. The classic example is frame and panel construction as on a door. Use of mortice and tenon joints means that all the grooves can be ploughed right through, quickly and easily. Haunches on the joints fill up the grooves.

So it may well be possible to design out the requirement altogether.

If not, then as said, it's a question of mallet and chisel at the ends until there's room for the plough.

(There are a few examples of plough planes designed to run up to or close to a stop, but their rarity is evidence that most professionals never needed one.)

 

[maznaz]

First off, in trad joinery or furniture construction, it's hardly ever necessary to cut a stopped groove. The classic example is frame and panel construction as on a door. Use of mortice and tenon joints means that all the grooves can be ploughed right through, quickly and easily. Haunches on the joints fill up the grooves.

So it may well be possible to design out the requirement altogether.

I did think about this for quite a while, as not stopping the grooves would certainly have made everything a lot easier. My issue was the visibility of the groove at the top of the frame. As this is for a chest, with the lid open there would be a visible aspect to the join where the groove reaches the top of the frame that I really didn't like. As I mostly make boxes I can't really see how to avoid that without a stopped groove.

 

[MikeG.]

Isn't there a joint there? If so, then the groove stops at the mortise or the shoulder.

 

[sunnybob]

There shouldnt be any problem doing that on a router table. I use the router table for all grooving. If 3 mm bites you, cut 1 mm. Get used to 1 mm passes and then go to 2 mm. Its called learning.
Or, use a 5 mm wide cutter and then adjust the depth to take a second 5 mm away.

But if youre using a slot cutter remember the ends of the slot will be curved so you will need to either shape the board thats going in there or cut out the last end pieces.