Technique for Routing a Long Deep Slot

[Owego]

I just finished routing 40 feet of slots, 1.5" deep, .5" wide, in oak.  My results were fine, but it took a long time.  My equipment, OF 1400, with a .5" x 2" double flute (straight) bit, attached to a CT.    I made multiple passes, 8 mm per pass.  Vacuumed the waste out of the slot (which was significant ) after each pass.  I have "up cut" bits but they leave the top edge a bit ragged so I didn't use one.

It occurred to me during the operation that only the bottom 8mm of the bit is doing any cutting, and the flutes do nothing to bring the waste up to the dust shroud.  It also occurred to me that using a 3/8" uncut, followed by the .5" straight bit might have been faster but by that time I was just about done.  Are there better techniques ?

Are there better bits or combinations of bits that can cut more aggessively (faster).

Thanks,
Tom

 

[jacko9]

Tom,

A Forrest King Dado set on a 5hp table saw and your done in minutes.

Jack

 

[CrazyLarry]

I just finished routing 40 feet of slots, 1.5" deep, .5" wide, in oak.  My results were fine, but it took a long time.  My equipment, OF 1400, with a .5" x 2" double flute (straight) bit, attached to a CT.    I made multiple passes, 8 mm per pass.  Vacuumed the waste out of the slot (which was significant ) after each pass.  I have "up cut" bits but they leave the top edge a bit ragged so I didn't use one.

It occurred to me during the operation that only the bottom 8mm of the bit is doing any cutting, and the flutes do nothing to bring the waste up to the dust shroud.  It also occurred to me that using a 3/8" uncut, followed by the .5" straight bit might have been faster but by that time I was just about done.  Are there better techniques ?

Are there better bits or combinations of bits that can cut more aggessively (faster).

Thanks,
Tom

Depending on the physical limitations: is the stock in situ, are the lengths sensible, or was it one continuous 12m long beam?

I'd consider using a TS55, even if you just ran it up the middle once it would significantly reduce the load on the router bit.
If convenient you could use the saw for both sides of the channel and just tidy it up with a single pass from the router.

It does depend on whether you're talking sticks or trees though

 

[MrGinCT]

I agree with Jacko9.  One pass with a dado set would give you exactly what you need and much quicker.  My 3hp Unisaw handles dado's like yours like a hot knife thru butter [big grin]

 

[teocaf]

the way i'm reading the OP's post is that he's looking for better techniques for his equipment, that is the router listed.  in other words, better routing techniques.  so far the suggestions seem to be regarding table saws and track saws.  that seems to me to be pretty unhelpful: "have you tried an Altendorf, they're super accurate for long cuts--make sure you get the scoring blade option to minimize tearout..."

I would also like to hear good suggestions for extra deep grooves with the router, for a design that you can't do on the tablesaw--my groove is curved. Are there some good bits out there that I'm overlooking?

 

[CrazyLarry]

the way i'm reading the OP's post is that he's looking for better techniques for his equipment, that is the router listed.  in other words, better routing techniques.  so far the suggestions seem to be regarding table saws and track saws.  that seems to me to be pretty unhelpful: "have you tried an Altendorf, they're super accurate for long cuts--make sure you get the scoring blade option to minimize tearout..."

I would also like to hear good suggestions for extra deep grooves with the router, for a design that you can't do on the tablesaw--my groove is curved. Are there some good bits out there that I'm overlooking?

Yes and No, my suggestion wasn't at all fatuous as in use a thunderous great tablesaw, my suggestion was merely that if he happened to have a TS55  and a rail (fairly likely they are festool too, this is a festool site...) they would offer a very quick and easy way of reducing the load on his router and hence reducing the number of passes required.

He didn't state curved ... actually he didn't state much at all, for all we know he has an altendorf just doesn't use it weekdays!

 

[Cheese]

[member=42221]Owego[/member]
We need some more information before the brain trusts can do their thing.
Is it a stopped cut or through cut?
40 feet equals 160 slots 3" long or 4 slots 10' long, it makes a difference in what tools to use. Even if you don't own a track saw, a circular saw would help bigtime with 10' long slots, not so much with 3" slots.
If it is a series of short slots, I'd make the first pass with the straight blade bit on the 160 slots and then swap out to an upcut bit and finish them off. You probably had to spend almost as much time vacuuming the slots out as you did routing them. The 8mm per pass seems reasonable for oak.
Is surface finish of the groove important to you? They make solid carbide roughing end mills for metal working. Has anyone tried one in a router on wood?

 

[bertv]

I would use a (slightly) smaller bit than the final width: first cut in the middle til correct depth; next two clean up cuts for the sides, minding the correct direction of routing. This way you will not have a 'tope edge'…

BTW, to minimize dust and chips you should lift the routerbit at the end of your pass and move the router back slowly to the starting point, (where you need to be anyway for the second pass) — with the machine on, of course. The DE will get most of the stuff that has been left, is my experience.

 

[nickao]

[attachimg=3]This type of work is one reason I sold my OF 1400.

With the OF2200 I am not kidding, that is a two pass operation.

You could have paid for an OF 2200 in time saved using a good upcut SPIRAL bit and an OF2200. I sure hope you were using an upcut spiral for that work. I actuality use an up/down compression spiral for that work to get the nice top edge. The Freud is one of the few with a very shallow upshear cut edge on the bottom so the first pass doesn't have to be huge for the smaller routers. We always have to plunge past that point or the wood will burn.

That must have taken days using an OF1400. I feel for ya. 

Here is the bit I would have used:

http://www.amazon.com/gp/product/B001J9FCJK?psc=1&redirect=true&ref_=oh_aui_search_detailpage

Notice the very short upshear cut length on this bit, I use these everyday and love them to bits. [wink] No changing bits, Anyone tries this bit I bet they never go back.

 

[nclemmons]

You could have used your downcut on the first pass and then switched to an upcut bit for the future passes.  Assuming you are cutting the same width slot, I would not think you'd get any tearing at the surface.

The 1400 should have plenty of power to handle it.  Agree the 2200 would have been better but a different bit might have improved chip collection with the 1400.

 

[nickao]

Oh yeah the bit is always a huge choice. I go with those Frued compression with the shallow upshear, try one you will love it with an OF1400, even an OF1010, they make the bits in a few shank sizes.

But that OF1400 always bogged down on me, I am always in a rush I guess. Since I started using the OF2200 I just dont use any of my huge collection of routers anymore. I was using my OF2200 with a little 1/8" bit the other day, my son though I was nuts. This job the OP did just required more power to get it done in any kind of timely manner.

 

[Owego]

Thanks for the input from all.  To clarify: The grooves were on the narrow edges of 12, 1.5" x 6" x 6' oak stock.  I considered the dado approach but didn't think I could control 6 footers, on edge, against the fence (or with a track saw).  All  cuts were "stopped", and precision was important as the slots were to receive tenoned componenets.  As some responders noted, my question was directed at router techniques.  "Up/Down" bits were news to me, thanks.  Also experience with higher powered routers was valuable.  It surprised me that a 2200 could plow a 1.5" x .5" slot in one pass.  What's it like to control by hand ?

 

[nclemmons]

Also experience with higher powered routers was valuable.  It surprised me that a 2200 could plow a 1.5" x .5" slot in one pass.  What's it like to control by hand ?

The 2200 is incredible powerful, smooth and heavier, thus giving you more control.  For the size of the router, it's really very controllable due to the weight, handle placement and smooth power.  Plus variable speed to boot!

 

[CrazyLarry]

Thanks for the input from all.  To clarify: The grooves were on the narrow edges of 12, 1.5" x 6" x 6' oak stock.  I considered the dado approach but didn't think I could control 6 footers, on edge, against the fence (or with a track saw).  All  cuts were "stopped", and precision was important as the slots were to receive tenoned componenets.  As some responders noted, my question was directed at router techniques.  "Up/Down" bits were news to me, thanks.  Also experience with higher powered routers was valuable.  It surprised me that a 2200 could plow a 1.5" x .5" slot in one pass.  What's it like to control by hand ?

Devil's in the detail! Given your application Dovetail's solution sounds the only one that'll work.

Bear in mind though his approach is a two part one, big 2200 and solid carbide bit, same bit in a 1400 would probably still need a couple of passes and a plain double flute bit in a 2200 would tend to give you tear out / burns at that depth in oak.

Also a 36mm hose will make a big difference to both routers when you're shifting that much material saving you a lot of time on the clear up each pass.

So what you making with them?

 

[Owego]

Thanks again all.  (CrazyLarry -  making siding doors)

 

[Woodentop2]

the way i'm reading the OP's post is that he's looking for better techniques for his equipment, that is the router listed.  in other words, better routing techniques.  so far the suggestions seem to be regarding table saws and track saws.  that seems to me to be pretty unhelpful: "have you tried an Altendorf, they're super accurate for long cuts--make sure you get the scoring blade option to minimize tearout..."

I would also like to hear good suggestions for extra deep grooves with the router, for a design that you can't do on the tablesaw--my groove is curved. Are there some good bits out there that I'm overlooking?

Yes and No, my suggestion wasn't at all fatuous as in use a thunderous great tablesaw, my suggestion was merely that if he happened to have a TS55  and a rail (fairly likely they are festool too, this is a festool site...) they would offer a very quick and easy way of reducing the load on his router and hence reducing the number of passes required.

He didn't state curved ... actually he didn't state much at all, for all we know he has an altendorf just doesn't use it weekdays!

 

[jacko9]

Actually, I was the person to bring a table saw with dado into the conversation.  Even though the OP asked the question about routers, the answer is to use the most appropriate tool that you have and the OP does have a table saw.  I always try to use the appropriate tool for the job.

 

[JeremyH.]

Dado's aren't the most accurate. They aren't the cleanest channel either, if you ask me. They're good making a channel for 1/4 material to go in mostly. They're also an issue with how flat your table saw area is right next to the blade. A perfectly flat, flat with the table itself, insert is important. If the wood isn't entirely flat you'll get varied depths too, and you have to do your best to press it down to the table.

However I'd still have run the track saw or something down it, not at finish cut measurements.

 

[Kev]

The new HK85 slot cutter would be brilliant for this - wish it'd land in Oz soon [sad]

 

[Lbob131]

Can you do a plunge  cut with the HK85  saw?
No one has mentioned shaper(spindle moulder)  with a grooving cutter fitted. AFAIK.