# Insert router bits



## crquack (Oct 10, 2008)

I have never seen these:

R/BIT INSERT TYPE STRAIGHT 3/4IN. - Busy Bee Tools

Anyone has any experience with this kind of bit? Are they truly worth the extra dough? The replacement inserts cost $9-12 per pair.


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## bobj3 (Jan 17, 2006)

HI

It's old tech stuff for lathe cutting tools so I got one just to try it out on the router table and I don't trust it, spinning at 20,000 rpm's.. it did cut well but now it's back in the box and it's going to stay in the box. 

http://www.littlemachineshop.com/products/product_category.php?category=-1550042347
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crquack said:


> I have never seen these:
> 
> R/BIT INSERT TYPE STRAIGHT 3/4IN. - Busy Bee Tools
> 
> Anyone has any experience with this kind of bit? Are they truly worth the extra dough? The replacement inserts cost $9-12 per pair.


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## jschaben (Jun 21, 2009)

bobj3 said:


> HI
> 
> It's old tech stuff for lathe cutting tools so I got one just to try it out on the router table and I don't trust it, spinning at 20,000 rpm's.. it did cut well but now it's back in the box and it's going to stay in the box.
> 
> ...


I've got one from Amana, #1084, and it seems OK. What makes you uncomfortable? I will say it makes lots chips real fast. It's a 3/4" D x 30mm CL.
Insert Non-Plunging Straight Router Bits-1/2" shank - Toolstoday.com - Industrial Quality Tools


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## CanuckGal (Nov 26, 2008)

Sharpco Canada sells a full line of cutters with replaceable tips. Frued has also started selling these types of cutters.


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## Hamlin (Dec 25, 2005)

Can anyone guarantee that the screws holding the blades/knives won't come loose during operation? Think of the vibration going through the bit while cutting. I prefer a solid bit. Just MHO.


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## jschaben (Jun 21, 2009)

Hmmm, I picked mine up off eBay for about $15. This thread got me a bit curious so I just checked on replacement knives. Not to bad, $5 ea but would need two at a time, still not bad...... minimum order 10
I think it is a good bit though. I haven't used it much in the table but used it hand held some last summer doing some outside work. Worked very well for me


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## CanuckGal (Nov 26, 2008)

I think many of the cutters for shaper tools are made this way. They are much bigger of course. I imagine they have been safety tested but still, the screws make me a little nervous too.


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## jschaben (Jun 21, 2009)

CanuckGal said:


> I think many of the cutters for shaper tools are made this way. They are much bigger of course. I imagine they have been safety tested but still, the screws make me a little nervous too.


The one I have is categorized with the CNC bits which typically run at much higher rpms and feed rates than mere mortals achieve. Overall, I'm comfortable with it. Probably wouldn't be running a discount bit though.


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## Phil P (Jul 25, 2010)

Hamlin said:


> Can anyone guarantee that the screws holding the blades/knives won't come loose during operation? Think of the vibration going through the bit while cutting. I prefer a solid bit. Just MHO.


I can't _guarantee_ it, but I've been using multi-trim (the type with top and bottom bearings) and template trim bits (top bearing only) with turn knives for a few years now (about 8 or 9 years) without any problems. The minus is normally that these bits cost a lot more than brazed carbide bits, the plusses are that they never have to go out to the sharpener - replacing tips is a 3 minute operation requiring just a Torx key (normally supplied with the cutter), "resharpening" is normally cheaper than sending out and I reckon that they are actually better on some materials like Corian, acrylic plastics, extremely hard wood, MDF, etc


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## istracpsboss (Sep 14, 2008)

I've some CMT ones and haven't had any problems with them. With all the health & safety legislation and product liability stuff, I can't imagine decent manufacturers would offer them if they were inherently likely to fall apart.

As Bob said, they are old hat for metal working lathe tools. Using them on an interrupted cut imparts far more vibration than woodworking and I've never had the torx screws
work loose.

I like the way the disposable blades can be turned around to offer other edges before needing replacing.

Cheers

Peter


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## BigJimAK (Mar 13, 2009)

istracpsboss said:


> I've some CMT ones and haven't had any problems with them. With all the health & safety legislation and product liability stuff, I can't imagine decent manufacturers would offer them if they were inherently likely to fall apart.
> 
> As Bob said, they are old hat for metal working lathe tools. Using them on an interrupted cut imparts far more vibration than woodworking and I've never had the torx screws
> work loose.
> ...


I've seen them advertised and wondered if they'd be a good match for "bit-eating" materials... like MDF. Yea, $30 for the body with one pair of dual-side cutters and 11.50 for each additional set would equate to $5.75 each time you wanted sharp cutters on your 3/4" bit. N ot worth a darn though if it doesn't feel safe!!


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## Pete_Judd (Oct 19, 2010)

I think that I would use some Lock-Tight on the set screws when installing new knifes.


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## pal (Feb 13, 2008)

We used these in a commercial environment for 10 + years without the screws coming loose, in fact the screws had a tendency to lock in if you overtightened them and you just stripped the head/slot out of them.


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