# Cutting up a router bit?



## Nicolaelapadus (Nov 1, 2012)

Hi all, 
I need to do a custom job for someone. A kindergarten. I need to do a fence for a lunch room, but the above fence should be 6-10 mm thick (1/4-almost1/2), so I choose mdf that is 10 mm thick. After figuering everything out, I realized I have to rout 196 m (643 ft)of chanels with a straight bit.
I bought a CMT. Just one. Is it going to last? The chanels should be 1/8 deep. The store guy didn't have a mortizing bit, so the one that I bought is something like a 1 long. When it's going to get dull can I cut it? Make it shorter so I can use the next 1/8? 
Yes no? Is it insane?
Thanks!


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## Stick486 (Jan 4, 2013)

Nicolaelapadus said:


> Hi all,
> 
> I bought a CMT. Just one. Is it going to last? The channels should be 1/8 deep. The store guy didn't have a mortising bit, so the one that I bought is something like a 1 long. When it's going to get dull can I cut it? Make it shorter so I can use the next 1/8?
> Yes no? Is it insane?
> Thanks!


no it's not going to last.. MDF is really hard on cutters...
regrinding (cutting off that 1/8") isn't going to go well even if you have the correct equipment...
tried that in an emergency so this is how I know....

How ever, as you cut the mortises stop and clean the bit and dress it to get more mileage..(meters)...

https://www.youtube.com/watch?v=Q5aQ_RnGxVw


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## Stick486 (Jan 4, 2013)

Nick, an MDF fence in a kindergarten environment may not be such a good idea..
MDF in the grand scheme of things is pretty fragile, doesn't hold fasteners well, prone to sag under it's own weight and is very heavy... 
expect an MDF fence to have a very short life expectancy....
is there a real wood alternative that you can use even if it's a better/best grade of ply wood such as Baltic Birch or close???


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## Nicolaelapadus (Nov 1, 2012)

Well, that's not good, cause I was the one to suggest mdf. let me explain it in detail. I have 7 sheets of 3 by 8 1/2 feet. Each gets 28 grooves that are 10 mm (more then 3/8) wide and 1/8 deep. They are not going through. So the hole sheet is going to be the same length. I'm going to glue it to the wall, and use fasteners every 2 feet. It's going to be painted, on one side. 
Nick


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## Stick486 (Jan 4, 2013)

Nicolaelapadus said:


> Well, that's not good, cause I was the one to suggest MDF. let me explain it in detail. I have 7 sheets of 3 by 8 1/2 feet. Each gets 28 grooves that are 10 mm (more then 3/8) wide and 1/8 deep. They are not going through. So the hole sheet is going to be the same length. I'm going to glue it to the wall, and use fasteners every 2 feet. It's going to be painted, on one side.
> Nick


you said fence and I saw a fee standing fence like "picket fence"....
this wall mounted panel is 8.5' to the horizontal and the 3' to the vertical... the groves will be vertical also??? So what you are making is a wall mounted open slat faux (Faux - Definition and More from the Free Merriam-Webster Dictionary) fence...

if so.. MDF will be fine and glue won't be necessary... 
keep in mind the MDF will easily follow any contours in/of the wall... also be careful handling the sheets after you grove them.. you can break them if you flex them or try to pick up the sheet from the flat position from the middle... have help all the way and think about what you are doing...

will one sheet butt up against the next???
do you need a jig to simplify repetitious grooving???
do you have a table saw???
what is the the measure from the center of the bit to the edge of the router's base???
what is CL (Centerline Spacing) of the grooves???


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## Nicolaelapadus (Nov 1, 2012)

Yep, the grooves run vertically. 
Yes one sheet will but up against the nex so, I will probably need a transition of some kind? I was thinking of cutting the grooved sheet so it will follow the pattern from the one before. If first will end up with a groove, the next will start as it is, with the factory edge.
I will desperately need a jig. Been scratching my head all day, couldn't figure one out completely.
Yes and no. I do have a table saw, but can't use it for finer work. Plenty of circular saws. And blades. 
This is tricky. At least in Romania. I have a Bosch 1617, been thinking Of using it with the plunge base and thake multiple passes. Distance from center of bit to edge of base...didn't measure it yet...on my colt palm router is 1 7/8. Been trying to find a centering cone but they won't sell it in Romania. 
CL -if I understand correctly, is 10 cm, so the bit will bit 5 mm from each side.
Thanks 
Nick


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## Nicolaelapadus (Nov 1, 2012)

Here's another stupid idea: I was thinking of using a circular saw with a homemade guide rail a make 3 passes and then finish it with the router. Can one mount 2 blades on a circular saw? Like a dado set?
Nick


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## Stick486 (Jan 4, 2013)

Yep, the grooves run vertically.
*now I got the picture...*

Yes one sheet will but up against the next so, I will probably need a transition of some kind? 
*cut a 10mm fillet on one edge and the butt it up against the uncut factory edge... you now have one each groove one that will blend easily...*

I was thinking of cutting the grooved sheet so it will follow the pattern from the one before. If first will end up with a groove, the next will start as it is, with the factory edge.
*I think that's what I'm suggesting...*

I will desperately need a jig. Been scratching my head all day, couldn't figure one out completely.
*stay tuned...*

Yes and no. I do have a table saw, but can't use it for finer work. 
*why is this???*

Plenty of circular saws. And blades.
This is tricky. At least in Romania. 
*what is tricky*

I have a Bosch 1617, 
*3" or 76.2mm from the CL of the router to the fixed base's edge*

been thinking Of using it with the plunge base and take multiple passes. 
*no need to take multiple passes*

Distance from center of bit to edge of base...didn't measure it yet...
*I have a few of 1617's - 3" on the American models...*
on my colt palm router is 1 7/8. 

Been trying to find a centering cone but they won't sell it in Romania.
*use a stubby brad point drill bit as a centering point...*

CL -if I understand correctly, is 10 cm, so the bit will bit 5 mm from each side.
*CL here is the is the center of the router...*

*now for the jig...
how many groves to a sheet do you plan on cutting counting the rabbit*

Thanks 
*no problem...*


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## Stick486 (Jan 4, 2013)

Nicolaelapadus said:


> *Here's another stupid idea*: I was thinking of using a circular saw with a homemade guide rail a make 3 passes and then finish it with the router. Can one mount 2 blades on a circular saw? Like a dado set?
> Nick


you got that right...


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## Nicolaelapadus (Nov 1, 2012)

28 grooves to a sheet. 
Ryobi tablesaw. Blade vibrates, it's not on a 90 degree to the table of the saw, so on...
Tricky is the fact that in Ro, Bosch does nat sell a centering cone. Weird.
Nick


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## Stick486 (Jan 4, 2013)

28 grooves to a sheet.
*I'll work out the measures..
stay tuned...*

Ryobi tablesaw. Blade vibrates, 
*try a new blade and clean the facing washers..
make sure everything is tight..*

it's not on a 90 degree to the table of the saw, so on...
*so adjust it..
read the manual it will tell all..
buy a Bosch 4000 series TS...*

Tricky is the fact that in Ro, Bosch does not sell a centering cone. Weird.
*anybody's cone will work....*


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## Cherryville Chuck (Sep 28, 2010)

Nick you don't necessarily need a centering cone. If you have a guide bushing that is the same size as the collet and a drill bit that is also the same size that will also center the guide bushings.

You can't run 2 blades on a circular saw because of the special washer that holds the blade on. It is only designed to hold one blade on. 2 blades would spin the washer and nut and not stay tight.

There is a jig for a circular saw in this thread that is also running now. http://www.routerforums.com/jigs-fixtures/47411-poor-mans-track-saw.html
If you read the instructions carefully you will see that it will also work for a router, without using a guide bushing. You only have to use the same router and same bit with it every time.


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## Stick486 (Jan 4, 2013)

Nick, what is the true length of one of the sheets in MM or CM???


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## Stick486 (Jan 4, 2013)

Charles...
Bosch guide bushings are self centering...


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## Nicolaelapadus (Nov 1, 2012)

1020x2800x10 mm
Charles...I have that jig. Made my own. I can make another one for the Bosch. I do not have bushings. And I can't figure out your instructions on centering the plate without the cone. Maybe because it's 1 in the morning. 
Talk to you guys tomorrow.
Night!


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## Stick486 (Jan 4, 2013)

Nicolaelapadus said:


> 1020x2800x10 mm


'bout time you got up....

you have 10CM center to center mortises...
you have 9CM wide faux fence pickets...

let's figure out what the CL measure of the router is 1st...

grab piece of scrap mount a straight edge to it and cut a groove... 
after you cut the grove and *DO NOT* remove the guide....
reset the router against the guide w/ the bit in the groove..
mark where the edge of the base where it is furthest from edge guide...
measure the distance between that mark and the edge guide... take that number and divide by 2.. what ever number you come up w/ is what the CL of the router is relative to the base's edge...
hint: write that number on the base w/ a marker for future reference...

I need to know this number......


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## Cherryville Chuck (Sep 28, 2010)

Stick486 said:


> Charles...
> Bosch guide bushings are self centering...


Good to know Stick. I don't own a Bosch so I'm not that familiar with them.


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## Nicolaelapadus (Nov 1, 2012)

Stick, got to wait until Monday. I'll do it then and post some pics. Thanks.
Nick


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## rwbaker (Feb 25, 2010)

I have been listening to this thread when I wondered if anyone had thought about painting a fence on the MDF? If the MDF has grooves and it is in a lunchroom for kindergarteners, they will playfully force coins, pencils and anything else they can find and dig at the grooves thus destroying the MDF in short order. A good artist could paint an escape route from the school and then the cover it with a fence in the foreground, thus presenting one of life's little hidden lessons. A cardboard overlay could be used as a fence template for spraying or rolling in short order. 

Just a thought - Baker


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## Stick486 (Jan 4, 2013)

Nick...

have you considered???

up spiral router bits???
they will clear the saw dust better and your bit experience less abrasion and last longer..
Freud Tools
or 1/4" sank bits.. 
cost less...

Dust collection...
MDF dust is some kind of nasty..

do you have something like these???
Straight Edge Clamps - Peachtree Woodworking Supply


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