Router bit question

[Kodi Crescent]

I'm searching pretty hard for a edge trimming bit for the MFK.  The guy at Woodcraft recommended a straight bit, but I can't find one with the correct dimensions.  There are plenty of mortising bits that fit the MFK.  What's the difference between a straight bit and a mortising bit?

 

[tbellemare]

491666 & 491670 are the recommended straight bits for the MFK.

491670 has replaceable knives, each with 4 usable edges.

Tom

 

[Kodi Crescent]

Thanks, Tom.  I'm asking more of a general question though.

 

[mouppe]

I'm searching pretty hard for a edge trimming bit for the MFK.  The guy at Woodcraft recommended a straight bit, but I can't find one with the correct dimensions.  There are plenty of mortising bits that fit the MFK.  What's the difference between a straight bit and a mortising bit?

I believe it is because the bottom of the blades on a mortise bit are angled to prevent chip build-up. For grooves, I prefer to use spiral bits however. With an up-spiral bit you get a fine finish on the bottom of the groove. With a down-spiral bit you get a better finish on the edges.

What type of edge trimming bit are you looking for? There are tons of flush trim bits here if you want a flush trim bit:-

http://www.freudtools.com/p-128-bearing-flush-trim-bits.aspx

 

[Gregory Paolini]

Kodi,

Generally, Mortising bits (used for hinge mortising) have the body of the bit hollowed out somewhat at the tip, in order to prevent contact and burning when cutting into the work surface.  They're designed to make a shallow plunge into the work surface, and if the tip were not hollowed, the solid center woild contact the workpiece, limiting depth of cut.

Some mortising bits have "over center" cutters, which extend the length of the cutter beyond the centerline of the bit, allowing the bit to plunge as deep as the router will travel.  Generally, this type of deep plunge, the kind you would use to make a mortise for a tennon, is better suited to up cut spiral bits.  Mortising bits designed for hinge installation are usually made for depths no deeper than 1/4 inch.

Hope this helps
-gp

 

[Kodi Crescent]

Thanks guys.  So I bought a MFK 700.  It was suggested that I use a straight bit for edge trimming.  Most straight bits are 3/4" cutting length or longer.  The MFK will only accept a bit with a 5/8" cutting length.  I see there aren't really any straight bits that fit the bill.  However, there are mortising bits that fall within the acceptable specifications.  I was looking for alternatives to paying the $40 for the Festool bit.

 

[mouppe]

5'8" carbide length. 1/4" shank. $16.

http://www.internationaltool.com/Straight-Spiral-and-Trim-Bits/Freud-04105.aspx?utm_source=frjan11&utm_medium=pdc&utm_campaign=sandcutaccy&utm_term=4105

 

[RonMiller]

I've been using the Festool straight bit made for this and it's excellent. $40 may seem alot but mine has lasted through hundreds of feet of trim. Just a thought.

 

[nickao]

5' 8" carbide length sure is long, hehe.

5/8" I think fixes your typo. 

 

[mouppe]

thanks, nickao. A 5' bit would be a good deal for $16!

 

[Jerry Sitton]

I was hoping to see pics of the stuff you were working on with that bit.  [eek]

 

[Jerry Sitton]

That would be the Hemi driven MFK.  [big grin]

 

[Kodi Crescent]

Thanks, guys!  I'll look into that bit.