Splintering when routing rail/stile grooves on cope & stick doors

[scott vroom]

Interesting....a step-down zero clearance system. Worth a try, US Plastics sells both 1/4" & 1/8" x 12 x 24 UHMW online for a reasonable price. One downside is the time it would take to set up and run the 4 passes, particularly if you're making 10-20 doors.

Assuming you are doing the sticking cut ....

Set your router table fence flush with the bearing as usual. Clamp some UHMW sheeting to the fence and take a shallow cut then remove the UHMW and make the full depth cut. I use a piece of 1/4" and a piece of 1/8 inch stacked against the fence. Make a pass then remove the 1/8", make a pass remove the 1/4" and put the 1/8" back in place, make a pass then remove the 1/8" and make the final pass.

I do this also for the raised panel bit.

If you are doing the cope cut use a a backer board behind the rail.

[scott vroom]

Cary, do you get consistently splinter-free edges on the final profile pass after the jointer step? I also am in the habit of milling wider rail/stile stock to start, it's a good hedge against mistakes rather that having to mill a new piece from scratch. I'm going to try your method...it adds little time to the profiling process. I'm not a professional but I do an occasional kitchen/bath/laundry/built-in storage etc job for my general contractor son when the local commercial shops are booked too far out to meet his schedule, which is becoming common around Central Oregon with the current housing boom. My hourly pay is dismal given my low productivity compared to the commercial shops, but it keeps me busy and I enjoy the work.

I always cut my rail and stiles wider than they need to be. I make a shallow cut the first time and then follow with the full depth. If I see that the profile is not to my liking, I run the edge the edge through the jointer to take a 1/16 of whatever it takes to get rid of the splintering/whatever and then back to the shaper. After the edge is good I cut to final width. This takes more time but I don't do it professionally.

[Cary Falk]

Cary, do you get consistently splinter-free edges on the final profile pass after the jointer step? I also am in the habit of milling wider rail/stile stock to start, it's a good hedge against mistakes rather that having to mill a new piece from scratch. I'm going to try your method...it adds little time to the profiling process. I'm not a professional but I do an occasional kitchen/bath/laundry/built-in storage etc job for my general contractor son when the local commercial shops are booked too far out to meet his schedule, which is becoming common around Central Oregon with the current housing boom. My hourly pay is dismal given my low productivity compared to the commercial shops, but it keeps me busy and I enjoy the work.

I usually do unless the wood is just problematic and I have to get a new piece(this is rare).

[Rod Sheridan]

Rail and stile bits always have a bearing. Without a bearing fence set up would be very difficult.

Why?

I set up my shaper fence without a bearing, why does a router table need a bearing on the bit if a fence is being used?

Regards, Rod.

[scott vroom]

Why?

I set up my shaper fence without a bearing, why does a router table need a bearing on the bit if a fence is being used?

Regards, Rod.

Rod,

Cope and stick router bits come with a bearing and are typically sold as a matching set which enables very quick set up, no set-up blocks/trial and error required for depth of cut. Bearings aren't required but they sure are convenient.

[johnny means]

im trying to think through how to make a zero clearance fence for a stile or rail router bit that has a bearing on it

I set the actual fence back by the thickness of my sacrificial material. I then push the sacrificial faces into the cut until they hit the bearing. This cuts a perfect profile into both faces. back them out of the cut a 16th or so and attach in place. The 16th just helps with heat build up and chip clearance.

[Kevin Jenness]

If you want to leave the bearing on just cut a vertical slot or drill a hole in the sacrificial fence for clearance for the bearing before breaking through.

[mreza Salav]

Do the ends of the rails first (with a backer board to prevent splinter at the end of the cut). Then do the rest.
Using good quality/sharp bits makes a big difference. Cheap/budget bits don't work as nicely.

[Jared Sankovich]

Are you having the issue with the same VG Fir from the other thread?

[scott vroom]

Not yet...I started this thread looking for ideas before beginning that project. I just finished an oak kitchen and fought the splintering throughout.

[Mel Fulks]

[QUOTE=Kevin Jenness;3089618]If your profile cutter(s) takes a full height cut you can eliminate tearout by overcutting 1/16" or so- if you want to end up with 2 1/4" width start with 2 5/16". Easiest way is with an outboard fence

I certainly agree on the extra 1/16 th thing and have always done that. But I see it as mainly a way to make sure all the
copes fit well by having that extra. Without that ,no matter how carefully you prepare your material ,you might have a little dip ithat might
make a muntin show a slight gap. And, of course...the extra 1/16th eliminates jointing edges ,as it will be removed.
by the profile run. With real short rails and muntins You can line them up end touching end and staple a piece of
plywood to the backs. That eliminates the dips sometimes found on short profiled rails and muntins....and even LONG
pieces....not cut with good guidance of an outboard fence.

[Robert Engel]

Scooter, there’s a couple ways to deal with it.

Checking grain direction helps a lot. Some wood is hard to deal with no matter what.

If needed, I rip a 1/16th off the profile edge and run it again. But you have to remember to make your material a bit wider.

Another way is to make a very shallow pass initially.

I’ve also seen some people make an initial dado cut on table saw.

ZCI sounds good, but how would dust collection work?

Last but not least, it can be about the router bits. Some bit sets are made (CMT I believe) that make a very slight round over on the groove edges.

[Kevin Jenness]

Tearout on cope/stick profile cuts, in my experience, mainly occurs at the groove edges. Tearout elsewhere is suppressed for the same reason that the overcut technique and zero clearance fences work-the finished surface is backed up before the tool exits the workpiece. Tearout elsewhere is relatively rare and can be attributed to contrary or figured grain, poorly designed or dull cutters, or too fast a feed rate. Sometimes it can be alleviated with a light, slow second cut.

You can reliably prevent tearout at the exit points of the groove by pre-scoring with a mortise gauge. It's an extra step but fairly quick and is independent of the fence setup.

"ZCI sounds good, but how would dust collection work?"

Works just fine.

[Dave Sabo]

Sharper bit ?

[scott vroom]

I'll be using a Whiteside 5990 Shaker Profile Stile & Rail Router Bit Set on the VGF doors I'll be making next week. I've used the set only once, 28 doors on a kitchen/bath job, alder species with some minor tear out on the groove edges. I don't expect cutter sharpness to be an issue. The Whiteside groove bit is a straight square cut with no edge rounding. For the red oak job I mentioned above where I had unacceptable splintering on the groove cut, I used a new Freud 99-760 round over rail/stile set. I think the red oak species may have been the culprit.

I'll run a few test pieces using a couple of the above suggested methods, will post results. Many thanks for all the responses.