Problems Routering with a Pattern and Bit

Rich Aldrich

Member
Messages
296
Location
Manistique, Michigan
This was my first time trying this technique. I tried routering the finished shape on a few pieces of oak today. I was using the pin, but when I got around the end grain, the bit really grabbed the wood. It was an inside corner on end grain.

I ruined two pieces and gave up.

A spindle sander would definitely work better, but you couldnt make a duplicate pattern.
 
I often make half a pattern if the shape is bilateral. I do half the pattern then flip the material and re-tape the template to do the other half; this avoids routing improperly with the grain. I have had occasion to make two patterns or more to get my shape as a single pattern would require routing "up hill" which often gives the result you are experiencing. Rule of thumb: always route down hill (with the grain sloping into the material and away from the cut edge in the direction of the cut [hope that made sense]).
 
And it can scare you witless the first time it happens. I agree with Glen, going into the end grain cut from the downhill side minimizes grab. Also remember that the pin is just for starting, to keep the router from throwing the workpiece across the shop. Once started, avoid pinching the workpiece between the pin and the bit, or somehow having the pin become a fulcrum.

Cheers.
 
Good tip Rennie! I just ordered my first spiral bits yesterday from Grizzly. But they aren't pattern bits but I think I'll be ordering some of those in the future!

Royall, you can still use the regular spiral bits you're getting for pattern cutting, by using a guide bushing in your router plate, just make the pattern smaller to accommodate the distance from the OD of the Bushing to the OD of the bit.

(I'm sure you know this though):D (Annnnnd..... the regular spiral bits are cheaper than the spiral pattern bits too):D
 
climb cutting will stop tearout, if i know i`m going to climb cut (i do every single cut in oak!) i make my pattern oversized and as heavy as possible.
scab some handles on to the pattern that will allow you leverage and keep your hands out of the line of fire.
if you need to rout all four sides of a piece make two patterns and do half at a time, try to cut endgrain first then remove tearout by routing the edge grain last.
 
A spindle sander would definitely work better, but you couldnt make a duplicate pattern. (KJB: Emphasis added)

That doesn't sound right to me somehow. There's gotta be a way to make patterns that will work with a spindle sander. I haven't done it myself, but here are a couple of ideas:
1) What if you made your own table insert that was 1/4" (or whatever) thicker than the stock insert? Let's say that the outer "wall" of the insert was 1/2" from the surface of the sanding sleeve. You would make your pattern so that the workpiece would overhang the edge by 1/2". Attach the workpiece to the pattern and with the pattern on the table, underneath the workpiece.

2) Suppose that method #1 didn't work very well because the insert kept popping out (no way to positively attach it, and you tend to exert a lot of lateral pressure against it) or you need to use a small spindle and the overhang gets to be too big to work with. You could do something similar with an "ox yoke" shape, where a thin semicircular arc on "your side" of the spindle joins up with a wide board on the backside. Clamp the board to the table, and away you go!​
Has anyone done this before?
 
Has anyone done this before?

yup, there are bearings available for sanding sleeves, if the pattern isn`t full of tight radiuses a simple plywood guide fastened to the table will work.
oh-yeah....bearings do not work with an oscillating sander, the up-n-down motion makes for good paper life but dosen`t do well staying on a pattern.
 
Royall, you can still use the regular spiral bits you're getting for pattern cutting, by using a guide bushing in your router plate, just make the pattern smaller to accommodate the distance from the OD of the Bushing to the OD of the bit.

(I'm sure you know this though):D (Annnnnd..... the regular spiral bits are cheaper than the spiral pattern bits too):D

Good idea Norman:thumb:, and no I didn't know:doh: I do now:D
 
Would things be just as bad if I clamped the piece to my work bench and used my patterning bit? I could still watch the grain and do a climb cut where appropriate? Would this be dangerous?
 
Have you tried a spiral flush trim bit? I just did 10 shelves with a radius on the end grain. Put the template on the top side rather then on the bottom as you would with a pattern bit that has the bearing on the oposit end. worked well for me. But I also after routing the entite piece,climb cut the leading radius a second time to get a smoother cut.:dunno::D
 
Thank you for all of the responses. I appreciate the help. This weekend I will try to route with the piece clamped to the bench and move the router around the piece.

I havent tried a spiral flush trim bit yet, but I think it is going on my list. Maybe I can get one before the weekend.
 
Top