Lesson learned, I think...

Roger Tulk

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St. Catharines, Ontario, Canada
I needed to cut a 3/8" groove in some sassafras, and set up my router table to cut the groove 3/8" deep. As I pushed the board along, it made a lot of bumping noises, and after about 20" It wouldn't go any farther. I stopped the router, and had a look. There was smoke coming off the bit, and thegroove was clean on the forward side, but the rearward side looked like it had been cut with an axe. It was very rougn and bumpy. I couldn't touch the bit, as it was HOT. I pulled it with a pair of pliers, and it came out with a little difficulty. First lesson, I hadn't tightened the bit sufficiently. The bit was black and blue and the top of one of the carbide inserts was missing.

I put in another bit, tightened it until it screamed (I have not used a ¼" adapter before; it had turned blue at the top. :rolleyes: ) and tried again. It was still a little rough, so I cut the speed of the router, made two passes at half depth and then at full depth, and finally got a nice cut.

This is with the Skil router I bought used over the winter. I never saw anything like this with my Mastercraft router in the table.I would not have thought that cutting a 3/8 x 3/8 groove would be a problem. Is there anything else I could have done wrong? I need to know if I missed anything so I can really screw it up next time. :eek:
 
I hate to admit this, but something similar happened to me once - including the carbide loss. Turns out I'd put the wing cutter on the arbor shaft backwards... :eek:
 
3/8 x 3/8 is quite a pass in any wood. I always make multiple passes. Easier in the long run.

+1. The rule of thumb I use is remove no greater profile area than 1/4" x 1/4" at a pass. I usually err on the under side so I would have done three skinny 1/8" grooves with a light pass as a final. YMMV.
 
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+1. The rule of thumb I use is remove no greater profile area than 1/4" x 1/4" at a pass. I usually err on the under side so I would have done three skinny 1/8" grooves with a light pass as a final. YMMV.


I've messed up a few pieces in the past by trying to get it cut quickly. Now I do just as Glenn does. Takes longer but the results are great.
 
roger, i am not sure if this happened to you or not but in some routers the bushing to accept the 1/4" shanks needs to be aligned with the slots of the collet to tighten properly..
 
That would be better done with a stacked dado set. Most of my router bits are either 3 or 4 wings. This helps alot on the cutting.
 
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