Shaper near miss-- what did I do wrong?

[roger wiegand]

I decided to make a cutting board with a curved "inlay" (through stripe, actually). I routed a groove, cut it apart on the bandsaw, then tried to use a flush trim router bit to clean up the edge, per youtube videos. As soon as I started the bearing on the router bit blew up. After a few choice words, I said "Hmmm, I have a shaper".

I set up the shaper as shown in the picture, with a rub bearing underneath to follow the edge of the groove and then a big flat cutter to trim the edge. The cutter and bearing are the same diameter, just like a router flush trim bit. I used piece of particle board to raise the workpiece so that my bearing wasn't hitting the table. I figured it would be much like using the flush cutter in a router table.

As soon as I touched the wood to the cutter there was a loud bang, with flying chunks of wood. The second picture shows the result.

Obviously I did something stupid, but I'm not sure what. I'm not anxious to repeat the experiment! Can one of you with more experience with a shaper educate me as to what I did wrong, and what the correct way to do this might be?

IMG_0050.jpg IMG_0054 (1).jpg

[peter gagliardi]

You started into end grain, was the first issue, coupled with what appears to be no "lead in" on your pattern. -The pattern should be longer than the piece being cut, especially if end grain is involved.
Also, that type of cutting benefits from high rpm, and slow feed. Also, cutter projection should be as minimal as possible, and/or more wings to lessen the "grabbiness"
Glad you are intact.

[Matt Day]

I’m not a shaper expert and I don’t totally understand what your design is, but assuming you were flush cutting a radius it looks like a case of funky grain (end grain?) and too heavy a cut. I bet the cutter dug in and spit it out, rather than shaving a light cut.

[Joe Calhoon]

That’s a tricky cut without a template. I see a starting pin of sorts, did you lever in with that? Starting a cut like that on end grain is not good either and it would help to bandsaw closer to the cut. The safe way would be to cut real close on the long grain so you are not removing much and gently start there.

[Joe Calhoon]

We shape a lot without templates just following a routed groove. The best is to use a dead collar with a lead in. There are a few systems available with Aigner and Suva the best. With the lead in you can approach the cutter with good support.
this is shaping a bricklaid door head and cutting a rebate in curved moulding.
8A52C1C0-05C2-47B4-935B-E2E5060144FE.jpg
4C2D040B-BD8B-49B1-B894-FC429AD96FF6.jpg
F1BBF80C-920C-427E-BE68-C5DB7AA4EAB4.jpg

[J.R. Rutter]

That is some serious knife projection on your cutterhead, OP. I would call that machine feed only.

[Ed Mazuronis]

Joe,

I'm in the process of building out a hobby shop in my basement and recently purchased a Felder KF700s (moving it from garage to basement next week). I'm planning to build furniture and cabinetry for our home. I've never used a shaper before and your name came up when talking to Greg at Rangate. Does your shaper course cover the operations used in furniture construction? I've read many of your posts and spending a few days learning and practicing the techniques (like the one above) would be invaluable for a beginner like myself.

[roger wiegand]

Thanks all, sounds like too deep a cut (it was about 3/16) and starting into the end grain with insufficient support. I approached the cut very gingerly, but I imagine the blade pulled the wood right in to the max cut (and then threw it out again). It happened in about a nanosecond. I'm guessing I'd want a cutter made for this purpose if I were going to make a habit of this kind of operation. I may just buy a new router bit-- it seems less scary on the router table!

Thanks, Joe, I hadn't seen that kind of setup before, it looks to be quite useful.

[Mel Fulks]

Good,helpful replies. But why don't spring hold downs get used ? In employments I've dragged them out of storage, and even made them. Used to see some photos with "guard removed for clarity" ,they are also gone.

[John Lanciani]

Irrelevant to the issue at hand but it looks to me like the spindle nut is upside down. Shaper setup is an area that attention to detail is paramount.
Also, I agree with J.R. that that is not a head meant to be hand fed.

[roger wiegand]

Irrelevant to the issue at hand but it looks to me like the spindle nut is upside down. Shaper setup is an area that attention to detail is paramount.
Also, I agree with J.R. that that is not a head meant to be hand fed.

You're right . The only way I've ever used the shaper before is with a power feeder and lots of featherboards. They didn't have a shaper in the high school shop where I learned about tool use many decades ago in adult ed, so I am still pretty ignorant about it. When I think back on it, the shop teacher at Palo Alto High School was a miracle worker in terms of transmitting a lot of information in a very compact period of time. I could use a couple hours with someone like that and my shaper to figure out how to really use the thing. I've read the books, but it doesn't work as well as someone with the drill sergeant persona standing there and saying, "no, dummy, like this!".

[John Kee]

Take the Shaper course that Joe offers, best money you can spend on Shaper operation and safety.

[Martin Wasner]

I've read the books, but it doesn't work as well as someone with the drill sergeant persona standing there and saying, "no, dummy, like this!".

I only learn things in one of three ways;

1. Wow, that really hurt and I should really clean up all this blood before it dries.

2. Wow, that was really expensive.

3. Being yelled at. (Thanks for the crippling mental defect dad....)


I don't have anything to add that Peter, Joe, or J.R. didn't already say.

The nut being upside down is kinda funny, I'm a psychopath about those details. Being raised by an airline pilot, where mistakes get you and a couple hundred other people killed, will do that.

[Peter Kelly]

[roger wiegand]

Take the Shaper course that Joe offers, best money you can spend on Shaper operation and safety.

I don't know about this. Could someone post or PM details?