Router safety question

[Brian in Dawson Creek]

I’m reading Pat Warner’s book titled “The Router Book” and have read the chapter on safety a few times but I still don’t understand why the cut in the photo is a dangerous cut other than the bit is exposed and maybe but I’m not sure and that the piece is trapped between the bit and the table, but then a slot cutter works the same way and are considered safe. You could flip the board over thus keeping the bit on the bottom side. A guard could be also be used, But lets say the bit is raised panel bit with back cutter … the bit would still be exposed. I’m missing something.

Thanks

Brian
4348

[Kiely]

The process in the picture could certainly be safer.

First of all, the exposed bit - if your hand slipped into the bit, it would be hamburger. It takes exactly the same amount of time to set the bit up on the bottom of the piece as it would to set it up on the top.

Second, with the bit on top of the piece like that, you risk kicking back your chunk of wood.

Although I don't understand what's being referred to in the thickness planer comment in the bottom of the pic?

Rabbets like this can also be done easily on the jointer. :)

For router safety you want, as much as possible, to keep the bit hidden under the piece, like for raised panels.

[Ron Evers, Beeton, ON]

Brian, this is a great example for my contention that ALL the woodworking should be on one forum. If there was a separate forum for routers I & I expect many others would not have seen your question.

I concur with Kiely, cut with the cutter buried. As for a panel bit with back-cutter, the idea scares the bejevers out of me.

[Brian in Dawson Creek]

Thanks all for the replies and clarification, and Ron I have used a small raised panel set with back cutter and was fairly comfortable with it just taking small bites at a time (moving the fence back). Even at that time I had a healthy respect for the back cutter and found I was using the GRR-Ripper more and more on the router table, my reasoning was why hold the piece with your hand when a GRR-Ripper could hold it just as well. I also have the big Freud raised panel bit with back cutter but as of yet have not used it as it’s just seems huge and that one does scare me a bit. In any event safety is always a good topic.

As for a separate router forum … the majority had spoken a long time ago in favor of no new forum … I thought it was getting quite around here and thought I would stir the pot some, seems like I step on some toes in the process.

Brian

[Mack C. in Brooklin ON]

Thanks all for the replies and clarification, and Ron I have used a small raised panel set with back cutter and was fairly comfortable with it just taking small bites at a time (moving the fence back). Even at that time I had a healthy respect for the back cutter and found I was using the GRR-Ripper more and more on the router table, my reasoning was why hold the piece with your hand when a GRR-Ripper could hold it just as well. I also have the big Freud raised panel bit with back cutter but as of yet have not used it as it’s just seems huge and that one does scare me a bit. In any event safety is always a good topic.

As for a separate router forum … the majority had spoken a long time ago in favor of no new forum … I thought it was getting quite around here and thought I would stir the pot some, [quote]seems like I step on some toes in the process. Hi Brian; I didn't understand the original question so I never attempted to answer. I see the difficulty now of the cutting bit being exposed. I have a set of T & G cutters where you can't help but have the cutter exposed. Just takes a little more care.

Oh yeah; don't ever poll again for a separate router forum!:lol: at least until the next time. I never answer the polls anyway. I'm way to laid back for that. I can go with the flow, lifes too short to get my tail in a knot, unless it has something to do regarding the strength of dowel joints vs mortise & tenon joints led by Frank D.

[Brian in Dawson Creek]

Hi Mack … now you have me thinking as I have the CMT slot cutter set and it also can set up to cut a M+T configuration … Hmmmm.

Oh yeah; don't ever poll again for a separate router forum!:lol: at least until the next time. I never answer the polls anyway. I'm way to laid back for that. I can go with the flow, lifes too short to get my tail in a knot, unless it has something to do regarding the strength of dowel joints vs mortise & tenon joints led by Frank D.
Nope … don’t plan on doing that again any time soon … Holy Cow:D :D :D

Brian

[Allen]

Rabbets like this can also be done easily on the jointer.

I could never under stand how this is done are all jointers able to do this ?

[Brian in Dawson Creek]

Not sure if all jointer can this … I know mine will but as it involved removing the guard I found a different method. Here is some info on the topic, scroll down to near the bottom.

Brian
http://www.woodworkersjournal.com/ezine/archive/67/qanda.cfm

[J.P. Rap]

I'm afraid to say you guys have all completely misinterpreted the statement.

Here is what it says. I highlighted the important part.


"A tongue produced this way-Both cuts referenced from the same face of the stock- is high risk woodworking. If your thickness planer is well tuned, there is never a need for this."

In other words, if your planer is well tuned, all your boards will be exactly the size you need and identical. There would be no need to cut a tongue in this manor. You simply cut one side, flip it and cut the other side. I'm not sure if the "high risk" is actually referring to safety or if he means poor technique. When I read it, I took it to mean there was a risk of damaging the tongue because the tongue is trapped between two cutters. The risk is in ruining your work.

Look again. I think you might agree with me. If you don't, let me know and we can duke it out.:p


Edit...on second thought...:oops:
I had assumed there were two cutters. One on top and one on bottom. It's difficult to tell but he may mean the first cut was done with the bit buried then it was raised for the second cut. However I'm sticking with my original statement as it's still valid.

[Kiely]

Rabbets like this can also be done easily on the jointer.

I could never under stand how this is done are all jointers able to do this ?


Not all jointers can do this - your jointer needs to have a 'shelf' on the infeed table big enough to support the piece you are rabbeting. You'll have to remove the guard, and slide your fence over. The distance from the edge of the blades to the fence are (typically) the width of your rabbet. Adjust the height of the infeed table to get your depth.

The side that goes against the fence is typically the inside of the box or whatever you are trying to make.

Bigger rabbets might need more than one depth and width setting. You are usually limited in the depth of the rabbet to a max of 1/2", because that is usually what most infeed tables will go down to.

So, for example you set your fence at 3/8" from the edge of the blades. You set your height of the cut at 1/4". Run your board on edge through the jointer, and you should have a nice 3/8x1/4" rabbet - perfect for a 1/4" drawer bottom. The 3/8 width give you enough room to nail into. Of course you'd go less wide when you use thinner pieces.

Hope this helps! :)

[Brian in Dawson Creek]

You’re probably right J.P... It could have been a little clearer in the article. You cleared things up … at least for me. As far as duking it out goes … no thanks, I’ve caused enough trouble for one day … thanks anyways.

Brian

[J.P. Rap]

Second, with the bit on top of the piece like that, you risk kicking back your chunk of wood.


I dont get it. Why would there be any more risk of kickback with this cut over the exact same cut with the cutter at the bottom. The only difference is the tongue is trapped by the cutter. I agree that might increase the risk of KB but only very slightly. So little in fact that IMO it's not enough to make it an issue.



the idea scares the bejevers out of me.

Bejevers HA! I get it! That's funny!:D

[J.P. Rap]

You’re probably right J.P... It could have been a little clearer in the article. You cleared things up … at least for me. As far as duking it out goes … no thanks, I’ve caused enough trouble for one day … thanks anyways.

Brian

I agree. It isn't very clear is it? It's poorly written in that there isn't nearly as much information there as there should be. A lot is left to the imagination.


Naturally I meant duking it verbally but I guess you knew that. Maybe you're right and you should lay low for a while.:rolleyes:

[Kiely]

I dont get it. Why would there be any more risk of kickback with this cut over the exact same cut with the cutter at the bottom. The only difference is the tongue is trapped by the cutter. I agree that might increase the risk of KB but only very slightly. So little in fact that IMO it's not enough to make it an issue.




Bejevers HA! I get it! That's funny!:D

Agreed JP that the risk is small - but if you've ever used a shaper you'll know what I'm talking about. A little bit of flutter in the piece as you push it and it can go. Granted that routers are very underpowered when compared to shapers but in a large router the possibility is there.

If the cutter is at the bottom and the piece flutters as you push it unevenly or whatever, the piece will just lift up, free of the bit and no kickback. If it lifts up and is trapped under the bit, it can go.

Of all woodworking processes, routing is the safest, and if my table happened to be set up this way I wouldn't worry too much about it. But it's good to know what's safe and why and how to make things as safe as possible and then make the right decision without going overboard.

[Ken in Regina]

J.P.

I agree and disagree. I agree with your interpretation but I thought the original caption was perfectly clear without interpretation.

To continue the analysis, there are two cuts being made. The first is made with the cutter low to take off the "bottom" side of the tongue. This would be done for each board. Then the cutter is raised to the high position in the photo. The boards are all run through again with the same face (reference face) on the table as for the first cut.

The purpose of doing this is so you can get a tongue of the same thickness in exactly the same position from the reference face of each board on stock that might not be precisely the same thickness.

As some have mentioned, if you have a thickness planer this technique shouldn't be necessary. If you don't have a thickness planer and the location of the tongue from a reference face is critical and the boards are not identical in thickness then it's the only way I can think of to do it.

The reason this is less safe than passing the board over the cutter in the lower position is that the board is trapped and can kick back or kick out. The most likely scenario when the cutter is in the lower position (board is above the cutter) is that the board will "float" or bounce.

A kickback from a buried cutter is not impossible but it's not common. On the other hand, with a trapped board a kickback is the most likely result of any misstep. The pictured cut also leaves the cutter exposed so a slip of the hand will have painful consequences, also less likely when the cutter is under the board.

Last observation: I suspect that a router is a far more common shop tool than jointers and thickness planers in hobbyist shops.

...ken...

[J.P. Rap]

Kiely...Agreed.



I agree with your interpretation but I thought the original caption was perfectly clear without interpretation.

Perhaps it was perfectly clear to you and I ( and perhaps others) but I got the sense those who replied weren't sure what what was going on. That seemed to be the reason for the question in the first place. Also, There was some confusion as to the reference to a thickness planer...Another reason for my interpretation

I don't believe this is a "high risk" cut. I do agree there are better ways to do it but like any cut, the risk has to be dealt with properly. Feather boards would be a good idea here. .
Cheers