# Location of Sommerfeld's rubber grommet



## FSorace (Feb 21, 2011)

Hi all,

New to the site (and routing) and I've been lurking and reading a lot. Truly a wealth of knowledge and experience on this forum. Thank you all for sharing.

I have recently purchased the Tongue and Groove set of bits from Sommerfeld. His videos demonstrate how to set the height, etc, and once set, the other bits are are interchangeable without further adjustment. He shows a little grommet that the base of the bit rests upon.

I'm using a Porter Cable 7518 table mounted router. I'll probably butcher the terminology here as I describe my question(s).

Can anyone tell me where Sommerfeld's grommet is supposed to end up? If I remove the top nut, which is connected to the collet, is the grommet supposed to go into that piece (and keep the shaft of the bit from protruding) or below it ? The space below that collet is pretty deep so if I put it below the collet the bit bottoms out. If If I put the grommet into the collet, will that affect how the shaft of the bit is secured?

It'll probably require a call to Sommerfeld's on Monday, but I thought I'd take a chance and see if anyone knew.

Thanks,

Frank


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## bobj3 (Jan 17, 2006)

Hi Frank

I do it both ways. put a grommet in the bottom of the hole or if it's to deep I glue a grommet to a short dowel rod and put it in the hole BUT I also use a rubber washer that's press in the collet nut ( see below) almost all collets work the same way they grab the router bit at the top of the collet and Not at the bottom of it..so to say the router bit can just sit right on the washers..a faucet washer works just right that you can get from the hardware store in repair kits and they are just the right size for the collet..



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FSorace said:


> Hi all,
> 
> New to the site (and routing) and I've been lurking and reading a lot. Truly a wealth of knowledge and experience on this forum. Thank you all for sharing.
> 
> ...


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## FSorace (Feb 21, 2011)

Thanks, Bob. I did something similar to what you suggested. First I laser cut some 1/2" cicles out of 1/8" plywood and dropped them in with the rubber grommet on top. 

The tonge bit's shaft is longer than the grove bit and I noticed that the resulting cut did not line up as in the video. That's when I took the collet out and noticed how deep the well was. 

First I laser cut some 1/2" cicles out of 1/8" plywood and dropped them in with the rubber grommet on top...and that didn't take up enough space. Then I went the dowel method with the grommet on top...but it wasn't high enough to keep the bit raised to the proper height. I then looked at putting the grommet into the collet, but I didn't know if that was going to create a safety issue. 

Another question....Does dowel spin..and if so, will it rub/wear out that grommet...or is that entire 'throat' spinning along with the bit?

Thanks for the answer...you took a load off my mind!

Frank


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## bobj3 (Jan 17, 2006)

HI Frank

"Does dowel spin" = No, it becomes part of the main shaft so to speak..it just goes along for the ride 

Just a side note,,,,many ask why the bit comes free in the collet, that's because they put it to deep in the collet, almost all router bits have a high side just under the cutter or to say bigger OD just under the cutter, most say lift the bit up by 1/8" and than lock it in place ,1/8" is not enough the norm and the rubber washer under the shaft of the bit takes that error out.

I use it on my routers all the time.. 

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FSorace said:


> Thanks, Bob. I did something similar to what you suggested. First I laser cut some 1/2" cicles out of 1/8" plywood and dropped them in with the rubber grommet on top.
> 
> The tonge bit's shaft is longer than the grove bit and I noticed that the resulting cut did not line up as in the video. That's when I took the collet out and noticed how deep the well was.
> 
> ...


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## jlord (Nov 16, 2009)

I have Sommerfeld bits & I just drop the grommet in the collet then insert the bit & bottom it out on the grommet. That's the only step I've ever had to do. Works great every time. Never bottom out a bit till it hits the collet. There's usually a transitional cove were the machined shank meets the bottom side of the cutter. You need to clear that transition to tighten the bit successfully.


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## FSorace (Feb 21, 2011)

Thanks, James. What I tried to do was stuff the grommet in as far as possible. What I didn't realize is there's about 3" of depth. I was using the bit to push the grommet deeper rather then letting it stop when it hit the grommet. 

It worked fine for the groove bit, but the shaft on the tongue bit was too short and the bit rested on the collet. That's when I realized I might have an issue.

Any problems with using those on 3/4" pine? I noticed in his videos he's using thicker stock.

Frank


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## jw2170 (Jan 24, 2008)

FSorace said:


> Thanks, James. What I tried to do was stuff the grommet in as far as possible. What I didn't realize is there's about 3" of depth. I was using the bit to push the grommet deeper rather then letting it stop when it hit the grommet.
> 
> It worked fine for the groove bit, but the shaft on the tongue bit was too short and the bit rested on the collet. That's when I realized I might have an issue.
> 
> ...


G’day Frank,

Welcome to the router forum. 

Thank you for joining us

I have that situation with a couple of my routers also.

If I just dropped the grommet into the collet, the bit would not touch the grommet even fully inserted.

I must dig them out next week end and confirm which ones have that problem.

I guess it depends on what make/model router you have.


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## FSorace (Feb 21, 2011)

Hi James,

I'm using the Porter Cable 7518. The grommet doesn't fall to the bottom...I pushed it down as far as I could with the tongue bit. Being that the tongue bit has a longer shaft, the groove bit bottomed out. 

I didn't realize how far down that opening went.


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## jlord (Nov 16, 2009)

Hi Frank, If using a Sommerfeld set The bits should be a matched height. No problem with 3/4" stock. If using Sommerfeld bit he sells a setup jig called ezset. It will held with setup with a handfull of his bits. Just dial in the thickness of your material & it will put you in the ballpark.


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## BigJimAK (Mar 13, 2009)

Frank,

FWIW I have a 7518 in my table and use grommets with Marc's bits. In my case I found that one grommet was two thin but two stacked were perfect. I put them in about a year ago and they've been there ever since. It permits me to just drop in the bit, no matter whose, and know I have a safe amount engaged without bottoming out.

Jim



FSorace said:


> Hi all,
> 
> New to the site (and routing) and I've been lurking and reading a lot. Truly a wealth of knowledge and experience on this forum. Thank you all for sharing.
> 
> ...


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## FSorace (Feb 21, 2011)

Jim

Are the two grommets entirely in the collet or is any portion of one sticking out of the bottom? 
Eventually I did as Bob mentioned and put a dowel in the shaft because I pushed two grommets all the way in using the bit. I didn't realize how deep it was and didn't know if they needed some absolute support from the bottom. Being new, I also didn't realize that the bit was gripped at the top, not the bottom, until Bob mentioned it.

Slowly but surely, I'm learning. Thanks for everyone's help.

Frank


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## FSorace (Feb 21, 2011)

Thanks for those links, James. They have some great podcasts.

Frank


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## GJD240 (Aug 4, 2011)

I am using the Sommerfeld Tongue and Groove router bits and EZ Set Jig with a Porter Cable router and have been unable to get the bits adjusted properly. Sommerfeld's recommendation was to insert a dowel into the collet and then place the grommet on top. My first attempt was using an approximate 3/4" piece of dowel and the cuts are much closer, but still about a 1/16" off. Hopefully adding a second grommet will do the trick.
Greg


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## bobj3 (Jan 17, 2006)

Hi Greg

The key to using the Sommerfeld Tongue and Groove router bits is once you set one bit DON't move the router up or down when you switch bits..your joints will come out right on the button..every time.

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GJD240 said:


> I am using the Sommerfeld Tongue and Groove router bits and EZ Set Jig with a Porter Cable router and have been unable to get the bits adjusted properly. Sommerfeld's recommendation was to insert a dowel into the collet and then place the grommet on top. My first attempt was using an approximate 3/4" piece of dowel and the cuts are much closer, but still about a 1/16" off. Hopefully adding a second grommet will do the trick.
> Greg


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