# Router insert plate opening size



## rcp612 (Oct 22, 2008)

I'm putting together a new router table and am concerned with the insert opening.
I have a Rockler plate which I kept from my "old" table and decided to follow the idea (well,,,,,almost ) in the PW link where Bob Lang shows how to install a plate.
I decided to use a 3/4" mortise bit with a 3/4 bearing installed on the shank for following the template. Then, with a 1 3/8" O.D. bushing and a 3/8" straight bit, cut the opening leaving a 1/2" shoulder all around for the plate to sit in. 
Looks great!! But, the plate now has somewhere around 1/32" space all around it. Looks good but, the plate is sloppy in the recess. 
Good for me for trying this in a piece of scrap before going to my new table top.
Now, what did I do wrong, or, what should I have done different??
I'm not going to cut the new top until I get the right fit in scrap or know how to make it right after the fact.


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## bobj3 (Jan 17, 2006)

HI Roger

In the video from Bob L. he tells you what you must use to get it to come out just right..

1/4" bit and a 3/4" guide then a rabbit bit but it's not a real big deal to fix what you have now, put out your heat gun/hair dryer ,cut one puce of laminate to go all the way around inside the hole (cut it a bit long) heat it up and push it in the hole,let it cool down then glue it in place and use your trim router bit to get it to fit right on the top edge then put the laminate on the top..
You can use the plate to get it in the hole just right and to hold the laminate in place..

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rcp612 said:


> I'm putting together a new router table and am concerned with the insert opening.
> I have a Rockler plate which I kept from my "old" table and decided to follow the idea (well,,,,,almost ) in the PW link where Bob Lang shows how to install a plate.
> I decided to use a 3/4" mortise bit with a 3/4 bearing installed on the shank for following the template. Then, with a 1 3/8" O.D. bushing and a 3/8" straight bit, cut the opening leaving a 1/2" shoulder all around for the plate to sit in.
> Looks great!! But, the plate now has somewhere around 1/32" space all around it. Looks good but, the plate is sloppy in the recess.
> ...


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## Mike Wingate (Apr 26, 2009)

Wrap a few turns of tape around your bush to give you the correct offset, and cut again for real.


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## jschaben (Jun 21, 2009)

rcp612 said:


> I'm putting together a new router table and am concerned with the insert opening.
> I have a Rockler plate which I kept from my "old" table and decided to follow the idea (well,,,,,almost ) in the PW link where Bob Lang shows how to install a plate.
> I decided to use a 3/4" mortise bit with a 3/4 bearing installed on the shank for following the template. Then, with a 1 3/8" O.D. bushing and a 3/8" straight bit, cut the opening leaving a 1/2" shoulder all around for the plate to sit in.
> Looks great!! But, the plate now has somewhere around 1/32" space all around it. Looks good but, the plate is sloppy in the recess.
> ...


Hi Roger, Only thing I can think of is to double check and make sure the template is exactly right and put a caliper on your mortise bit and bearing.


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## rcp612 (Oct 22, 2008)

jschaben said:


> Hi Roger, Only thing I can think of is to double check and make sure the template is exactly right and put a caliper on your mortise bit and bearing.



Good point but, I already checked the bearing diameter, the bit diameter, and,,, even checked to be sure the sides of the template were square. (3/4" MDF)
The plate actually had to be pulled out of the template making me think that my routed ledge would be just as tight.
The other posts suggesting tape on the bushing, or following Bob Langs sizes won't work in this scenario. I'm wanting to route the ledge for the plate 1st then do the cut out inside. This way, in my mind, I can match the corner radius of the plate which I can't see happening with a rabbiting bit, and make all my cuts referenced from the template, which fit the plate perfectly.
I'm going to try other ways today unless I run out of scrap.


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## jschaben (Jun 21, 2009)

rcp612 said:


> I'm wanting to route the ledge for the plate 1st then do the cut out inside. This way, in my mind, I can match the corner radius of the plate which I can't see happening with a rabbiting bit, and make all my cuts referenced from the template, which fit the plate perfectly.
> I'm going to try other ways today unless I run out of scrap.


I kinda guessed that that is what you were up to. Can't figure why the template is a tight fit and a flush cut is larger. 
What radius do you have on the plate?


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## rcp612 (Oct 22, 2008)

jschaben said:


> I kinda guessed that that is what you were up to. Can't figure why the template is a tight fit and a flush cut is larger.
> What radius do you have on the plate?


I have checked over and over and IMO the actual radius is either 5/16" or metric. 
The 3/8" radius (3/4" bit) is so close that I was just going to go with that, assuming the sides and ends would offer the support needed to keep the plate centered. And, the small gap in the corners would be a great place to store dust!!! :sarcastic:


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## rick7938 (Jul 19, 2009)

That is why I always cut a template in 1/2-inch MDF, get the fit just right, and use a template bit. There is just too much room for error using other methods. It may work for some, but it has never worked perfectly for me like the template has.


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## Duane867 (Oct 25, 2008)

bobj3 said:


> HI Roger
> 
> In the video from Bob L. he tells you what you must use to get it to come out just right..
> 
> ...


I just shimmed mine ( and it works great ) , but thats a dang good idea.
I may give that a try.


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## Mike Wingate (Apr 26, 2009)

I made a template by "boxing" the plate with 4 pieces of ply, double sided taped to the blank template, then using the correct bits to give me a good (exact fit).


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## RanL (Jan 24, 2009)

May try using epoxy and micro balloons. Works great for bedding actions in rifles. Put some release agent on the insert and then put the epoxy along one side of the table. Should be able to get it as tight as you want it.


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## BigJimAK (Mar 13, 2009)

+1 on the template... get it perfect (or good enough). You don't goof your table and can always make another template if necessary.

Just my opinion..


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## jschaben (Jun 21, 2009)

BigJimAK said:


> +1 on the template... get it perfect (or good enough). You don't goof your table and can always make another template if necessary.
> 
> Just my opinion..


Jim - That's part of the issue,, He says the template fits the plate perfectly. I have seen a lot of suggestions on how to fix the problem but few on how to avoid it. 
Re-read the first few posts and you will see what I mean. Dogged if I can think of what the problem might be.


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## bobj3 (Jan 17, 2006)

Just a butt in post

If you use a PATTERN bit you will not have the error  and use a 1/2" thick MDF template.
OR the
3/4" Dado clean out bit on 1/4" thick templates,then use a brass guide and a 1/4" bit to cut out the hole..

I like to use the 1 1/8" bit
http://www.mlcswoodworking.com/shop...html/pages/bt_flush.html#pattern_flush_anchor

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_dado.html
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=


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## jschaben (Jun 21, 2009)

bobj3 said:


> Just a butt in post
> 
> If you use a PATTERN bit you will not have the error  and use a 1/2" thick MDF template.
> 
> ...


Hi Bob - I always appreciate your "butt in" posts, I usually learn sumthin:dance3:
The original post said he used a 3/4" top bearing mortise bit. I was thinking that would be the same as a pattern bit? He said he also mic'd the bit and the bearing and the pattern is 3/4 MDF. 
I see what he is trying to do. He is trying to more closely match the radius on his plate. The method given in the video will not give him a 3/8" radius and a 1/2" ledge. :blink:


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## rcp612 (Oct 22, 2008)

bobj3 said:


> Just a butt in post
> 
> If you use a PATTERN bit you will not have the error  and use a 1/2" thick MDF template.
> OR the
> ...


I understand what you're saying Bob but, just what is different between a pattern bit and a 3/4" morticing bit with a 3/4" bearing on the shank ??
Also, why must I use 1/2" MDF for the template ?? I used 3/4" MDF because the length of my bit wouldn't allow me to use thinner material and maintain the cut depth I needed.
And, to re-state my dilemma, the plate fits my template very tightly but, my "test" cut-out in a piece of scrap is about 1/32" bigger on all sides. I may be a little anal but I want to do this perfect. 
I am getting a new bit, a Whiteside, and will try that out this week as time allows. The bit I was using was a Holbren but I've never had any problems with his bits but, then again, I've never done anything that is so precise as I want this. Maybe I'm just going over the edge on this project.


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## rcp612 (Oct 22, 2008)

Just saw you were posting at the same time as me John. +1 on your take of my "problem".


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## jschaben (Jun 21, 2009)

Roger, one other thought. Could you have tipped the router a bit making the initial cut?  Wouldn't take much on a 3/4" pattern. I double face tape a piece of pattern material to the router base to keep that from happening.
Actually, Bob's second sentence about a 3/4" Dado clean out bit should be the same thing as what you did, that's why I was trying to think of a execution problem rather than a hardware problem.


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## bobj3 (Jan 17, 2006)

Hi John

Using 3/4" thick template is fine, both bits will do the trick.
Using the dado bit works the best,it's easy to sand the corners on the plate to fit right in the pocket.
Using a 1/4" thick template makes it easy and so many of the templates they sale for the plates are 1/4" thick..the norm..it's a one time thing the norm..

I will say using the rabbit bit is a bit more than the new user wants to take on..keep it in the KISS way is best for the new users..of the router.. 

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jschaben said:


> Hi Bob - I always appreciate your "butt in" posts, I usually learn sumthin:dance3:
> The original post said he used a 3/4" top bearing mortise bit. I was thinking that would be the same as a pattern bit? He said he also mic'd the bit and the bearing and the pattern is 3/4 MDF.
> I see what he is trying to do. He is trying to more closely match the radius on his plate. The method given in the video will not give him a 3/8" radius and a 1/2" ledge. :blink:


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## BigJimAK (Mar 13, 2009)

Roger,

Let's see if I understand, because my answer will only apply if I do.

* You have a template that your plate fits in snugly.
* when you use a 3/4" bit with a 3/4" bearing to cut your "practice" tabletop, the plate has slop in the resulting recess.

If I understand what you are saying and this is the case, I can only think of a few possibilities:

1. The bearing or bit are not exactly the same diameter (bit larger).
2. The center of the bearing is not aligned with the center of the bit.
3. The bit is "bent" enough to cut a slot wider than 3/4" (such that when that part of the bit passes the edge of the template, it cuts deeper.

You indicate there is slop in the resulting cut. This means the bit is undercutting the template, if the template is the correct size. Obviously the through-cut for the opening doesn't affect slop. Tipping the router could cause it too but if the slop is fairly even all around, you'd have to be mighty consistent in your tipping! 

I hope I understand correctly and I hope this helps.


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## rcp612 (Oct 22, 2008)

I got my Whiteside 5/8" straight bit with 1/4" depth of cut along with a 5/8" bearing for the shank. Same results. :'(
So, not one to give up. I started placing my pattern boards on the new table top and, after making doubly sure that the plate was square and my pattern pieces were square I set the long side in place. Then I set one short (side) piece with a credit card between it and the first piece. I did the same for the other end piece. After removing the plate the pattern pieces were placed without the credit cards thus giving me a smaller template to work with.
Voila!!  Perfection !!
As to the whole problem from the start, I still don't know what went wrong. But, it's done now and I can move on.
I'll be sure to post pics later, after I get batteries for my camera.


Now where did I put those credit cards ??? Oh well, they were my wife's anyhow.


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## jschaben (Jun 21, 2009)

Hi Roger, glad ya gotter done.
To bad you couldn't find out what the basic problem was. Sounded like a good plan......


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