Router Table Insert Recommendations

[db5]

I need some advice on how to best do this:

I’m building a router table and have some 3/8 Plexiglas which I will use for a router table insert plate. I already have the dimensions but also have read much about insert rings. The recommendations are that the rings exceed the router bit by 1/8 to ¼ inch and I can buy those from several sources at outrageous prices if you hate spending money you don’t have.

However, since I have a large sheet of Plexiglas what do I need to know is in cutting these? I do know that Plexiglas heats rapidly and have done some experimentation and have concluded that I might want to put the saw blade in the freezer for a few hours before cutting Plexiglas. Haven’t tried it but it is a consideration.

·Can I use hole cutters to drill the center?
·Do I drill the center before making the insert ring?
·Can I use a bandsaw to cut out the circle and then a sanding disk to smooth it?
·Do I cut at a high or low speed?
·Do I sand at a high or low speed?

·What important thing did I not ask?

[JPG]

I need some advice on how to best do this:

I’m building a router table and have some 3/8 Plexiglas which I will use for a router table insert plate. I already have the dimensions but also have read much about insert rings. The recommendations are that the rings exceed the router bit by 1/8 to ¼ inch and I can buy those from several sources at outrageous prices if you hate spending money you don’t have.

However, since I have a large sheet of Plexiglas what do I need to know is in cutting these? I do know that Plexiglas heats rapidly and have done some experimentation and have concluded that I might want to put the saw blade in the freezer for a few hours before cutting Plexiglas. Haven’t tried it but it is a consideration.

·Can I use hole cutters to drill the center?
·Do I drill the center before making the insert ring?
·Can I use a bandsaw to cut out the circle and then a sanding disk to smooth it?
·Do I cut at a high or low speed?
·Do I sand at a high or low speed?

·What important thing did I not ask?

I doubt freezing the saw blade will help much.

Any cutting must be done at a speed much slower than a typical wood cutting operation. It is the heat generated by the cutting that leads to melting of the work piece. Sanding must also be done at a slow speed.

Feed rate must also be reduced. I have been pleased with the 'machinability' of plexiglass, but learned quickly the stuff mentioned above.

Too aggressive a cut can produce chipping.


Bottom line, go slow!!!

[dusty]

I doubt freezing the saw blade will help much.

Any cutting must be done at a speed much slower than a typical wood cutting operation. It is the heat generated by the cutting that leads to melting of the work piece. Sanding must also be done at a slow speed.

Feed rate must also be reduced. I have been pleased with the 'machinability' of plexiglass, but learned quickly the stuff mentioned above.

Too aggressive a cut can produce chipping.


Bottom line, go slow!!!

Do you have a scroll saw with variable speed controls?

[reible]

I need some advice on how to best do this:

I&#8217]

However, since I have a large sheet of Plexiglas what do I need to know is in cutting these? I do know that Plexiglas heats rapidly and have done some experimentation and have concluded that I might want to put the saw blade in the freezer for a few hours before cutting Plexiglas. Haven’t tried it but it is a consideration.

·Can I use hole cutters to drill the center?
·Do I drill the center before making the insert ring?
·Can I use a bandsaw to cut out the circle and then a sanding disk to smooth it?
·Do I cut at a high or low speed?
·Do I sand at a high or low speed?

·What important thing did I not ask?

Hi,

I'm a little confused as to what you are attempting to build here??

Yes I know you are building a router table and that you are planning on using the 3/8" material for the insert. After this is where I'm confused.

It is important to know what you want to end up with. Router bits can range in size from over 3" in diameter to very small, say 1/32". Commercial router plates deal with this with inserts. Likely as not they have a set of larger inserts that are not a "standard" size or mounting method.

Once you get to the smaller size openings, around 1-1/2" you can buy brass inserts in sets to cover your needs. These are made to fit one of two standards.

Other methods exist on a manufactures whim, either the router maker or the table maker can force their design on you.

The second type of inserts are called guide bushing or template guides. They are designed to help guide the cut, offset from the bit by predetermined distances. Once again they come into play on the smaller size openings. Again two standards exist as well as manufactures designs.

In the case of plane inserts you need to only be as accurate as the bit clears the edge of the hole. Guide bushings however need to be concentric with the axis of the router, and this needs to be quite close. If you build to use the guide bushings the placement for the inserts will be fine.

Since the router mounts to the table insert you should start with the location of the router shaft and then determine the location of the mounting holes..... yes you can do it the "other way" but it is a lot harder to get the alignment right. If going with standard sizes they make kits that make the process a lot easier.

Once you are sure what you want you have to make a plan to follow. Drilling in the proper sequence and stock mounting are areas to focus on.

So far as working with the material I think you have already been playing with it and that is the way to learn so keep it up. One hint here is to leave the paper on, it comes off only at the end.

Ed

[Ed in Tampa]

I need some advice on how to best do this:

I’m building a router table and have some 3/8 Plexiglas which I will use for a router table insert plate. I already have the dimensions but also have read much about insert rings. The recommendations are that the rings exceed the router bit by 1/8 to ¼ inch and I can buy those from several sources at outrageous prices if you hate spending money you don’t have.

However, since I have a large sheet of Plexiglas what do I need to know is in cutting these? I do know that Plexiglas heats rapidly and have done some experimentation and have concluded that I might want to put the saw blade in the freezer for a few hours before cutting Plexiglas. Haven’t tried it but it is a consideration.

·Can I use hole cutters to drill the center?
·Do I drill the center before making the insert ring?
·Can I use a bandsaw to cut out the circle and then a sanding disk to smooth it?
·Do I cut at a high or low speed?
·Do I sand at a high or low speed?

·What important thing did I not ask?

Here is what I would do.
If you decide to use a circle cutter I would first drill the hole for the pilot bit.
Then I would mount that pilot bit in my router and using it to center my router on the plate mark the location of the screw holes to hold the router to the plate.
Then I would drill those holes and mount the router if all goes well I would then go ahead and drill out the center hole to fit the inserts.

You could also do this if you have a bit that will make a hole large enough for the insert.
First using a small drill bit drill your initial hole.
Then chuck that drill bit in the router and use it to position the router.
Mark and drill the screw holes to connect the router to the plate.
Mount the router with the bit large enough to make the insert hole.
Slowly lower the router/bit onto the plate allowing it to cut the material.
You want a flat bottom plunge hole cutter the size of the insert hole to make this cut.

Food for thought
Plexiglass is a commonly used material for router table inserts but i'm told (I have no experience of this myself) that plexiglass will sag with time if the router is left hanging from it. Most newer inserts are aluminum, phenolic resin board or carbon fiber.

[Cavediver]

Here is what I would do.
If you decide to use a circle cutter I would first drill the hole for the pilot bit.
Then I would mount that pilot bit in my router and using it to center my router on the plate mark the location of the screw holes to hold the router to the plate.
Then I would drill those holes and mount the router if all goes well I would then go ahead and drill out the center hole to fit the inserts.

You could also do this if you have a bit that will make a hole large enough for the insert.
First using a small drill bit drill your initial hole.
Then chuck that drill bit in the router and use it to position the router.
Mark and drill the screw holes to connect the router to the plate.
Mount the router with the bit large enough to make the insert hole.
Slowly lower the router/bit onto the plate allowing it to cut the material.
You want a flat bottom plunge hole cutter the size of the insert hole to make this cut.

Food for thought
Plexiglass is a commonly used material for router table inserts but i'm told (I have no experience of this myself) that plexiglass will sag with time if the router is left hanging from it. Most newer inserts are aluminum, phenolic resin board or carbon fiber.

I know this is probably common sense, but do not turn the router on with that drill bit in the chuck.

[frank81]

To answer the question about working with plexi, as was mentioned cut slower because if the material gets too hot it melts and reforms behind your blade. Hand tools are best, but if you need to speed it up I've used a reciprocating saw for rough cut then sanded with a dremel followed by hand sanding with automotive grade paper (1000 grit).

If you want the cut edges to be clear, sand as smooth as possible then lightly pass a torch over it until it looks like you want it to.

[reible]

I had a few moments at the end of my workshop day so I shot some pictures for those who might be interested.

Background, the PC trim router has a small base which works great for doing what it was designed to do, but when I was doing some work the base was just too small. Routing out areas can leave you with no place left for the router to sit, expanding the sub base will fix that. You can think about this as the same thing you might do if you were going to table mount the router and needed a plate to mount it to.

I had some material so this is what I built.

[ATTACH]21134[/ATTACH]

I believe this is 3/8" in thick and is quite rigid. I opted for this shape due to what I was working on and has worked for other projects just as well, yea it might look a little odd but it works.

Here you can see the mounting screws that attach the sub base.

[ATTACH]21135[/ATTACH]

In this picture you can see the parts that a kit would include. You have a drill rod and insert with matching hole. Please note that this hole is the one that gets drilled first. Then you have pointed threaded screws that fit the router base. They are used to find the location of the hole so you can get them in the right place. The insert and drill rod provide the starting point and you work out from there.

This photo shows the concept of how this all works. Keep in mind any time the sub base is removed you re-assemble it using the same process. The locating datum is always the router shaft.

[ATTACH]21136[/ATTACH]

This shows an insert installed. The one installed is 1/8" and is recessed in a counter bore so the sub-base can slide over the material without any interference.

[ATTACH]21137[/ATTACH]

A nut holds the insert in place as shown here.

[ATTACH]21138[/ATTACH]

Just one more picture but I've hit the limit here so I'll continue on the next post.

Ed

[reible]

Mounting in the same manner is a guide bushing, as you can see it extends beyond the sub base where a template might be used as a guide.

[ATTACH]21139[/ATTACH]

If you have questions ask away.


Ed

[db5]

Thank you all for your recommendations. That has rightfully caused me to not rush forward and think through this process.

Just acquired 510 table tubes, which I will adapt to my router table (work in progress). I won’t give you the details but they came from the same source and were free. Seems he was saving them for a project. He had upgraded to a 520. They moved into a house in the neighborhood that had a 3-car garage, which was what he had before. His wife used the 3rd one for her stuff and he had a storage shed. He can’t have one in this association and she seemed to think she still had the third garage. After a discussion they reached a compromise (I’d liked to have been a fly on the wall to hear that one). They will share and he will get rid of stuff and so will she; one for one. She picks what is most important to her and then he does. Everything else goes. These tubes were not on the top pick list.

So, I picked them up and have removed the tubes previously attached to my work-in-progress router table and will replace them with these. The PCV tubes are free, along with the spacers, to anyone who wants them. Pay-it-Forward and I’ll ship free. They are the same width as the 510 table.

One of the members here traded me spacers and jack-screws for two tubes so I didn’t have to order them from SS. I’ll post pictures of the change along with exact measurements and recommendations for anyone who wants to duplicate this. Thanks to Glenn C. I may be able to sell the extra tubes I have on eBay and recover the outrageous price I paid for the tubes from my neighbor. With the longer tubes I got I think I got a good deal.

I'm giving some thought into also making this an extension table but haven't decided how best to do this.

Recommendations are requested.