# Chamfer Bit for Acrylic



## OBG65 (May 5, 2018)

I'm thinking about using acrylic/plexi glass in some of the things I want to delve into. Mostly I want to do some chamfering and rounding over the edges. What bits do you recommend - brands, angles, radius, shank, cutting length, and diameter - for acrylic. Do you recommend table routing, hand held routing, or both. When routing the material do you start with the ends using a backing board to prevent chip out then do the edges, or it really doesn't matter. I ask because when I use a chamfer plane, I do the ends first with a backer board to prevent the chip out.

Thanks for the advice.


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## Stick486 (Jan 4, 2013)

*What is Acrylic?*
Acrylic is a clear plastic that closely resembles glass but has many advantages, making it in excellent substitute in many applications.* Compared to glass, acrylic is:
Lighter in weight by half 
Stronger and more impact resistant 
Offers better insulating properties 
More transparent 
Acrylic does have several main disadvantages. it’s more expensive and it can melt and burn if exposed to a direct flame.* Because it doesn’t transfer heat well, special care needs to be taken when working with acrylic to avoid creating heat, which may cause stress that can lead to crazing. it is nick sensitive which can lead to cracking. it doesn't do or hold weight well. it will sag under it's own weight.

*How to Cut Acrylic*
Acrylic comes with a protective masking on both sides.* Keep the masking on for as long as possible throughout the fabrication process to protect the finish.
There are several ways to cut acrylic, but regardless of which method you use, you will want to prevent your cutting tools from becoming a source of damaging heat.* One method is to use a table saw, preferably with a carbide-type blade with 10 teeth per inch.* Acrylic can also be cut with a CNC router, a CO2 laser or a water jet.* Note that each cutting method will create a different edge finish.
Choose a saw blade that is designed for cutting acrylic. *The blade’s teeth should be fine, of the same height, evenly spaced, with little or no set.* Be sure to feed the acrylic into the saw blade at a steady rate — feeding it too fast or too slow can cause the edge of the material to melt.
Thin pieces of acrylic (1/8″ or less in thickness) can be scored like glass using a scribing knife, metal scriber, awl or utility knife, and snapped apart. Note that this process does not work well for long cuts and may not leave an edge that is flat enough for capillary gluing.

*How to Drill Acrylic*
Acrylic can be drilled successfully but there are two situations you need to avoid: creating heat and twisting the material.* Heat generated by a drill can cause the acrylic to melt or crack, and any twisting or grabbing by the drill bit can cause the material to fracture.
A normal twist drill can be modified for use on acrylic with a bench grinder. *Use specially-ground and polished drill bits that are designed for use with acrylic.* You can modify the bit by grinding small flats onto both cutting edges, so the bit cuts with a scraping action. If the drill is correctly sharpened and operated at the correct speed, a long curly strand of acrylic will be created during the drilling process.
Drill speed is an important factor.* Set the drill press from 500 to1000 RPM. *Always begin and end the drilling of holes at a slow-feed rate. *If you are drilling a series of holes, allow the bit to cool off from time to time to avoid heating the acrylic.
A piece of plywood can be placed behind the acrylic to give the exiting drill bit something to dig into and prevent it from grabbing the acrylic as the drill speed winds down.* To prevent cracking the edge of the acrylic sheet, do not drill too close to the edge (1.5 times the diameter of the hole measured from the center would be considered “too close”).

*How to Finish Acrylic Edges*
Several factors will determine how well you need to finish the edges of your acrylic pieces: *how the project is going to be used, if the joints will be glued, the type of glue you plan to use, and the type of joint desired.* During the early planning stages of your project, remember that choosing the right saw blade for your initial cuts can greatly minimize the amount of edge finishing needed down the road.
There are several methods for finishing the edges of a piece of acrylic.* For details, go to “Finishing Acrylite Acrylic Sheets.” 

*How to Glue Acrylic*
Solvent cements are recommended to create strong, transparent and durable joints on acrylic pieces.* When using solvent cements, always work in a well-ventilated area away from heat or flames.* Wear protective goggles and clothing and follow the manufacturer’s instructions.
Capillary cementing is the most popular method for joining acrylic. To create perfect joints, make sure that all surfaces that will be joined together fit without force and are flat, straight and clean.* Hold the pieces together using masking tape or a clamp and keep the joint in a horizontal plane so the cement doesn’t run out.
Apply the cement carefully along the entire joint. For box-corner joints, apply the cement from the inside edge.* On flat joints, apply the cement on both sides if possible.
For best results, use a needle-nosed applicator bottle. Allow the joint to set for about 30 minutes before moving the joined pieces. *Note that maximum bond strength takes 24 to 48 hours.

Acrylic can be purchased in sheets, tubes or rods of varying thicknesses and is a popular material for windows, aquariums, shower doors, skylights, picture frames and more.* Some brands of acrylic, such as Acrylite and Lucite, come in different colors, textures and performance grades.* Once you understand the guidelines of working with acrylic.


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## Stick486 (Jan 4, 2013)

OBG65 said:


> I'm thinking about using acrylic/plexi glass in some of the things I want to delve into. Mostly I want to do some chamfering and rounding over the edges. What bits do you recommend - brands, angles, radius, shank, cutting length, and diameter - for acrylic. Do you recommend table routing, hand held routing, or both. When routing the material do you start with the ends using a backing board to prevent chip out then do the edges, or it really doesn't matter. I ask because when I use a chamfer plane, I do the ends first with a backer board to prevent the chip out.
> 
> Thanks for the advice.


now for your question..

Freud Quadracut bits can't be bit...

for blades..
https://www.freudtools.com/products/LU94M010


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## sreilly (May 22, 2018)

Good info I think I had from a previous post from Stick. Timing is good as well as I've been going through a new book to me but old reference for a lot. The Router Magic book by Bill Hylton is full of interesting and useful knowledge including the making of jigs using acrylic. One thing I noticed from searching blades yesterday, many seem to include non-ferrous metals cutting as well. Having nor real world experience in either I would expect the better choice is getting a blade designed for the material you're actually cutting.


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## senebraskaee (Apr 29, 2012)

*Acrylic*

I just finished a small (6" x 6" x 5/8") cover for a project. It had 6 holes and one large tapped pipe plug. Two methods that worked well for me:
I used a band saw to cut the irregular shape. Once I found the right feed rate it cut very well. To fast and it will melt and seize to the blade.
For drilling someone suggested a stepped drill bit run a very low speed. I find twist drills are very risky for an amateur like me but the stepped bit worked like a charm. I used a small stream of compressed air to keep the bit cool and had no problems.
Good luck, acrylic is interesting stuff!
Mike


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## harrysin (Jan 15, 2007)

I've cut and routed all kinds of Acrylics on the band saw, saw table, hand held router and router table. Unlike wood I have never experienced chip-out and I use standard woodworking bits. I've never used a backing board.


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## OBG65 (May 5, 2018)

Thanks for the info Stick. I already use W. L. Fuller Plexi-Point bits or the ones from McMaster-Carr for drilling, I use a 14 TPI blade on my bandsaw, and the Freud LU94M100 80T blade for the table saw. I like the looks of the Freud Quadra Cut round over. Any suggestions on a chamfer bit.


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## Stick486 (Jan 4, 2013)

W.L. Fuller of RI..
top shelf..

LU94M100 80T???
do you mean LU94M010 80T???

you'll love those Quadra-cuts...
chamfer.. I'm a Freud addict...


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## TenGees (Sep 12, 2012)

I found that plexi cuts and routers quite easily. The worst problems arise with a jigsaw and poor blade. There the cut can glue itself back together behind your blade... too much heat. Router bits can get gummed up which will also create heat problems.


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## ger21 (Feb 10, 2019)

> Any suggestions on a chamfer bit.


Any high quality, sharp bit will work. 
I would highly recommend keeping bits for plastic separate, and use them for plastic only. Once you use them on wood, they won't give as clean a cut in plastic.


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## OBG65 (May 5, 2018)

Yes Stick it was a typo. It's the LU94M010 80T. I also have an Oshlund SBP-100080 80T blade for plastics as well.

TG - at what speed do you run your router at when working with acrylic/plastics?

Gerry - great idea. Looks like I'll be spending some additional $$$ on router bits.:wink:


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## bobgramann (Mar 28, 2010)

Depending on what you’re doing, you might consider spending extra and using polycarbonate (Lexan). It’s a lot friendlier for machining and doesn’t crack with sharp edges.


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## OBG65 (May 5, 2018)

That's a good suggestion Bob. Thanks. I'm looking at making display stands for some people I know that own gun stores and go to the shows.


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## swCObob (Feb 12, 2021)

Stick486 said:


> *What is Acrylic?*
> Acrylic is a clear plastic that closely resembles glass but has many advantages, making it in excellent substitute in many applications.* Compared to glass, acrylic is:
> Lighter in weight by half
> Stronger and more impact resistant
> ...


I need to drill a 2" diameter hole in a 12"x24"x3/8" thick piece of acrylic, to use as a bowl making jig. 

What is most suitable for making the 2" center hole, a hole saw, forstner bit or my only 2" router bit, a 4 wing Whiteside spoil board bit? Would it help to use a drill press and water the cutting?

Will a standard metal bit work for safely drilling the small diameter router plate mounting holes? Thanks to anyone who has experience. Bob


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## ger21 (Feb 10, 2019)

If you have any good quality plywood (or even MDF), drill a 2" hole in that and use it for a template to route a hole in the acrylic. I'd first use a slightly smaller hole saw to remove most of the material, and the router to clean it up.
When you drill through acrylic, it can ship or crack on the back side, making it substantially weaker. Routing will give the cleanest hole, which won't impact the strength.


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## swCObob (Feb 12, 2021)

ger21 said:


> If you have any good quality plywood (or even MDF), drill a 2" hole in that and use it for a template to route a hole in the acrylic. I'd first use a slightly smaller hole saw to remove most of the material, and the router to clean it up.
> When you drill through acrylic, it can ship or crack on the back side, making it substantially weaker. Routing will give the cleanest hole, which won't impact the strength.


Thank you.


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