Tim's Laser Cutter Extractor

I have made my laser cutter from a Desk-Top CNC Machine.

• It started of as 3018 Desk-Top CNC Machine kit.
• I tried cutting 3mm hardboard with the milling tools and frankly the speed at which it could do it is a joke and the mess it makes was too much.
• So I decided to try a laser attachment, it was able to cut 3mm hardboard ten times faster.
• Cutting Plywood is even faster,
• No mess to really speak of.
• The only issue with cutting with a laser is the smoke, so an extractor is a must.

This Instructable is how I made an extractor for the modified 3018 (3036) CNC machine and made attachments to make it a good laser cutter.

• My extractor is for extracting the smoke from cutting Hardboard and plywood.
• My extractor is designed for a 3018 CNC machine that has been modified to 3036
• If you cut materials that give of toxic fumes, then this is not for you.

There where a few things I did before getting to the point I made the extractor, I will only cover these areas briefly, the step taken should have come with instruction.

• The first step was to add the laser.
• 300mm x 180mm was not a large area to to be cut things with a laser, so the next step was to double its work area to 300mm x 360mm.
• My next step was to make some sort of extractor to remove the smoke. I didn't want to put the whole thing inside a sealed box that gave no access to it. I decided to design and make something slim and stylish.

As the CNC machine has a solid flat bed to work off, I also made some special stand-offs.

• I made a tool to make the stand-offs which as good as the honeycombed trays.
• I also made clips for holding the 3mm materials I use. (3D Printed)

The laser will cut thicker than 3mm, but my setup is based around using 3mm materials.

I have done other things previously to my Machine.

• 3018 CNC Machine [Modify Side Guards] - Instructables
• 3018 CNC Machine [Fitting Limit Switches] : 20 Steps - Instructables

3018 Desk-Top CNC Machine kit.

• It is all based on one of these kits.

3018 Desk-Top CNC Machine Upgrade.

• If you don't have a 3018 Desk-Top CNC Machine and thinking of getting one, see if you can get one already upgraded.
• I don't know where the sellers get the numbers from but it is not 3018 to 3040, it is 3018 to 3036. It is 2 x 3018 beds side by side.

Laser

• I have gone for the LASER TREE CNC 3018 Laser Module Kit.
• I love this laser, but the adverts, lets say under perfect conditions and materials.

Air Assist

• I recommend Air-Assist.
• Using Air-Assist, gives a cleaner cut and helps cut things that have a glue in it's construction.
• Shop around for the type in the image, It's an aquarium pump, those branded with the word laser tend to cost more.

Hardboard. (cheapest material)

• I have used 3mm Hardboard with a white finish on one side for the construction of my extractor.
• I don't see no reason why you cant use 3mm plywood or 3 mm acrylic. (screws may be an issue with acrylic)

Extractor Fan

• 12v 4" Fan
• I shop around eBay for this, I tend to look for things that have what I want inside them, usually it is cheaper than going to a store that specializes in a type of product.
• I found a cheap fan for a truck that plugs into the cigarettes lighter. search for Dual Head Car Cooling Air Fan 2 Speed 12V It was cheaper to buy this than a motor and fan blades.
• I have used an old 12v adapter (wall-wort) to power the fan.

Flexible Ducting

• 4" Flexible Fan Ducting (100mm)
• When buying this be aware the length you order is with it stretched as far as it can be stretched.
• I would add 15 to 20% more to what you think you need when buying it.
• The length will be from your machine to hang out the nearest window.

3D Printer.

• Some parts are 3D printed.

Switch

• I put a small switch and socket on the extractor fan for ease of use,

Screws

• Screws use are M1.7x6mm self tap screws.

Springs

• I have use a couple of small light springs for positioning some movable parts.

Glue

• I used PVA Glue to glue it all together.

The usual DIY tools and bit and pieces.

I started off with a 3018 CNC Machine Kit.

• I thought about making my own from parts sold separately, but I found the kits to be cheaper.
• I do suggest when building one of these kits, you put it together on a good flat surface.
• The kits come with good instruction so there is no point in repeating things.

I will say: If you want one to do any metal machining go for a more expensive one. One constructed completely of metal and has larger Linear Rods. preferably one with bronze bearings.

• Although this has 10mm linear bars, it has Roller Bering guides, and you get too much chatter trying to mill metal.
• It's OK for wood and soft materials.
• The motor you get with it is slow, well it is fast but compered to a good milling motor it is slow. If you don't want to spend hours on a project, this is another consideration.

That's the reason I am converting it to a laser cutter.

One more point to make.

• Get one with the remote control. It makes thing easy to do quick jobs.

To start with I got my self a nice powerful laser.

• It was a square shape in plan and I made a bracket that attached it in front of the motor.
• This was great, but after getting some experience using it I found the pros and cons to using a laser for cutting so to speak.

This is what I learned:

Laser Power

• Obviously more power the better.
• This is not the consumption, the input power, be carful sellers like to advertise the Big Numbers. If the input power is bigger than the output power, that's what they are going to advertise to mislead you.
• You need to make sure it is the OPTICAL Power that is advertised.

Laser Diode

• The big laser diodes that are used don't produce a round beam of light, it is rectangular. Usually the rectangles length is twice the width. So a single diode laser will cut twice as good in one direction than it will cut 90 degrees to that direction.
• Best to get a laser that has 2 diodes inside. these are fixed in place 90 degrees to each other. Well there are prisms/mirrors to effectively set the 90 degrees to each other. In effect by the time they have gone through the lenses the beam is round and cut with the same power in all directions.

Lenses

• Some lenses are better than others. The smaller the focused beam is the more the power is concentrated in one place.
• Fixed Focused Lens. The laser I have has a fixed focus lens, once you find the correct hights for cutting different thicknesses it's OK.
• The important thing is: Your material being cut need to be level throughout, this is one more reason I am converting a CNC machine to a laser cutter, I can fix the material level so the laser cuts at the right height all round.

Lens Protection

• If a laser dose not have the correct optics, the optics will degrade over time. Usually there is a Glass/Crystal widow to protect the main optics from damage. It's a good idea to get a laser where this is replaceable.

Air Assist

• Get a laser that you can easy attach Air Assist.
• Having Air Assist improves cutting immensely.
• Some material like what I use, Plywood and Hardboard, have glue in them, it's part of there construction.
• Glue does not burn into soot, like wood, it melts under the laser. Air Assist blows all that shit out of the way so the laser can cut through.
• To get a good deal with a pump, search for a good aquarium pump, the pumps used for deep aquariums.

The lase I have is the LASER TREE CNC 3018 Laser Module Kit.

• They have made this roundish so that it fits in the clamp for the motor.
• It has all the points mentioned above.
• I have had it a while, and so far I am really pleased with it.

Choosing a laser also depends on your budget.

• If you can find and afford better one go for it.

3018 to 3040 wtf. This is a good example of large numbers is better advertising.

• The upgrade is two 18cm wide by 30cm long tables put side by side.
• So that is 18 x 2 = 36, lets round it up to the nearest 10 for advertising = 40. Yey we have 3040.
• The upgrade get you a 300mm x 360mm Table, 3036.

Any ways for use as a laser cutter this is a great upgrade. Double the work area.

• I would not recommend this upgrade for use with the milling motor.
• The table support bearings remain the same distance apart in all directions.
• The over-hang of the table from the bearings is tripled.

Because of the 10mm thick reinforming brackets underneath to hold the two tables together you loose 10mm in Z clearance.

• This is no issue for laser cutting, the materials I can cut are not thick enough to matter.

A Note about the Reinforcement Brackets of the kit.

• Some of the bolts are countersunk so that they clear the front and back of the machine.
• If the counter sinking is too much the bolts foul on the table and you are unable to tighten the Brackets to the tables.
• To remedy this it will be necessary to shim the bolts with washers.
• It needed washers that fitted inside the countersinking, I 3D Printed plastic ones to the right thickness.

My extractor is based on air flow.

• The idea is we control where the air comes from and we direct it where we want it to go.
• I have mounted the fan at the back and it acts like a vacuum cleaner.
• Although I say like a vacuum cleaner it is not a vacuum we want, it is movement of air, the faster it moves the better.
• The theory is: If all air is drawn to where the fan is then all the smoke will get drawn away with it.
• Having holes and places where the air can enter the machine is not a problem as long as it all is able to exit via the fan.

So if you have upgraded you machine to this stage you should be able to cut the parts.

• I have made my extractor cover out of 3mm Hardboard, It can be made out of 3mm plywood.
• Hardboard takes longer to cut, there is a lot of glue in hardboard, so you have to go slower to melt it out.
• Plywood is quicker, but still has glue, not so much. Still with plywood you get imperfections where it is glued together the inner layers are not always as nice as the outer layers. Some times when I cut plywood I will create two G-Code files, One with the Propper cut speed. The second is what I call a clean-up file, it is the same as the first file but at the top speed of the CNC machine, if there where some places where there was some imperfections in the wood this run will rectify those areas where not cut all the way on the first run. If it is good quality plywood the second run is not usually necessary.

Usually Hardboard is sold in large sheet at your local DIY centre.

• I cut the sheets down into 300mm wide strips, that being the width of the work area.
• All the files are based on using 300mm wide material and cut on this machine.
• As I use hardboard with a white finish on one side any parts that are handed will be handed in the files.

I little nugget of info about laser cutting hard board.

• When you cut hardboard, as I say before, it is full of glue and you have to go slower to melt the glue out of the cut.
• However there is a good result from this.
• The molten glue forms a thin seal on the edge of the hardboard, giving it a lovely finish. You don't end up with a crumbly edge like you do with other methods of cutting hardboard.

Software.

• I have my own software that I use to convert the DXF files to G-Code.
• I don't currently use my software to send the G-Code to the machine, I probably could.
• I use the Remote that came with my machine.

The Remote.

• The Remote is great.
• It has a slot for an SD card where you can copy files to, it is the large sized slot, but my remote came with an adapter and a 1Gb micro SD card.
• You don't need to remove the SD card from the Remote, the Remote has a mini-USB. All you need to do is unplug it from the CNC machine (10p DuPont cable) and plug it into you computer via the USB.
• The Remote acts like USB Drive when plugged into you computer.
• Once you have copied files to it, reconnect the Remote to the CNC machine an off you go.

Part Names

• I have named the parts in the images. To help I identify where they go.
• The Front Flap is slightly shorter than the Rear Flap.

There are several 3D printed parts.

• I used PLA to print all may parts.

The fan housing is specifically designed for the Fan unit bought of eBay.

• If you build this I do hope you can still get the type I bought.

Here is the list of plastic parts.

• 1 x Fan_End.stl
• 2 x Fan_Mount.stl
• 2 x Fan_Retainer,stl
• 6 x Flap_Hinge.stl
• 10 x Hinge.stl
• 1 x Power_Socket_Bracket.stl
• 1 x Switch_Mount.stl
• 1 x Switch_Mount_Nut.stl
• 2 x Bracket.stl

The fan assembly is basic.

• First you need to dissemble one of the fans from the original unit.
• It is held to gather with small screws.
• Remove the front of the fan, so you just have the fan, motor and cage as one unit.
• This then fixes to the Fan_End.stl with four screws.
• The flexible ducting should slide over the Fan_End.stl with a spiral fit.

There are two types of hinge.

• One type for the flaps front and back of the machine,
• One type for the air seals at the sides.

These being small pieces, some fettling may be required.

• There are two screws that act as the pins.
• The outer holes of the hinges should be a slack fit around the screws, the may need reaming with a drill bit.

I hope once you have the pieces cut and when you look at the image, It becomes obvious where all the parts go.

• The whole thing is made up of two assemblies. A Front and Back piece
• The front Assembly is designed to be lifted of to give access to the bed.

Hopefully from the four labelled views you can see where all the parts go.

• The majority is glued together.
• There is a front and rear flap that is hinged.
• On the Front piece there are two side pieces that hinge outwards.
• Both the assemblies are symmetrical left to right.
• There is a piece at the back underneath that is screwed in place using two plastic brackets.

There are two side pieces that hinge outward.

• When closed they stop too much air been drawn in at these points.
• This is to force the air to come from other places and drag the smoke in the direction we want.
• These two pieces need to be hinged so that they move out of the way of the laser module.
• There are springs on the inside to close these pieces when the laser unit move away.

To get a nice clean cut on the underside of the material being cut, it is best to have the material raised from the bed.

• There are expensive honeycombed tables, but we already have a nice flat table, we just need supports.
• Because of our flat table using a honeycombed table on top would not let the air disperse verry well.

I have a solution that is jus as good and is cheap.

• I have made a tool to make corrugated strips mad from drinks cans.
• Because the strips are corrugated they stan up and have the strength to support the material being cut.
• You can pace as many as needed on the bed to support you material, and the air is able to flow in between them.
• If you like you can make them in to rings, If I do I always place the across a channel so the air still has somewhere to go.

Clan a Drinks can and cut it open.

• Measure off 3mm strips.
• Cut out all the strips.
• Place in "Tim's Corrugator" and rotate the wheels to feed the strips through.

Parts for "Tim's Corrugator"

• I cut mine out of 3mm Hardboard with a white finish on one side.
• I used two M1.7x10mm self taping screws to fix it together.
• DXF file attached.

Front Stand-off

• I made a piece to sit along the front, it is amongst the the extractor parts.
• It needs three plastic parts Front_Support_Bracket.stl printing to hold it in place.
• This reduces the smoke for long jobs where the table comes out the front flap.

To hold my 3mm material in place I have designed some plastic grips.

• The grips consist of two parts
• One is a stand-off.
• One part holds/grips the material down.

The part that holds the material down does so as you slide it in from the side.

• It has a slightly tapered top.
• The more you slide it in the tighter it gets.
• The stand-off is separate so the the material get clamped down to the correct height.

I hope this was of interest to some thinking of Getting/Making a Laser Cutter.

• I know it was all about mine bout hopefully some things may help in your choice should you be looking to get one.