Introduction: CNC Milling Machine

Heavy CNC milling machine project started in 2015.

A lot of different working steps are necessary to build a big CNC machine with good milling performance;

Building a big and accurate mold for casting the epoxy granite.

Aligning the linear guides and ball screw.

Setting up the electronics; stepper motors, spindle and the home switches the power supply and the connection to the computer with the CNC controller Linux CNC.

And finally a housing for clean and optimal machining experience.

Step 1: Planning and Making Decisions

It took me some time researching about CNC constructions, CNC parts, casting and possibilities before i could start. I decided do make a heavy epoxy granite CNC for high speed milling. The components are low price CNC parts from China. One first thing to decide is the working space for the x, y and z axis. In my case 450mm x 350mm x 200mm.

Step 2: The Plan

My working space was defined and i made a plan so i could order the right length guiding rails and ball screws, also the amount of epoxy resin had to be calculated, inserts bolds, and plywood for the mold.

Step 3: The Mold

The heavy CNC machine granite is a two part structure, the base and the bridge. Therefore i had to make two big molds. The molds are made out of thick plywood with the lamination on the inside. Some dry layers of liquid wax are important for separation after the cast is cured.

Threaded bolds, made on the lathe by modifying big hexagon bolds, are positioned through previously precisely drilled holes and fixed with screws. They are for mounting the guiding rails, ball screws and stepper motors on the cast.

The aluminium pipes inside the mold make the holes for the bolts that hold down the bridge on the base.

Every inside corner of the mold is sealed with silicon bevor waxing all laminated faces.

The bottom side of the mold must be perfectly flat for casting, the mold has to be positioned on a reference granite plate.

The mold is now ready for casting.

Step 4: The Epoxy Granite

The epoxy granite is a mixture with epoxy and gravel filler with different grain sizes. The sizes are chosen to make the most possible dense gravel mixture. This saves expensive epoxy and it makes the machine heavier and more stable.

One important thing is to make sure that the mold lies flat on a reference surface.

Thick layer of epoxy can get hot during hardening. the heat can bend the wooden mold and destroy the surface. Clamped down the mold on the reference surface to prevent it.

Mix the epoxy with the dry gravel and sand, carefully by hand, not to get to much air bubbles inside the epoxy granite mix.

Pure the epoxy granite inside the mold and use strong vibration device to shake out every air bubbles. The impact drill is just a tickle for 300kg (The epoxy granite the granite reference plate and the mold with claps)

Hope for the best and let it cure.

Step 5: The Linear Guiding Rails

The guiding rails need to be positioned perfectly to each other in any direction, starting from the x rails.

The X rails must be parallel and straight. The Y rails than need to be aligned to the X rails and they also must be straight and parallel. The Z than has to be aligned to the Y and Z rails.

Step 6: The X Y and Z Axis

I made the moving parts on the x y and z axis primarily from wood to be able to machine them from aluminium later. It was my only option since i had no other metal cutting machine.

Step 7: The X Thread Grid Plate

The x axis is moving the grid plate in x direction. To machine a part, it has to be mounted on this plate by screwing it to the thread grid.

Step 8:

The z axis moves the spindle motor up and down. For clean and straight cuts the spindle must be mounted perfect vertically to the x fixing plate. The construction must also be rigid to hold up the forces during heavy milling.

Step 9: Machining the Aluminium Parts

I machined all the aluminium with my wooden CNC setup. It worked great but at the end i noticed that the wooden structure was about to get retired, luckily not until i finished all my parts.

Step 10: Electronics, Cover and Lubrication

One big subproject was the electronics with the stepper motors, spindle setup and limit switches. Also the covers to protect the linear guides and the central lubrication for the sleds and the ball screws.

Step 11: The Housing, Dust and Cooling System

The machine than needs a housing for water cooling, dust collection and safety. I made the frame from stainless steel and plexiglas doors and windows. The working space is covered and sealed so every drop of water should run back into the cooling water system.

For dry dust collection while milling wood i have made a dust shoe to remove dust directly from the cutting tool.

Step 12: Cover

The x axis rails and the ball screw is covered with a telescope cover made from 2mm aluminium sheets. I cut it with the Jigsaw, made the V-grooves with the router and bend it by hand.

Step 13: Cooling Water Drain

The water for cooling the milling tool has to be directed into the collection container with a filter to circle the water.

Here is how the water drain was made with an angle grinder. We bend it by hand and weld the corners.

Step 14: Testing and Milling

Finally milling with the own machine is the best part when everything works well. I still need some upgrades and some more steps to complete the machine in total. Although i am milling since 2016 and constantly making my CNC upgrades alongside. Here are some projects i made with the machine.

Step 15: Testing the Performance

By cutting high quality aluminium with the CNC machine.

Step 16: Experimenting

There are many possibilities wit a router on 3 axis. One experimental milling project was engraving a round wooden bar.

Step 17: Find Milling Projects

Now its time to continue to be creative and start some milling projects like artistic 3D models, engravings or just parts for a new project.

Step 18: Let the Machine Do the Work

When everything worked out well you can relaxe, whats left is to feed the machine with material and it will replicate your part.

Comments

author
Pikaubanitro (author)2017-03-08

Du solide! Bravo

author
3D Meister (author)Pikaubanitro2017-03-09

Danke You! :)

author
caseybarsness (author)2017-03-01

Very cool project! Did you use rolled or ground ball screws? And what is there precision? (C3, C5, T7, etc..). Also, what size are the linear rails? 25mm?

author
3D Meister (author)caseybarsness2017-03-03

The linear rails are 23. The balls screws are rolled 16, maybe C7.

author
mahdmod.musafani (author)2017-02-26

That's so sweet project! Read this in the morning and have been designing my own version of epoxy frame CNC all day :D Super inspiring!
Do the ball screws really need a system to lube them instead of the user manually adding some oil every now and then?

author

Thank You!

I made the piping system with pneumatic hoses and connected all sleds and ball screws to reach them all from the outside with one hose ending. The ball screws are hard to access and greasing every singe sled its always a dirty business. If you want to run your machine through the day than grease is its best friend. I will connect the hose with a automatic grease gun later.

author
lathe_makeatio (author)2017-02-26

Very impressive and well done! Can you move it without a forklifter? Seems to be very heavy.

author

The total weight with housing is about 800kg the machine is about 400kg. I moved the machine twice with the workshop crane. It was an adventure. It took me 3 hours to move it 35m and 6 Steps up to my new workshop room.

author
jthomas6080 (author)2017-02-25

how much time spent to build it? what was the cost?

author
3D Meister (author)jthomas60802017-02-26

I started in the beginning of the year 2015 and i spent nearly 5000€ to build this machine without housing. The housing made from stainless steel and plexiglas was a gift, i saved it from disposal.

author
sanjaykray (author)2017-02-25

amazing project

author
3D Meister (author)sanjaykray2017-02-25

Thank you!

author
baecker03 (author)2017-02-25

Please throw up done videos of milling. thanks

author
3D Meister (author)baecker032017-02-25

Done!

author
Swansong (author)2017-02-23

That's really neat! If you include some written instructions along with the progress photos in each step it'll get more attention from the community and be able to be featured on the site. :) https://www.instructables.com/id/How-to-Create-a-F...

author
3D Meister (author)Swansong2017-02-24

Thank you for advice.