How to Build Epoxy Granite Machine Base 

A great video! Thanks for taking the time to share this with us. Here are some ideas I hope you find helpful. 1) To eliminate the cosmetic surface bubbles you can paint the mold with a coating of straight epoxy first. You could also color this epoxy to form a "gel coat" effect. Let it set up, or gel, before poring in the rest of the epoxy. If it isn't set enough, the epoxy granite mixture will "wash" it off. If it gets too hard it won't bond chemically with the epoxy granite and may flake off later. 2) De-gas the epoxy sand mixture in the bucket with your vacuum. That would help get rid of all of the little bubbles. Then be careful when you fill your mold to not create too many new bubbles. The bubbles you make pouring the epoxy into the mold will be large and those will rise to the surface quickly. 3) Packing ratio. Others have mentioned this. If you want to reduce the percentage of epoxy, you need to have different sized particles in your solids. If they are all the same size you will have a packing ratio of only about 64%. Mixing together sands of different grain sizes can increase you packing ratio and decrease your epoxy usage. 4) Epoxy does not bond to polyethylene. You can make your mold out of polyethylene as it machines nicely. There is also poly tape that can be used to to make a non-stick surface. Wax is still a good idea, but if you miss a spot it wouldn't matter much. 5) Sand blasting your aluminum parts is the gold standard for getting good adhesion with epoxy. Do it shortly before casting to prevent the aluminum from having time to grow a new oxide layer, and wear gloves to prevent contaminating the surface with skin oils. 6) Gloves: Wear them whenever you are using epoxy. Look up "epoxy contact dermatitis" to see why it is important.

More,more,more,please. Fantastic build and awsome video. Thank you for your generosity.

This is the only video I have ever given a thumbs up. People should be required to watch this prior to uploading instructional videos. Thanks man.

Very. Cool. Game. Changer. This also solves the problem of the DIY guy who wants to make huge machine tool frames but has no access to iron casting equipment. Awesome project and video. Added to many of my playlists. But also added to personal favorites.

WOW! That's just one of the best explaining videos I've ever seen! If not THE BEST! Thank you so much for your great scientific work and for sharing it with everyone! Just great. Cheers mate!

Returning to this video for more insight / inspiration. The quick links to different sections of the video is a winner. Definitely implementing that. Thanks again.

Your finished product is a work of art.

I used to work making cultured marble and granit. We used powder and resins. Mixed it for about 2 hours, added dye, and laid it on a glass top shaker table. We shook it over night. Very informative though, as I'm wanting to build my own machine with a 4th axis for vertical round grinding, vertical free turn, and of course as a mill.

I think I've read your article on this about 10 times now. Great to see some videos too. A long-term review of the microscope / base would be interesting. Will keep watching for more videos.

First off great video. Very informative. I worked on an R&D project using Metal Injection Molding. The goal was to maximize the density of the metal balls and minimize the plastic filler. I learned that if you have fairly uniform diameter balls, the amount of plastic was about 17% (by volume) to have a mixture that had no interstitial voids with the minimum plastic. This 17% figure will always be the same for any mixture using uniform ball (or rocks here) size regardless of the size. Somewhat counter-intuitive to me. This would seem to be applicable if you assume that the sand grains are fairly uniform in size. You can get a denser mixture by using significantly larger rocks with the sand filling the space between the rocks. Here in Florida, I would put the fillers in the oven to drive out any moisture.

4 years later and still super useful. Thanks!

Thank you very much for sharing your work. You have put lot of time and effort to educate people like me. Keep up your good work. Good luck.

Really enjoyed the video, great and thorough walkthrough!

Well done young man!?! The most beautiful and solid machine base I've seen outside of pure granite

Great work here! You inspired me to think of a couple things that might help. 1) a cheap shaker motor is easy to make: just use any motor, bur on the shaft you put an imbalanced load. 2) Instead of using an impossibly big vacuum tank, use the atmosphere itself by doing the opposite: mix the epoxy inside a pressure tank. That's way smaller. When you're done mixing releasing the air bubbles that were at high pressure should vent off easily into 1 atmosphere. When you pour it take care to not create bubbles. They shaker table should help with the rest of any trapped air.

Saw your article on this. Recognized immediately from the cover. Nice video and nice projects!

Splendid video, great work!

Thank you Adam for this very intresting video.

Hey Adam, such a great addition to your page that, like so many other, I have read tens of times, which have spread the knowledge, experience and inspiration for this amazing technique. Thank you so much for sharing 🙏🙏🙏

Excellent video! Well done! I love the experimentation.

Super, super, super idea! I'm gonna build a mold for my 1k x 1k cnc router. You've opened my creative mind to endless structural possibilities with this option. What about welding a rebar reinforced inner structure, along with the aggregate/epoxy mix? You could do smaller pours and let set. You could pour a whole table, layers at a time and finish off with mounting options to secure your rails to or whatever your machine desires to function. Rebar is cheap. You could also integrate fence posts for structural support and not have alot of money in it. This idea has so much potential! Thank you for this video!

Excellent presentation, result and video documentation. Thank you.

At the start: "RU-vid, why are you recommending this?" By the end: "My 3D printers are gonna be really heavy in about a week."

Very nicely done, thank you for the video

Thanks for this video. I've built a small vertical mill from aluminum, and the poor edge finish on cuts due to vibration is a real shame. This seems like a great approach for a small scale CNC mill

absolutely fantastic technical video, good job

This is my favorite video to be honest was so excited to see more of it please do a update of sorts

A really great job and demo. Thanks.

You, sir, are an artist

Great video. Thanks for sharing the lessons learned!

Super friend you posted most useful videos for solid machine base this process is very useful to mould any type of shapes and also no need to melting cast iron process also shaping metals right 🙏i appreciate and support your ideas, skills , hardwork because i know machine base body making is very tough jobs

In our plant we have two Hardinage CNC lathe that machine metals to 0.0001” tolerance the beds are made from epoxy granite. Good material. Your machine looks like it would be very strong and stiff. I like your explanation on modulus and dampening.

Thanks a lot man, really pleasant to watch; great videos

Hello Adam! Good choice for the base but I was more interested in the precision aluminium sections and how you went about procuring them. Perhaps you could try the electro magnetic vibrator ( without a motor and eccentric weights ), which have a small amplitude of vibration about 1.6 mm, also used by construction people. Also you could use silica flour as fines. This and the sand should be dry as the heat generated will release some steam. Anyway you've been acquiring the skills as you went along. Best wishes!

Well researched excellent tutorial. God Bless you.

Amazing videos man and thanks a lot for sharing all the hard work you have done to save us all a lot of time and pain! :)

Outstanding information, thank you. I now have the knowledge to make a proper base for my audio turntable (yes, I still play and prefer vinyl records) and my 3D printer.

Awsome video, very well done and explained

Very interesting! Love your style!

being careful not to mix in air when mixing will help. Mixing larger batches so your paddle mixer can be kept below the surface. great video, subscribed!

extremely good video!!

Incredible work, thank you for sharing - liked and subscribed

Wow--That's quite good!

Great video! I'm planning on reinforcing and expanding my small milling machines column and base and make the switch to linear rails on all 3 axis. This information is very helpful.

Fantastic project!!

Thank you for posting this!

brilliant video!

Great video!

Been wanting to build a cnc mill and saw a cement beam on the ground as I was walking today and it lead me here haha

If anyone is looking for large quantities of black iron oxide, Alpha chemicals sells 10lb bags of it for $10

Awesome video, thank you

Nice work!

I'll take note of your advice, thank you.

Thank you for sharing !!!

Wow. Very informative.

Verry nice done!

This takes it to that next level. With this technique, it would be interesting if applied to a desktop lathe either hybrid or one off. They do suffer vibrations something fierce. Great build and presentation!

That’s pretty wild! I’d love to see of the final product in use. 🇦🇺🤜🏼🤛🏼🍀😎☮️☮️☮️

Awesome content!

Using Alexander Slocum's or Culpepper is a great reference for damping in equipment design.

A few of my ideas... step 1 mix just clear expoy and harder together brush spray into mold... let it tack up the us a heat gun to pop bubbles... on the surface of mold let it set up for several hours.. Step 2 mix epoxy with harder and black pigment or paint... spray over the clear expoy let it tack and use heat gun to pop bubbles repeat a few times on corners or vertical surfaces where you need thicker covage...let it dry or tack almost dry.. Step 3.. mix expoy part a b add optional dye then add sand.... the harder... apply with spreader or bondo spreader to mold 1/4 to 1/2 thick coat as a surface finish to finished faces.. let it dry Step4 next day mix expoy with sand and some small gravel...fill mold up to 1/ 4 below desired depth...mix new top coat with expoy sand mix and Harder etc... to give smoother finish on under side This is how I get flawless smooth expoy granite.

Very interesting. Did you check for the flatness how true and absolutely flat is...?

This is awesome.., why didn't I think of that?!?! Custom Machine Beds, here I come 👍👍👍

nice tutorial, i will see if i build my cnc with epoxy instead of aluminium

Nice job . Really Nice

Well done, thanks!

Thank you for your video!

Some suggestions: 1. To improve mechanical characteristics, use - a single digit percentage of epoxy - an aggregate with significantly better packing density - preferably grey cast iron or at least steel as reinforcing and interface members as its CTE matches that of the composite described above 2. Feel free to coat the inside of the mold w/ your material of choice (most of the time I use carbon-filled (i.e. toner powder) epoxy which gives a nice, shiny, smooth, jet black surface) before you start filling the mold w/ your actual mix. This way you don't have to factor in aesthetics even when you're supposed to design your composite to achieve the best mechanical properties. 3. Reinforcement might not even be necessary at all if your machine frame was designed to take advantage of the compressive strength of the composite, which can be brought up to 200+ MPa if you're open to using a more decent mix. Machine tool manufacturers don't seem to bother reinforcing their frames. 4. Vibration is the way to go. Vacuum pumps don't take epoxy vapor particularly well.

What a fantastic video, thank you! :o) Liked and Subscribed.

Amazing and I love the explaination of the loss coefficient. I'm definitely going to be looking into that. But what is the machine you designed for it? Plus I've heard that a lot of the big machine manufacturers use iron epoxy bases as well

Thank you for the deep explanations. The use of rocks has an issue, that the surface of the rocks you used is very rough. So air can stay at the Rocks. Classic concrete has stones out of the river, they are round to eliptic and can withstand high pressure. The amount of air stuck at the rocks is smaller. And this rocks are very cheap and you can use less epoxy. Good for bigger projects.

Nitpick: your design criteria was all about the material science of epoxy granite but my layman's assessment of your prototyping was what looked/poured best. While air gaps are probably not great, how can you know if some ratio with air bubbles might be much better than what you went with in the end? You didn't test the characteristics you chose it for via any means I saw: vibration resistance and stiffness. Thoughts?

That was a great video

I just want to see how it gonna work 👏

I haven't finished watching the whole video, but I'm thinking "I'm gonna build it!"

finally, good content

I just watched a special on submarines and carbon black as a dye adds to sound and vibration deadening by multitudes very interestingly I'll be using it if I try that that's actually why submarines are black even though blue would be better so as no to be seen and a palm sander on its side vibrates the bubbles out just fine vibrating it along the sides of mold

I have been looking for this for a long time now. Thank you 1000 times. I just finished a steel gantry mill and it vibrates worse than a tuning fork and i need a solution. This is it. I'm going to fill it and encase it with epoxy granite. lets see it run!! Best Matt

Nice work! I was thinking cast the base from Portland cement mortar, then paint it with dyed epoxy resin, or another type of resin. It would be cheaper and do the same thing. I don't know if you could make it look as good.

Hello, its really good effort, thank you for sharing, do you publish video on milling ?

Are plans for the rest of the CNC machine available? Also, I wonder if you could further reduce vibration by filling the hollow aluminum tubes with additional vibration dampening material.

Thanks for the info. Would “green sand” that they use for casting moulds be a viable option as it seems finer than most regular sands?

My theory: using a vacuum chamber or high pressure to get the bubbles out will propably lead to maybe only epoxy filling the voids. You want the filler material as dense as possible though. Vibrating the material would be the best choice then I think. Your vibrator table seems to not be sufficient enough, maybe try a small electric motor with an offcenter weight on the shaft, and something to control the motor speed maybe. Would also be cheaper. Only using sand is also not that great, since it still is kinda coarse. There's some basalt based grit that's used for filling the gaps between walkway stones, it has bigger particles (maybe 1/16") down to dust like particles. Should work nicely.

I had never before heard of epoxy granite before today

Might I suggest drying the sand by baking it in a oven for a while in my limited experience with resin and fillers moisture in the filler really messes with strength and leaves tiny bubbles in the material due to a chemical reaction.

Very cool, have you done any kind of rigidity testing to see if it works as well as on paper?

Super cool any guidance on how to attach a 18 x 6 desk milling machine to a granite surface plate ?

I really enjoyed this, thanks for sharing! #Peter#Brown has experimented with dies before and found that black pigment can be obtained using crushed charcoal, which works really well with epoxy. Should be cheaper than the dye you mentioned. 😁

Great video!! Do you plan to bring more content?

Nice video! Clearly and logically presented. A few questions. Have you thought of introducing aggregate into the mold as you have a base of epoxy and sand mix in it. In other words use the aggregate as a filler. As you have the vibrating table working the aggregate will sink into the mix quite easily. Second thought. As you have shown that you have access to a vacuum pump how about simply making a vacuum bag out of window setting tape and heavy polyethylene house vapour barrier? Connecting supplies in the form of bag to hose are available in a few places. The pump will only draw the air out of your bag. Your test sample that foamed up most likely never had an actual vacuum drawn but was in a leaking chamber. When I'm doing vacuum veneering I generally use a shop vac to evacuate the bulk of the air and even a small shop vac can create a quite useful vacuum. Useful enough that pretty much anybody that can fold up a heavy plastic bag can get this accomplished. In a pinch good quality duct tape can be used to create and seal up a polyethylene bag.

Very good quality, great presentation. Not sure if the question has been made but what is the base for? CNC, 3D printer or something else.

Is there any way we can see your machine running?

Thanks for the video. But there are questions: What properties of this granite?(attenuation decrement, compressive strength, Modulus of elasticity) You made a beautiful bed.

some fine dust, possibly like cement would help wet the mix like a paste with fewer voids

That looks very nice.. what machine is that ?

Awesome project! Would it not be better to make the exoskeleton out of cast iron?🤔

Great video. Just one small point. It may seem obvious, but you should have emphasised that the mould should be levelled very carfully before pouring the mix.

Outstanding content. In 2 part polymers with fillers, I have always been told you need to mix part a and b together then mix in the filler to prevent differential adsorption of one part in the filler (sand in your case) which would inhibit a full cure. You're method seems nice since you're not rushed by the curing epoxy during mixing. Did you notice any softness in the end product?

you can also add carbon flakes (carbon fibers) to reinforce

Fantastic work. How much did this machine base weigh in the end?