Building The 5-Axis CNC Machine in a Small Room: A DIY Journey. (part4)

[@GatorGlider]

3D print your mold using PETG. You can then use regular mold release. You can 3D print the mold with several pieces so that you can assemble it in such a way that will allow you to assemble it where the final piece compresses your epoxy mixture. You can leave small channels for the epoxy to escape. The idea being that you want only the amount of epoxy necessary to bind the matrix together. The end part should be extremely stiff and strong.

[@a-cnc-f]

Making molds with a 3d printer is very interesting. I have tried it before. I have even tried using water soluble filament and melting it after the epoxy hardens. I would like to experiment more in the future.

[@GatorGlider]

@@a-cnc-f The process is called compression molding. Easy Composites has a really well done video on their channel.

[@RoboArc]

Need pressure though

[@GatorGlider]

@@RoboArc A workbench vise is what I use.

[@a-cnc-f]

@@GatorGlider Thanks for sharing.

[@DinosRcModels]

I don't think I have to give any advice to someone like you, but the only thing I feel like saying after seeing some of the work you've done with carbon fiber is to recommend using a breathing protection device. Carbon dust is deleterious to very high levels if inhaled.

[@a-cnc-f]

It seems so. I think it's my bad point to emphasize workability even if I understand it. I'll be careful.

[@volodymyr3169]

Thank you for a very interesting video! Please be very careful when working with carbon fibre, especially when sending it with a file. Airbon micro fibers are harmhull for the lungs. Also, epoxy particles can trigger long term allergy if inhaled. Good ventilation and a mask are required.

[@AdamS-nd5hi]

Mix the loose fibre into the epoxy granite like you do with the sand. You i saw a video where they mixed it with concrete to increase its rigitity. Same with carbon nano tubes

[@a-cnc-f]

Yes, it is. I thought about that as well. I may try it next time, but the reason I didn't mix carbon into the epoxy granite this time is because I figured that covering the surface with carbon fiber would be strong enough. Later, carbon fiber is expensive, so I wanted to keep the cost down.

[@JosefdeJoanelli]

The hand waving not matching up with the AI voice is really distracting

[@СергейСергеев-г1е4щ]

Необходимо добавлять волокно в раствор эпоксидного гранита и всё перемешать, только тогда вы сможете добиться желаемой прочности.

[@svenkrause3433]

You are wrong! 8-10% Epoxy ist enough, its NOT too try!!! Read and understand why this ammount is enough!!!

[@a-cnc-f]

In general you are correct in your opinion. I have made epoxy granite many times. My initial goal was to get the epoxy percentage to 10%. However, I could not get the air out of it successfully. You need a vacuum pump, sand and gravel ratio, etc. But I do not want to buy a lot of stuff. From my experience, in my hobbyist DIY projects, I put more epoxy and focus on fluidity. Sand is heavier than epoxy and will settle down. A layer of epoxy will form on the top and bubbles will form on the surface. Finally, add additional sand or other material to the epoxy layer.

[@xav6427]

you were supposed to mix chopped carbon fibre with aggregate and epoxy if you wanted to gain tensile strength

[@DMonZ1988]

i thought you were going to put the chopped carbon fiber into the mix as an additive. i believe this could enhance the granite properties, and actually make the machine a little bit lighter. as for the surface finish and using carbon weave as an outer skin with tensile strength, using a well made mold like you did with your original epoxy granite build should give you a good result and clean surfaces that do not need to be ground, or at least only very little only when it comes to aligning and final tolerances of the machine. as you can see it is not completely impossible and for this fine finishing the dust and labour will be minimal. piling on carbon by hand is obviously very rough and crude. anyway i am sure you have gained valuable experience and i am excited to see how you will continue, and to see the machine take shape. the result will be impressive, i am sure of that!

[@a-cnc-f]

thank you. There are many things that are inadequate, such as equipment, experience, and knowledge, but I want to make something as good as possible.

[@basilstadnik1342]

ну ты заморочился с эпоксидкой и волокном , что бы пузыри ушли нужна вакуумная машинка

[@kogger8519]

Пузыри будут выходить бесконечно из щебня. Его ещё надо было бы прокалить перед началом.

[@stezz90]

I work with it everyday. Carbon fiber is very easy to work with abrasives because it has fragile behavior. It became a problem for common cutting tools because it's abrasive itself and will destroy the cutting edge. Mix fibers in the granite, you will not gain much stiffness by only skinning the exterior with that little thickness . If some of the pieces you need have a clear and easy load path, use unidirectional fibers along the stress direction. Remember that (common) carbon composite with cloth or chopped fiber isn't that stiff, less than aluminum per volume. It's stiff related to the weight. If you need high stiffness you will need a lot of carbon fiber, not just some layers here and there.

[@a-cnc-f]

It is a great honor to receive comments from a professional person. Thank you for your valuable input.

[@Cliff_P]

carbon fiber. I'd be scared to get that carbon fiber dust on me.

[@xfxox]

have you thought about ordering a thick carbon slab and cutting a frame out of it?

[@a-cnc-f]

I am now thinking of making the aluminum plates on both sides carbon. However, I am concerned about the price.

[@EdwardKilner]

I started watched in proper sequence. Am really enjoying each one. Excellent video, audio, and diction clarity plus speed. Best of luck. 🇨🇦

[@a-cnc-f]

Thank you. It is very encouraging. Video production takes more time than we imagined.

[@JoeyWinkler-fw9hp]

this is awesome to see, but I have to stress PLEASE WEAR YOUR PPE, (gloves and a respirator) this stuff can seriously damage your lungs and irritate your skin

[@a-cnc-f]

You are right. I found out by doing it.

[@mc3702]

If you are going to share it as open source when the machine is finished, I would love to do it. But I am thinking of building it on normal aluminum or steel plates, not epoxy. I would be very happy if you could share the case dimensions for this. Good work. I follow with interest.

[@a-cnc-f]

The basic concept remains the same, but the design will be gradually modified to make the machine even more interesting. It will not be open source, but once the design is finalized, I am planning to create an online course for the purpose of manufacturing it, including 3D models.

[@ColonelAngus101]

I don't think wrapping the part in cloth will do much for tensile strength, or strength in general. Instead, think reinforced concrete. Try using carbon fiber rods, which have very good tensile strength, not the cloth. So, for example, if you were to make a part that needs good tensile strength in one axis, add 2 (or more) rods so that one rod stretches and other compresses as force is applied on that axis (and vice versa).

[@a-cnc-f]

Thanks for the advice. I will consider various, ideas.

[@l3d-3dmaker58]

love your work, but please be careful with carbon! it's very irritating and dangerous, full respirator and goggles or facemask def needed, and wear disposable gloves over long sleeves if you can (wet sanding is good too)

[@a-cnc-f]

thank you for the advice

[@hiddenloaf2302]

Whenever you're sanding or cutting composites please always be wearing gloves and a respirator mask. That dust is nothing to mess around with. Additionally I think it could be a good idea to mix the carbon shards into the core epoxy mix to distribute it throughout the part rather than just having it on the outer most portions of the part.

[@a-cnc-f]

thank you for the advice

[@nendhang]

cool

[@1112-i5h]

Просто продолжай делать это,ты меня вдохновляешь.

[@BuildItAnyway]

For a cnc you want good dampening, good thermal expansion properties, good amount of mass and good amount of stiffness. Carbon fibre excells in one of these, the rest not really.

[@a-cnc-f]

Carbon is not perfect. That's why I use it with epoxy granite.

[@bhnjhbjhbkgkkvhnhmbm]

Also the mass of epoxy granite helps a machine to stay still and resonate less

[@BuildItAnyway]

UHPC performs better and is usually cheaper FYI@@a-cnc-f

[@СейфСергиенко]

🙏💯🔥

[@datastreamcowboys]

forged carbon fiber is best done in a mold where it can be compressed.

[@a-cnc-f]

I have received similar comments from several people. I have recently thought that compression casting and machining carbone fiber would be interesting.

[@oilio5465]

Have you considered mixing the carbon chips with the Epoxy ceramic mixture. Glass fibre and others fibres are often added to concrete for reinforcement

[@oilio5465]

Also look up forged carbon fibre. Compressing the mould is key Don't forget your ideal carbon fibre to resin ratio

[@a-cnc-f]

I thought about that, but figured that the surface is what matters for tensile force.

[@xyzxyz6095]

Yes !!!

[@lucyblack5210]

バキュームポンプでエアー抜かないとね

[@a-cnc-f]

そうですね。 そのことは、考えてはいるんですが、ポンプの購入するかどうかを考えています。 車のブレーキのエア抜きに使う手動ポンプを使おうかと思ったのですが、問題はパーツを真空にするための入れ物をどうするかということです。 また、その箱を何処にしまっておくか？うちが狭いので。。。

[@wiradharma7030]

Mine use forged carbon combine with tempered aluminum for bolt attachment. I also use it to attach part which is bolted, act as dampers. For a thicker and longer parts like the gantry i put whole hollow steel inside, I also put pvc foam as core material to save $$$. Micro baloons add rigidity, mix it with epoxy resin. For cnc application cure it around 80°C, do not cure it higher than 100°C it will be too brittle and got less damping properties. Mine mainly use at moving parts like z axis, and vibration dampening. Forged carbon are much stronger than common cf if you put long strain of carbon, i got it from unidirectional carbon fiber. I got plenty cd from my 90s car wide body project.

[@wiradharma7030]

Used compressed air to your body and clothes before taking a shower. It'll get worse if you take a bath before cleaning the dust. Clean your work area and change clothes immidiately. The dust will stay in your clothes even after you wash it. Woven fiberglass is a nightmare compared to just carbon fiber. I did not feel a thing from cf dust.

[@a-cnc-f]

You are familiar with carbon fiber. I am not very familiar with it, but I find it very interesting. I can only do DIY level, but I think it is a very attractive material.

[@a-cnc-f]

Carbon fiber is quite dangerous. Handle with care.

[@wiradharma7030]

@@a-cnc-f Many youtube video demonstrate handling micro baloon without proper mask. This material rated at micron, and almost weightless. I use 3m auto painter/lab mask when handling aerosil.

[@Wulfy_exe]

Cant wait till the next update 😁👍

[@jackskalski3699]

I'll just say this... I subbed. I also am building a crazy DIY machine and I'm super interested in your carbon fiber - epoxy granite adventure. Keep it up :D

[@michaelrasinsky334]

I like you project very much, such a compact design! I had basically the same idea - epoxy granite cnc frame with chopped carbon fiber on the surface. Mostly I did it to get a nice surface look. I regretted it later though, cuz it was a lot of extra work laying all that fiber, especially around the inserts, and I got air bubbles trapped in there. Carbon plates is a great idea, use them as a mold and get a nice surface all at once, but mb the adhesion will not be as strong as in monolith epoxy pour.

[@a-cnc-f]

In terms of integration, I think carbon plates have a disadvantage. As you said, using a plate would be a great advantage in order to make it look beautiful.

[@akosbuzogany2752]

In ship building they use heated vacuum chambers to cure the epoxy. It cures quicker and air bubbles are removed from the whole volume. Vibration alone might not be enough.

[@a-cnc-f]

We know that. But it is difficult to have all the tools at the DIY level. The simplest and hardest way is vibration. But as for heating, I may try it.

[@akosbuzogany2752]

@@a-cnc-fHeating will just speed up the curing process. As for vacuum, a simple vacuum cleaner attached to a thicker plastic bag would do.

[@a-cnc-f]

@@akosbuzogany2752 I thought that heating would soften the epoxy and make it easier to release air. The idea of vacuuming it up sounds interesting. I don't need to purchase any additional equipment. I will give it some thought. Thanks.

[@akosbuzogany2752]

@@a-cnc-f Heating just speeds up the hardening process. I fill electronic components with epoxy. They harden in one day normally. If I put them on the top of the radiator (around 50 Celsius) they harden in a few hours. Look at the datasheet of your epoxy, it should contain information how temperature influences hardening. A temperature above its melting point will make it softer of course :) Take care of the ventilation, you don't want to breathe it in!

[@a-cnc-f]

@@akosbuzogany2752 Thank you. It will be helpful.

[@mosiyukvasil]

maybe cheaper to outsource the forging of all metal structures with cast iron (china market or on local market)

[@VIJAYzk]

COOL man! cant wait to see it machining. CFRP is such a great technology.I've been using forged carbon parts for drones for an year now

[@sommersetcoker5455]

gloves....

[@a-cnc-f]

Yes. I am not good,

[@nccyr1]

This is an exciting journey, I will follow your progress for sure! Thank you for sharing it with the rest of us.

[@SergeiPetrov]

Finished factory carbon fiber plates have maximum rigidity if the manufacturer has not violated the technology. It is quite a painstaking task to independently achieve Young's modulus as from a reference book. I think you should make several bars with and without lamination instead of a cube and compare from the bend to the standard load. This will be interesting material and will reduce the cost of technology trials.

[@a-cnc-f]

Thanks for the advice. It seems that people have different ideas when it comes to carbon fiber epoxy granite. As for strength, your opinion may be correct. For me, the purpose of using carbon fiber is very much about appearance, so I will use the plate for my next test. I received the plate yesterday.

[@eelcohoogendoorn8044]

I agree; cut carbon plates (and profiles) glued together on the inside, filled with sand-epoxy, sounds like a very approachable and capable machine frame. One thing is that you need to make sure to plan ahead of time as to where to put metal threaded inserts on the inside since drilling or tapping either CF or granite isnt really a thing. Bonding the insides with carbon L-profiles cut to size is probably a lot less messy and easier than trying to make sure some interior hidden corner is properly saturated and not sagging away or anything. Might cost a little more but I imagine it will be worth your trouble; also gives you more freedom in the order in which you assemble things (ie, one sideplate first, the other later; not really going to fly if you want to fill the corners with cloth).

[@a-cnc-f]

I think in much the same way. I am looking forward to the next test.

[@julienboucaron9780]

Interesting approach using the carbon fiber as a super rigid shell. Regarding the finish, I know for railways, people use self-leveling epoxy to attain precise tolerances: they apply the self-leveling epoxy, then meticulously scrape the surface using a straight edge and ink as a guide.

[@a-cnc-f]

thank you for the advice.

[@Rickertt]

Here is a drinking game: take a drink every time carbon fiber or epoxy granite is mentioned. Take two if they are mentioned in unison. Warning! This game may be a danger to your health.

[@a-cnc-f]

Yes, it is. Be careful not to drink too much.

[@xillianto]

One thing that comes to my mind, is that on cnc milling machine, weight is your friend, and not to make it as light as possible.

[@a-cnc-f]

Usually you are right. However, this machine is super small and is designed to be hand-held and moved by hand. It needs to be heavy enough to be hand-held.