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  1. #61
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    Default Re: My carbon fiber CNC gantry

    Hi Wizard ,
    Sorry to confuse you , I figured someone wanting to build a carbon gantry may have a broad understanding of the process and components . That said , I will explain .
    Hybrid laminates are a mix of various materials like carbon/kevlar or carbon /S or E glass . There are many different hybrids and these address various aspects where for instance carbon /kevlar would be used where both stiffness and impact resistance is needed . Remember these cloths are a mix of properties , so do a little of each .
    The different weaves where developed for lay or how the cloth drapes on a plug or in a mold , say for instance unidirectional cloth does not like to take a tight turn in length ,but a twill weave at 0/90 or +45-45 would lay much better . These weaves can also add to the stiffness of the component being fabricated .
    Cross linked resins are not that new and in the case of polyester resin it's the isopthalic polyester where non cross linked is orthopthalic polyester . A cross link is a much stronger bond on a molecular level so makes for a stronger resin .
    This cross linking has been used in epoxy development where the molecular chain has been altered in a way that it betters certain properties .
    Proset epoxy is a Gougoen Brothers product ,the makers of West Epoxy and is a cross linked epoxy . It is used by a lot of high end custom boat builders these days because of its broad properties ,like it makes a very good infusion resin with a 9 hr pot life and it can be used for wet layup with a brush and roller with the use of a different hardener . The various other manufacturers have their own take on these various resins including System Three .
    For something like a self built gantry ,using prepreg or high temp cure resins is cost prohibitive and the amount you win by going this route is not the same as the substantial investment made in the purchase as these components can cost substantially more .
    Post curing helps remove any volatiles left in the resin after the initial cure . These components are usually solvents or plasticizers which can soften the resin if left behind making for a weaker bond . The post cure process is usually a uniform heating up of the component to help the off gassing of the volatiles . Most components continue to off gas over its lifespan and some polyester race boats that where post cured 15 years ago still offgas the strong MEK smell if drilled or cut into . The same for some of the solvent based epoxy boats built years back .
    Post curing can distort a component if it is not properly supported so a lot are post cured in a mold or on a plug under vacuum .
    A lot of the low temp cure resins are being used now for less distortion and will cure at temps between 160 -180 Fahrenheit which is attainable with a propane space heater in a plastic tent or a hotbox made from polyiso insulating foam sheets like sold at Home Depot .
    The best way to go is to actually call all the various suppliers and tell them what you want to achieve and ask what product they would suggest you use . These guys work with all these component daily and most are aware of what works and what doesn't . Collect as much info as possible ,then make a decision which way you want to go . If this is not your everyday job ,I suggest to do a test patch first to get familiar with the process and the workability of the components . Do a small section in the mold with the full layup you have calculated to work and see what it takes to do the job . If possible work in an air conditioned room and use slow set hardener for a longer pot time , so you have ample time to fix any holidays or wowies you may make .
    The use of a vacuum bag will also help hold things together and can be set up prior to laminating , so it's easy to pull over and seal , then start to pull a vacuum and check for bag leaks . A bag leak will introduce an air source into the laminate and can pull enough resin out of the area to form a dry spot which would destroy the component . Let the resin kick off and while that is happening build your tent or hotbox around the component ready for post cure . Most of the new resins only need a 24 hour post cure with a cold shut off at the end , unlike some of the older resins that required a slow rise and fall with a 48-72 hour cure, this can use a lot of propane if you don't have an efficient oven .
    If you intend to secondary bond anything onto the component , it is a must to use a material called peel ply which is a woven polyester cloth that is draped over the component before the bag goes on . What this peel ply does is pre prep the surface so you don't have to abraid the surface and solvent wipe which can trap solvent in the adhesive . It also allows the amine blush to come to the surface of the peel ply and is removed when you pull off the peel ply .
    Amine blush is a waxy layer created by the reaction during the epoxy cure that floats to the surface ,and needs removing before anything else can adhere to it . It can be removed by washing with soap and water and a light abraiding with a Scotchbrite pad or the use of peel ply .
    Most fabricators will leave the peel ply on until they need to bond as it keeps the component surface isolated from dirt ,they will then mix a batch of adhesive ,pull the peel ply and apply the adhesive and whatever they are bonding . Any masking or setup work can be done around or through the peel ply if necessary.

    I hope this explanation helps you understand a little more and answers some of your question
    Regards Roc



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    Default Re: My carbon fiber CNC gantry

    Quote Originally Posted by jono5axe View Post
    Goemon, I had another thought - re post-cure and epoxy agregates.

    My earlier comments on post-cure relate to laminates, and I am not so sure about the situation with epoxy/aggregate mixtures. I would expect the same to apply in general terms, but possibly to be less important as the quantity and mass of the aggregate fill is so great that it modifies the resin behaviour to an extent (shrinkage, geltime, cure, exotherm, etc). I would expect that post-cure would still be desirable for high tolerance machines, but possibly not very important otherwise. Mild elevated temperatures and time will achieve complete stability sooner or later.

    Jono
    I don't think adding a granite mix or sand will sufficiently change the resins heat deflection temp to mitigate any potential issues from using low quality resins. Other properties can be changed though. For example, I added chemicals to make it flame retardant and carbon nanotubes to increase stiffness.

    I have tried most of the commonly used resin brands and so far Adtech 820 is the best for wet lay ups. It has the highest stiffness and heat deflection temp without any post curing. It's noticeable better than West systems in every way except price. For most people, 180 degrees is probably good enough to use without post curing. For those with curing ovens like me, it can be post cured to 350 degrees giving it similar heat resistance to most heat cure prepregs.

    I make my own prepreg these days and keep it in my freezer ready to use. It's far more cost effective and I get better results than most of the bought-in prepregs I have tried. I recommend it you haven't tried it yet. It changed everything for me.

    I think that heat curing or post curing large parts, such as people building larger CNC machines, is always going to be an issue for hobby users. I own a composites business so it makes sense for me to have a curing oven. I doubt I would want a large curing oven or hot box in my house if I was just a hobby user. M wife would kill me. I think there are some credible alternatives these days though thankfully.



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    Default Re: My carbon fiber CNC gantry

    Quote Originally Posted by wizard View Post
    Hi Roc;

    This statement: "With all the hybrid laminates ,the different weaves and the different modulus of carbon and the newer cross linked low temp set epoxies , there is no need to go with the extremely expensive components ." is perhaps the thing that inspires the most questions in your post. For those of use not familiar at all with these techniques we have no idea where to get thee new materials, For example "newer cross linked low temp set epoxies". The "newer" is a big question as I know where to get epoxies for wood working such as System 3 but I have no idea if that is the type of epoxy you are talking about.

    Basically many of the industry sites online are confusing as they either over simply or just leave out details. Hoping for some informed pointers here to advance my research into these processes.

    My advice for any hobby users is:

    Buy your resin from Soller composites. Choose their Adtech 820 and a hardener that is suitable for the size of the part. If it's tiny, their fast hardener is fine. If it's huge and you need more time for the lay-up, their medium or slow hardener is better. I know of no better epoxy laminating resin for small businesses or hobby level users looking for professional results.

    Don't worry too much about the choice of cf fabric.

    Medium and high modulus carbon fiber fabrics and hybrid carbon Kevlar fabrics are nothing new. They are commonly available from most composites stores. Personally, I wouldn't worry about that for this purpose. High modulus cf has increased stiffness to weight ratios at the expense of being more brittle.

    I use some high modulus layers in my cf rifle stocks where high stiffness with minimal weight is important. As many have pointed out here, the goal is not to achieve the minimum possible weight for CNC parts. In other words, you can achieve the desired stiffness using more layers of standard modulus fabrics and.... more importantly.... using a smart part design.

    Most high mod fabrics that are easily available are unidirectional. Anyone that wants some can find it easily enough with a google search. Rockwest composites is one example of a store that sells it. Be aware though, some of there are harder to use for beginners.

    Regardless of what fabrics are chosen, make sure you understand the direction of the weave. The seller should be able to explain this. Fabrics are designed to be strong in one, two, three and occasionally four directions. Find out which directions it is for your fabric and plan your lay up in a way that makes parts strong and stiff in the required directions.

    - - - Updated - - -

    Quote Originally Posted by wizard View Post
    Hi Roc;

    This statement: "With all the hybrid laminates ,the different weaves and the different modulus of carbon and the newer cross linked low temp set epoxies , there is no need to go with the extremely expensive components ." is perhaps the thing that inspires the most questions in your post. For those of use not familiar at all with these techniques we have no idea where to get thee new materials, For example "newer cross linked low temp set epoxies". The "newer" is a big question as I know where to get epoxies for wood working such as System 3 but I have no idea if that is the type of epoxy you are talking about.

    Basically many of the industry sites online are confusing as they either over simply or just leave out details. Hoping for some informed pointers here to advance my research into these processes.

    My advice for any hobby users is:

    Buy your resin from Soller composites. Choose their Adtech 820 and a hardener that is suitable for the size of the part. If it's tiny, their fast hardener is fine. If it's huge and you need more time for the lay-up, their medium or slow hardener is better. I know of no better epoxy laminating resin for small businesses or hobby level users looking for professional results.

    Don't worry too much about the choice of cf fabric.

    Medium and high modulus carbon fiber fabrics and hybrid carbon Kevlar fabrics are nothing new. They are commonly available from most composites stores. Personally, I wouldn't worry about that for this purpose. High modulus cf has increased stiffness to weight ratios at the expense of being more brittle.

    I use some high modulus layers in my cf rifle stocks where high stiffness with minimal weight is important. As many have pointed out here, the goal is not to achieve the minimum possible weight for CNC parts. In other words, you can achieve the desired stiffness using more layers of standard modulus fabrics and.... more importantly.... using a smart part design.

    Most high mod fabrics that are easily available are unidirectional. Anyone that wants some can find it easily enough with a google search. Rockwest composites is one example of a store that sells it. Be aware though, some of there are harder to use for beginners.

    Regardless of what fabrics are chosen, make sure you understand the direction of the weave. The seller should be able to explain this. Fabrics are designed to be strong in one, two, three and occasionally four directions. Find out which directions it is for your fabric and plan your lay up in a way that makes parts strong and stiff in the required directions.



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    Default Re: My carbon fiber CNC gantry

    I totally agree with what Goemon says on every level , don't overthink the components , get what is available and in your price range and go from there . With a clever design that perhaps uses fasteners to tie the two halves together, it is possible to assemble and try it , if it has to much sag ,vibration or flex , you can pull,it apart and add extra layers of laminate . S-glass fiberglass is sometimes as stiff as carbon in certain applications at a cheaper price , so you can probably use this to add layers or you can bond in full length tubes like Goemon did .
    There are many ways to skin this animal and it's up to the builder what the parameters are that are acceptable and what his or her comfort level is working with the materials .



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    Default Re: My carbon fiber CNC gantry

    Thanks

    For people like me that don't have the background simple advice like this goes a very long ways. One of the reasons I prefer steel is that I know all the local vendors and the not so local vendors and generally have a good idea what to specify. When it comes to composites I might as well be shopping in the feminine hygiene aisle, I just have no idea what is what.


    Quote Originally Posted by Goemon View Post
    My advice for any hobby users is:

    Buy your resin from Soller composites. Choose their Adtech 820 and a hardener that is suitable for the size of the part. If it's tiny, their fast hardener is fine. If it's huge and you need more time for the lay-up, their medium or slow hardener is better. I know of no better epoxy laminating resin for small businesses or hobby level users looking for professional results.

    Don't worry too much about the choice of cf fabric.

    Medium and high modulus carbon fiber fabrics and hybrid carbon Kevlar fabrics are nothing new. They are commonly available from most composites stores. Personally, I wouldn't worry about that for this purpose. High modulus cf has increased stiffness to weight ratios at the expense of being more brittle.

    I use some high modulus layers in my cf rifle stocks where high stiffness with minimal weight is important. As many have pointed out here, the goal is not to achieve the minimum possible weight for CNC parts. In other words, you can achieve the desired stiffness using more layers of standard modulus fabrics and.... more importantly.... using a smart part design.

    Most high mod fabrics that are easily available are unidirectional. Anyone that wants some can find it easily enough with a google search. Rockwest composites is one example of a store that sells it. Be aware though, some of there are harder to use for beginners.

    Regardless of what fabrics are chosen, make sure you understand the direction of the weave. The seller should be able to explain this. Fabrics are designed to be strong in one, two, three and occasionally four directions. Find out which directions it is for your fabric and plan your lay up in a way that makes parts strong and stiff in the required directions.




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    Default Re: My carbon fiber CNC gantry

    For me there is much to learn about how such materials would be useful for machine tools. I've been working with metals since I was old enough to enter my fathers garage so there is a lot of knowledge with respect to metals that came from a long time and a bit of the school of hard knocks. I'm too old to spend time learning that way so anything I can pick up from you guys is very valuable. So thanks for the comments.


    Quote Originally Posted by rocrat View Post
    I totally agree with what Goemon says on every level , don't overthink the components , get what is available and in your price range and go from there . With a clever design that perhaps uses fasteners to tie the two halves together, it is possible to assemble and try it , if it has to much sag ,vibration or flex , you can pull,it apart and add extra layers of laminate . S-glass fiberglass is sometimes as stiff as carbon in certain applications at a cheaper price , so you can probably use this to add layers or you can bond in full length tubes like Goemon did .
    There are many ways to skin this animal and it's up to the builder what the parameters are that are acceptable and what his or her comfort level is working with the materials .




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    Default Re: My carbon fiber CNC gantry

    Quote Originally Posted by wizard View Post
    Thanks

    For people like me that don't have the background simple advice like this goes a very long ways. One of the reasons I prefer steel is that I know all the local vendors and the not so local vendors and generally have a good idea what to specify. When it comes to composites I might as well be shopping in the feminine hygiene aisle, I just have no idea what is what.

    I can totally relate on that. I like working with composites because it is what I am most familiar with. All the different grades of steel are very confusing. It's not complicated. It's just that every purchase involves trial and error which adds time, cost and stress.

    Once you try experimenting with composites they can become addictive (just like milling metal). I still love watching this stringy fabric cure into parts that are stronger than aluminum, titanium and steel. There re is always something new to learn.

    My favorite cf material to use is a 4x4 twill. It's definitely not the cheapest but it produces super stiff parts and is very easy to work with. Much easier than the more common and less expensive 2x2 twill fabrics. It has a really special look to it too.

    For something like my CNC build, I am using mostly a mix of 2x2 twill, chopped cf strands and tri-axial fabric. You can buy 2lb of chopped cf strands off eBay for $30 these days.



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    Default Re: My carbon fiber CNC gantry

    Hello Goemon, any further progress on this carbon gantry? I have just finished my composite gantry layup and was finally feeling like I had achieved something in my router build, so came back here to read about this thread, but it has gone quiet.... Did you manage to get a carbon beam made? Is it stiff? My final design turned out as a rectangular section 4.5m long x 600mm high x 400mm deep with internal bulkheads every 400mm. Seems to be bombproof, but won't really know how stiff it is until we are up & running. Still a wee while away from that yet. Regards Jono.



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    Default Re: My carbon fiber CNC gantry

    Quote Originally Posted by jono5axe View Post
    Hello Goemon, any further progress on this carbon gantry? I have just finished my composite gantry layup and was finally feeling like I had achieved something in my router build, so came back here to read about this thread, but it has gone quiet.... Did you manage to get a carbon beam made? Is it stiff? My final design turned out as a rectangular section 4.5m long x 600mm high x 400mm deep with internal bulkheads every 400mm. Seems to be bombproof, but won't really know how stiff it is until we are up & running. Still a wee while away from that yet. Regards Jono.
    I have made a lot of progress since I started this thread and my build. I have gone through a number of designs but I am fairly confident that the one I have curing in a mold right now is the one I will use. I am going with a fixed gantry which is 48" long by 24" tall and 8" thick. My gantry and base are being cast as one solid piece. It is made from a mix of carbon fiber (12lb dry strands) plus 7 layers of woven 4x4 twill weave fabric , carbon nanotubes (2kg), fiberglass strands (8lb dry) epoxy granite and a bunch of carbon fiber wrapped steel reinforcement rods embedded in the mix in three directions (i.e. parallel to the X, Y and Z axis). It also has a 5/8" steel plate cast into the mix to hold the screw threads for the linear rails.

    I made a test beam using this mix prior to starting on the finished gantry and it is without a doubt the strongest and stiffest part I have ever made. I put in on two bricks and added weights on top in the center of the beam to test it's stiffness. A 3" x 3" x 48" beam of the mix easily held 1000kg without any visible flex at all. It could have held more but I ran out of weights and room.

    I have been slowly building up layers in my gantry mold over the last week. It being done slowly to minimize stress from the heat so I am still a few more days away from finishing it. I will probably leave it in the mold for an extra 5-7 days to make sure it's cured enough for me to move it to my curing oven (for post-curing).

    The bottom line is that I am very happy with my choice of materials. I'll end up with a machine that is many times stronger and stiffer than anything I could have bought ready made. I think there is a lot of potential for machine parts made with a carbon fiber / epoxy granite mix. It has many advantages over iron and steel.

    btw, when I researched this topic originally, I found a number of commercial CNC machine builders who already use carbon fiber gantry beams, cf milling heads, cf z-axis columns and other cf parts. Check out this bad boy:




    It's a massive 8' by 16' CNC router with a carbon fiber gantry and z-axis.... They use cf for the moving parts because the reduced weight allows it to travel faster without sacrificing any stiffness.



    The cf Z-axis.


    This is a carbon fiber milling head made by another company.

    I also found a carbon fiber 6 axis robotic arm milling machine that was one of the coolest things ever....

    Attached Thumbnails Attached Thumbnails My carbon fiber CNC gantry-img_3962-jpg   My carbon fiber CNC gantry-img_3961-jpg   My carbon fiber CNC gantry-img_3963-jpg  


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    Default Re: My carbon fiber CNC gantry

    This is my gantry (with vac bag on it..). The finished machine will be similar to your autoscale image

    Attached Thumbnails Attached Thumbnails My carbon fiber CNC gantry-dscf0409-jpg  


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    Default Re: My carbon fiber CNC gantry

    Machine, meet Art! WOW!



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    Jono; if you dont already have a thread i urge you to start one yourself covering this build. Carbon fiber in machine tools is very new to most of us so the more information the better.

    Your vacuum bag picture inspires a lot of questions. Apparently you have a male mold sitting on a thru shaft Axel. Photos of that mold, how it was made and how you would remove it are of interest! In a nut shell for many of us in the machine industry this approach is completely new to us.

    Quote Originally Posted by jono5axe View Post
    This is my gantry (with vac bag on it..). The finished machine will be similar to your autoscale image




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    Default Re: My carbon fiber CNC gantry

    That Autoscale machine is a lot like what I've been dreaming about lately, but I hadn't thought of a carbon knuckle for the 5th/6th axes. It seems that carbon fiber lamination has a lot of potential for making moving parts lighter and stronger, but I question whether it's worth doing on a fixed gantry (bridge) design, where the weight doesn't matter - or may actually be a good thing. If you're using epoxy-granite and steel to build your beam, why do you need carbon fiber too? It would make a lot more sense on a moving gantry than a fixed one, although I guess it doesn't hurt.

    [FONT=Verdana]Andrew Werby[/FONT]
    [URL="http://www.computersculpture.com/"]Website[/URL]


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    Default Re: My carbon fiber CNC Gantry

    Quote Originally Posted by Goemon View Post
    Btw, in case anyone is wondering why we should bother making carbon fiber CNC components, this clip shows why CF is superior to steel and aluminum for applications where strength and rigidity are important:



    I like this clip because it shows a real world example of a steel part vs the same part made out of carbon fiber. It doesn't use theoretical data from charts etc. The CF part is 3 times stronger and noticeably lighter.

    As the forces on CNC components come from predictable directions, I think it could be a great application for carbon fiber. This is especially true for diy builds of benchtop high speed machines where there is potentially a need for components that can be easily moved without sacrificing strength or stiffness.
    This video is about completely irrelevant to the cnc discussion. Or do you plan to make your own ballscrews from large diameter carbon fiber?
    The reason why CF is used for drive shafts is that weight in something that needs to be made to spin requires a lot of torgue.
    Changing from steel to CF makes a huuuuge difference in the acceleration of the car.

    Sven http://www.cnczone.com/forums/diy-cnc-router-table-machines/320812-aluminium-1250x1250x250-router.html


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    Default Re: My carbon fiber CNC gantry

    I'm with Awerby. Carbonfibre in an epoxy-granite base & fixed gantry is an oxymoron. Bases & fixed gantries do not accelerate therefore can be heavy, whereas low mass in moving parts means higher performance (accelerations, velocities) with smaller & cheaper hardware (motors, slides, etc).



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    Default Re: My carbon fiber CNC gantry

    Wizzard, I described the composite method/process to build this beam earlier in this thread, in detail.

    I will consider doing a build thread, but considering all the out-there questions and quite strong views put forth already on this thread, I am a bit apprehensive of having to reply to all that in a build thread. If I do do a build thread, where should I post that?



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    Default Re: My carbon fiber CNC gantry

    Quote Originally Posted by awerby View Post
    That Autoscale machine is a lot like what I've been dreaming about lately, but I hadn't thought of a carbon knuckle for the 5th/6th axes. It seems that carbon fiber lamination has a lot of potential for making moving parts lighter and stronger, but I question whether it's worth doing on a fixed gantry (bridge) design, where the weight doesn't matter - or may actually be a good thing. If you're using epoxy-granite and steel to build your beam, why do you need carbon fiber too? It would make a lot more sense on a moving gantry than a fixed one, although I guess it doesn't hurt.
    Carbon fiber offers the option to make a part lighter without sacraficing strength or stronger for the same weight. Carbon fiber parts are only light if you design them to be light.

    It is mostly true that making the machine lightweight is not a priority for my build but I still have to be able to lift the CNC base onto my machine table so it's not totally irrelavent.

    Carbon fiber has a number of advantages for machine parts that aren't related to weight. When people talk about weight being an advantage for CNC machines, it is important to note that just being heavy is not the end goal. It's about stability and vibration dampening. With machines made of iron, they require a lot of mass to be stable and have acceptable vibration dampening. Carbon fiber is an all-together stronger and stiffer material with vibration dampening properties that are 20x better than steel (if made properly). Less weight is needed for the same results.

    All materials have advantages and disadvantages. By making composite parts with a range of materials, it is possible to benefit from the advantages of all the materials while mitigating the properties that are problematic. The reason why I am using multiple materials for my gantry and base is that it produces a superior part.

    Carbon fiber parts are typically hollow which is not optimal for vibration dampening. When I need parts to be light, I fill the void with urethane foam. For a fixed gantry, my epoxy granite, carbon fiber and carbon nanotubes mix makes a better filling for the woven carbon fiber skin. That all gives you a very strong beam with excellent vibration dampening but none of these materials have a high surface hardness. In other words, they suck at holding screw threads. The embedded steel plates and tubes provides a mounting surface that can hold screw threads for the rails.

    Steel on it's own is great for holding screw threads and it is stiff (if it's thick enough)but, it sucks for vibration dampening, it's expensive, hard to process (for me), not as strong as cf and too heavy to lift in some cases. There is a reason why milling machines use iron instead of steel. Steel is far from optimal on it's own.

    I could certainly get away with using fewer materials but I want the best machine possible. Being able to use premium materials is a key benefit of a diy build. I have done a lot of experimenting and I found this combination of materials to be superior to everything else I tried.



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    Default Re: My carbon fiber CNC gantry

    Quote Originally Posted by jono5axe View Post
    Wizzard, I described the composite method/process to build this beam earlier in this thread, in detail.

    I will consider doing a build thread, but considering all the out-there questions and quite strong views put forth already on this thread, I am a bit apprehensive of having to reply to all that in a build thread. If I do do a build thread, where should I post that?
    The forum instructions say to post build logs in this forum: http://www.cnczone.com/forums/cnc-wo...r-project-log/

    And I agree you should post a build log. You dont need to solicit advice, just post the pics of how you built it.
    There are strong opinions here but there is also a lot of knowledge.



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    Default Re: My carbon fiber CNC Gantry

    Quote Originally Posted by CaptainVee View Post
    This video is about completely irrelevant to the cnc discussion. Or do you plan to make your own ballscrews from large diameter carbon fiber?
    The reason why CF is used for drive shafts is that weight in something that needs to be made to spin requires a lot of torgue.
    Changing from steel to CF makes a huuuuge difference in the acceleration of the car.

    The part of the video that is relavent is the test showing how the parts hold up under force. The steel part starts to visibly bend and then break with 1/3 of the force of the carbon fiber part. More importantly, there is no visibly deformation in the carbon fiber part until there is enough force to break it. That is relavent to the CNC discussion.

    Large gantry beams bending under cutting force is a common enough complaint. Strength and stiffness is a key requirement and carbon fiber is an excellent material in this respect.

    I have explained the benefits of used a composite mix below but to understand it, the point you need to let sink in is that carbon fiber has advantages for machine parts that are not related to weight. No matter how many times I explain that carbon fiber parts don't have to be lighter and that you can design them to be stronger instead, it never seems to sink in.

    The simple fact is that if you gave me 10lb or a square foot of carbon fiber and the same in steel, I would be able to design a stronger stiffer part with the carbon fiber.



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    Default Re: My carbon fiber CNC gantry

    Quote Originally Posted by jono5axe View Post
    This is my gantry (with vac bag on it..). The finished machine will be similar to your autoscale image
    Nice. I'm definately interested in comparing notes when we're done.

    How come you decided not to make it in a female mold? Is it related to size and weight - i.e. The difficulty pulling a part so large from the mold?

    how do you plan to deal with the pattern left from the bagging film? Is there a smooth release liner under the film?

    Is the steel tube sticking out to rotate a mandrel for a filament winding process?



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My carbon fiber CNC gantry

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