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  1. #81
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    Quote Originally Posted by jupdyke
    Hello All,

    Iand a Black and Decker 1 Horsepower, 5amp, 30,000rpm router. Hopefully I am stealing the router from my father, and if im lucky I will get the 80/20 free since im part of a student organization. I will post some design blueprints later this week, and would love for you all to critique it. I am curious if a 1hp router will be able to cut aluminum or not? Anyone know. Also what size torque for the steppes would be good so I can start watching e-bay? 150 ounce inches?

    Joshua Updyke
    Hello Joshua,
    You should start a new thread for your build.
    Yes you can cut aluminium with a router.
    I hope you are talking about cutting with your cnc machine. Wouldn't cut aluminium with hand held router.
    You will have problems. They mainly relate to the aluminium melting as you cut. Most of the problems are due to not being able to clear the chips fast enough. Spiral router bits help. Low feed rate (about 4-6 inches/minute). I only cut 0.5mm per pass. Some say crc helps but I find continious stream of compressed air better.
    Lol
    Paul



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    Default I'm sorry this seems to have trickled to a stop...

    Hello all, I'm de-lurking after reading both this thread and the hardware store cnc thread start to finish in the last 2 days. Let me start by saying THANK YOU to everyone who has posted here. It was exciting to read what you have done so far, and your hopes for where you were headed.

    I was REALLY hoping that either of these 2 projects would have resulted in a "standard" design, based on best practices. I'm finally ready to start my own project, and was hoping for some distilled down, tested designs. That way I could get busy making chips fly, instead of re-inventing the wheel. I decided to post in this thread because this is more the type of machine I'd like to build. It's ok to limit oneself to hardware store items, but it seems kind of artificial, especially when so many better items are available from other stores and the web. (The disagreement about whether to allow square steel tube was the killer for me, it's readily available at most home centers, and every city in the US has somewhere you can buy steel. Worst case it's available mail order.)

    There are so many great projects in the worklogs, and so many great ideas in this and the hardware cnc thread, but sometimes the choices are overwhelming. And some of the gaps are just mind-blowing. Like WHY to choose steppers over servos, WHAT actually goes between the CAD drawing, (the G-code) and the drivers, to actually make the machine DO things. Not to mention why choose different methods to drive the axis' like direct coupling, reducing gear boxes, threaded rods, rack and pinion, belts and pulleys...

    I'm not suggesting this is the right place for a primer on how and why, but I would think it's the right place for some discussion about approach and choices when designing a "reference" system.

    I have fairly sophisticated building ability, and access to a well equiped workshop, although no real machine tools like mills or lathes. I feel confident that I could execute any design presented here. And I can read the worklogs and borrow this good idea from here and that one from there, but the whole point of these threads seems to be to learn from others experiences and distill that knowledge down into what business calls "best practices." To that end, we would need to avoid what I think happened in the hardware cnc thread, people got bogged down in detail, and lost sight of the whole. Would it not be better (and reinvigorating to the thread) to identify the "big chunks" and work in parallel on them instead of working in tiny detail, each item in series?

    For example, every machine needs these "chunks" or modules:

    supporting structure/ frame
    work-holding table (x axis?)
    spindle/ router holding structure (y and z axis?)

    Then look at choices- moving table or moving gantry? what support for the moving parts, shopbot style? rails? tubing? (square? round?) angle? Purchase or make?
    What drive mechanics? threads, pulleys, rack? Linear induction motors?
    What drive electronics? What are good choices for the guy who doesn't want to learn electronics and build his own possibly dangerous power supplies/ controllers.
    What type of material to cut and what does that require in terms of hold downs, table structure, chip removal, cooling lube? How does that determine the structure of the other parts?

    then look at the pieces:

    support frame, made of what? how ridgid? how big?

    work holding, made of what? move table or gantry?

    etc.

    Then apply the whole groups ingenuity to solve the problems out of commonly available materials, using simple techniques, with the goal being not the worlds sweetest homebuilt CNC router, able to hold .00001 of an inch over 10 ft of travel, perfect and innovative in every way, and oh yeah only costs beer money, but to provide a CNC that can hold real world tolerances, be built by a reasonably handy person, without esoteric materials, tools, or skills, with the goal of actually finishing the machine and cutting stuff!

    So, is there any interest in covering some of this ground again, and trying to restart this project? It's possible there isn't really a need for this sort of "reference design." Maybe the people who are drawn to build their own machine tools are also the kind who need to do everything "their own way." But even then, I think there would be great value in having a starting point for basing your own design and custom details on. A design that is "good enough" for 90% of people, that uses proven techniques and materials.

    I'd like to hear your thoughts on that possibility too.

    With respect,

    zuk



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    Default Some more specific thoughts...

    izzlestar- I really like your guide trucks and the use of angle iron. I know though, that all the steel angle I get has mill scale on it, and so isn't particularly smooth. How well do your bearings run on the surface? Do you get much or any tool chatter as the gantry moves up and down slightly when the wheels roll over the imperfections?

    The other choice would be aluminum angle which in a normal "mill" finish is very smooth. I saw some discussion that aluminum would quickly wear. Does anyone have any direct experience with this? Do we know what real pressures an average gantry would exert? Would bigger or more bearings solve the wear problem?


    achiestdragon - - I love your use of Unistrut. I have used it to build many structures to mount high end projectors and optics. It is versatile, cheap, and available at most home centers in the US. Further it is stiff and has many different bolt together options. It is a great alternative to welding. Most importantly for this forum though is its stiffness. It is much stiffer than 8020 aluminum extrusion. This means less deflection, and a more rigid machine. Granted that the dimensional tolerances are not as tight as 8020, but the low cost, easy availability and stiffness far out weigh any downside. AND your technique for mounting your guide rails is brilliant in its simplicity. I can't believe that no-one commented on it either here or on the Hardware CNC thread. (Others, if you haven't already, take a real close look at this. Even if you don't like unistrut the same principal would work with aluminum U channel, or even 2 angle irons back to back and slightly apart.) I think this is a real, viable way to use CR rod, or drill rod, or ground rod, or even pipe as the guide track, without machining complex mounting hardware.

    Anyway, food for though, and I need to get to sleep. Hope to see soem comments soon,

    best,

    zuk



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    not been in a position to do mutch with the machine at present
    i split with my ex and have moved since then , still have to get the machine over here
    and hope it fits in its new home
    going to be spring/summer this comming year before i get around to really have a chance to use it and finish it off , i really need it to machine out aluminium sheet thats the main reason for requireing the extra strenth , so going to need a coolant system and tray for it
    unistrut is a good material to work with , its makes for a strong frame and allows for easy assembly , the final design i did is welded together but and posed a number of other problems in allowing for it to be aligned

    its one thing to undertake welding if you have suitable jigs to allign the parts but if out then it can make the machine unusable , i opted to make all the axis adjustable that
    allthough it may take longer to initialy allign the machine it can be done without rebuilding
    using unistrut in the right way and allowing for adjustments to each axis should be possible making a machine that would handle quite high loads like ply or some hard woods , and not suffer from the seasonal veriations in the size of the wood used on the designs being discused at the time
    guess that idea would need a set of plans to make one easy to reproduce using unistrut
    the other thing i managed was all i had to build my machine was hand tools and hand drill and a mig welder , i did not have access to a full workshop to acuratly mesure and cut out ply like the other design was going
    i think this is because most are experianced in wood work and shy away from using other materials , but for me i would need a cnc to mange to cutout the wood acuratly enough in the first place

    although the machines is heavy about 85kg thats why i had to build a stand with casters for it



    bad point ,well looking for a 4mm milling cutter with a 1/4" shank to fit the router is a pita here in the uk , think i may get a couple of collets made for it
    at least the router mounting lets me replace the bosh router with a bosh drill

    i did make this using it

    although i hate working with mdf but it proved that the machine works

    dave



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    Impressive. You left the machine with the ex !!! Very trusting I must say.

    Jason

    Last edited by Jason Marsha; 11-13-2006 at 09:46 PM.


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    Wink

    So are the tracks for the router?

    OK a bit small for that. Maybe you could mount a flame thrower on it and chase RC cars. That could be fun.

    But seriously what are they for?

    Paul



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    Talking Starting my first build! Want to follow along?

    Hello everyone:
    I have been reading and following the CNC zone for almost a year now, and I am ready to get started with a mid range build. I want to try to document the build and I am looking for ANY constructive imput along the way. I started another thread here www.cnczone.com/forums/showthread.php?t=27181.

    I would like to move either to this thread or start one of my own if that would be more appropreit.
    Let me know what you think of the preliminary drawings, and you are welcome to chime in as I go along.

    Regards,
    Bob C.



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    Default here's some one who's building BIG!

    I spotted this which led me to research which led me here. Any how check this out: http://www.grabercars.com/content/view/67/2/
    It's a 3mx3mx2m router table, or at least the beginning of one. He's got solidworks files there too. Would this be considered mid range?



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    Default cnc router

    Hi friends,
    I am intrested to buy or build a cnc router for engraving light metals like aluminium and its alloys.
    if any one can guide me? my mail id a_gsan@yahoo.co.in



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    Default Thoughts from a newbie

    If I missed this in another post, I am sorry. If not, wow is this an OLD idea.

    Back in the 1940s and 1950s J V Romig (I think) put together a bunch of plans for Popular Mechanics which used concrete for working parts of metalworking machines. More recently, people who are building milling machines out of cheap drill presses have been filling the columns with sand/cement mixes for two reasons: 1) sand/cement is massive, it limits resonance and 2) sand/cement is rigid, it limits deflection.

    If the rails were thinish steel conduit filled with sand/cement mix, might this be a reasonable way to to make rigid, non-resonant structures without great cost?

    Last edited by SirDave144; 01-09-2007 at 11:18 PM. Reason: Typographic error in the fourth word.


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    Default A frame idea.

    Has anyone considered making the frame from tubing/pipe/dom amd Keeklamp pieces or equivalent? (see http://www.keeklamp.com/us/)

    Advantage: No welding, no drilling, just a pipe cutter and a hex key, may be cheaper than the tooling.

    Disadvantage: limited to 90 degrees for rigid connections, expensive.

    Thought (mentioned elsewhere), fill the pipe with sand/cement mix for rigidity and dampening.



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    Quote Originally Posted by SirDave144 View Post
    Has anyone considered making the frame from tubing/pipe/dom amd Keeklamp pieces or equivalent? (see http://www.keeklamp.com/us/)

    Advantage: No welding, no drilling, just a pipe cutter and a hex key, may be cheaper than the tooling.

    Disadvantage: limited to 90 degrees for rigid connections, expensive.

    Thought (mentioned elsewhere), fill the pipe with sand/cement mix for rigidity and dampening.
    Wouldn't that be more towards the entry level size?
    For intermediate I was thinking something along the lines of salvaged shop track. the smaller, factory railroad rail looking stuff that used to be used for overhead track.


    I have a couple of pieces salvaged from a previous job, factory still running since the 30's

    Last edited by rovingmind; 01-12-2007 at 12:30 PM.


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    Sir David144:
    It seems you have not considered the deflection of the rails either initially, or when a load {the '\"Z" ,"Y" axis'} moving along the "X" axis.
    ALL pipe will deflect a given amount based on length and wall thickness when suspended between two points. It is a law of gravity.
    And trying to use your idea would severly limit the lengths of any of the axis'.

    Read through some of the DIY builds here will give you many ideas, as well as forwarn you of potential pitfalls.

    Regards,
    Bob C.



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    Default Filled pipe as a way

    Quote Originally Posted by Bob Cole View Post
    Sir David144:
    It seems you have not considered the deflection of the rails either initially, or when a load {the '\"Z" ,"Y" axis'} moving along the "X" axis.
    ALL pipe will deflect a given amount based on length and wall thickness when suspended between two points. It is a law of gravity.
    And trying to use your idea would severly limit the lengths of any of the axis'.

    Read through some of the DIY builds here will give you many ideas, as well as forwarn you of potential pitfalls.

    Regards,
    Bob C.
    Thanks for the thoughts, Bob. My issue was not deflection, but vibration. Yes, all pipe deflects (it's a law!), but that can be compensated for with predeflected pipe .

    Steel pipe and rod tends to "ring" when excited by an impules. The ringing tends to cause wiggles in lines at certain speeds. The damping effect will reduce the ringing, positional errors can be compensated for in software if they are repeatable.

    Just as a thought, would a hunk of threaded rod to a plate and a support in tension (during fill) and between two plates (during curing and operation) so the rod is in tension and the pipe is in compression improve the structural properties? Also concrete/cement-sand mixes tend to be VERY stiff in compression which would (I believe) reduce deflection.

    Dave 8{)




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    Pre-stressing is usually to allow a beam to lay straight when suspended between end points. With a gantry the load is shifting along the beam so pre stressing will not have much benifit. You need to reduce the flexing of the beam as much as possible by increasing the strenght in the direction of the gravitational force. This can be improved by width of beam but this has weight problems. To reduce the weight you can use tortion box design or composite make up. Concrete in tubing is a composite which uses the strength of concrete together with the light weight (when compared with steel) bound by the steel tubing which will prevent the concrete cracking due to point loading.
    Hope this helps. There are some engineers here that could proberbly explain it better.
    Paul



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    Default Construction Materials

    I have been following this thread for a while now. Most of the talk has been about steel aluminum or mdf. How about good quality baltic birch plywood? or a machine made with mulitiple materials? For the Axis ways what about ground steel shafting? I know you can buy lengths at metal supermarket. These materials while not cheap or hardware store stuff are not crazy expensive either. Both materials can be worked with hand and basic power tools. Baltic birch plywood could also be machined on the hardware store CNC machine. I have seen very good stationary wood working tools made from birch plywood. Plywood will damp some of the noise caused by the router and the steel shafting is less likely to deflect under load also it provides a very good surface for the bearings to travel on.



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    Default Mid range cnc router

    Gentlemen,

    I’m new to CNCzone. I’ve read through both this thread and the Hardware Design thread. Very interesting. First a bit about my background so everybody understands that I’m not just talking off the top of my head. Machine shop was my major back in high school. After high school I went to work for a machine tool company that produced gear cutting machines. There I was a two year apprentice and got to work on every kind of machine in the machine shop. Then actually worked on the machines themselves to produce master parts, plus customer training. Then I worked a very long stint on the assembly floor bringing the machines to life. Ran machines from full manual operation to 6 axis CNC machines. So after 30 years I’m retired and now have time to spend on my hobbies.

    So with that said I’d like to offer my 2cents. I don’t believe you can design a machine without first knowing what it’s supposed to machine. I see no mention of what this router is supposed to cut. Is it, wood, Styrofoam, machineable wax, aluminum, brass, steel, etc. Once that’s decided then you can figure out what materials and electronic equipment you need to fulfill the job.

    Obviously the harder the material machined and the faster you want the machine to cut the more you will need a rigid machine. If your just going to make Styrofoam parts rigidity and accuracy, plus a faster feed rate, does not need to be that great. If you want to make parts out of aluminum or brass for say a model airplane, model train or steam engine then you need more precision and to get that precision you will need rigidity. So it depends on what you want to do with your cnc router that will determine the materials used.

    Some were in the near future I hope to build a router to make parts for my model railroad, live steam, and RC airboat hobbies.

    Regards,
    Bernd



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    Default Activity

    Guys and Gals, what happened all activity on this thread has stopped, did I miss the final design direction?

    Paul



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    Default possibly new design ideas

    some ideas:
    1.
    forego traditional bearings - use polished steel on steel or steel-teflon-steel sandwich. All the serious xy tables I've seen seem to have large steel on steel areas.

    2.
    use carbon fiber over stout wood , instead of metal, for structural parts. cost comes out comparable and strength if done right may be better

    any old timers have some feedback?



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    I just joined a few months ago, so may not qualify as an old timer but....

    The only real benefit of the bearings is they offer a bit of friction reduction, sealed lubrication, and make a nice replaceable package when they wear out. HDPE, Teflon and bronze bushings are also options. Metal on metal is used in machine tools all the time. *THEY* are the tradition. Just a bit fussy to fit. They even use wood for bearings in big hydro-electric turbines. Usually lignum vitae.

    Why the synthetic carbon fiber instead of natural carbon fiber (Wood)? You might be able to get a tiny bit lighter with a synthetic carbon fiber structure but the total composite of wood + carbon fiber + resin will most likely be heavier as a unit. I assume that you are not planning on getting the CNC machine airborne so it probably isn't much of an issue either way . Take a look at Matthias Wandel's home made bandsaw (Woodworking for engineers) The section of video where he hooks up his dial indicator and measures the flex hanging his weight on the arm of the saw and he gets about half the deflection with his wood framed saw compared to the cast iron saw is pretty eye opening.

    Quote Originally Posted by rutman View Post
    some ideas:
    1.
    forego traditional bearings - use polished steel on steel or steel-teflon-steel sandwich. All the serious xy tables I've seen seem to have large steel on steel areas.

    2.
    use carbon fiber over stout wood , instead of metal, for structural parts. cost comes out comparable and strength if done right may be better

    any old timers have some feedback?


    Last edited by dkirtley; 01-22-2011 at 05:24 PM. Reason: I can't spell.
    My uncensored views and CNC Router planning: http://reinventingcnc.blogspot.com/


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Mid range design #1

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