It has been a year, beyond the 525…

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This topic contains 120 replies, has 20 voices, and was last updated by  Ryan 4 months, 2 weeks ago.

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  • #31309

    Ryan
    Keymaster

    Okay I have a few updates in mind but I think I like doing this in sections.

    First issue the legs. They are currently the weakest link.

    Options, ideas?

    1)Get rid of the locks, legs, and feet then just use a 4″x4″? Hard to level..
    2)Use angled braces? Extra parts…
    3)Make all 4 corners the z axis? Yikes…lots of hardware and electronics
    4)Hard mount the corners,make the z axis the bed? harder to make a table, lots of carpentry involved.
    5)Rework the current parts use two tubes side by side, make the lock and feet fit both? A little extra tubing.
    6)Use the current setup and add allthread from the top through the table and bolt it all together? I see a lot of parts getting crushed this way.
    7)New feet, the corners and locks seem solid to me, the feet seem to be the weak link? Easiest.
    8) #7 plus a place top mount guy wire for the taller builds? Options are cool.

    #31311

    Ryan
    Keymaster

    Or…

    9)Leave them alone they only seem to be an issue with more than 4″ of Z axis.

    #31315

    1)Get rid of the locks, legs, and feet then just use a 4″x4″? Hard to level..

    Easy and effective solution. The leveling can be done relatively easily using shims or a few layers of paper. The only concern I have would be wood expansion/contraction overtime.

    2)Use angled braces? Extra parts…

    Better than nothing but it will be weak.

    3)Make all 4 corners the z axis? Yikes…lots of hardware and electronics

    Too complicated, and it will need 3 more motors. Leveling will be a nightmare and rigididy will vary depending of the height of the machine, so results won’t be constant.

    4)Hard mount the corners,make the z axis the bed? harder to make a table, lots of carpentry involved.

    In my opinion, the best solution, but it will not be for beginners and it will ruin the whole point of the MPCNC: being an entry level easy machine for people to experiment with.
    But it could be another complementary version. Like beginner version, versus experts version.

    5)Rework the current parts use two tubes side by side, make the lock and feet fit both? A little extra tubing.

    Could be an easy solution and this should work better than the original, if I understand correclty what you are saying (putting two tubes at each corner, oriented at 45 degree, one inside the frame and one outside, right?). I don’t see any downside aside from extended printing time for all these corners and supports. Might do the trick. Could also add more tubes, 3 or even 4.

    6)Use the current setup and add allthread from the top through the table and bolt it all together? I see a lot of parts getting crushed this way.

    It will improve rigidity, but needs to be crazy tightened, which will be hard on the plastic parts, but they can be made pretty solid. Tightening will have an impact on leveling, so it will make things complicated: people will have in some cases to chose between a leveled machine and a rigid one.

    7)New feet, the corners and locks seem solid to me, the feet seem to be the weak link? Easiest.

    In my opinion, new feets will greatly solve the issue, but I can’t think of any feet design who can solely solve the problem, unless having massive feets that will take hours to print. Unless, as mentionned above, a feet design using sereval tubes. Could be two or cound even be 4.

    8) #7 plus a place top mount guy wire for the taller builds? Options are cool.

    Didn’t understand this point.

    In my opinion, if you wish to have maximal rigidity without making too many changes, the solution 5 is the best. It will not solve everything, but it will definitely be better.

    An other solution would be to print the feet/tube/bottom corner support as a whole, single part. But it will take a long time to print.

    I believe the best way to have something rigid is either the technique I used for my table, which has a lot of other advantages, like versatility but makes things very hard to square the first time, or, as someone else suggested a few days ago, to attach the structure to a wall, which is clearly the best thing to do but might not be practical for everyone.

    As for other suggestions I have:
    -add parts or spots to fit the endstops, especially on Z axis
    -Add some cable management parts,
    -consider a more rigid center carriage, maybe using two parralel tubes instead of just one per axis. I think this is not easy to do but it should be feasible.
    -Same remark for the Z axis, it may be possible to use 3 or even 4 tubes intead of 2, by mirroring it. This could greatly increase it strenght, which could be useful for tall builds. Not sure this is a priority though.

    Hope that helps!

    1 user thanked author for this post.
    #31329

    Barry
    Participant

    @Dui, ni shuo de dui.
    Don’t want to add more crap to the Z. It will make it heavier, which will sag the X Y tubes.

    @Ryan

    I have an idea. Have to go to work though, will post later.

    #31331

    David Walling
    Participant

    I’m not finished building mine, so take this with a grain of salt.

    To me, the best plan would be to add bracing in the corners. Any time you have a 90 degree turn in a design, there’s the chance for racking. In the steel stand I just built for my reef tank, I added 45’s in every corner… probably overkill, but I’m supporting 2,000 lbs 3 feet off the ground.

    In your design, this could be added either as a printed part, or some type of metal. It could even be as simple as using metal barstock and bolting it from the leg to the horizontal pipes.

    The hard part is, you don’t want to do this in a way that sacrifices x-y travel of the gantry. Having to make the horizontal parts longer to accommodate more bracing would be a negative.

    If the corners and locks are solid and it is just the feet, then maybe they just need a larger footprint. Maybe try to incorporate some type of metal L bracket into the feet design to help brace the xy load on the feet that causes them to flex.

    #31334

    Jeffeb3
    Participant

    2+5+7/8=7 7/8
    Make new feet. But add a mounting hole. Small builds can leave it at that. Paranoid people can add a brace at a 45. Other people can attach another piece of conduit. Large builds can add a wire to the other corner.

    One of the key design pieces is how you mount it perfectly square, especially if it will have the conduit continue through the table. I remember I printed the first 5mm of the feet to use as a guide to get the holes in the right place. It would be nice if there was something that would hang over the edge, and register to the corner, even if it’s just for drilling. Sort of like the jigs used to mount handles on cabinets in the right place.

    #31338

    Jim Hildebrandt
    Participant

    I have considered using 3/4″ threaded pipe flanges and 4″ pipe nipples for the corners.
    http://www.homedepot.com/p/VPC-3-4-in-Black-Malleable-Iron-FPT-Floor-Flange-16-521-604/205955667

    #31339

    Barry
    Participant

    Jim has my idea, except I’m thinking of using either large diameter threaded rod, or a long bolt with an adapter plate to do the fine adjustment for leveling.

    #31344

    Bill
    Participant

    How feasible would it be to replace the two tubes on the Z axis with four 8mm smooth rods and either linear bearings or brass and graphite bushings? Seems like that wouldn’t affect the weight much and would increase the rigidity. I don’t know if dust would then be more of an issue though.

    #31345

    Martin DB
    Participant

    I’ve replaced original legs with this design

    http://www.thingiverse.com/thing:953976

    #31353

    Ryan
    Keymaster

    I’m listening and thinking through all of these critically. There seems to be no issues at all at 4″ and under, which is ideal and what was intended. But I ripped apart one of my machines to try a few of the ideas out.

    I appreciate the help!

    #31356

    Barry
    Participant

    I think we’re overthinking it. I don’t have the parts to check, and I’m pretty sure I have the scale off on my example picture, but wouldn’t this work? Two pipe flanges, and a section of pipe. Use a pipe clamp(red line) through two of the top flange bolt holes. The bottom flange gets screwed to the table. The pipe is screwed in loose, so we can turn it like a turnbuckle, this will move the top flange up or down, depending on which way it needs to go. Once you have it where it needs to be, a dab of superglue, or even some silicone will fix it in place. Shouldn’t need to go crazy with the glue, it’s just to keep the pipe from turning from the vibration.

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    #31362

    Ryan
    Keymaster

    I love the CGI on that!

    I had originally looked into those flanges but they are something like $8 each.

    Were any of you around for my 2nd or 3rd version of the legs? They were printed and I had intended on making them parametric.

    #31369

    Barry
    Participant

    That’s a lot of plastic!

    #31375

    Ryan
    Keymaster

    It’s hollow.

    #31376

    Ryan
    Keymaster

    But still a lot of plastic.

    #31379

    @Barry: that is why I was asking for a double tube mod for each axis. It would greatly limit the flex and would allow people to put heavier stuff on the gantry. In my opinion this is the only “flaw” to an otherwise great design,
    So my point is not to “add more crap” to the Z axis, it is to strenghten it to allow people to “add more crap” if they need to. Like a more powerful router motor, for instance.

    @vicious1: those printed feets that you posted seems to be a good solution. What was the result of your tests?
    The only issue I see on the pictures are:
    -the little hole on the top is a bit small. The bigger bolt you can fit, the better.
    -how do you attach it to the table? The way it is attached will be critical, it needs to be super strong.

    #31380

    Ryan
    Keymaster

    You would get more more rigidity in a smaller area with a larger diameter tube instead of 2 tubes with much less hardware involved. The LowRider is supposed to fill the need for a larger machine gap instead of trying to maintain a 4th size machine. If I do a large diameter build I would have to know that size is available everywhere in the world, but then why not just the lowrider?

    Do you really need more power? I can’t bog down my 660 even a little bit. I smashed it into some aluminum and damn near broke my MPCNC because the dewalt just kept chewing. The dewalt will easily rip apart the machine before it bogs.

    Those legs were from 2 years ago, they worked great. The hole in the top matches the corner bottom same as the current part has, and some glue in the gap is still ideal there. The table screws were at a 45 degree angle you can see one of the holes in the pic.

    #31381

    Mmmfishtacos
    Participant

    Sort of off topic but I want a sanding bot.. I hate sanding, after spending 12 years in auto body If there was a machine that could sand for me, I would build it.

    #31382

    Ryan
    Keymaster

    Quick question, I have just seen another comment about “shapeoko being so much more rigid compared to the MPCNC, but that’s why it cost thousands” I have seen this so many times. Along with other comments from people that do not own one saying how weak it is by its looks alone.

    I promise I won’t get mad at anyone or hold it against you but has anyone ever tried the two machines, are the other ones that much better? I honestly can not imagine if the had the same cutting volume there would be much rigidity difference. Aluminum is pretty flexible, the extrusion is not ultimately rigid. It was designed as a quick building platform like an erector set not as a rigid rail, not even getting into any other design aspects. Is it that people assume that it is super strong or is it actually more rigid? I have never been able to touch a shapeoko or xcarve, I have tried to wiggle a few others.

    This machine does what I need it to, I can cut everything all the way up to aluminium. A steel cutting machine is not on the near horizon, so the only thing I can see to do is increase rigidity and speed without tripling the price. Hence the leg questions, but I am starting to feel like it would be better if I just put a suggested maximum z length instead and focus on the next improvement.

    #31383

    Ryan
    Keymaster

    Next machine on my list is a hardware counting machine, then a automatic bagger for it. Have some sensors on order…I want to expand the Micro-manufacturing ecosphere..

    #31391

    @vicious one: I like to machine quickly, because I cannot afford to be too noisy for too long (I have neighbors). That’s why having a powerful router motor is important, because I can crank up the speed quite a lot.
    I made several tests with different routers and power clearly matters, especially when I’m attacking plywood which is a pretty inconsistent material, with great variations in strenght.

    Again, in my case I really have no problem at all, because I use special tubing who almost doesn’t flex. But I hear that apparently most of you guys are concerned about tubes bending, and that most of you cannot find the kind of tubes I use at affordable prices. So doubling the tubes would be better than nothing and would still work for everyone.

    Using a tube with a greater section for the two middle axis is also a good option, probably the most elegant, but it will reduce a bit the workable area and it will need some serious design mods. Using two tubes seems much easier to me.
    I think I’ll try to design it when I’ll have some time later, to see if this could work.

    Of course making the whole thing smaller is a solution, but this only works if you don’t plan to 3D print big things. The lowrider is great, but it is an only CNC milling machine, the MPCNC remains more versatile in this way, that’s why it still has my preference and that’s why I think having the ability to make it big still makes sense.

    #31394

    Mmmfishtacos
    Participant

    The only cnc I’ve used is a shopbot, and I’m pretty sure that machine can cut anything you throw at it. But it’s also like 14 grand. I can’t answer your question now. But I will be able to fairly soon. Maybe by the end of summer. I still have to get my garage in order for both machines.

    I think the main thing that draws me to the x carve is actually their forums and the projects you see created there. As it answers the question of “what can I do with this”. And rigidity is actually the last thing on my mind. But if you look over their forum you’ll find a pretty big modding community there that are after rigidity and have made some pretty solid machines from the bones they where given. Plus I think the easel app is a pretty big draw to the whole package as it simple to understand and can have you cutting pretty quickly. While it does cost about 1600+shipping (300) in it’s normal package, I’ve gotten the machine down to 1000 with tossing the extras and making the waste board which really drives the shipping cost up.

    The big draw for me to your machine is it’s looks. I like the way it looks. I have no real clue what to expect as far as performance. But it seems like a fun project that ultimately I feel I’ll be more proud to show off over the xcarve. And if It’s anything like your printer than I’m sure I’ll be pleasantly surprised by it’s performance.

    One thing I would suggest is setting up a project page, similar to what they have, and show people what can be made. That really why we buy or build these things to begin with.

    #31396

    Ryan
    Keymaster

    Thanks for that. I would expect the xcarve and it’s large box tubing to be very rigid. I honestly have not spent too much time looking at the design but those rails should be pretty skookum.

    A gallery of cuts and uses previous projects is a great idea, I just need to figure out the best way to go about it.

    #31397

    Ryan
    Keymaster

    Well I had to double check I have them all mixed up the shapeoko has the box tubes, with a standard build of 16x16x3 and is partially assembled! Wow they have made some changes.

    The xcarve med is 20x20x2.5ish using 20×40. You are right the projects tab is pretty sweet.

    #31399

    Jeffeb3
    Participant

    I thought the next machine was a mostly printed espresso machine!

    #31400

    Ryan
    Keymaster

    Pfffft, I have a nasty caffeine habit right now. Pretty much coffee, breakfast, emails, more coffee, shiping, coffee, repeat. No MPJava from me, gotta cut back.

    #31405

    I agree with what mmmfishtacos said, the community is very important, and, IMHO, it lacks a bit about the MPCNC.
    Don’t get me wrong, there are plenty of interesting users, with interesting experiences and knowledge to share, but the forum is a bit too calm, there is not much activity.

    I’ve already said that, but some useful features are missing in the forum, and that makes regularly participation difficult:
    -cannot host the pictures on the forum while having them displayed inside a post
    -Cannot add as many pictures as we want in a post
    -cannot edit a post whenever we want
    -cannot add a youtube video directly inside a post

    I try to put as many pics as I can whenever I post, because pictures worth a thousand words, and because that is the best way to gain interest from new users to join the community. But each time I write anything here, it takes me a considerable amount of time. I have to resize the pics, host them on a separate website, etc. On most other forums I use, I can just integrate the pic in my text without much operations. I cannot possibly be the only one having this concern, many people here are hosting their pics on other platforms and share access links to them, wouldn’t it be better to see them directly?

    Same thing about the time limit to edit posts, which doesn’t allow to edit the first post of a thread so that everyone can find the information without having to browse between all the pages. It’s a standard on most forums.

    When I first saw the MPCNC, I wasn’t convinced at all it would work. Seemed too weak and wobbly for me. I had a hard time to find actual results of things beiing made with it, since there were not many pictures. By chance, there were a few videos on youtube and that’s what convinced me to give it a try, otherwise I would have passed. My point being: people need to see that this stuff is working, they need pictures and videos, and this would be nice if it was easier to share them here.

    Anyway, I’m a bit off topic maybe, but it would be nice if those things were taken into consideration.

    #31420

    Ryan
    Keymaster

    Okay, site updates instead of hardware updates, no problem.

    Dui, working on your suggestions .

    Inline images- so far only a paid upgrade but I will do it if I can not find another solution.

    number of pics- It was 4, I upped it to 8. There gets to be an issue where it gets flagged as spam and the compression slows things down too much and you get a timeout. I suggest grabbing a few post in a row if you are doing something that might take more than 8 pictures, Like is done in XDA developers.

    Size limit- I have increased the file size limit as well, the compression should work, still worried about server timeouts if it takes to long. This was leftover paranoia from us crashing servers constantly. The new host and semi dedicated server should help with the CPU cycles to accomplish this. Sorry things had to get limited to stop the site from crashing so often and never got increased as the server quality did. We also use 5gigs and climbing fast.

    Editing, I upped it to a few years-I have found in the past if someone gets pissed they delete all their posts and we are left without the info, but we can try it again.

    Youtube in the post should work now, this was disabled because it was overlapping the next post. If it isn’t fixed I am doing everything in my power to fix it.

    showing the capabilities-I will try and do some sort of user gallery, I hope no one gets too offended if I do not use their work, maybe just my own things. On that same note I will try and put up a picture or video once a week or so. Maybe it’s time to hire some help so I can.

    overlapping links (barry), I have reopened my ticket and hopefully we can get this sorted out.

    Swapping forum backend is an option but that would mean a different login and possibly a messy transition. Last resort.

    1 user thanked author for this post.
    #31422

    David Walling
    Participant

    Sweet work! You’ve been busy today.

    I ran into an issue on my post where I tried to link to an image. My image is only hosted via http and this site insists on linking as https. It shows up as an empty box (or broken link). Anything you can do about that one?

    You can see what I mean in the ‘new build from texas’ thread I started.

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