It has been a year, beyond the 525…

New Home Forum Updates It has been a year, beyond the 525…

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This topic contains 125 replies, has 22 voices, and was last updated by  Ryan 1 year, 4 months ago.

Viewing 30 posts - 61 through 90 (of 126 total)
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  • #31776

    David Walling
    Participant

    Hey. Nothing wrong with pink parts. Makes mine look like a Willy Wonka machine.

    #31778

    Ryan
    Keymaster

    Just something wrong with a pink LowRider….gold sounds so much more fitting….actually gold sounds perfect. Just have to find some matching rims and tires for it now. Gold prints, black flat parts, green wheels? Sounds like a color scheme only a low rider can pull off.

    #31783

    David Walling
    Participant

    Not sure… can you somehow imbed glitter into the filament for a flake effect?

    #31785

    Ryan
    Keymaster

    Glitter Flake HTPLA – Stardust

    I’ll have to ask for a gold blend, I think we are getting somewhere with this.

    #31792

    Jeffeb3
    Participant

    It would add to the part count, but can you print fuzzy dice?

    #31793

    Ryan
    Keymaster

    Hairy lion style fuzzy dice for sure!!

    #31794

    Jeffeb3
    Participant

    In hot pink?

    #31798

    David Walling
    Participant

    Actually. The hairy lion would work great like a hood ornament. We can mount it on one of the corners so it doesn’t add weight to the Z axis.

    #31799

    Ryan
    Keymaster

    I don’t know, dice sound perfect, purple hairy lion dice.

    #32029

    Tom Cole
    Participant

    You saw the brace I made that connects a leg to an adjacent wall. I only installed 2 of them. One on each leg furthest from the corner of my shop where the MPCNC is located. My SWAG is that it reduced movement in the rails by 75% and that is with only 2 legs braced. The problem is that many machines are not in a corner. My alternative there would be lock collars that not only held the vertical legs, but also held a gusset at a 45° angle down to the bed. 4 gussets total would work.

    I like the ball screw on Z better than the threaded rod. The threaded rod has enough advantage to push the entire machine up and out of its leg locks. There’s room to dial that down. I don’t care about that so much that I’m going to tear down the machine to swap though. It works now.

    #32034

    Ryan
    Keymaster

    Thanks Tom, I appreciate the feedback. I have to start making some clear constraints on the machines size so I don’t spend so much time telling people to stop making it so big. I will have to find the place place to clearly state 4″ Z travel is the max you should go unless you want to use these braces, these midspan supports, etc.

    The machine seems to be working very well and the questions now are all getting much more technical so I feel we are making progress.

    My immediate non-daily routine todo list right now is,
    -More clearly defined dimensions, and why.
    -Portfolio page or some sort of “look what this can do” gallery
    -Find a way to database some feeds and speeds (not easy with such a variable machine)
    -Update the z axis.
    -update the parts, links page
    -forum spacing overlap on phone browsers.
    -Maybe hire some part time help….

    The new Z is pretty easy to swap out, I just did it. I need to put up the parts soon so a few others can try it out, but I am 90% sure the kits will start shipping this way in a few weeks.

    #32035

    ualdayan
    Participant

    Well, I’m going to kind of reply to multiple posts at once.

    For the legs – what I’ve done is I took the leg parts, combined them in tinkercad, then added on a ~3″ rectangle in Tinkercad along with 4 screw holes, basically my legs are 1 printed part, nearly full infill, screwed down to my bed tightly on all 4 corners of each leg. That really helped with my legs, and also made sure all 4 were the same height. I painted them red, even though they were red originally because the plastic I used was $2-3 a pound ABS (I make my own filament with a Filastruder), and it had glitter like reflective material in it that I tried to cover up.

    On the lead screw – glad you’re thinking of using them now – I’ve been using one since the early days (remember when I first mentioned the whole 32 microstepping, throttle issue because the Z axis needed so many steps with what we were using originally). I kept having problems with the coupler early on – this was with the early early version. The printed coupler kept failing and I kept having to run and do emergency stops as the router went too low and was eating my table (and the flexible coupler seemed to cause Z problems back when I tried it), so going to a leadscrew both solved all that (integrated leadscrew motor – no coupler), and really enabled me to do 3D carvings at good speed.

    As for rigidity – the XCarve I don’t really think of it as being more rigid than a MPCNC. The Shapeoko though – it’s just so heavy I feel like it probably would be – although I know that’s your pet peeve – I ‘feel’ like it would be, I don’t know that it would be. I think the production of a MPCNC, the way we make it, can lead to way different results for different people. Sometimes people’s printers will just be slightly off. Other times – people will make mistakes that make things worse. I know I’ve made some real bonehead mistakes. ‘I know, I’ll print this in polycarbonate.’ ‘I know, I’ll print this in PETG. It’s so much tougher.’ Yes, they don’t break like PLA – but they also don’t hold things rigid like PLA. PETG I can flex in my hand with 90% infill parts – so I really messed up when I printed all the 525 revision middle parts in PETG.

    Right now I actually do want more rigidity, and need to find out why my MPCNC keeps going out of square. If I square it up, then turn the motors off, one side actually visibly moves 2-3 notches on the belt. I need to replace pretty much everything I’d printed in PETG back in PLA for rigidity, so hopefully that problem will resolve with new parts. Luckily I do have about 20 pounds of 4043D and 5 pounds of 3D850 (I tried sanding a 3D850 part once – and the metal file broke, talk about strong). I haven’t decided yet if I want to convert my MPCNC to a 3D printer/experimental base (things like trying to make a CNC Airbrush painter) and get a steel CNC (not steel cutting, steel components) I’ve had my eye on (nearly $2k for the frame, and then you still have to buy 425 oz steppers, and a 1.5K spindle seperately, with a 48″ x 48″ cutting area). I want to start cutting things faster, things like using a tapered ball nose bit, and doing 3D carvings without a roughing pass, just straight down full depth (the tapered bits can take it amazingly).

    Alternatively I’ve thought about changing over to the 1″ stainless steel tubing version – one of the things I’ve never liked is over my 36″ span the EMT conduit seems to sag a bit in the middle. The last time I went looking it was kind of hard to find with the wall thickness I remember reading we needed to aim for (everything I found was either thinner or much thicker). I’ll admit I’ve also pondered the Lowrider, or even making another printed CNC after they hit their 2nd revision (I won’t mention the name, but you can probably guess. I don’t know if you consider them competition or what – they don’t sell a kit so they aren’t direct competition anyway).

    1 user thanked author for this post.
    #32242

    rkrammes
    Participant

    With the 1″ stainless 525 version @ 2’x2′ x/y and 4″z cutting area, I only see play in the feet. This is even with the whole machine printed in petg. Also, I needed a pretty beefy tool mount. I haven’t challenged the machine much, but I have seen some movement at the feet when something went wrong in the cut or I just lean on the machine a bit.

    I did have coupler problems and just ended up putting in a brass coupler. I would be interested in a lead screw on the z. I noticed big improvements when I switched to a proper z lead screw on my 3d printer. Just my personal experience. Keep up the good work.

    Oh, I think something that would help me is some videos showing too slow/too fast/just right for feeds and speeds. What should it sound like? What should the debris look like etc? I guess I’m kind of a visual learner.

    #33260

    Marco Pifferi
    Participant

    What kind of leadscrew should be used ? There are two common sizes available: tr8x2 and tr8x8

    #33369

    Ryan
    Keymaster

    8mm diameter, 8mm lead, 2mm pitch, 4 start is what I use. You can use anything really.

    #33372

    Marco Pifferi
    Participant

    I can buy two models here : tr8x8 that moves 8mm per turn or tr8x2 that does 2mm per turn.
    Most 3D printer seems to use tr8x8

    #33373

    Ryan
    Keymaster

    The ones I sell are as stated above and the part was design to fit that nut.

    300mm LeadScrew and Nut

    #33374

    Marco Pifferi
    Participant

    What are the settings for Merlin ? How many steps per mm ?

    #33379

    Ryan
    Keymaster

    Depends on a lot of things without knowing all of them this might help.

    T8 Leadscrew Compatible Parts

    If that doesn’t please start a thread with all the details of your build.

    #33463

    Lance Hall
    Participant

    Ryan, do you have an ETA on when the kits will start shipping with the new T8 leadscrew? I will be done printing my 3D parts today and ready to pull the trigger on the kit order.

    #33477

    christian ritchie
    Participant

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

    Options, ideas?

    Disclaimer:
    My MPCNC isn’t running yet, but I have assembled it except electronics and belts.
    /Disclaimer

    I think my plan is to cnc holes in my table, and a few layers (~6″ deep) of MDF, to support the verticals, and make them too long(like a foot or so), and adjustable height.

    Second thing I’ve given some thought: Unsprung weight.
    If the xy motors were stationary, the xy carriage would be less massive, so the forces would be reduced at the same speeds.
    Also, if the Z motor were attached to the middle asm, it wouldn’t need to lift itself or the leadscrew.

    Third thing: If the z axis could be suspended with a spring to counter its own weight(or the weight of the tool attached + z axis…), it could be belt drive, and equal speeds in x/y/z would be no sweat. That would be differentiating performance for a diy cnc machine.

    #33483

    Ryan
    Keymaster

    Lance, maybe I can put up an option later this evening. I have all the parts but pricingg might be tricky. I have to take a real hard look at the numbers and labor savings.

    Christian, adjustable height was the intended reason to have the feet hollow, most of us just take so much time leveling it we don’t move it. The option is nice though.

    XY steppers, having them on the corner means more parts, longer belts, bigger footprint. The speeds at which we cut I feel effect would not be noticeable. So I made assembly easier and the machine cheaper having them on the rails/rollers.

    Z stepper on the gantry would be awesome but it means the leadscrew would need to stick up. I chose the current setup to keep the screw covered from dirt and debris in the little tunnel and the footprint at a minimum. I am always looking to change this. I have tried a belt driven Z, but would like a higher gear ratio because I don’t like working with springs (they are expensive and would limit the expandability of the machine and raise the price).

    Maybe it’s time for a “Pro” version?

    1 user thanked author for this post.
    #33599

    Steve
    Participant

    Hi, Is there going to be new firmware for the Mini Rambo?

    #33600

    Ryan
    Keymaster

    Steve, New firmware is coming for the mini rambo. The current firmware is based on the later version of RC8 so there is not much difference at all.
    Are you having some sort of issue?

    1 user thanked author for this post.
    #33928

    SomeOldGuyCoding
    Participant

    Probably already answered, but dang if I can find it. Vicious1, how does your new T8 design affect the “Rapid Feed Z” setting in Estlcam?

    #33931

    Ryan
    Keymaster

    It can go much much higher, 80mm/s max before losing much power….. but I still have the firmware limited to 8.4mm/s. I haven’t done any real testing on speed yet. The weight of the spindle might have a big effect, and the accel will severely limit it as well since it is such a short distance traveled.

    The bigger picture is more power at slow speeds, so builds with Z issues have a better chance of not irritating the builder!

    #33932

    Ryan
    Keymaster

    If my math is right. 60rev/min*1min/60sec*32000steps/rev*1mm/400steps=80mm/s and that is under the 40k limit for the rambo at 16th stepping, so 50mm/s max for the Ramps at 32nd stepping.

    1 user thanked author for this post.
    #34086

    Steve
    Participant

    “Flash or correct the firmware Z steps, with 32nd stepping 788 steps for the Z axis seems to give me the most accurate results.”
    Where does the edit go, Configuration.h?

    {/**
     * Default Axis Steps Per Unit (steps/mm)
     * Override with M92
     *                                      X, Y, Z, E0 [, E1[, E2[, E3]]]
     */
    #define DEFAULT_AXIS_STEPS_PER_UNIT   { 100, 100, 2267.72, 100 } //MPCNC}
    {/**
     * Default Axis Steps Per Unit (steps/mm)
     * Override with M92
     *                                      X, Y, Z, E0 [, E1[, E2[, E3]]]
     */
    #define DEFAULT_AXIS_STEPS_PER_UNIT   { 100, 100, 788, 100 } //MPCNC}
    #34088

    Ryan
    Keymaster

    It is already there in your second chunk of code.

    #34089

    Ryan
    Keymaster

    I have firmware posted already pre-configured, should not need to edit anything.

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