@claustro said in Best lead screw - ball bearing mount system:
I can't understand the shaft collar and 15 degree angle bearing. What would be the advantages over thrust bearing and regular ball bearing like I did?
I realize now that your picture above shows the screw and shaft, without the coupler mounted.
A shaft collar:
An angular bearing is very similar to a regular deep groove, but the surfaces the balls contact are at a slight angle. They can take axial load, in one direction, and radial load. They seem to be a specialist bearing only available with tight tolerances and a high price.
Having a 600mm diameter Delta (24" in barbarian units) limits your options. I've not seen any commercial surfaces like PEI or Bite made in this size. Very very rare, if any. The print bed is approx. 6mm thick. It is sold as a glass tabletop, approx. $40 USD, on Amazon.
Therefore, I use glass w/hairspray for everything. Thorough cleaning with water or alcohol between sprays really helps. I've never seen anything approaching a chip.
Probe is a smart effector; no problems with glass. Calibration is in my start g-code, for every print.
If something REALLY doesn't want to come off the bed, allowing it to cool to 40C and a spatula usually gets it... if not that, then just allow everything to cool to room temp (20C or so) and somewhere on the way you'll hear a loud pop as the different expansion (ok, contraction) rates of glass vs. plastic work their magic.
That contraction trick: It helps that this is a big printer and I print big things. (Right next to it, there is a Prusa Mk3S for printing smaller things. It, of course, has the flexible steel bed with whatever coating Joseph decided. Alcohol cleaning, EVERY time, is the key to that one. Works fantastically well.)
I have some 6" wide (150mm) Kapton tape, and I occasionally use this on the glass with water spray and a squeegee to apply the tape itself, in parallel strips. Not really for any specific material, more when the mood strikes me.
Thanks for the insight, I will post results, i'm still a couple weeks away from running, waiting for a new design Bondtech Bmg X2 with direct mosquito mounts. still machining parts for the print carriage
CNC and 3D printing does not uses same tools... For example, CAM softwares don't know how to manage bridges or so.
I don't think driving the 5 axis is a problem; it's more a matter of a clever slicer to take advantage of additionnal axis.
I checked all the diagonals.
The base of the printer is perfect.
The problem is the top square that is off of about 5mm (!)
I still have to check all the 4 sides even if they seems ok.
Can you suggest me a flochart for squaring the frame? Sometimes I have the feeling that I straight some part only for crook a other one.
Received allegedly genuine MGN15 HIWIN rails, and no reason to think they're not. Smooth motion, no binding, no play, hard steel. About the same price as the MGN12 rails from the thingiverse link.
Also tried one of the cloned MGN12 rails which supposedly was okay-ish. No play (chose medium preload). Even after through cleaning and re-lubricating the motion was ever so slightly binding randomly along the length. Hard-ish steel.
Asked a different vendor for recommendation for a cheaper alternative, ended up ordering a samle of a cloned HGH15. No play, a little gritty but smooth motion after a quick clean, only had thin oil, not anything super sticky. Relatively hard steel; Same price range as the genuine MGN15 rail, but two bearing blocks with two rows of balls. Think the CNC will be getting the cloned HGH15 rails for X and Y, and genuine MGN15 for Z. Cloned MGN12 may find use on a printer if replacing the balls and polishing the races results in smooth motion.
To understand the basics, I suggest you take a GCode file generated by your slicer, open it in an editor, and look up each GCode command in one of the pages linked to by @oliof. Slicers don't use many different GCodes.
To understand many of the configuration GCodes used by RepRapFirmware, do the same for the config.g file.
Thank you for the input!
This will in turn drive a screw, so as far as the belt drive go I should only need the 16:40 gear ratio. Into a 2mm pitch screw should give me 4000 steps/mm and optimal layer heights for any multiple of 0.025 which is seemed quite convenient as I'll likely use from 0.1mm and up in 0.05mm steps. (1.8deg steppers x16 microstepping) Well thats wrong, Prusa cal thingy ignores microstepping for optimal z height for screws?! Oh well, different gear ratio it is then..
Found a page with simpler math for working out the center distance from the two pitch diameters and belt length without having to resort to nasty trig functions so will incorporate that
K=4 * L - 6.28 * (D + d)
b=(D - d)^2
c=(a - 32 * b)^0.5
C=(K + c) / 16
I print various brackets that have no real fine detail but need to be tough and so use PETG using 240 deg nozzle temp, 60 deg bed temp (blue tape) and zero fan. 3 walls and 20% gyroid infill and they come out just fine. I reinforce some regions in the part with 90% infill as you can see here
I figured out that it's nearly identical to the Bondtech Mini gears, since I completely overhauled an old extruder design (with the Bondtech Minis), used the Hobb Goblin in the new redesign, but never changed the settings, and it printed a calibration cube perfectly.
For those who find this topic later, the final answer is the effective diameter is 7.28mm
The teeth of the Hobb Goblin digs way deeper than the Bondtech, which is great for my 2.85mm filament, but it might be even a bit too deep for 1.75mm (only guessing, I can't test this since I don't have 1.75mm filament).
I'll put an adheisve magnetic sheet on top of the aluminium, the steel sheet will then stick to the magnet. Meanwhile ahesive PEI straight on the aluminium. Its good to 120C so hopefully it'll cover my needs for ABS and PETG for now.
With the bed being 120x120mm I only use about 70 watt or so, so I went with the small SSR modules with 2 channels, so I can add enclosure heater from the same heater wire. SSR only get up to 30C wihtout heatsink or active cooling at that load so it'll be fine as it is.
@alexander-mundy said in Delta arm length:
If I remember right from a long time ago in school, regardless of offsets in the below screen shot with the arms at 60 degrees isn't the hypotenuse (delta arm length) supposed to be 2 X the adjacent (delta radius) for a right triangle?
Why, yes, it should be! Let me take a look...
Edit: Now fixed.
However, I need to look at it again, however, because I changed this:
rodAngle[balln] = 180 - Math.cos(oppositeSide / DELTA_DIAGONAL_ROD) * 180;
rodAngle[balln] = Math.asin((oppositeSide * (Math.sin((Math.PI / 180) * 90)) / DELTA_DIAGONAL_ROD)) / (Math.PI / 180);
Which are just different methods of calculating the same thing... and verified in a debugger that the produce identical (numeric) results, yet the second one works and the first one does not... very bizarre.
I attempted a poly tower, but it ended up poorly because the slicer can only handle even numbers, so I had to print two shells and that kept the heat too close.
Normally I print that model with one shell.
Thanks, I will try again.
I used hair-spray and it helped, but I am so glad I haven't seen any cracking or warping issues, and the best part is parts seem to be 100% accurate, a 20x20 cube comes out at exactly 20x20.
That FilamentOne place was fast as hell to get it out to me, ordered Saturday, got it Monday!
I have suspicions it's made by Filimentium, same reel design, and the company used to sell that brand.
Going to re-print my cooling duct since the one I have now is a rough mess- $9 glow in the dark ABS on ebay gets you $9 quality.
Thanks for the information. Extrapolating (yea I know) the line it appears to fall inside but right at the edge of the area. I don't know if it will make any real world difference but I think I'm going to try the SS-01E which is a low force model.
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