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http://reprap.org/wiki/CoreXY
Re: z- axis nut (long brass) supplier - 12 years ago
Is a loose fit any issue, given that there is a constant load in one direction on the threads? ISTM that backlash in the gears or the nut-trap would be an issue, but loose threads will not result in any backlash in the Z movement so long as the Ormerod is operated upright in a gravitational environment! Dave (#106)by dmould - Ormerod
Re: Sagging MDF, the Q & D fix that anyone can do - 12 years ago
Quoteappjaws1 Thank you Erik, I followed your instructions and found this mod very easy to do. I am sure that bed instability has been the root cause of all my problems so I can't thank you enough for a good solution. I have been thinking about the insulation problem, it strikes me that we need a material that can adjust itself to different thicknesses, my gap ranges from 8mm at the rear to 5mm aby dmould - Ormerod
Re: M105 SD card NOT being read on start up - 12 years ago
Quote88Zombies I just find it strange how my PC can write to/read from the SDcard no problem. Most probably because the timing of the signals sent & read from the SD card by the Duet is different to what the PC uses - the supplied card is probably a particularly slow card, and whilst most PC readers will detect the speed and adjust the signal timing accordingly, the Duet does not appear to dby dmould - Ormerod
Re: Test prints - 12 years ago
QuoteGregL More importantly, and where I need your collective wisdom, I have completed my first ABS print. First layer temperatures 235, 105 Second and further layers 230, 100 Layer height 0.1 Splitting (noisy) occured during the printing on the curved corner nearest the Duet - and those parts of the wall buckled. How can I improve things? Greg I was getting warping and splitting with ABS as welby dmould - Ormerod
Re: X-rib broke after a few prints - 12 years ago
I believe the updated part in the Omerod master moves the nut trap from the laser cut part to the printed part. You could therefore print out the updated part and fit that. Half my nut trap broke off as well, it appears to be a weak spot, but the other half has held up so far, though I will get around to updating the printed part one of these days! Slice the STL yourself - do not use any of thby dmould - Ormerod
Re: Nozzle Temperature not reaching target temp - 12 years ago
Make sure you have the latest firmware - there was an error with the temperature readings of early firmware as supplied with the board, so you must update (follow the links on the commissioning pages to see how to update your firmware). If you have the latest firmware, ensure that the heater is fully in the aluminium hotend block, and that the thermistor is properly inserted with all of its bodyby dmould - Ormerod
Thoughts on hotend temp - 12 years ago
I've noticed that prints appear a bit "sharper" and "cleaner" at a lower hotend temperature, so it is tempting to use, but IME they are also weaker, and can delaminate because the layers are not fused as well as with a hotter temperature - so I've decided to use the highest temperature that does not show significant deformation. The other thing I have seen is that if part of a print contains a sby dmould - Ormerod
Re: Remote Wifi operation - 12 years ago
This is a handy thing to print if you need to extend your WiFi range ... Dave (#106)by dmould - Ormerod
Re: ABS Ormerod parts - 12 years ago
QuoteKevM Thanks for the advice guys, my ABS arrived today so i'll start printing over the weekend. Are there any recommended changes to the standard Ormerod settings for Slic3r that would suggest ? The only changes needed are the temperatures. Dave (#106)by dmould - Ormerod
Re: DIY 12V supply for the budget-conscious - 12 years ago
Quotekwikius To raise the temperature quicker why not add some device above the bed. Could be just another blanket of foam/corrugated cardboard or an active device with a heater in it? (You could then double up using another PSU while its heating) regards Andy That's what I already do - using the foam from the PSU packing as you have done. Dave (#106)by dmould - Ormerod
Re: X axis problem - 12 years ago
To save time waiting for the replacement, you might visually inspect all the components around the stepper driver and connector to ensure they are all soldered. Many Duets have been supplied with unsoldered connections and it is usually a simple task to solder any that are bad. Dave (#106)by dmould - Ormerod
Re: should all moving parts be lubricated - 12 years ago
I think it is worthwhile printing spare sets of all gears before they wear out, which I am sure they will before the rest of the machine reaches end of life. In fact printing a spare of all the printable parts sooner rather than later would be prudent, though it may be wise to wait to see what updates and improvements become available. Dave (#106)by dmould - Ormerod
Re: Improvement to IR sensor mounting - 12 years ago
Quotedc42 Quotedmould I also intend to fit a white LED strip under the heatsink cover to provide illumination for the print, as suggested elsewhere. I suspect that this fixed illuminator might achieve the same thing and obviate the need for the resistor. I doubt it - visible LED lighting does not produce a significant amount of IR. Does the phototransistor only respond to IR? I would have thoby dmould - Ormerod
Re: should all moving parts be lubricated - 12 years ago
As an opinion rather than a knowledgeable definitive, I think the important part that should definitely be lubricated is the Z threaded rod. Probably a light grease would be best for that, but I've used a thin coat of 3-in-1 oil on that thread and also on the X, Y and Z rods for the linear bearings and very sparingly on all the plastic gear teeth. I doubt that the belts should have any lubricatby dmould - Ormerod
Re: X axis problem - 12 years ago
The axis confusion is because we usually look at the Ormerod from the direction of the X-axis arm, and think of this as the front of the printer, whereas the correct orientation from the axis POV is looking from the connector side of the Duet enclosure, which I think of as the left side of the printer. As my maths teacher used to say many years ago - you can remember that the X axis is the horizby dmould - Ormerod
Re: Improvement to IR sensor mounting - 12 years ago
OK, understood, that makes sense now. So it's the equivalent to providing a base bias current to bring a transistor into its region of greatest amplification - if you had access to the base of the phototransistor you might have been able to achieve it that way instead. Next time I take my Ormerod apart to make modifications I will be making your modulated IR mod, but I also intend to fit a whitby dmould - Ormerod
Re: Improvement to IR sensor mounting - 12 years ago
Quotedc42 John, 1. Yes that is still the circuit I am using for the modulated sensor. However, if I were building it again, I would reduce the 1K resistor between collector and emitter to about 470 ohms, because I think this will further reduce the sensitivity to ambient light. Not sure I understand your reasoning about that. Surely that resistor keeps the LED partially on all the time, reduciby dmould - Ormerod
Re: Double Helix Z-Gears - iamburny Style 
- 12 years ago
I discovered that I had left a washer out between the big gear and the bearing after fitting the new gears. That was causing the friction, not your gears, which now work perfectly. Greg, the gears do exert a longitudinal force - if they are not aligned. So if the small gear starts to wander along the motor shaft, it should be automatically pulled back into alignment by the big gear. Note thatby dmould - Ormerod
Re: Test prints - 12 years ago
A bit of flaring at the base of a print is caused by zeroing the Z axis slightly too low before you start the print. IME it helps the print to stick, so is often necessary - a few strokes of a needle file or sanding block will fix it afterwards. Maybe print the grandkids some nautilus gears out of fluorescent or glow-in-the-dark filament. Or maybe a whistle - umm - on second thoughts, scrub thby dmould - Ormerod
Re: Terminal block on Duet melted - 12 years ago
Oh yes, a slightly loose terminal screw or strands missing / unclamped in the block can introduce enough resistance over a small volume to heat the wire significantly at those currents. The hot wire starts to oxidise over time, which eventually increases its contact resistance further and it suddenly gets red hot. I've seen it happen many times! Also I second Treth's comment - twist stranded wby dmould - Ormerod
Re: Stepped test print - 12 years ago
Is it by any chance at about the same thickness as the circular dial piece? If so that may be a clue - If I recall correctly, the last layer or two of the dial piece involves a lot of short fast moves as it prints the radial indents, which is where missed steps typically occur, making it no coincidence that it occurs at the same place on two runs. If the Y belt is too tight it could put more stby dmould - Ormerod
Re: Double Helix Z-Gears - iamburny Style - 12 years ago
Quoteiamburny Hi Dave, I was very careful with the distance between centre's and diameters of the gears, and when measured with my vernier caliper the new ones were +/- 0.05mm, I have noticed though with the particular PLA (blue) that i'm using at the moment i do get some shrinkage which maybe why the fit of mine is damn near perfect. Also there maybe other variables involved due to printer diffby dmould - Ormerod
Re: Bouden extruder hysteresis problem - 12 years ago
Several things you could try. Tick "only retract when crossing perimeters" and try unticking "External perimeters first". You could also set more than 2 perimeters and try "infill before perimeters". At a push you could try setting retraction to 1mm or even disabling retraction altogether (set to 0 mm) Also maybe try a solid infill (set to 1). Dave (#106)by dmould - Ormerod
Re: Question about support material - 12 years ago
Or print at 45 degrees as Ian suggests, but on a raft and a thin support wall instead of a chamfer. Dave (#106)by dmould - Ormerod
Re: Double Helix Z-Gears - iamburny Style - 12 years ago
Just fitted your Z axis gears - at first test they appear to have less backlash. Before, I went down in 0.1mm increments until the first time I could just feel a sheet of paper being gripped, but then if I went up 0.1mm the paper was still weakly gripped, up another 0.1mm and the paper was loose then back down 0.1mm and still completely loose. With these gears there is no discernable differenceby dmould - Ormerod
Re: New Ormerod Web Interface - WIP - 12 years ago
Quotebobtidey Capture shows that the bits missing from the big file are sent and are all in the last packet. Reception of the packet is acknowledged and the M29 to close the file follows on about 20msec later. So I think there is some hazard which can lead to the last packet getting lost. I think this may possibly be caused by a similar bug that I recall from many years ago when I wrote my firsby dmould - Ormerod
Re: Multiple Extruders - 12 years ago
I can foresee a fair number of snags being hit when that is attempted, with a heavy batch of modifications being required! Dave (#106)by dmould - Ormerod
Re: Possible Duet replacement - Raspberry Pi addon board - 12 years ago
QuoteRadian Hi Dave. For my laser I currently use LinuxCNC which comes as a special distro claimed to be based on a real-time version of Linux. I have no idea what worst-case latency to expect with Raspbian but I've seen reports of 10ms which would be an issue. ARM assembler is my favorite too I started on the very first generation (when the A in ARM stood for Acorn). I recently tried out the Acby dmould - Ormerod
Re: Possible Duet replacement - Raspberry Pi addon board - 12 years ago
QuoteRadianBut I wonder if I2C fast enough for this kind of application? A quick back-of-an-envelope calculation shows that with an I2C clock speed of 100kHz, it would be capable of feeding full-step commands to both the X and Y axis separately to drive them both in excess of 200mm/s, so it is theoretically plenty fast enough to max out the motors (and the I2C could probably be driven at a fasteby dmould - Ormerod
Re: Commissioning - cannot talk to Due - 12 years ago
Quotedavidsmith_uk Bad design perhaps, which has been commented elsewhere about this style of USB socket. A while ago I purchased a device (mains power monitor) that had the same type of USB socket. It fell off a desk onto the carpet, and that was sufficient to sheer off the USB socket completely - very weak design. My solution was to cut the plug off the USB cable and solder the wires directlby dmould - Ormerod