Yes, it is very flexible indeed. I can twist the bracket 45 degrees end to end easily so you wouldn't want to make a production bracket from it without additional bracing. The attraction, for me, is it's toughness; the upright that attaches to the x-carriage is only 3mm thick yet it's utterly inseparable (by hand) from the fan mount. Also, the fragile end lugs just bend rather than snap whenby threedyprinter - Mendel90
Thanks Chris. I shall try 245C this pm. The E3D is rather tempting; I could add nozzle size to the already unmanageable number of parameter tweaks required to get a good print!by threedyprinter - Mendel90
I want to print nylon at the recommended 245C. It's extremely close to the temperature at which peek softens (248C). So far, the max. I've dared to try is 240C; am I OK to go higher? Is there a recommended alternative head that gives the same performance at higher temperatures?by threedyprinter - Mendel90
Almost there now. Drying the filament for 4 hrs at 80C made a huge (unbelievable) difference. It almost totally removed the snap, crackle and pop, and greatly reduced ooze. At an extruder temperature of 240C and print speed of 30mm/s for perimeters and 60mm for infill, I can now get excellent finish at .3mm layer height. The M90 fan bracket I'm printing as a test piece is indestructible with baby threedyprinter - Mendel90
Yes, it was a standard Dibond M90 from nophead with a 0.4mm nozzle. The base was glass, smeared (when cold) with a thin layer of PrittStick*. (If the glass is hot/warm the glue doesn't go on evenly.) The printing was at a bed temperature of 90C throughout. This allowed good adhesion during the print and fairly easy removal when cold (water + scalpel). *PrittStick : Maybe called something diffby threedyprinter - Mendel90
I broke my M90 x-carriage cooling fan bracket. One of the little lugs snapped off. I printed a new one in PLA. (It functions much better than ABS as it's stiffer and holds the fan assy. pretty much parallel to the bed so there's a little more naked nozzle showing and less chance of catching.) I printed the bracket again with some Taulman 618 nylon just for fun. At a nozzle temperature of 238Cby threedyprinter - Mendel90
@François THANK YOU! The craft archive helped me a lot.by threedyprinter - Skeinforge
> Why do you need to level it more than once? Because: A. After the "disaster" the bed was no longer level, and I suspect there will be more disasters and relevellling whilst I experiment. B. Eventually, I want to use the bed for PCB work with frameworks which will also need levelling.by threedyprinter - Mendel90
@rhmorrison Brilliant! - thanks very much. Some really good links there too. @ahmetcemturan Gasp! Commented source code! I'd never thought to look there. Thanks for a great tip.by threedyprinter - Skeinforge
I've tried this link several times in the last week or two to get the latest manual for SF. It's always broken. (Some sql / php error) Anyone got an up to date alternative or a pdf link please?by threedyprinter - Skeinforge
@richgain Thanks for that, I had entirely missed that page. @nophead Wow, thanks for such great detail. I've got something to aim at now. Having just suffered my first "disaster" where the print, still attached to the glass, ended up on the floor, maybe I'll just try and perfect building a small part first and move on to the extruder later. Actually, I think I shall build something to hold my dby threedyprinter - Mendel90
I too was impressed with everything about my M90 especially the support you get from Chris and Mary. Have fun assembling it. It took me 3 days and I shall be 60 in 10 days time! It would have been quicker but there are so many other things that have to be done when you're retired . Good luck, Bobby threedyprinter - Mendel90
Chris, I want to make another extruder assy. Can you give me a bit of info on how the printed parts in my Mendel90 kit were printed. Filament type. Layer height. Nozzle size. Slicer used? Machine used? I'm asking because I'd like to know if I should expect to achieve the same quality with my standard M90 or whether special techniques would be necessary (heated chamber, smaller nozzle ... ?).by threedyprinter - Mendel90
Thanks Chris. It's great to get instant answers. I think I shall up the temperature a notch to make sure each layer gets bonded properly. Bobby threedyprinter - Mendel90
I've noticed that when printing with white ABS (from plastic2print) things go pretty well generally. With bridges and support however the print fails sometimes and you can see hairy, unbonded strands of filament with brown nodules at their ends. The outside of my print nozzle is pretty clean so I'm wondering what this "brown" is; it looks as if it's burnt but I can't see how that could be. Extruby threedyprinter - Mendel90
>Maybe if you are in Linux. On Windows you can just click on the arduino exe on the SD card and it just works. In the end that's pretty much the case for Linux. # cd path/to/Mendel90/Windows/arduino-1.0.1 # arduino (or path/to/wherever/arduino/is/installed/arduino) open path/to/Mendel90/Marlin/Marlin/Marlin.ino Must confess I was a bit amazed when the whole thing worked (including uploading)by threedyprinter - Mendel90
> Ha, I would regard shimming the endstop as faffing and changing one line of code as not. Harrumph, I would say cutting up a bit of plastic as opposed to fixing up a development environment when your dinner is on the table is pragmatic! >>Which way is the bed bowed and how have you measured it? I used a dial gauge; removed extruder assy. and tie wrapped it in place. It sits snugly inby threedyprinter - Mendel90
The couplers are the right way up. BUT: some oil had seeped down (I oiled the lead screws prior to testing as per the manual) and must have been a bit over-zealous. Anyway, I degreased, fitted heatshrink and tried again. Perfection. Not a hint of slipping. I'm not quite out of the woods yet, the first few layers get mushed a bit (partly because the bed is bowed in the middle by .1mm) and I havby threedyprinter - Mendel90
You're correct, it doesn't matter whether the coupler is turned manually or by the motor. In fact, I have just printed the android test piece and, as it was finishing and winding the carriage up to the top, both left and right Z couplings started clonking. Each clonk was accompanied by the carriage dropping by a mm or so on the side that clonked. When it reached the top, the carriage was visiblyby threedyprinter - Mendel90
My M90 is operational. (Everything worked first time!) I'm trying to level the bed along the X axis. Levelling the carriage by twizzling the right Z coupling results in the coupling slipping round the lead screw. (Twizzle,twizzle,twizzle, CLONK!) I degreased the lead screw thoroughly before assembly. The coupling is tight (no gap between the shells) on the lead screw, ~2mm open on the motorby threedyprinter - Mendel90
Thanks Chris. I spent a few minutes sliding the bearings to and fro and that helped marginally. Rotating the bearings on the shaft helped quite a lot. Nothing outstanding though. I expected a motion like the glide of my lathe's tailstock; these LM8UUs, even when not sticking, have a definite vibration - very off-putting! I also hunted for lubrication tips. Not finding anything definitive, I deby threedyprinter - Mendel90
Thanks Chris. Expectations have been adjusted!by threedyprinter - Mendel90
I've just started building my Mendel90. I'm currently working on the X idler assembly. After fitting the 2 LM8UU bearings I tried them out with a straight rod. I imagined the action would be silky smooth. It wasn't. Many sticky points. I could stand the rod vertically with the assembly stuck. I used a different rod. Same result. I forgot the idler assy and tried a single bearing on its own, jby threedyprinter - Mendel90
@VDX @nophead Thanks for the pointers chaps. I guess a bit of suck it and see is called for as there are several other factors involved (beam focussing, laser control) which I have little gut feel for.by threedyprinter - Mendel90
Whilst I wait for my Mendel90 to arrive I'm designing a UV pcb exposer similar to this . It was going to be a standalone device but then I thought about using the M90 to do the Y positioning of the pcb; so I need to know the accuracy of positioning the M90 Y axis. According to the M90 build manual there are 80 steps to the mm (in Y). 1 step = 1/80mm = 0.0125mm (~0.5 thou) I was surprised, giby threedyprinter - Mendel90
Thanks for a superb answer Alan. As for the link, I just wouldn't have believed that quality was possible; guess that's the problem with new technology, my 20th century gut feelings about things don't hold true anymore! Nylon - I spent hours looking at RichRap's experiments with nylon618 . Amazing. I think I shall be ordering an M90 very soon. Bobby threedyprinter - Mendel90
I came across this blog article from 2011 Q0. I've never seen a print in the flesh, but most reprap prints I've seen online appear to be nowhere near this quality? Q1. Could I expect the same performance from a stock M90 or would I have to faff around buying smaller nozzles / extruders etc. ? ( I'm guessing that, in any case, a lot of experimention and "media familiarisation" time would be reqby threedyprinter - Mendel90
@nophead Ahhh! Thank you for that, I was slowly coming to that conclusion. Shame really, I have no beef against 8 bit hardware for small applications as it's so easy to code in C whilst taking full advantage of the hardware; I felt that the Arduino environment would just get in the way. For 3D printing I suspect a 32bit MCU (maybe with a lightweight RTOS) would be so much more flexible. I did seeby threedyprinter - Mendel90
@nophead @Alzibiff Thanks very much for that info. - all is clear now. Can I ask a stupid question? It seems to me (a very old electronics and software engineer) that most reprap controllers revolve around Arduino. I have built several NXP arm and Atmel based systems from scratch, but never investigated the Arduino world at all. What is the big benefit? Are we just using standardisation of pinoby threedyprinter - Mendel90
I'm thinking of buying a Mendel90. I've been very quickly poking around looking at Marlin firmware and got confused. According to the Mendel90 Melzi MCU is an Atmega1284P. However, the makefiles / configuration at seem to be setting up for a 664P. And, somewhere else (cannot remember where), I got the impression that a Atmega2560 was used. Any clarification gratefully received.by threedyprinter - Mendel90