neotko

I see. I will try the springs idea this week. Other idea I had this morning was that using a caliper and add a z+ or z- when the head changes? The problem it's that one could hit the bed but since they are on the bay it shouldn't be much throuble. If I get free time this week I'll give it a go but I still need to solder x2 fans for the second head. Also my fan design it's suffering from pla meltdown (they hold for now) but I need to move them a bit away, or maybe I'll just ditch them and finishing my crossflow fan setup. The good stuff it's that the head design it's totally modular and easy to replace the parts. Adding springs or removing fans it's just a minutes operation. And it's printing nicely. So now I need to focus on the gcode, drilling a new hole for the y endstop and getting the spring idea working.

Well the hangar/bay design it's much better now. Just manual docking. The movement it's clumsy because I was moving the heads with just one hand to hold the phone. Also while finishing assembling the second head now I have a 0.7 height difference. I think it's the peek (one it's new and the other it's heavy used). I think I'll search m4 size aluminium springs and add them between the wood that holds the ptfe isolator so with the upper screws it can be 'recalibrated' to solve both head heights. Now I need to find the springs.. Umm maybe with the spring of a pen and cutting it in 3 parts. Other solution it's to manually file the wood that holds the isolator but don't seems like a hood idea on the long run. I have changed the docking bay to have a little curved space so the cables don't push the head. Foehnsturm how do you adjust both heads? Are they exactly the same or you have any alignment mechanism?

Single head printing. So far the head holds just fine. Printing new hangar/bay hopefully this one will work and I'll be able to show a video of the head changing. So nothing exciting to see just yet.

Well at least finally they send the items, can't wait to see your version. I can't really show a video of the changing. I just did the basic change 'by hand' moving the heads. I just finished a new hangar I'll check the small head printing something more than just a small flat area, will be a nice test also to see if works at 50-80mm/s or if the head flys XD (I hope it doesn't...) One good think (I' think) it's that the UMO+ has the second extruder on the oposite direction, so the bowden 'push' should be fine for each extruder.

I'm stuck on the head changer. The magnets have enough force to hold the head, and I can print ok (I just finished installing everything 4h ago). I think my 'small' design can't be this small. I need to put more magnets, to have a better 'catch' of the head and I need to change fully the dock station because the side sliders of umo and maintly because the tension of the bowden. If I place the parks on the end of the machine the bowden pushthem, so I changed the orientation to put in on the front and it holds better but my hangar has many flaws now that I see it with the head. I need to make a helper like the one foehnsturm did to push the head on the hangar and propably I will have to redesign some stuff to use a stronger magnet. At least I can print with the mod (one head for now). EDIT: Lol it works, I was using one of the 3 bad versions of the hangar... My desk it's a mess of prototypes. Well I still need to change the hangar, but not the lower part, just the upper area so the left-right sliders go in just a bit. The magnet now that I'm using the correct bay works fine, but not superb. Good think it's that when using one head the printing area it's 197x196mm, so if you take one head outside you can use almost the same area. With 2 heads I think it will be like 175x175 or something alike.

As far as i know the x/y rods are the same mm and uses the same bearing. It should work specially if you change the sliders (um2 use plastic injection parts that are smaller than umo). Also you would need umo+ For the electronics to use the same pt100 that the heater uses (or more modding?) and that head would need 5v fan to cooldown. The slidders I think they need more modding since the endstop it's designed to be somewhere different. Also the ptfe they sell I'm sure isn't the cool glass coated that ultimaker sells (you can buy it from them). If you want to do this it's propably better to buy the parts on china and get an olsson block instead of that um2 copy. In the end I don't think you would gain any quality but could be fun I plan to make my second umo+ with the black slidders of um2 and use my minihotend mod to gain a bit cm.

Read this post then https://ultimaker.com/en/community/view/10657-a-different-multi-extrusion-approach-um-tool-printhead-changer

You can have that already I think search L-CHEAPO

Magnetic dual head extruder! Oh wait... Chocolate cake extruder with dual flavors! Umm... Piezoelectric head movement, no gears for zero backslash. Optic register with perfect memory to resume printing. Optical laser register to scan printed object and continue at any point. That's all I can think off

Well the dripping it's almost non existant. Specially with E3D nozzles. I also have like 16 (not kidding) china ultimaker replicas modified for 1.75 that work well but because the hot area it's bigger they drip a bit more. My road to 1.75 wasn't easy and some say that 'just changing' the bowden it works but to have perfect workflow and zero jams (specially with weird materials) I had to change the heat break and the nozzles. The feeder it's not a problem since the default umo+ works perfectly if you file the plastic just 1mm so the minibearing/black plastic can push just as good as with 3mm. Also I can print a bit lower on C since there's less plastic. I still never did the speed test since I just print fine. Thinks that I tryed and failed: - Using robert feeder without changing the stepper it's just a bad idea since understrusion pops at 5mm2. I did that 2 weeks until gived up and whent back to the default feeder. - Just using a ptfe 6mm/2mm (they exist in the market for buddas) works but you need to change the bowden clamps and the white ptfe (not your case but for default umo+ this applys). - Without changing the nozle/heat break tube it works but there's a lot of dripping. One good werid think it's that I could atomic it easyly with one ptfe 3mm/2mm pushing a few times and I was able to leave the nozzle totally clean without wasting filament (I should tell this somewhere it might help others..) Atomic ptfee ! So yeah. It works buying extra stuff (nozzle/barrel). You can retract faster and less mm or more for super clean retracts but I never did the speed test . In theory I should be able to push more filament since it's smaller... And that's my trip to the 1.75mm. I did it maintly cos I had a lot of euros in good quality filament (colorfabb, etcetc).

Finally I have almost everything, I'm waiting for my mini laser MDF parts but I think I'll just cut some wood by hand and replace it later. I changed the design for 20x4x2 magnets, but just because the magnet shop it's taking too long to order my N50 10x4x2 magnets. If my math it's correct (probably it isn't) the final print area will be 20x17 with 2cm2 (+/-) on the sides that can be used for nozzle cleaning. Also for my solution I'm using 1.75 filament (because I changed my UMO+ to work with it) so nozzle dripping should be minimum. Also I have a new hot end insulator tube in Titanium that I'll check with this. And I have another insulator tube made in titanium + tungsten coating that should (in theory and on paper) make printing with materials like wood (retractions specially) to work perfect. Here's the photo of this weekend that shows how small the head will be with the x2 4cm fans. I did this part so it's a one unit that fuses (by the long screws) to the head as a one piece block, easier to control and should make the unit well balanced. Redesigned aluminum holder. It has one advantage, you don't need to uninstall almost everything just to take the cable out. Probably on a later version I'll add something to clip the cables on the upper part near the bowden. The important area I think I did better it's that now the head and the fans are perfectly aligned, so the air always hits the same area from the sides, not like on umo+ default design that focus most of the air to where the head isn't, so it should make the cooling more even.

Hello. Just wondering about the 40W heater of UMO+. I found some 20mm / (5mm shorter) 6mm 24V 20W Heater. That should fit on the alu block of UMO+. My question it's. Can I just plug a different heater on the UMO+ & if it's well under specs and just run a PID autotune should be fine right? I ask this because I'm trying to assemble a new umo+ but I have outsource almost all the parts (except the board etc etc). And with x2 20W there's should be enough room to use 2 extruders + bed, right? I want to do this because I already have a power supply of 220W from my UMO+ (on my UMO+ I use a 280W power supply).

Ea cierto que 20 micras no es algo que se usa en mas de 1/100 impresiones en el dia a dia (como mucho). Yo también uso 60-70 para piezas especiales pero últimamente y para cosas que son muy finas (literalmente) y usando los procesos del simplify3d hago áreas a 40 micras o 20 dependiendo) y consigo mas fuerza estructural. Me explico. No resiste lo mismo una capa hecha de solo una pasada a 60micras que 4 capas a 20. No es algo que haga mucho pero cuando una zona se me queda muy delgada consigo hacerla mas resistente dando mas capas. Y como con el s3d no hay que complicarse mucho para hacer procesos diferentes no hay q dedicarle mas de cinco minutos para refinar ls zonas creando tantos procesos como necesites. Eso si el s3d es una chusta reparando stls, hay que dárselos muy mascaditos.

Try the led pwm connection. The led pwm and fan pwm circuits are identical and if the fans work when you connect them on the led pwm then you could modify merlin changing the pins.h Check the +\- and all connections before doing so (I almost broke the board 2 times so I prefer to truple check everything)

For LMK12LUU you need 'square flanged' Search "Square Flanged Linear_Bearing LMK12LUU 57mm" height (probably called 'Thickness'). There are plenty of places to buy it, even amazon

Btw if you really want to have a better fan system and lower the weight, search for 'crossflow fan' on this foruma. Now that's a efficient cooling system.

Well if you really need to use 40x fans you might cut the aluminium (you taking about umo+ right?). And save the midde area that keeps the hotends protected. I did that . I also did another design that worked much better than my two previus but right now I'm focus on the head magnet changer. If you want to use other fans check first where they will grip (and how). To protect the pla printed fans I use an aluminium textile heat insulator that I got from ebay (someone linked it somewhere on this forums). It's called mtex heat shield. Works great and it's just like a textile more or less.

I have an UMO+ and I'm quite happy with it. Yes it can do 20 micron, but it takes a lot of time to print at that resolution. When I want to print high quality I just go 60-70 microns. Good think it's that with some slicers (with cura too if you like using plugging's etc) it's that you can make some areas at 40-60 microns and others at 0.1-0.2 so you can speed up the process and get some high layer details. Anyhow the nozzle it's 0.4 (or 0.25 if you buy others like E3D or china-stuff). The think it's that at 20-70 microns you really need good quality filament, you won't be getting good results at any resolution with bad filament but at that microns it's even more noticeable. So yeah, you can print really tiny high quality items, but remember the x/y will always be the size of the nozzle, but the z it's where you can get some extra quality. Also, depends on the material. With some coconut filament I don't get any 'lines' at 0.15 because of the viscosity. Anyhow this printer it's really nice, and the mods available are just great. If you wan't a less-hands-on machine UM2 it's also a superb option, specially with the olsson block to have different nozzle sizes.

I think this post might be interesting for you. https://ultimaker.com/en/community/view/10657-a-different-multi-extrusion-approach-um-tool-printhead-changer

PLA in general starts to get problematic at 240 (sugar goes brown). But higher temperatures are a must when going high on mm3. If it's low it takes longer for the plastic to reach the good temperature and when extruding the filament might get friction if pushing much on low temps. So it's just a matter of speed/heat. At 0.1 the amount/time it's smaller so it's easyer to keep the filament melting but at really fast speeds you need to go higher.

Also check the filament it's no bigger than 3mm. Um2 uses 2.85mm and anything bigger than 3 will have resistence going the bowden

The mm2 at 0.3 are much higher than at 0.1 and at 210C it might have small resistance to push the filament. Maybe try 220-230 for the first layer and change to 210 at layer 2 with the z pluggin.

Well the final-beta2 design seems rock solid. Now I need to wait for the new aluminium cut to arrive and I also made some 3mm MDF wood cuts for the area that holds the hot end isolator coupler (to use it in pairs and get 6mm). I still need to solve the fan design but now that both extruders are going to be on the end of the machine (I hope the bowden tension don't send them flying) anyhow the hangar and the hotend redesign seems to work just perfect. I'm going to use x3 10x4x2mm magnets N50 (1kilo each) so that should make a grip of 6kilos. If the magnets don't hold enough the hotend I can always design more room for magnets on the upper area without much problem. So until my new alu & wood arrive I won't be able to test much more. Here's some pictures of the size adjustment and how small footprint should have. Don't mind the print quality I'm using a very very cheap white pla kilo to run the tests.

My 5 cents. Improve the 'first page' (when pressing Forum after having to press Community (btw 2 clicks to go to the stuff it's a bad idea)) so there's no need to go into each subsection to see if there's something new to read. (I loved that from the old design) Fix the 'remember me'. I have to keep writing my login and it doesn't remember me T_T No preview post on a reply to a topic? Many stuff I like. I would love a 'night mode' because it's toooo white to use it at night. But the design it's clearly better. I see what the designer though on the first page of community, a facebook-ello-boxy stuff. It's nice, but if that's the first page, please make it auto-reloads / make a infinite scroll that reads from old stuff or add 'pages'.

Well today arrived the item, (didn't bough that one because of that 'reverse' option). Got this one, and connected it to the 19-24V output (the 2 pin near the start of the board) and it works like a charm. I forgot how noisy it's the fan. Anyhow it works, I just need to finish my dual extruder magnet stuff and I'll get my hands on a good 3d printed support for this model & casing for this external PWM.