neotko

I had some trouble the past week with the z alignment initial tests, specially when using the springs, if the angle of the head isn't very 90º the head starts to leave marks on the prints, like small extra blobs filament going to the sides of the print. That's why I bough some good quality springs and I'm waiting for the new wood to arrive (the delivery was going to arrive today but no luck since they printed it on the wrong material). On UMO it's not going to be easy, at least on my mod. The problem for going too small it's that the real tension it's done by 3 screws and one extra that need's to be adjusted by a screw attached on the bottom, because if I used the 4 screws I was going to need to make the head 5-7mm bigger. I did some tests with the 'good' springs and they are quite nice, that's also why I did another fan setup, to leave some room for the m3 washers (around 7mm dia). With the washers and the bottom screw everything seems to be ok but I have leave the design on hold until the new magnets arrive. Also the fans will have a small window of cooling for the peek area, to avoid for the head going up (also should help while printing wood afaik to keep the peek cooler). In a perfect setup the solution for umo stock head I might be using a spring like the one that um2 uses to keep the ptfe inside the peek, but the size of the ptfe that umo/umo+ uses leaves only 1mm of area to push it and I prefer for now not to go that road unless my x4 m3 springs fail to keep everything fit while adjusting the z, just because that road would need more aluminium to keep the strong force of the spring from breaking the wood/pla. Also, I think that the Z problem it's something that won't be much problem for others, yesterday after breaking one peek that was almost new I finally saw that it was 1mm different, also the 'melting' of the upper pla added some play from a used head to the other that it's just waiting.

I thought of that! But the weight of the head touching the table if they ain't perfectly stable on the hangar. That's also another reason that makes me think the best area yo place the heads it's at the end of the machine. There's more room and if well places the hangar could be made on pourpose so the head it's slightly angled so the head never touches the bed. But with bowden I don't think I'll be able to doit. But yeah if the z difference it's very small it should be gcoded. And it should not be a big difference. I wonder if using the end of the machine and make it park on a small angle could help use much wider z (and tools).

Tryed the semi-old fan design (design 14) and seems to work fine. Installed some heat shield (it's like a fabric so it's easy to cut) and attached to the upper part to block the heat from getting on the magnet area. [/media] This a photo of 2h into the print, the heat outside the nozzle don't leave with the fabric, but for the first layer it's better to have the fan on minimum to be safe and don't get deformation on the pla. Final versión should have to be abs or xt at least. EDIT: Uploaded it 2 times and this %$&! forum keeps rotating it... EDIT: Ok finnaly.. Also good stuff, printing my (hopefully) last design for the fans, easyer to print and the overhangs are getting nice air from the simetric fans (one it's deformed because didn't used the fan on minimum after 15mins trying to fix some leaking with my nozzle because bad assembly). Today I will have the laser wood parts and next week the new 10x5.5x2mm 150C neodinimum magnets (1kilo force each and I'll use 3).

I found that for really superb top layers the infill at 26% changes it's pattern and makes for a 'less holes' pattern that covers really sweet. On cura ofc.

I think you could try flatlike ultiarjan says. Make it a two piece item. With some hole for glue or a small clip-on (difficult for that size). Also if you can change nozzles using a 0.25 nozzle for small stuff it's great. To cool the print go slower or print some at the same time.

Well the change of magnets I think it's mandatory. PLA could work also since I ordered some wood laser that will be pushing the ptfe etc. To change the magnets on my design it's really easy (I just did in 6mins befofe giving some snack to my 2year boy XD). Also changing the size I stay on the 6cm max tall (to use the umo screws) and I have changed the hangar bay so it's taller to provide better stability while parked. The problem/advantage with my design it's that it uses the space to it's maximun. So the magnets to use can't be bigger than 3mm depth. That combined with the 150C factor of magnets it's hard to get thin magnets of this kind but the web foehnsturm used has some that I have just ordered. Anyway I think I will release the beta design since the basic idea it's easy to scale, the hangar works soo sweet and I just need to finish very minor changes. The only part that can't be printed it's the 4mm laser cut aluminium. And must be on one piece or the design assembly it's a nightmare.

Umm I just think I'll have to modify my design all over. After reading about the degradation on the magnets at high temperatures at this web and got me thinking that my very little and strong magnets won't survive a ABS print because the heat. I being doing some heat captures on my setup, because I'm testing some titanium nozzle at the same time. and the Upper area goes easily to 50-70C when they are on 0 movement. When the printing goes and the first layer has pass (fan starts) they stay at 45-60C. The problem isn't the magnets that are clamp, that area heats very little since it's almost closed by the magnets itself, the problem it's the exposed magnets. I saw again the magnets that Foehnsturm uses and they are N45SH so they can go without trouble to 150C, that sure will allow for ABS print etc (but the printed material of the hanger won't survive the enclosure if the enclosure goes higher than 100+ C. I'm going to think about getting 150C magnets (my room it's full of magnets). And probably I'll use some N44H magnet of 2mm that I can fit on my small heat. So... let's start over XD Btw, so far 2 weeks printing with one head on my current design (with small modifications on springs etc) and it's printing rock solid, with good quality. Main problems on ump (not um2 since you can use the full aluminum x2 to have a good material) it's that the heat goes up and up and deforms the pla. I have now one head 2mm different just because small heat deformations while doing tests (head not moving and sometimes I did forgot to put the fans on). I think on the long therm for this mod to work on ump it might need some laser cut wood or something that might keep the heads protected from heat while on standby. I'm going to take some days to think.

Well that would happen on practicaly any fdm printer. When changing from x material to y (being different plastics) the atomic it's just a must. Also check filament sizes (anything bigger than 3mm will stuck since ultimaker uses 2.85mm filament). Edit. The Pla literally burns at 240C and goes brown (it's sugar based). The traces of PLA that stay on the nozzle will burn and go brown at ABS temperature (but you can use 240C for pla if you print at very high speeds but it's not recommended). The think that propably jam your brand new nozzle was that. If you go from any material to other kind, sometimes even changing brands, the best think to do always it's atomic pulls. There's also some cleaning filaments that can be used to 'capture' any residue and leave a clean nozzle, but they are expensive compared to a simple atomic pull. For my cleanings if I use my 3mm extruder (2.85 filament) I just use a ptfe 3mm and push it though, then lower the heat and pull to get all. This way I don't waste filament.

I got 2 for 1.75mm from china. If you want info about the original check the github

Super. They have the od and 5N force thanks a lot!

Well everything seems to be working now, but for this to trully work I need to put full pen springs or find where to buy this size springs on a harder material. Also I need to change the design of the fan area to make room for spacers. At least the holder for the heads works perfectly after doing some last and hopefully final adjustments. I don't know how many hours I have put into this, can't wait to have it finally working...

Small update. The titanium had a desviation of the inner angle. Ok after a heavy test the pla did not stick. It can be removed by just pushing it. It will take me another 2 weeks or so to have a proper prototype but yeah tugsten coating makes pla to not stick. I'll post videos and temperature screens when I get the propper prototype.

Just in case someone it's interested, Titanium TC5 coated with tungsten disulfide ws2 don't work. The pla sticks to it like glue and jams in 10-15mins. On the other side, the heat outside the peek (tested on umo+) goes from 150-160 externally to 105-110C. Expensive test, but worth the try

On my UMO+ 1.75mm E3D drips much less than ultimaker-kind nozzles. You could try to increase the tool change retraction on S3D (I think it's on advanced) and maybe add an extra extrusion for the pickup to compensate the filament lost on the drip. Ofc a priming tower should work. Also, since there frontal area it's almost lost when dual, you could add the priming tower there as a standard. You could pre-render the gcode and copy-paste the tower and make it render it every time after picking the block.

I'm sure that this isn't your problem but on my mod I had understrusion for a long irritating day and in the end was that the bowden clamp replica (3d printed) was 0.12mm bigger than the molded plastic. I had to use a low speed rotating device to clean evenly (that's what I get for using cheap pla) and now it's extruding perfectly. I think that the clamp was doing more force than the necessary to hold the bowden and that added extra tension to the feeder.

Yeah put temp sensor 20 if you use pt100. 0 it's for disabled. With that changes you should be ok. I found how to s3d tool change script. It's quite easy. I will write the correct stuff this sunday (I hope) but it's something like: EDIT. Deleted code that was wrong I didn't have more time to test since I'm having a problem with one of the extruders... But that script will give you the idea I think. Edit: Ok just 5 mins in front of this and now I get it. It's really really easy (Don't use this numbers ofc it's just for the preview and etc etc) But it does work, check the preview on S3D {IF NEWTOOL=0}G0 F15000 X100 Y100 {IF NEWTOOL=0}G0 F7000 X0 Y100 {IF NEWTOOL=0}G0 F15000 X0 Y0 {IF NEWTOOL=0}G0 F7000 X100 Y0 ; {IF NEWTOOL=2}G0 F15000 X190 Y100 {IF NEWTOOL=2}G0 F7000 X190 Y0 {IF NEWTOOL=2}G0 F15000 X100 Y0 {IF NEWTOOL=2}G0 F7000 X100 Y30 Now I just need to do the full movement instructions, and should work.

To use that feeder on umo+ you need a different stepper motor with 400steps and 0.8 angle. The same that um2 uses. For fans depends if you want to keep the aluminium or change it all. There are plenty options on youmagine

Well tiny update. So far the 'springs' on the head where on a bad positioning that caused a leak because the white teflon isolator changed the angle. The solution (I should have think of this first) was easy, just by moving the springs directly on the upper part of the wood, so the isolator it's always being pushed onto the peek). Like this: Also used a third spring on the back screw to help with stability. The head it's printing like a charm, after 12h prints no leaks and perfect prints. I'm also finishing a better hangar, so it can be removed and used as one need's it. Without any american tape or similar, and if you want to secure it you can use the lateral holes of the end stop to combine it with the endstop. Anyway it's a semihard fit, and it's really easy to remove. Also finished soldering the 4 fans for the two heads and did a full clean up on how the cables go through. I hope to be able to run some two head tests this weekend, but I need to learn how to script the head change on Simplify3d or do it manually. Any head changes I do by the ulticontroller work and work really nice. I'll try to post the stls next week as soon I don't find any other critical bug on the design. Anyone have experience scripting the tool change on Simplify3d?

Maybe build a thermal sensor system outside running from an external source and set a swith that connects to the 2 panic switches that make the um2 turn off any activity http://ultimaker.com/en/community/view/6578-ultimaker-2-mainboardsafety-jumper

You could try saving the gcode, editing the settings (I think it writes the cura config on it right) and then import settings from the gcode?

If you want a easy firmware creator (just in case you plan to change something in the future), you could try the @Amedee firmware generator, I works like a charm https://bultimaker.bulles.eu

On S3D you can 'overload' the thick walls to push more filament if the 3d design isn't 0.8 wall thickness. Cura will try it's best to fill the gap if the design isn't of that thickness. But we can't see that without the cura layer img.

There's a simple solution for the head heigh if the Ultimaker method doesn't work for you. Get a pen, cut the spring in half and place it on the upper part of the aluminum peek holder (the one that it's 4mm tall and has 8mm tall because the screw areas. I just did yesterday on my mod to allow me adjust 2 heads that have 0.7 different height (probably because one peek has many hours and the other it's brand new). This way, with the springs you can do a more selective tension adjustment by using the upper screws. But for UMO standard head you should add 4 springs, since you don't want the heads to have a bad angle. If the springs you use are 'too tall' you can cut them a bit. BTW I have not tried this on standard UMO dual extrusion, I done it on my working progress magnet changer based on the idea and designs of Foehnsturm -> Link to the forum post Anyhow if you unscrew the tube/nozzle yes, it will leak for sure. EDIT: Don't try this on the standard UMO head block. The only way to make it work it's by adding something to keep the preasure of the screw... It's hard to explain, but if you put the springs where I said it will make the ptfe isolator to move and that will make a leak (inside the peek). So to have perfect adjust on dual heads (on the kit experimental) you can only play with the upper screws. The springs could work, but doing more changes than what I said.

Arhh can't edit on mobile. Ok this it's the video of the head aligment with the spring

Well. Basic head alignment does work. Got a pen and took the spring and cut it in half. Atm I'm printing with the lowest height to check if affects or fails and so far everything works. Next step assemble the hangars and get my hands on the gcode.