jemma-redmond

Yeah, the biology people have a mac with osirix on it... but we didn't have much luck doing dicom to stl conversions.. I've used other software but the tutorials are cryptic to say the least. I shall have to ask around and see if anyone knows any better software packages....

well ok, you probably won't believe this but its working again... I disconnected everything and pretended I was playing buckaroo (you know where you put the mining gear on the donkey and it kicks it off if there is too much) so I plugged all the wires in one at a time and then it bloody well worked!.. I've setup two extruders and what I did find was a dodgy wire coming from one that was causing the machine to switch off.. Now hopefully that IS the problem this time but who the hell knows? Perhaps today it will explode in a fireball? :-P

That's exactly it. The machine switches off and does not power back on even by pressing the switch. Yes that's exactly what I have observed. It's bizarre. I'm going to test the parts on the other printer and see if they are ok. I'll let you know.

So believe it or not, the fault is the temp1 port on the board. Any cable plugged in, any even with no sensors causes the machine to shut down. temp2 works fine but of course it could still be a fault with the cable but it checks ok...

So I finally had time to put the machine back together, it worked fine until I plugged in the temp sensors and heating elements then the board blew again!!! What a pile of expletives of a machine.

yep, there are many methods... s[pray printing, syringe extrusion, pump extrusion etc etc thanks for the link, that is useful, I have shared it with the diybio group... you might find that useful to join, you may get some more info there... :-P

Hello!! Ok with regards to converting dicom to stl, I cheated, as it was like too much effort. So I found online a japanese mri database, its been translated into english and has a complete human body up there as dicom files converted to stl's so I used that as a proof of concept. I don't have a direct link, you will have to do a search but its there, somewhere's... As for the pump, I made a few of these, I'm not convinced by these, I have medical grade dealies here for dispensing fluids, they work well but the pumps you can print? With pla its way too unreliable, too much friction, too much heat, I would imagine the abs would not be much better sue to warping. I think you would have to get the parts sintered and even then I would probably avoid using polymers, stainless steel seems to be the way to go. As for precision, I am doubtful... I feel there will be a lag between extrusion and the pump activating which will mess up the build but i have yet to really try this.

H! So I replaced the reg on the board and hooray it worked! It cost like 1.50 euros from maplin. However with the other blown board I replace the reg and the 19V led lit up but when I plugged in the mega, nothing, no power to the mega and thus no power to the display. Soooo what other components usually go on the mainboard apart from the regulator? I have another faulty board and I was thinking of swapping parts from there. But I'd like to narrow down the possibilities... any advice? Ta Jem

Hullo again! So I've been modifying um's to extrude all sorts of viscous liquids... My background is in nanobioscience and I've done stuff like print finger bones (regular pla) and seeded them with osteoblasts (bone cells) and yes they grow well... anyways, I have also printed dicom (mri) data using a um into liquid, like arteries, reproductive, carcinoma's, etc etc it was just proof of principle. So I was wondering what experience you have had printing bio goop yourselves? What kind of mechanisms were you using? We used something based on organovo;s and also integrated the diybio bioprinter inkshield dealie into a um hybrid and it worked not so bad I would say. Has anyone integrated any pump systems into the printer? heating coils to control the viscosity etc? What needles did you use and how low could you go? I found the triangular plastic nozzles worked way better than the metal needles for example.. Thanx! Jem

I'm printing biogoop, so I don't need a temp sensor... I have changed the start and end code so it does work fine however I would rather redeploy the sensor elsewhere in another printer or keep it spare also the more parts and widgets you have on a machine the more likely it is to break... so for the sake of simplicity I was looking to remove the sensor that's all. It's no biggie..

That is, if I unplugged the temp sensor I would usually get a max temp error but is there any way to disable this? I'm using a printer for an application where I don't need a temperature probe and it would be easier just not to have it on the machine....

Ok, soooooooooooo I had a dodgy board 1.5.7, the 19v led lights up but the regulator overheats and the voltages are weird so i figured it was faulty, so as that was all i had i cut that one out and resoldered it onto the board in the picture. The result? The 19V light went on. but the regulator was still misbehaving, plugging in a known to be working mega still resulted in the 5V led line not lighting up, and the uni controller display not powering up. So I'm pretty sure at this stage its the regulator... I swapped the mega into a working machine (my diybio/bfb3000/ultimaker hybrid) and it worked fine. So thats ok. I can only assume there was power surge somewhere while I was working on the machine. However this is supposedly a state of the art lab in a biomedical facility so surely this cannot happen? ha! probably not. So I've put all of the machines onto surge protection sockets just to be safe. I'll be in the city later so I'll pick up a regulator from maplins and do the repair tomorrow, if it works, horray! if not, boo!

well, not sure how a pic would help... there are no burnt components, no corrosion, no breaks in the circuit, voltages shows 19V going in, less than 1v coming out on the 19V fan output beside the L7812VC transistor or regualtor? at the back... there is no voltage across the regulator, there is a 4.7k resistor soldered in for a heated bed, the sensor was wired in but not for power etc so I don't think this has anything to do with the problem...

Hi, I've been having lots of fun with um1's constantly repairing them. However the latest one is the mainboard, the power went (for no reason). The lights won't come on, the power supply is fine (tested on another machine) power cables tested, mega 2950 tests fine. So while I would love to spend another 250 euros on electronics that keep blowing up, I was just wondering if anyone had been able to successfully repair the mainboard and if so how did they do it? I have about 3 damaged boards so far... (don't ask, ((groans and puts hands on face)) :-P

hullo! well I found wood chips again in the extruder so I tried to clean them out and I did and then guess what happened next? The power went, nothing, I checked all of the cables on another machine and the power cables are fine. I plugged it into the usb and its stuck staying max temp and switching on and off. I did'nt touch anything that could have damaged the electronics. I have asked for more funding to get an off the shelf machine and parts to rebuild the bits from bytes machine (which works way better) as I think I have (or rather the uni) on around 1K in spare parts for these machines... so not worth it.

Ok I'll do that... The extruder has jammed again... I'm going to take it apart to take a look. I always seem to have major problems putting the bowden tube back into the extruder and I am wondering if the bottom wooden plate and the top don't match (I was given a load of spares from different people) the extruder has started leaking again and i got a spectacular plug this time...

Ok, its working now as it should... some of the parts were worn and not making proper contact so i replaced them... The belts are still slipping and the quality is not great but I think its more from wear and tear...

thanks daid, its working!!!!!!!!!!!! but we shall see for how long.... I'm going to be keeping a close eye on it... I'll keep y'all posted... but quality is a lot better. It does appear that there was a lot of gunk getting into the extruder head.

Ok all of that has been fixed... but still it jam's. So this is what I have done 1. replaced all the filament in the tube, 2. cleaned out the nozzle 3. removed debris in tube 4. cleaned gripper in feeder mechanism 5. dismantled feeder and rebuilt with new parts Now the problem seems to be the feeder no matter what won't push through filament, it grips, but not strongly enough and so it gets stuck. At this stage EVERYTHING has been replaced, everything has been fitted properly. But still it just will not work!

I used two screws to align the extruder head better as I thought it was slightly skewed... guess what? It worked better.. until some filament leaked out got on the heating element it would appear and has burnt it out. Now I have to change the heating element.

The problem is happening as far as I can see in the extruder when the filament is leaving the bowden tube. It is simply too curved, it curves inwards and then gets caught. That I believe is where the real problem lies. It's not really possible to take a photo of this without cutting the extruder in two. Even if I replace ALL of the parts all over again including the filament I'm not sure this will fix the problem. Now there is one thing, its very very humid here at the moment, its making a lottta people cranky (including me), I do wonder if that is contributing to the curling effect of the filament? But how to resolve this I do not know.

So what is happening now is, if I hold down the feeder at the back, I can push through the filament, then it gets stuck and the bowden tube starts lifting back out. I really really cannot understand how it keeps on jamming. Everythings been replaced, there is no build up of gunk, nothing, yet it keeps on jamming. There is no fan there but I never had this problem with out the fan being there before.

Ok thanks for that, however I am sure the levers are in fact correct. I took apart the feeder (as I hadn't assembled it) just to check, it was put together ok, however the wheel does not touch the filament at all. Its out by 1 or 2mm, furthermore the spring at the back prevents the screw from going all the way in. I removed it and I can set the wheel correctly but that's irrelevant as the wheel is too far away. As far as I can make out its the same with the other feeder mechanism. It appears to be just the way the parts are made... I have also attached a photo showing the filament removed again, as you can see its starting to plug and its at an angle almost like the alignment is not correct but I cannot see how I can correct it. It appears to be in alignment.

Ok, someone kindly explained to me where the option was to upload photos so hopefully....

Fitted upgrades, extruder still jamming... I don't think this machine is fixable. Its plugging or the feeder wont push through.. I'm all out of ideas at this stage.