I had a similar problem with my first printer. Before trying a new hotbed or another PSU I just installed a very crude isolation layer below the heating PCB: a couple sheets of thick cardboard wrapped in aluminum foil. It worked like a charm and now that bed warms up much faster and reaches 120ºC+. Also, my results with ABS and hairspray were sort of hit and miss, with more misses than hits. Out of desperation, I tried UHU glue. That's also working very nicely.
See, I prefer in general printing in pla, so if I can just get this one print off, I'll be delighted. I'm using an aluminum bed with 4 resistors heating it. I know the glass slows down the heating and max temp, so without having to replace the psu or bed, I suspect the cardboard might work. I also think I could get my hands on some dense rigid foam sheet insulation. I'm an architect by trade so we probably have product samples somewhere in the office. It would be worth a shot seeing as how I'm so close yet so far!! You wouldn't happen to have a photo of your insulated bed? Oh and thanks for the tips all!
The extent of samples found in the office were marmoleum, carpet, a roofing membrane and a hydrophobic plastic, so nothing there really. A work colleague made the valid point that this is just like normal business. You have an objective, then hit problems, ask for advice from people who've over come them, fix the problems, and the solution improves your business, so go team e3d? Anyway, if the cardboard DOESN'T work, I'm going to start saving for a new bed and PSU. I found somewhere with a really nice 300x300 PCB bed but I'll need a new timing belt too, and I'll figure out the PSU when the time comes. In any case, I've found 2 good ways to fund this. First off, a buddy in work needs a prototype printed in PLA, one colour, and is going to pay me pretty well for it. And secondly, with the 2 bangles I've already made in PLA, I've had 3 people asking to buy them at 50 euro each, so between the two, I can fund it I think. At the very least, this topic does provide a good record of some problems/solutions that people might come across, not just with a dual extruder! edit: as far as PSUs go, would this suffice for a setup of 2 extruders, 5 motors, 1 heat bed and 3 fans? http://reprapworld.com/?products_detail ... =1591_1659
I will try to take a photo when I get home. In the meantime, I'll link a GPL image from the Mendel90 build manual. My second printer is a Mendel90 and that's where I got the idea from. As for PLA vs ABS, I also very much prefer the former. But my Prusa i3 arrived in a very sorry state, with poorly printed parts and some almost broken. I have to rebuild it. I'm thinking PLA for most of the structure, but I do not dare having PLA parts near the hot end or even the motors. Hence this fight to get to grips with ABS printing. Regarding a PSU for your machine, I hadn't noticed before that you have a 300x300mm bed. Do you have the specifications for that 300x300 PCB heater? Somehow, I suspect a 20A PSU may fall short of the requirement, not to mention most electronics (RAMPS?) can't deal with that much current. A 24V or even mains powered heat bed, controlled through a relay, might be a better idea. Having said this, i must warn you that I'm at the very early stages of learning about 3D printers. Take my words with a (very large) grain of salt, just in case I've got it very, very wrong.
Yeah there's a 24V option as well, but it's only 15A. I'm currently running RAMPS, but I'll be switching to RUMBA soon. I'll do the maths this evening. As for the cardboard, looks like it'll do the job nicely. Cheers for that!
They make 24 to 12v adapters that can handle significant wattage , it may be advisable to run the bed at 24V via a solid state relay and the rest of the components on 12V.
I know someone who's running that 12v supply to power a kraken, rumba and 5 motors with a heavier duty bed than mine. He might be worth an ask. I'm just thinking though, let's say my current psu, for arguments sake, is 12v and 5a. Surely as long as a new one will handle considerably more amps than what I currently have, I should be ok, right?
You can run the E3D off a 24v PSU without any issues. I wrote a little how-to on this a while back; viewtopic.php?f=7&t=2&p=2#p2
ah brilliant! Thanks for that! After a very quick read, it looks like I'll have to have a little look at the RUMBA config to make sure I can limit the PWM section for the motors and bed too. I think I'd feel safer at 12V, but if 24V is a better option after a bit of tweaking to the config, that might be better. Maybe all is not lost!
Ok, so I'm a bit confused about my current psu. It says that it outputs 18a at +12v combined. Thing is, it's got a few 12v rails, so I'm now thinking that because there's only one of the 12v rails going to the board, it's not getting anywhere near 18a. I'm going to check how many amps are actually going to the board, but in 2 weeks time when it's payday, new psu, definitely. Isn't there an old saying where anything worth doing isn't easy?
So I thought to myself last night "oh I wonder how many amps are actually going into my printer..." Took out the old multimeter, set it to amp mode, put it on the points where the PSU connects into it. Hmmm... it's reading 0, how odd. Then there was a spark, and it shut off. and wont turn back on. Not sure whether I fried the PSU, the RAMPS, or both, but either way, I've a new PSU en route. In the spirit of being ever the optimist, it gives me a good excuse to go and replace both the PSU and migrate to the new RUMBA board, essentially forcing me to make the daunting leap to the new board.
Yeah I connected it wrong. Very wrong. That's what shorted it, I'm sure of it. In any case, I've the new psu delivering on Friday, so I've the week to do a few design bits, Like the new gantry and motor brackets, and a few bangles to print when it's done to get my business started.
Nightmare! Sorry to hear that, it's always a bit of a pain when you let the magic smoke out. We are actually now selling PSUs on our site, may or may not be suitable for your particular application, but they are fairly generic. http://e3d-online.com/RepRap-Spares-Ele ... RepRap-PSU
ugh! That would have been ideal! But that being said, the new one is 'In Transit' and due to arrive on Friday, so hopefuly I'll be back up and running with more power in no time. I've a sneaky suspicion it didn't do much good to the RAMPS board either, but, I did start last night on programming my RUMBA board. I found a neat little guide that is really detailed and very easy to follow, with plenty of pics to help out along the way. I know I'll have to do some tweaks once I migrate to my e3d hot ends, and the e3d thermistors, but i know there's some guides here on doing that, so I'm not worried. I know there's a few people who either have or are thinking about going to the RUMBA board, so this might be worth a look. It was a great help to someone like me who's not too experienced in the programming side of things!! http://dorkpunch.blogspot.ie/2013/02/me ... mware.html Thanks again for the help Josh. I still feel like I'm making progress, albeit a bit slower than I had hoped!
So, power supply just arrived. Talk about daunting! This one is about 1.5 times the size of the old one, and I've to do a little bit of modding before I get going on it. It doesn't have a normal mains plug connection, so I'm going to have to get a socket and integrate the socket into the printed enclosure. I have a few at home from my days building guitar amps, so it's not a major job, but I'll have to be careful making sure I can really isolate the live, ground and neutral wires so I don't make any risk of shocks! I'm really digging the silver mesh finish, like the one you guys sell, so I'm going to try to design the enclosure in such a way that I can expose that a little, possibly mount it and the RUMBA board on the side of the printer, running up the frame so it gets a bit of a viewing! I know form follows function, but doesn't mean I can't make it look good too
If you get a socket - do get a fused one! I am sure you will - but please insulate everything well, especially if you are leaving the PSU on show
Yeah, I kinda wonder if I could take the fused one out of the old PSU.... The plan is to make an enclosure that'll have a little section for the mains connection, with the three wires coming out into this PSU, but I'm going to integrate a little separation window, where there will be a divider between those three wires, and any other wires going to/from that PSU, so the only way to get at the 3 mains wires will be to remove the screw(s) holding in the divider. Seems like a good way to ensure my own safety!
