tommyph1208
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Posts posted by tommyph1208
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Alrighty then... I'm hoping my 350W PSU is large enough to drive both printer and HB...
My heated bed is a MK3 alu heated, and specs say about 5.4 ohms of resistance when powered by a 24V supply... that makes around 107W... Adding the 160W of the Ultimaker should still leave me with enough... hopefully
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Wow... So you are telling me 120W were going to the steppers and a few fans?
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Dual extruder means dual hotends which are by far the component gulping up the most watts on the UM, isnt the standard heater cartridge 60W?
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Nice prints!
Did you know that you can vapor polish ABS prints with acetone fumes to improve surface finish and overall strength of the printed part?
The print will become smooth and glossy and layers will melt together more, maybe even fixing your few bad layers...
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Will you be adding a heated bed to the tantillus?
If so, what heater will you be using?
I have an idea that 'i might want to try building one of these with a friend at some point, but have had a difficult time finding any 10x10 cm. heat elements
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Generally (if you were looking at another converter), you just have to watch out that you have enough "Dropout" voltage
You also have to watch out for what max current its rated at...
This one says 12A which should be more than enough for driving the UM.
It also says to add a heatsink if consuming more than 100W, I believe I saw somewhere else people estimating the UM to draw around 75W max, so it should be fine even without a heatsink..
I got two different ones, but very similar to it...
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Also: Start simple... Your first print (your first many prints actually) shouldn't be some fancy dragon or complex architectual structure... Go with the Ultimaker robot, or even just a cube
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I believe you are right about PWM, but as gr5 mentions, maybe the mosfets actually do this PID at roughly 100 ms. intervals?
If it doesn't work I will have to go with bang bang mode
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Haha guilty of that too sometimes.
Exactly the way I was thinking but without the relay. I was going to unsolder the Mosfet, take a wire from the gate pin to the mosfet thats on a external board that then allows you to use the 24V with the loveliness of PWM! Also gets rid of that ticking from a relay!
I bought myself a DC-DC Solid State Relay which should be able to switch on-off every 10 ms. or so... So no ticking... and I guess at those switching speeds PWM is still an option?
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I am planning to do the exact same thing with my machine so also curious if nobody has input to why it wouldn't work...
Seems like people are generally misinterpreting your intentions though...
The way I understand you (and the same way I was planning to do it) is like this:
- Buy a 24V PSU large enough to handle both printer and HB (I think 150W might be too small, I got a 350W myself)
- Connect the HB directly to this PSU through a relay controlled by the HB outputs on the UM board
- Connect the UM board to the PSU through a DC to DC converter that regulates down to 19V
So HB gets 24, UM board 19 and you don't need to change anything on the board itself
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Moving towards an E3D upgrade for my UM original, first parts assembled:
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There is a setting somewhere that cuts off some of the bottom of the object ("cut off bottom" or something similar), check that you didn't mess with that one...
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Print a handle for it:
http://www.thingiverse.com/thing:22819
Also I would probably somehow remove the feeder and bowden tube as that is what sticks out the most
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You might also want to check out doodle3d (http://doodle3d.com)
It extrudes 3d models from simple 2D drawings and is available for both PC and iPad...
Might even be targeted at children below 12 years of age, but still worth a look...
They also have a so called "Doodle3D WiFi-Box" to go with it, which connects your 3D-printer wirelessly to your laptop, computer, tablet or smart-phone, with the Doodle3d software running on the actual box...
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Yes,the pictures..I got used to the internet speeds here in Switzerland and I don't pay attention to what I upload!
Anyway, next time I'll resize them first..
It is a recording dummy head that help to make binaural recording which lets say simulate the human hearing.
Hide away I hope you don't mean the cap. The head has to be closed and filled with absorption material in order, 1st not to resonate like all hollow stuff do and 2nd The sound must reach the microphones only through the ear canal.
Long story short it has to be as close to a human head as possible.. which means closed.
Yes I did.. you can see the other pictures in the album. Although I'm not happy with the finish where the support was touching the model. It's impossible to remove all the support structure.
This explains alot, thank you
And nice to see an UM used for this kind of project
(what is the project by the way? Research of some kind within the field of acoustics?)
Next obvious and interesting question would of course be if the resulting plastic head is "good enough" at representing a human head? How are the resoults so far?
Would it eg. be even better to print a skull as the inner part, place it in a slightly larger printed mold, and then fill the gap with silicone, (or that ballistics gel stuff they use all the time on shows like mythbusters)?
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Hi all,
This is lets say my first serious print, the rest were small test pieces to see what the printer can do.
It still needs stuff to do with it but the printing part is done.
you can see more here..
Nice print... but my god those images are huge :shock:
What is it for?
And just out of curiosity: Why hide away her brain, instead of making the head eg. perforated/mesh/wire style?
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Guys, as I read your postings, I really started again to think about my initial idea to build a HB too...
I took a look at the spec for the MK3 alu HB at the page likned above and I hope that someone can help me understand the connections...
With a MK2 it´s more or less fine (for a mechanical guy like me) but with this pattern I´m a bit screwed...
The big pads are for 12/24V and ground - that´s clear.
But for what are two the small pads near by?
The NTC pads are for connecting the termistor - but where to place it - as usual in the middle of the plate or as on some picures shown as SMD directly at those pads?
Additionally I can´t find a hint if or where I could mount a LED for status...
I would be very happy if someone could point this out for me....
As I understand it the thermistor can be placed pretty much anywhere as the Alu plate has a very even heat distribution so maybe directly at the connectors is fine.
On my MK3 there are two connector pads just below the NTC (I think those are the same drayson is referring to... they are smaller than the 12/24V connectors and larger than the NTC)... as far as I have understood it, these for mounting the LED....
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May I ask why you are selling?
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You definitely don't want to use the current plug/socket and switch to supply everything.
Naturally I would exchange the plug and switch with the one of the PSU I'm buying, and then connect the UM board directly to that PSU...
I still don't know whether or not I would like seperate on/off switches for printer and heatbed... Probably not since the heated is only drawing power when switched on by a relay anyways....
Does anyone know of any PSU suppliers in Europe that might have what I'm looking for? Buying from outside EU add some VAT, Taxes and fees that I would prefarably like to avoid, though buying from china might very well end up being the cheapest solution regardless of the mentioned fees.
Any experience with chinese PSUs of any type? Do they live up to their specs and your user requirements?
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Yes, it should work. If you supply the UM with 20V, this will also increase the printhead heater power a little bit. I guess this won't matter much, though.
You can easily calculate how much power the HBP will draw at whatever voltage:
U = R * I
means: Voltage (U) equals Resistance (R ) * Current (I). Units are Volt (voltage), Ohms (resistance) and Amperes (current).
And, second formula:
P = U * I
means: Power (P) equals Voltage (U) * Current (I). Units are Watts (power), Volts (voltage) and Ampere (current).
Example 1: A 12V, 200W power supply can deliver 16.7 Amps of current.
Example 2: A heated bed which says "12V, 100W" will draw 8.3 Amps of current and have around 1.5 Ohms resistance.
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The MK3 heated bed says "1.4 to 1.6 Ohms for 12V" -> that makes 8 Amps of current = 96 Watts
It also says "5.0 to 5.4 Ohms for 24V". That makes 4.6 Amps of current = 110 Watts.
So I guess the target power of the MK3 heatbed is 100 Watts. You shouldn't go much higher than that.
If you take a 20 V PSU and use the 24V configuration, than you get 20V divided by 5.2 Ohms = 3.8 Amps. That makes 20V times 3.8 Amps = 77 Watts.
So you lose almost 30% of power.
If you take the 12V configuration with a 20V PSU, you get 13 Amps = 260 Watts -> this will most probably make the MK3 go up in smoke...
As Owen already said: Always leave some headroom for the PSU. If you take a 200 Watts PSU and draw 200W from it, it will run hot and possibly not live as long as it should.
It depends on the PSU, but usually the ideal load for a switching PSU is 65 - 80%. Go for that range and you shouldn't have any problems with that.
/edit
corrected a calculation error on the second example...
Thank you for that little recap of Ohms law
The wiki actually says:
"Running 24V on the 12V terminals will heatup the heatbed to 100 degree in only 2 minutes (Your printer controller will regulate the power to the heatbed in order to get your preset temperature.)"
But nothing about it going up in smoke though... So it might actually be worth a try if the 30% loss makes it too slow?
Just had a quick look at my standard UM PSU and its rated at 120W... that + the 260W for the heated bed and then overshooting to land somewhere around the 65-80% of total PSU capacity gives me at a 20V PSU between 475 and ~585W
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It's definetly better to use 2 PSUs.
I don't know about the UM warranty policy, but I think that if you decide to use a different PSU than the one supplied (absolutely no matter whether it's almost the same or something completely different), you will void your warranty for the electronics, which is 200 Euros if you have to replace them.
-> I may be off with that policy thingy, but that's the standard.
Also, if I'm allowed to say that, the UM1 electronics board is not really suited to drive a high current heated bed, even if there were a sufficiently powerful PSU. I'll take the standard low-power switch which is used to switch the DC supply on the electronics on and off as an example. This thing already sparks enough as it is when flipping.
So, the best way to go is using a relay (or even better: a MosFET switch, maybe tonight I get around to posting something about that) and a second PSU.
A standard 200W industrial PSU that you can get on Ebay or a more decent electronics shop is usually small enough to fit under the printer (print some extended feet for the UM if necessary) and is pretty cheap.
I bought my printer second hand, have no warranty whatsoever...
I absolutely agree about driving the HB through a relay rather than directly through the UM board, but as I see it this really shouldn't have anything to do with whether you could ALSO drive the UM from that same PSU?
As Ownen mentions; As long as the PSU current is somewhere close to the standard UM one (19-20V) and has enough power that you can drive both units from it, it should work right?
Question sort of remains though about exactly how many watts the HB will draw from the PSU if 20V is supplied to its 12 or 24V port, and what will this off value mean for its performance, (heat up time, likelihood-of blowing-up etc.)
Also, I am still uncertain about the possibility of the PSU momentarily dropping from the 20V to something lower when the relay kicks on the HB... like: How much of a drop, how long to recover, and what will this do to the printer mid print?
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Using the relay your temp will be regulated and you can apply 24V to the 12V terminals to get fast heating.
You will get double the current running through the cables and relay though and 4 times the power into the HB.
Your power supply will obviously need to supply 4 times the power as well.
It's all a balancing act. Voltage of PS chosen. Connecting to which terminals on the HB(12V and 24V). Trading of power required to speed of heating and cables required and if you want to run the UM off the same PS then that adds to the mix. Going lower voltage to the UM is possible down to about 15V but you can get slightly less performance from your stepper motors.
If you could find a high powered 19V PS or 24V adjustable PS (Common I think, mine is adjustable but only puts out 360W), you could try running the 12V HB circuit from the 19V. It will be quick but you'll need fairly high power, I don't know how much and reasonable cables and relay. It would be good if you could find someone who's done this to find out the current and power required.
Hoping that someone stumbles upon this thread
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Maybe try checking your nozzle, both inside and outside... I saw a post somewhere of a super macro shot of a nozzle tip that had been beaten up quite badly, a little chunk had been chipped off etc.
The guy who posted it had then sanded/polished it back down for a nice even round nozzle exit hole and it had improved his print quality significantly... Alternatively you could try buying a new nozzle somewhere, they aren't that expensive...
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Myself and a few others have blown up the on board MOSFET like this. I don't know how but some people have gotten lucky. Mine only took about a minute to blow.
The trouble with running a 24V HB at 20V it will heat up much slower. Change in power is proportional to the square of the change in voltage.
So if you halved the voltage the power will be a quarter of the original.
The upper limit of voltage is about 30+ I believe. Limited by what the stepper drivers can take and the 12V reg. (which will heat up much more with higher voltage)
Yes I heard horror stories about that and definately don't feel like trying out my luck ith direct 24V to the UM... I have no problem withusing a relay...
Regarding the curret used to power the heatbed; I have this quote from the RepRap wiki (http://reprap.org/wiki/PCB_Heatbed):
"It has dual power mode optimized for 12 or 24V but you can also use everything in between (16V, 19V what have you) (Your printer controller will regulate the power to the heatbed in order to get your preset temperature.)"
Does this basically refer to PWM mode of heating? Which is not what I will be using with a relay...? Or am I completely off?
The wiki also mentions all sorts of other options, like:
"With 15V on the 12V terminals will maintain approx. 115 degree Celsius without regulation"
and
"Running 24V on the 12V terminals will heatup the heatbed to 100 degree in only 2 minutes
(Your printer controller will regulate the power to the heatbed in order to get your preset temperature.)"
Complete heated bed kit for Ultimaker
in Third party products & modifications
Posted
Im doing the same thing:
- 24V 15A Industrial PSU: http://www.ebay.co.uk/itm/LED-Lights-Devices-Switching-Power-Supply-24V15A-AC-DC-PSU-360W-110-220-230V-/181317124619?pt=LH_DefaultDomain_3&hash=item2a3757c20b
- MK3 Alu heatbed: http://reprap.me/alu-reprap-heater-board-mk3.html
- Voltage adjuster/Buck (down to 19V for the UM): http://www.ebay.co.uk/itm/131065094245?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
- DC/DC Solid state relay: http://www.ebay.co.uk/itm/190836925629?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648
Plan is to adjust the 24V down to 19V for the UM board using the buck
Have the UM board control the SSR via the heated bed port, SSR is connected to heated bed and directly to the 24V PSU