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To get the same energy density as a 120W 200x200mm bed with a 400x400mm 24V bed, you'd need a 120W*4/24V=20A supply.
It could work, but switching 4 amps worth of 120VAC might be better
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DaveX
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Reprappers
From
(remove the 'nosmiley' bit to follow the link -- this forum's siley post-processing munges urls and code with '' in them )
I bought mine from the folks at -- I sent them an email linking to the STLs on thingiverse and they printed them up for me.
I think many folks watching could do something similar.
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DaveX
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Reprappers
Is pronterface really frozen, or is it waiting to push other commands into the electronics.... maybe see if you can toggle the 'Watch' control or clear the output log. You could also start up another pronterface or try to connect with pronsole ot Repetier host or something to prove if its Pronterface or your electronics that's frozen.
The car battery would give very clean, strong power, so I'
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DaveX
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General
Is it Pronterface that's frozen, or is it that your connection to the electronics/USB is dropping and disconnecting?
I'd check that you get clean, solid supply to the logic side of your electronics. If your electronics are something like , you might add a capacitor between VIN-AM and ground, or maybe one of the alternate powering suggestions there.
If you are losing USB connectivity, check th
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DaveX
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General
RAMPS controls the heatbed by switching the low side of the heatbed to ground or not. If you don't have the +12 on both sides of the heatbed terminals when idle/not calling for heat, then the problem is somewhere in the +power-in/fuse/+heatbed-out circuit.
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DaveX
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General
By default, Marlin's PID doesn't kick in until +/-10C, and outside of that uses bang-bang. If your heater at full power is strong enough to move your process by 10C in a second or two, you would need the system to start tapering off from full power earlier. As is, with the Marlin defaults, it is clearing out the integral accumulator at 190 and 210C, and it has to re-build up the integral ter
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DaveX
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General
If you are trying to solve a problem of 50x50x50cm parts deforming during the build, then a scaled up heated bed might not fix everything.
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DaveX
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General
QuoteHelmi
nophead,
I haven't tried it that way but guess that won't change anything. As i found out so far Inkscape on MacOSX is forced to use the X11 server which means starting the GUI version no matter what. Sounds like a problem for scripts like yours.
Currently downloading the ubuntu image - hope to get it running there more smoothly. Could be a good choice for inkscape generally (the few
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DaveX
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General
Quotecnc dick
I guess it's all up to the individual to me all of those large ones you see there do not produce anywhere near quality prints and their is only one showing a large print and because there is no enclosure there is cracks in the print because of shrinkage. This is just a small test piece of bottle opener I printed on my machine look closely this is what I call acceptable
The bottle o
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DaveX
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General
Pointing this toward the wiki:
has a link to a 1m^3 LeBigRep with a video, and a few other larger machines and discussions.
by
DaveX
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General
Re-running it with [1000,500,500] would get you these values:
Compiling design (CSG Tree generation)...
ECHO: "X rod length: ", 1150.5
ECHO: "Y rod length: ", 582
ECHO: "Z rod length: ", 680.169417382416
ECHO: "foot rod length: ", 436.5
ECHO: "leadscrew length: ", 580.169417382416
ECHO: "base rod length: ", 1134.5
ECHO: "top rod length: ", 1118.5
Compilation finished.
You could build it, but
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DaveX
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General
QuoteMatidas
I'm not well versed in Openscad, so I'm not sure how to run the code.
I downloaded the code from ,
switched to the v1 branch with 'git checkout v1'
changed the build volume in 'wallace.scad' from [200,200,95] to [100,50,50]
and opened with Openscad and compiled it.
The compilation computes these rod lengths:
ECHO: "X rod length: ", 250.5
ECHO: "Y rod length: ", 132
ECHO: "
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DaveX
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General
Yes, you can make a 100x50x50 print area Wallace. The printed parts are all the same no matter the working area, but the threaded rods would be different. Running the v1 branch of the code through OpenSCAD would calculate the rod lengths you'd need for different build areas. You could make it with longer rods in the Y and Z directions and let them stick out until you decided to cut them off.
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DaveX
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General
The heaters don't need regulation, but the logic-side does.
I was using a salvaged ATX and had 5V 50mV peak--to-peak 50kHz noise feeding into my system and confusing my ADC. Filtering the +5 for my cheap electronics cleaned that problem up.
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DaveX
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Reprappers
Quotejpan
Ok, still I have a question:
When you auto tune with M303, do you randomly set temperature and round times?
Thanks
You should set the temperature to around your expected operating termperature. The C value in an M303 C3 command is how many times you'd let it cycle around the setpoint before giving you a final answer. All that is happening during the cycles is that it is turnin
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DaveX
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General
What's the resistance of your cartridge heater? What amps are you pushing through? With a heater rated 40W at 12V, by P=IE and E=IR means the voltage across the heater should be 12V, current should be 3.3amps, and the resistance of the cartridge should be R=E^2/P = 144/40=3.6ohms. Are you getting 12-13V at the power supply, or is that across the heater? If those values check out, then 40W
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DaveX
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General
kP/kI =Ti gives time constants of 9/(.2/.5)= 22.5 time units versus 20/0.027=370 time units so the I should be a lot more responsive. (You may want to double-check the unit conversions in -- If you sum the error 2 times/second into temp_iState, the units of "error" would be C*hs where hs is a half-second, and you want your kI to convert that into counts, so it is applied as counts/(C*hs). So
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DaveX
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Ormerod
Quotedc42
Yes the controller does clamp the I term. However, the I term was being clamped at far too low a value, so that if the commanded temperature was greater than about 100C, it would never be held, because a substantial P term was needed to keep the controller in the steady state. The controller was effectively a PD controller except at low temperatures.
It clamps the I term poorly. The I
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DaveX
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Ormerod
The chips don't do true analog output, so the voltage is full voltage, but pulse-width controlled by the MAX_BED_POWER number interacting with a PWM counter. Marlin's PWM counter actually 0-127, but defines things in terms of 0-255. and divides by two.
1) nope, they won't damage your board. Reducing the cycling will significantly extend the life of the relay.
2) soft_pwm_bed works with th
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DaveX
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Firmware - mainstream and related support
It doesn't sound unlike the noisy input power problem I saw using a poor-quality ATX power supply driving a breadboarded set of electronics.
What electronics are you using?
What thermistor table/configuration?
How rapidly is rapidly? (10s of seconds could be physical tuning problems, sub-second isn't physical noise, its electronic.)
Could the rapid fluctuation have been happening during t
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DaveX
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General
I'm sorry, I didn't notice that you clearly said 'servo'--I was thinking about heaters and fans. If you are using the Servo.cpp stuff, it looks like it sets up its own timers and prescalers, so any adjustments you make there to match your own needs would probably be OK on the Marlin side. I don't know what control system your speed controller takes--if it takes 5V it should work, but if it tak
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DaveX
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Firmware - mainstream and related support
I had a similar problem with dirty input power driving my AREF. I could filter the thermistor input all I wanted, but the sloppy AREF gave bad ADC readings. A 100uf cap cleaned it up.
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DaveX
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General
You may need to do some conditioning on the signal. The PWM output on Marlin could be the softPWM with a 7Hz period and a variable duty cycle, or a hardware fast PWM with a 30KHz or so, with 0/+5V ouput. If your speed controller can take that signal directly, then you can hook it. If not, you might need to filter the PWM into an analog signal and amplify it to match your speed controller's inp
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DaveX
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Firmware - mainstream and related support
"too much material is extruded" depends on your "ExtrusionFactor" which looks like it is supposed to be some ratio between the cross-sectional area of the extruded trace to the cross sectional area of the filiament. If you are extruding 10% too much material, reduce ExtrusionFactor to ExtrusionFactor/1.1.
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DaveX
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Developers
QuoteJanski
QuoteNewPerfection
Have you run PID auto tune? Are the nozzle and heater block insulated somehow?
I have ran auto tune for the Heater but not for the bed. What would be the command for auto tune heater bed that is connected to ramps 1.4 "D10" port?
I am also insulating the block.
Please advise
Janski
I don't know about ramps, but the Marlin autotune bed command is M303 E-1
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DaveX
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Reprappers
Just use the last set of autotune values. They have excessive precision compared to the process--you probably couldn't notice a difference if you varied them from the autotune values by 10%.
'M303 E-1' would autotune the bed, if your Marlin is configured with #define PIDTEMPBED.
See for some details.
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DaveX
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Reprappers