odvratno.zgodan

You are right, I should have uploaded the picture of the connections. Here it is. My problem is not the heat bed turning on, but turning off. Once it heats up it doesn't stop. It's the same with whichever relay I'm using(car relay or SSR).

Hello, I am having a problem with my heat bed. It's not the official UM HB but the one designed by prusa(Mk2) with a dedicated power supply. So everything has been working well for a couple of months and some time ago I started having some strange problems. I'll first list the problems: 1. When the heat bed turns on the extruder temp. drops around 15°C, I suspect it's only the sensor(thermocouple) reading 2. Some times when the heat bed reaches it's target temperature it doesn't stop but continues heating. I have tried to set the temp off manually in pronterface but that doesn't stop it. I even tried unplugging the UM power supply(but not the USB from my computer) and it still didn't stop working.The only thing that stops it is unplugging the heat bed power supply. Now the HB setup: 1. Prusa HB Mk2 2. HB thermistor 3. 12V 30A power supply(not connected to the UM board in any way) 4. Controlling method(car relay, DC-AC solid state r., DC-DC solid state r.) At first I thought the problem was with the component(car relay) that I was using to turn it on/off. So i changed it for a soft start circuit with a FET(same problems), then I changed it for an DC-AC solid state relay(same problems), and next I bought a quite expensive industry grade DC-DC solid state relay(Fotek SSR-40DD) but still I have the same problems. So I read somewhere on the forum that the UM board heat bed FET when it has an error it doesn't pull the pin down but instead stays open thus being always on. So my question is did anyone have similar problems? I have a couple more things to try out: 1. Connect the heat bed SSR to the heater 2 pins instead of the heat bed pins and change in the firmware the pins. 2. Connect the SSR to some other pin(have to find which ones are free) 3. Should I put a resistive load on the heat bed FET going out of the heat bed SSR(the one that goes to GND on the UM board)? This doesn't seem right to me but I'm becoming desperate. The solid state relay is rated to "open" from 3-32V and it's load rating is 5-110VDC 40A.

Hi Daid, I would very much like to be a tester. Great work said!

They tested this, because of the gap between the PEEK and the heater block, this problem is gone. As less heat is transferred up to the brass.But the brass is screwed in the PEEK anyway. The only difference is that now less heat is transferred( only through the brass pipe not the AL block). The main question is if that makes enough difference to solve the problem. Secondly the problem of clogging up was primarily because the bowden tube would pop out and then the clog would form. I already had do disassemble my hot end at least 5 times. All of them was due to clogging. A few times the white clip striped the bowden tube and lost it's grip on it.

I have to agree with 3DTOPO. I think that threading the bowden tube was the best way to go. Personally IF I order the new hotend I'm going to make a spare part(the white one). Also I'm not a big fan of compressing everything with the 4 screws so it would hold(over tightening flexes the bottom wooden plate in the front-right corner). As a result of this system it seems to me that the nozzle isn't flat to the build surface(I may be mistaken). Now that I have finished ranting, I have to say that I like the new nozzle design(not the whole hotend). Seems it will be quite easy to change nozzles(eg. 0.4mm and 0.8mm).

Any news about the mac version? I can't find a download link and my netfabb doesn't update automatically when I open it.

Hmmm, might be that 8mm is not enough, though it worked till now. I blindly followed the instructions from the assembly manual so I will try to make it a little longer. Also I will cut 1.5cm from the end so it has better grip.

Can you tell me on which picture you see the gap? If you meen the angle of the tube on picture 2 it's not bent, it just looks that way. I'm printing at 200C. I know that the temperature is right because after uncloging the nozzle and putting it back together, I tried manually to push the filament and flows very nicely. I also have the bowden clamp by owen and the white clipper near the hotend. There is no gap at least before it starts printing. I know the tube should protrude exactly 8mm so I measured it with a caliper before assembly. Also what should be the length of the bowden tube? Can I cut 1cm where it's weared out so the white clip has a better grip?

Hi everybody. I have been a proud Ultimaker owner for some months now. A few days ago I started having problems with the extrusion head blocking. The bowden cable starts to pull out for a few millimeters and in the place between the bowden and the PEEK pla starts to clog it. After that happens it is extremely difficult, practically impossible, to push the filament. The print temperature is OK because I tried to feed the filament before printing by turning the extruder gear. It ran VERY smoothly. I have disassembled the extruder head 7 times in the last two days and I really don't know what else to do. Every time I unclog it and try to print something it clogs in a mater of minutes. Here is what I have done so far: - As my UM isn't working I asked a friend to print me a Bowden clamp so now I have the white clip and the bowden cable in place. - I think it's not a software problem because I tried slicing the model in netfabb and in skeinpypy and the problem persists, although skeinpypy retracts some of the filament before printing(any ideas) - Cleaned the nozzle 7 or 8 times until it was totally clean(did it with compressed air) I suspect that as the extruder pushes the filament there is a buildup of pressure on the bowden tube and it starts to pop out. Here are the pics of the extruder head. The start position of the bowden tube is marked with a red line so I could measure how much it pulled out.