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Is anyone experiencing regular issues with repetier host freezing with repetier firmware during a several hour print? I'm running on Mac OSX. Basically it happens when unattended so it MIT be related to screen saver kicking inor something. But I have also had 2 hour prints complete unattended. I have tried both the repetier protocol and ASCII protocol in the printer setup and have experienced this with both. When it happens, the printer and host are unresponsive. I have to disconnect and reconnect in order to regain control.

I am running windows 7 and my problem with repetier host is when I access the EEPROM menu the host freezes. When it freezes I can see in the column where numbers should be the next line's description. I normally have to restart repetier and my printer a couple of times before I get a good read.

When you say unresponsive, does the LCD still work?
Can you upload a large file to SDCARD?
I'm using OSX and I have changed the power management options to stop it sleeping, because it did bite me in the ass.

In addition there seems to be an issue where there are a lot of serial port errors, pushing the estop button in the host when you first connect toggles the state of the reset line on the Arduino and for some bizarre reason this seems to greatly reduce the error rate.
The author is aware of this and is going to change the behavior in the next release.

Yes, the LCD is responsive. I haven't tried loading to the sd card so I'll try that now. I'll disable sleep and see how that goes too.

Thanks,
Michael

mhackney wrote:Yes, the LCD is responsive. I haven't tried loading to the sd card so I'll try that now. I'll disable sleep and see how that goes too.

Thanks,
Michael

You should also try hitting the estop button when you first connect, the big red one in the top right corner of repetier host, it takes a little while for the board to reset when you do it, but for me it was the difference between comms errors every few hundred lines of GCode and none in 2 million lines.

Will do.

I was in the middle of a print and all of a sudden my hotend temperature plummeted. I verified 24V to the heating resistors but measured no resistance. I did not smell the magic smoke when this happened. I've now taken the hotend apart and the thermistors are indeed fried.

I have replacements so good to go for that. I should say that the hot end goes from RT to 230°C in about 50 seconds with this supply and that may be damaging them. There is a parameter in Repetier -

// maximum time the heater is can be switched on. Max = 255. Overridden if EEPROM activated.
#define EXT0_PID_MAX 255

Perhaps lowering this to about 1/2 might limit the power to the hot end and not cause damage.

So, if you are using a 24V supply, proceed with caution until we have more info on this.

Yeah you're pushing almost 8+A through those resistors with 24V, it wouldn't surprise me if they failed.

are the resistors and thermistors able to handle 24volts?

I wasn't sure, that is one reason why I left 12volts powering the rambo. I liked having the idea of dedicated supply for the heatbed anyway.

cambo3d wrote:are the resistors and thermistors able to handle 24volts?

I wasn't sure, that is one reason why I left 12volts on the other rails. I liked having the idea of dedicated supply for the heatbed anyway.

The thermistors are fine they are "powered" from the 5V USB source, you can't put 24V safely into the arduino, so the jumper has to be set to use USB for power.
The resistor is a different question.

As Polygonhell said- I am powering the Rambo from the USB. Now that I am adding a dual extruder setup, I am going to dedicate the 24V supply to the heated bed and use the 12 volt supply for the extruders, fans and motors.

http://www.ebay.ca/itm/221168698861?ssP ... 757wt_1398

Have you seen these yet? Looks like a nicer cleaner way of heating the hotend. Less chance of shorting out too.

What, you mean like this:

[img]http://mhackney.zenfolio.com/img/s1/v57 ... 0404-3.jpg[/img]

I've been wanting to put this on for a couple of weeks so this made a good excuse. It has a nice slide in fit into the hot end. I used a little Omegatherm 201 heat compound and held it in place with Permatex Copper. Should be ready to tryout soon. This is exactly the unit you linked to on eBay - same vendor. It also eliminates that gnarly twisting of resistor leads and crimping to wires. The silicone covered wires with this heater are a good 2' long.

This is also a little sneak peek at the Quick Change Tool Holder in process. Not all of it is shown though.

LOL, you mean like this? It's the all metal hotend I had resorted too untill my replacement comes. I may end up keeping it though it worked really well for the 1 print I got off before my thermistor issues.

They have both 12v and 24v too!

Yes, at the time I bought mine I had intended to use it on my H-1 to test - it is a 12volt system. But, as I mentioned above, I am going to use my 12V and 24V supplies together now. Just makes sense, especially with dual extruders, to have 2 supplies.

Awesome! I picked up a ten pack of these the other day. The discussion on thermal adhesive got me thinking and I ordered then that night.

I have my hot end back together with the 12V cartridge heater. I also rewired so now only the heated bed is powered by the 24V supply and everything else by the 12V supply. Things are working great. I retuned the PID for the cartridge heater. It heats up to 230°C in just a little less than 2 minutes. It seems to hold a more constant temperature than the resistors, very little temp fluctuation. It makes for a neater install too. I have about 8hrs of print time on it now.

mhackney wrote:I have my hot end back together with the 12V cartridge heater. I also rewired so now only the heated bed is powered by the 24V supply and everything else by the 12V supply. Things are working great. I retuned the PID for the cartridge heater. It heats up to 230°C in just a little less than 2 minutes. It seems to hold a more constant temperature than the resistors, very little temp fluctuation. It makes for a neater install too. I have about 8hrs of print time on it now.

Have you tried two cartridge heaters?
Carl

No, I don't see any reason to do that! One has more than enough Umph (technical term) to get the job done. I'm printing Taulman Nylon with one no problem. I have thought about filling the other hole with a brass rod to add extra thermal mass and a bit of bling!

Nice, I bought a 12v 40 watt heater on eBay and measured it to see if it would fit.

Are you powering it from the same ports that the resistors were plugged into?

Yes, exactly. It is basically a drop-in replacement. You only need one though. And don't forget to auto-tune the PID.

Michael, what temps are you using for the nylon?

- dan

245 C - but this is actual temperature as measured by a thermocouple that was inserted into the barrel and touching the nozzle. You basically sneak up on the temperature - I went 3 degrees at a time until I got a good flow.

What about bed temp? What build surface?

- dan