Printing with Pronterface compared to straight from SD card?

I am new to 3D printing but I have been doing a lot of studying. I recently bought a MakerFront RepRap Prusa i3 PRO and I have made several good prints with it. Yesterday I printed from an SD card for the first time using a RepRap LCD display an SD card reader that I added to the printer. The print came out horrible and looked very much under extruded.

I was printing with yellow PLA filament that I had been using with good success the day before. In both cases I used Cura software to create the G code. The print came out nicely running from Pronterface and my Windows computer. But it came out horribly using my SD card and the RepRap display interface.

I checked to make sure the bed was level and I don't believe that I changed any settings or temperatures to effect the print. So I think that maybe the Marlin software is controlled differently from Pronterface than from an SD card.

Can anybody tell me what to look for, or how to make my corrections for using an SD? I'm aware you can tune from the LCD screen but I thought that the G code controlled extrusion, retraction, and temperatures.

Any ideas would be appreciated,
Mark

What were the slicer settings you used?

There are very few differences between using host software and using SD cards, except that the SD cards will be more reliable.
One difference is that people who use host software often slice with temperatures set to 0, then use the host software to set the temperatures at print time. You can do the same with the LCD/encoder/SD card interface, but you have to remember to set the temperatures.

All the line widths, speeds, etc. are in the gcode file, so you should not have to do anything different whether you use host software or SD card.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Thanks for the quick reply Digital Dentist. If by slicer you're talking about the Cura program, I have my temperature set at 193 for the extruder and 60 for the bed. But there's a chance I over-road the temperature by using my LCD screen. I told it to prepare for a PLA Print but maybe I caused the problem. I am going to do some tests and see what I can find out.

Normally if you use the LCD panel to preheat for PLA it will set the temperatures of the bed and nozzle to PLA appropriate temps (though you may want to edit it for your printer). If you then tell it to print from the SD card, the temperature settings in the gcode file will override the printer's preheat values and it will print based on what the gcode say it should do.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

If you add a display and SD card you also adda lot of code and instructions that need to be processed.
If the CPU or the internal buffer can't handle it your print comes out really bad.
A check at very low speeds could confirm this as the machine has less CPU and buffer load this way.
Means is you half the print speed and the print comes out fine you might have a problem with the hardware being too limited.

I use both, and can't detect any differences between using an SD card and USB. Well, apart from the SD card prints not stopping when I plug in a USB camera to monitor it, of course.

tbh SD card prints seem to work a bit better, as the communication is not limited to the baud rate of a USB-Serial connection. Sometimes with complex paths I can hear the printer stutter when using USB, whereas when printing from the SD card this doesn't happen.


No idea what's going on with your system.

Out of interest - Does your control board already have an SD slot. Is it possible to have 2 and does anyone know how that is handled by the controller?

Thanks for the great replies and insight everyone provided!
Thanks to Digital Dentist, I realized the problem was likely to be user error or a mechanical issue. I went to basics and checked everything I could. When I went to print, I pulled on the filiment and discovered that my extruder was bound on the heatsink/fan assembly and the filiment was loose in the extruder. I loosed the fan screws and the extruder tightened right up. I then printed both from computer and SD and both results looked good!

Here are some replies to above questions.
My display has 1 SD slot and here is where I got it. [m.ebay.com]

I got the Marlin/Arduino firmware from an individual on Maker fronts forum. I have had it connected for a few weeks but didn't know how to print from SD until 2 nights ago.

I am working on me measuring each of my 5 spools of filiment so that I can properly set the printer to run any filiment from SD. It is exciting to be able to leave the computer off.