Will Slic3r work with a RapMan 3.2 by BFB?

Hello, I read that Slic3r should work with most 3D printers. But I am not having any luck using it with my RapMan 3.2. The file extension is .bfb. The exported gcode file is not recognized by the printer. Is this possible or am I just out of luck? I was so excited after finding this site and the Slic3r software. But I am starting to think that I may be one of the unlucky ones who is stuck with Axon. I have basically given up trying to use this printer due to issues that are not handled by Axon. The brim feature seemed like the answer to my problems (lifting corners on my models). Any help is greatly appreciated! Thanks, Todd

From what I read the RapMan should work with standard G-codes (you'll have to change the file extension to "bfb" of course). Maybe you could post a bfb file that works on your printer and I can see if I can spot what may be the problem.

Dave

Hello Dave, thank you for your response! I tried doing that last night. But the printer would only initialize and then stop and state that the print is finished. I will attach a file that has worked. I will need to reduce the size of the part so it is small enough to attach. Thanks again, Todd

Ok, here is a file that is working on my printer. It is part of a knife handle. I am trying to make a Karambit knife out of a video game for my grandson. He wants it for his collection shelf. Thanks! Todd

P.S. I forgot to ask which printer type I should choose in the Slic3r setup? I currently have it set up with the RepRap version. Thanks

Edited 1 time(s). Last edit at 12/02/2015 11:12AM by TCannon.

OK, I see the problem. Your printer uses a different technique than what I am used to - instead of having the G code provide the length of extrusion for every move, it uses an "extrusion speed" command to use for all following moves in conjunction with "extrusion on" and "extrusion off" commands. I have tried all the "flavours" of G-code that Slic3r has, but none of them output that type of format. Post-processing the G-code to change the format would be possible but fairly complex because there is no straightforward way to deduce extrusion speed (and speed changes) from extrusion length and print speed - though it could certainly be done. Note that the extrusion rate is not necessarily the same for the entire print - if the extrusion thickness changes (e.g. between perimeter and infill), there will be a change in extrusion rate. I assume that the extrusion speed would also need to be changed if the print speed changes - which it may do in certain cases for different parts of a print. Therefore any post-processing application used to convert would have to take those factors into account, and so be a relatively complex (but far from impossible) bit of coding. I see no easy solution. I don't see any plugins for Cura that would make that work. Maybe Simplify3D has such an output available (I don't have a copy with me to check), but I don't see RapMan listed as a supported printer on their website so I suspect not.

You could do a web search to see whether there might be a firmware version available for the RepMan controller that will allow it to take standard FFF G-code files.

One rather extreme solution would be for you to replace the printer's controller with a more standard controller. I am familiar with the "Duet" controller [reprappro.com] - also available from other sources - and looking at the RepMan 3.2 manual it looks like it would drive the printer with no problems - it's even possible that the existing connectors would fit onto the Duet board with no changes to the wiring loom. You'd just need to put the appropriate values into the configuration file on the Duet's SD card (X, Y, Z, E steps per mm, thermistor type, X, Y, Z endstop switches and homing files). You would lose the front panel control of the printer entirely, but gain an Ethernet web control that is far more versatile. There is a touch-screen add-on for the Duet that is available should you need standalone control of the printer.

I noticed that your sample G-code file appears to be set for printing in ABS. The hotend temperature of 260 deg is very hot - I use 235 for ABS. A colder extrusion temperature may well help with your warping issue so you might try that. Also the RepMan 3.2 has no heated bed AFAICS - ABS is almost impossible to print without a heated bed.

Dave

Hello Dave, thank you so much for your time. I was afraid it would end up being something like that where I could not use Slic3r. I did forget to mention a couple of things. First of all, I have added a heat bed to my printer. I have been printing the ABS parts with a bed temp of around 100 C. I also lowered the nozzle temp down to 230 after the first layer. While this did improve the part, the lifting around some of the edges is still unacceptable for a quality part. I have been wondering if it were possible to change out the control board for something more advanced. So thanks for that information. I guess upgrading the control board is going to be my only hope for better ABS parts. Thanks again for all of your help! Todd

ABS parts generally don't like square corners, especially on hollow boxes. If you can modify a design to have rounded corners it helps a lot. The ambient temperature should be reasonably warm (>20 deg C). Any draught can cause the print to warp - open and close doors slowly while printing, no open windows, careful of draughts near a fireplace etc. A heated chamber is best - to make an ad-hoc chamber simply cover the entire printer with a large bin bag (it will be heated by the bed heater). Monitor the temperature under the bag though - if it gets too hot you can damage the printer (electronics & motors overheat, plastic parts deform), and don't leave it unattended. Using a full-height skirt (if your slicer has that option) is another method to keep draughts out and the temperature more even. You can also try reducing the bed temperature after the first layer (you might try 100 for first layer and 80 for the rest - 70 is about the lowest you should go for ABS). It can be a bit of a black art - one print can come out perfectly, and the next part printed with the exact same G-code file will be split or badly warped.

Bed adhesion can be improved with a suitable coating and may hold your problem corner down (though you might then get layer splits instead). I paint my bed with ABS dissolved in acetone which is very inexpensive and seems to work well. You could also use solvent cement (used to join plastic pipes and available in hardware stores) which is slightly better but rather expensive to use all the time. You can dilute it a bit with acetone. The coating comes off with the print so you have to re-coat for each print. Acetone is available online and from fibreglass supply stores. Avoid using nail-polish remover - not only is it ridiculously expensive, but it can contain added oil.

Another method is to print the part in sections of smaller height and join them together afterwards. Use acetone to "glue" ABS - it forms a chemical weld that is stronger than the normal layer bonds.

Dave

Edited 1 time(s). Last edit at 12/03/2015 11:11AM by dmould.

You should use KISSlicer. It will export the correct type of gcode for the Rapman and the quality is significantly better than Axon. I'll attach my config files with the settings I've spent months refining! I know it's 5 months late but hope this helps. Download KISSlicer from their website. The first time you open it, it will create these four files in the same folder as the program. Replace them with the four I've attached.

Edited 1 time(s). Last edit at 05/15/2016 03:00AM by ryandgarrison.

Thank you for your files! I just bought a Rapman 3.2 for $50 and thought I would give it a spin, and don't you know a google search away and I found your advice and files. Perfect! It's up and running just fine with your settings.

Now I'm trying to upgrade the firmware, getting a "Verify Failure" when verifying the Hex file. Got it from 3D systems website.

At least it's working now!