I use the glass off an old scanner. Works well.by Dabble - Tantillus
Did you look for shorts on the RAMPS board?by Dabble - RAMPS Electronics
Depending on your OS and the editor that you used to edit the configuration, you may have old copies lying around....by Dabble - General
Looks like a bad connection between your power wire and the power connector. A bad connection will mean that there is high resistance and hence heat will be generatedby Dabble - General
Thanks for the explanation. Unfortunately you will be delivering 4 times the power to the two sections wired in parallel, compared with the 2 sections wired in series. I bought a new board from think3dprint3d and I am very happy with it. My advice, for what it is worth, is to use the board to print smaller items, up to half the size of the board. The alternative is to build a small external cirby Dabble - General
It is not clear to me exactly what you have done. It does seem to me that you have different paths for your current with different resistances and hence the current will not be distributed evenly among your heating elements. The result would be uneven heating. If I am wrong, please show a picture or post a circuit diagram.by Dabble - General
Been thinking about what I will do with the bed. Before I had the idea of PWMing it I ordered a new one from think3dprint3d, by chance the one you recommended, and it is on its way. I have not yet had a response from snipermand which was where I ordered the first board from. My power supply has a 21A and an 18A 12V supply so it should be able to handle the current. The MOSFET will probably fry hoby Dabble - General
Unfortunately the while the power to the bed is halved, the power to the fuse is not.... I tried increasing the power to 3/8 after 75 degrees but this blew the fuse. The resistance at 70 degrees is about 0.8 ohms, my multimeter is not very accurate at these values, so while I am sure that the resistance increased, it is hard to say by how much. I like your idea of rewiring the PCB. I did not realby Dabble - General
You are correct that it is a software PWM, it is crude but appears to be effective. The rate seems to be very slow. The logic is that bed_is_on is incremented from 0 to HEATER_BED_DUTY_CYCLE_DIVIDER repeatedly. When bed_is_on is 0 i.e. for 1 out of HEATER_BED_DUTY_CYCLE_DIVIDER times, the heat bed is turned on. I found that a value of 4 i.e. turn on for 25% of the time, worked for me.by Dabble - General
I have a heated bed PCB with a resistance of about 0.6 ohms. I had read in other posts that these are essentially defective but I decided to try it out anyway with a RAMPS 1.4 configuration. It worked for about 3 prints at 60 degrees however when I tried to raise the temperature to 110 degrees the fuse on the RAMPS blew and since this time I was not able to even get to 60 degrees without the fuseby Dabble - General
When Slic3r works it gives good prints quickly. Unfortunately I have found that it will not correctly slice all parts e.g. http://www.thingiverse.com/thing:8675. KissSlicer also slices very quickly but also had problems with this part.by Dabble - General
Following up a post from Leav: Reporting on a new (?) bed material for printing on without a heated bed and an improvement on an old extruder design: I believe that the paper that was used is known as construction paper, which is used for making architectural models. I have managed to get some good prints with no warping using ABS on this paper. There is a small amount of paper residue attached tby Dabble - General
Did you check the connection speed? The speed will depend on how you configured the firmware.by Dabble - Skeinforge
I think that the need for active cooling on the steppers depends greatly on the type of steppers. I have 2 different types. The smaller ones actually produce more torque but heat up quickly. The larger one appears to work fine without active cooling but did not have enough torque for the wades extruder.by Dabble - General Mendel Topics
Thanks for the tips. I am just getting ready to start printing and was wondering whether to try PLA or ABS firstby Dabble - General
Did you install the jumpers under the stepper driver boards?by Dabble - RAMPS Electronics
I also used a drill press at a fairly slow speed, along with a vice. Any parts that had to match closely I drilled one through the other. For the motor mounts I made a template in order to get the holes exactly right. Regarding the horizontal y axis perhaps I was lucky, or careful to drill the holes at 90 degrees, because I have a pretty good plane. The problem of a twisted plane was not somethiby Dabble - General
In order to correctly match the holes in the top vertices and the z-motor mounts I connected one side and redrilled the other through the z-motor. I did not find a metric set of drilling instructions and SAE ones are minimal which forced me to understand how it all has to be assembled before drillingby Dabble - General
Thanks! Once I get my reprap working I will start looking into this. Even if it only checks the position immediately before starting the extruder, I imagine that print quality will improve.by Dabble - General
Has anyone tried attaching a digital caliper to the X and Y axis? I recently picked up a cheap one that has a port for connecting it to a computer. I haven't had time to investigate it but it seems to me that this could solve some of the problems with accurately positioning the print head.by Dabble - General
Looks like Poster Board also known as Bristol Board to me.by Dabble - General