Here is my current X-axis design- very modular and scalable. I uses a linear guide screwed to a 1" square aluminum tube and NEMA-23 motor- you can probably use a NEMA-17 motor. The X-min limit switch is on the motor mount and is bumped by the linear guide bearing block. The belt tensioner/idler has a mount for an X-max switch if you want to use one. This assembly bolts to the Z axis screws inby the_digital_dentist - Reprappers
If you're planning on printing with ABS, plan on enclosing it and keeping the electronics out of the enclosure so it can be operated at elevated temperature. I think you've got a good start. Try pushing on the frame. If it flexes perceptibly, make it stiffer. If it flexes when you push on it it will move when a bed or extruder carriage is moving back and forth. If the frame flexes print qualby the_digital_dentist - Reprappers
I recently replaced a ceramic/glass cooktop in my kitchen and did a little research on the material. It's called Ceran, made by Schott in Germany. It has a near zero CTE. I attempted to liberate the old glass top from the electronics assembly that is glued to the bottom of the plate, but was unable to do it without breaking it. Maybe that material can be purchased for reasonable price in smalby the_digital_dentist - General
Are you planning on printing cookies and baking them as they print?by the_digital_dentist - General
I have had no issues with my XL. It is difficult to change the filament because of the tension on the pinch roller springs, so now I keep the hex wrench handy and release the tension before trying to change filament. I use 1.75mm filament and haven't had problems feeding it into the tube. I'm considering designing a tool to release the pinch wheel to make it faster and easier to change filameby the_digital_dentist - General
Questions: What happens when it fails- pump fails or tubing gets pinched/clogged, pierced/cut, etc.? Will the pump motor last longer than a typical cooling fan motor?by the_digital_dentist - Plastic Extruder Working Group
I think meshmixer should be able to do it, but I haven't used it much, so I can't tell you what to do with it to correct the problem.by the_digital_dentist - Printing
It looks as though you took two parts and just mashed them together with some overlap. That doesn't work. In your CAD file once you've positioned the parts you have to combine them to a single solid before you export as an STL file. There is usually some sort of "combine" or "join" function on a solids menu that is used to do that, but it varies depending upon the CAD package you are using. Tby the_digital_dentist - Printing
I have not heard of an automated process for that, but Slic3r allows you to manually specify print layer thickness based on Z coordiantes. After loading an STL file, click on the settings tab, then the layers tab. You specify the layer thickness and Z range over which it applies.by the_digital_dentist - 3D Design tools
You could place a couple fans along side the bed and turn them on after a print has finished using custom gcode. That should speed the cooling of the bed. If you go with aluminum, definitely get cast tooling plate. Extruded plate is not flat enough in the size you're talking about. If your bed moves in the Y axis you'll have a high moving mass which will require a more powerful motor if you wby the_digital_dentist - Mechanics
Sometimes the motor will slip but it will sound like the belt is slipping. You can check that by making a mark on the drive pulley with a marker or a piece of tape. When the noise occurs is the pulley actually turning or is it stuttering without turning because the motor is slipping? If the motor is slipping, check the current, speed, and acceleration settings. Make sure the grub screw on theby the_digital_dentist - Printing
If the problem is at the bed and not the X axis, it's probably a structural problem, not the material from which the bed is made. A lot of printers are relatively flexible and after you apply some effort to remove a well-attached print the bed ends up in a different position than it was before, requiring releveling/zeroing. The cure for that is either beef up the structure so it doesn't happenby the_digital_dentist - Printing
I have a 1/4" x 12" x 12.5" cast aluminum tooling plate bed with a 450 W kapton heater powered by a 24V transformer with AC power switched by an SSR. I turned the max PID frequency in smothieware down from 20Hz to 8 Hz. The thermistor is screwed to the bed. There is currently no insulation on the bottom side of the bed, except for a small piece of silicone foam that is covering the thermistor,by the_digital_dentist - Reprappers
Your scope photo is impressive, but the avalanche is over in under 250ns and the ringing voltage has dropped below 20Vpk in under 1 us. The FETs in the RAMPS board are rated for 50A continuous and the SOA curve shows that they can handle >100A for 100 us (that's 400x the duration of the avalanche in your scope image). I don't think avalanche is going to be an issue. Marlin PID operates at aby the_digital_dentist - Reprappers
Acetone boils at about 56C. That Peltier junction device is like any other semiconductor - you'll have to be very careful to ensure you can dissipate the heat it produces or you'll kill it very quickly. Your idea seems overly complicated to me. Acetone isn't expensive or toxic enough to bother with vapor recovery. I think a real problem to be solved is circulating the vapor so it treats theby the_digital_dentist - General
I think at 50 or 60:1 it's going to have a very low maximum printing speed, especially if you're using 1.75mm filament.by the_digital_dentist - Mechanics
Checking alignment or axes is best done printing a rectangular solid. A rectangular solid will have two diagonals in each plane. You can check all three axes for orthogonality by measuring diagonals in the XY, YZ, and XZ planes. Leveling the bed does not compensate for axes that are not orthogonal. It only lets the first layer stick to the bed. If the axes are not orthogonal circles won't beby the_digital_dentist - Printing
Running a 12V heater from a 24V supply will dissipate 4X the power at 100% duty cycle (maximum PID duty cycle setting of 255). If you set the duty cycle to 25% by using a maximum setting of 63 you'll get the equivalent power dissipation of a 12V supply. Since it is taking too long to heat at 12V, you can set the maximum duty cycle to maybe 70 or 75 to increase the average power to the bed. PIDby the_digital_dentist - Reprappers
I think he means to get a big 24V supply to power the bed and then a smaller 24VDC- 12VDC converter to power the controller and motors.by the_digital_dentist - Reprappers
Check the couplers that connect the Z axis screws to the motors. If one or both are slipping the Z axis will never behave properly. Make sure the motors have adequate current.by the_digital_dentist - Printing
If the controller runs on Marlin or Smoothieware (and probably others), PID control is an option that should be turned on. Bang-bang control allows relatively large swings in the bed temperature that will cause artifacts in the Z axis of the print.by the_digital_dentist - Reprappers
I'm not entirely sure. When I switched to the DSP driver + 32V supply on the belt driven X axis it became weirdly quiet, so I guess the answer is yes. I never operated the Y axis motor without the DSP driver so I don't know how it would behave with a chopper driver- the pololu drivers I have can't handle the current that the motor needs. I did some earlier tests on the Y axis screw drive withby the_digital_dentist - General
Have you checked the Z axis? Maybe the screws are getting out of sync due to binding, slipping, etc.by the_digital_dentist - Printing
Increasing the voltage should get it to heat up faster, but be careful if the power supply is near its current limit. If it's good for 20A at 12V it will only be good for 17A (or less) at 14V. If you exceed the designed power limit it will die quickly. In my experience, if the power supply's cooling fan turns on, you had better turn the voltage back down because the supply won't last long if iby the_digital_dentist - Reprappers
If you haven't calibrated the machine you will naturally have all sorts of printing problems and they will continue until you calibrate the machine. Calibration includes adjusting motor currents, setting maximum speeds and accelerations, steps/mm for all axes and the extruder, running PID autotune for the bed and hot-end, limit switch functions, bed leveling and zeroing, etc. You may find thatby the_digital_dentist - Reprappers
Check this site for an explanation of how to tweak the settings for optimal infill: richrap.blogspot.com/2015/01/slic3r-advanced-perimeter-tuning-3d.htmlby the_digital_dentist - Printing
They are usually only lightly attached (you can tweak parameters for that) so that the support material breaks off easily.by the_digital_dentist - General
Cura and slic3r will both generate support structures automatically.by the_digital_dentist - General
I suggest you patent the idea before someone beats you to it...by the_digital_dentist - General
Try this: It uses the belt's own teeth to prevent any slip. Even if the the center post were to break loose, the belt won't slip.by the_digital_dentist - Mechanics