tekkydave

I haven't written any code using OpenScad but I keep meaning to. The secret, like any coding is to break it down into manageable pieces that can be easily understood and reused as much as possible. A bit of analysis on paper before starting to code usually helps. Most simple 3D models can be reduced to a small number of simple shapes. Write a function for each shape and just stick them together. I can see the power of this as your model will always be precisely defined and can't be adulterated by the rounding errors and weird side effects introduced by a conventional 3D cad package. Having said that I currently use Sketchup for modelling so I'm used to it . I tried Fusion360 but couldn't get on with it. I need to try OS now

They would need a printed 'cup' thingy to hold them and stop the whole printer just rolling. Could be printed to give the right height.

Have you considered tennis balls as feet? Would absorb some of the vibrations.

Looking good. Is there any tilt front/back in the bed at all or has spacing the z-carriage wheels solved that issue?

I had it working and it seemed ok. I've gone back to using conventional optical endstops as it is quieter. Plus the resume on power fail doesn't work correctly with stall detection as it sets the axis zero to the nearest 4 full steps.

Soldering is ok as long as a good mechanical connection is made first. Be careful not to overheat the connectors though as the plastic melts easily on these connectors. I've destroyed a few myself trying to desolder connections. I would sleeve/heatshrink the connections after just in case.

Ha ha, don't worry I do that myself

Shouldn't drive 0 be connected to the LH motor? Not sure it would make any difference, though. Moving either motor by hand should move the carriage diagonally. Also check the order of the wires on the connectors. I had to switch the red & blue before using motors on the Duet which were wired for RAMPS. If you were using them on Duet before then probably ok.

Quite agree, Gina. My current D-Bot consumed most of my Prusa when I first built it.

I seem to be collecting crimping tools. I have one for RJ11/12/45, one for 1/4" spade type, one for duponts and recently bought one for JST connectors.

I've used JST-SM Plugs & Sockets for extruder motor, hotend & part fans and JST-RCY for the hotend heater circuit.

I got my Duex2 for £42.50 + vat (£51). At the time (Sept 2018) they had a special offer running.

It's a good point but the Duex also adds lots of extra i/o which may or may not be useful. It has onboard 12v regulator which allows me to have a mix of 24v and 12v devices without resorting to buck converters etc.

I found by previous mistakes that it is best to use the screws to maintain the plane of the bed and the z-axis wheels just need to keep it constrained in the x-y plane. My first iteration of the D-Bot relied on the wheels to keep the bed level. They were not very good at it

+1 for the 1-start screws. Gives very fine z resolution.

I would strongly recommend having 3 leadscrews each driven by it's own motor. I use this method on my D-Bot and the bed is rock solid. If you are planning on using the Duet then get the Duex2 Or Duex5 expansion board to give you sufficient drivers. You can also make the bed self-level itself https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors.

Wow! Yes I remember. It wasn't long before E3D stole the name for their extruder ? Thanks, Gina

The first thing that dropped into my head when I thought of large/powerful with beauty/finesse was "Concorde"

I have swapped the flexible couplers on my three z axis steppers for these plum (or spider) couplings The motors are a lot quieter now and I can achieve a much higher speed on the z axis. Previously I couldnt get above about 5mm/s without binding & stalling. Now I can get 10mm/s and more. I have set the max speed at 10mm/s (600mm/min) as any faster is probably putting undue stress on the steppers. I have 1mm pitch leadscrews so 600mm/min is equivalent to 600RPM.

The Aero has performed ok so far <touches wood> but I haven't done any particularly long prints. Are you using 1.75 or 3mm filament?

Are you bowden or direct & what length retraction. I generally use 1mm for PLA and 2.5mm for PETG.

Pics as promised. First the new leadscrew arrangement - one motor per screw. I have some better oldham-style motor/leadscrew linkages on order. The new x carriage including a piezo sensor embedded in the motor holder. The piezo electronics is hidden in the lid on top of the carriage. The Re-X carriage also has tension adjusters for the v-wheels and tensioners for the belts on the rear. The Duex2 expansion board connected to the Duet WiFi via a 50-way ribbon cable. I had to print a bigger enclosure. The boards mount back to back and hinge out of the enclosure for easy access. I have replaced the 80mm fan in the lid with two 60mm fans in the bottom of the enclosure. Finally my 1.75mm Aero Front ready for when the 1.75mm filament arrives

4 motors is possible but you would need the Duex2 or 5. If you are not using the E1 stepper that could be used with a Duex2 to give 4 channels (Z, E1, 5, 6). The current Duex2 version 0.8a is identical to the Duex5 except 3 of the stepper channels are not populated with driver chips. Earlier Duex2 models only had 2 of everything. The other thing with 4 motors is you need a bed/frame that will flex - the G32 process will try to remove any twist in the bed/frame. Mine is 6mm cast Ali so 3 motors is more appropriate - it adjusts each motor to put the bed in a horizontal plane. It's quite amazing to see it working. I deliberately wound one of the screws a few turns and ran G32. After probing in 3 places the screw got turned back to where it should be

It's been a while since I posted anything so here's an update on changes I've made to the D-Bot over the last few months: 1. I've changed the way the z-axis screws are driven. Previously I had a single motor driving all 3 screws via a belt & pulley arrangement. It worked ok but I wanted to try driving each screw with it's own motor. So I purchased another 2 motors and also a Duet 3D Duex2 expansion board. This gives me the additional 2 motor channels I need plus a whole load of extra input/output options for future projects. It also gives me an on-board 12V supply so I can use that for 12V fans without needing the buck converter I was using before. Having 3 independently driven screws means that the firmware (RepRapFirmware) on the Duet can automatically level the bed. Once you set up the exact positions of the screws, and the nearest point on the bed to probe it just does it by issuing a G32 command. You just need to set up the following config.g M584 X0 Y1 Z2:5:6 ; Drive Mappings: setup 3 Z motors connected to driver outputs 2, 5 and 6 M671 X-37:337:148 Y50:48:354 S3.0 ; leadscrews at front-left, front-right and rear-centre bed.g G28 ; home all axes G30 P0 X10 Y50 Z-99999 ; probe near LH Front leadscrew G30 P1 X290 Y48 Z-99999 ; probe near RH Front leadscrew G30 P2 X148 Y284 Z-99999 S3 ; probe near Rear Centre leadscrew and calibrate 3 motors ; re-home z axis in case it has shifted G28 Z You also need to ensure any Z values in commands like M92, M350, M566, M203, M201, M906 have extra values for the 3 motors e.g M92 X100 Y100 Z3200 E419 ; Set steps per mm becomes M92 X100 Y100 Z3200:3200:3200 E419 ; Set steps per mm 2. I also wanted to upgrade my E3D Titan to be an Aero model. I bought the Aero conversion kit but this meant I wouldn't be able to continue using the Orion Piezo module as it is not physically compatible with the Aero. I decided to switch to the Re-X Carriage as there is also a Piezo Mount option for it. This also needs a different electronic module from Precision Piezo - the Universal Piezo Z-probe PCB which has up to 3 inputs for piezo devices. I fitted a 27mm piezo sensor in the mount and it works extremely well. Much better than the groove-mount mounted Orion. 3. I have decided to switch from 3mm to 1.75mm filament. I'm finding the Titan can be a bit of a struggle to load 3mm filament, especially PLA which is often quite brittle. I have some 3mm to use up so I decided to build a 1.75mm Aero front that can easily be swapped in & out for different filament sizes. The Aero heatsinks are different for 3mm & 1.75mm - the 3mm has an M6 thread whereas the 1.75mm has an M7 thread. Obviously I would need to replace that. I also purchased a 1.75mm heatbreak, V6 heatblock and 24V 40W heater cartridge. I already had a spare nozzle and cartridge thermistor to use. With inline connectors on the heater and thermistor circuits it should be simple enough to unplug & unscrew the 3mm Aero Front and plug & screw in the 1.75mm version. I have some 1.75mm filament on order so we'll see how things go. I'll post some photos later.

I suspect the problem may be down to FC refusing to use non-64bit drivers. I'm not really supporting this project anymore and I dont have the tools to make changes to the driver which requires windoze ( I only use Linux these days). If you get hold of the latest free copy of MS Visual Studio you can recompile the driver easily for your platform. All the source code is on the AAF Sourceforge site. Hope that helps. Dave