Thursday, 18 August 2016

3D Printing PLA Not Sticking

I have found that using blue masking tape works for helping adhesion of PLA on heated build plate. Though the brand I bought was not very good in that the print wouldn't stick to the plate. 3M blue masking tape is apparently the best for this. While I waited for this tape to arrive I used hairspray sprayed onto the glass build plate , this provided good adhesion for my prints. I like the idea of the blue tape as it's less messy than the hairspray method. 

CTC Replicator 1 (Dual) Clone RFI problems

Occasionally the display on this printer becomes garbled and the reset has to be pressed. I also noticed that when this printer is on it affects the speed of my fibre to the cabinet FTTC broadband. As a licensed Radio Ham I did notice that there was little or no RFI (Radio Frequency Interference) filtering at the mains input or any ferrite sleeves over wires going to the motors and thermocouples etc. I think that the switchmode power supply is probably causing RFI to be transmitted along the mains and then it's being picked up by the telephone line so reducing the broadband speed. I will retrofit filters and ferrite's to reduce the noise made by this machine. The graph below shows the slowing effect of this printer on my broadband speed.
I have since moved my printer to another room away from the telephone line until I get it filtered better.
WARNING! modifications to your machine may damage it or cause a FIRE! you have been warned. Be CAREFUL with Hot things like your printer!

CTC Replicator 1 (Dual) Clone Printing Issues Still!

I continued to have printing issues and it took me a while to solve. I found that the filament drive stepper was clicking all of the time and had got worse over time. I had disassembled the hot-end many times but nothing seemed to help. I then compared the hot-end channel 1 with channel 0 and noticed that the heater block was loose on the hot-end feed tube on channel 0. This meant that the block was heating up ok and the temperature was reasonably accurate but the heat transfer to the hot-end was very poor. This resulted in me having to turn up the heat to around 250 DegC to get any amount of flow from the nozzle. So I tightened the feed tube onto the heat block and re-assembled everything , immediately it began to print like new again. I was able to back off the digipot values to 118 from 122 on the printer settings and no feed clicking was evident during extrusion. Happy days!
 WARNING! modifications to your machine may damage it or cause a FIRE! you have been warned. Be CAREFUL with Hot things like your printer!

Friday, 12 August 2016

CTC Replicator 1 (Dual) Clone Extruder Clicking

My CTC Replicator 1 Clone (dual extruder) which I had for a good while and had done some really nice prints , then eventually I couldn't print anything. It would feed filament in a stop start fashion usually ending in a big bundle of filament. The symptom was the right extruder stepper drive just clicked when trying to drive filament though the hot end. I dismantled the 0.4mm nozzle and heat tube and found no blockages. I then set the extruder in motion heated but without the nozzle and it was still clicking while driving. It just seemed that the stepper motor didn't have enough torque to drive the filament. I looked around the interweb and there were mentions of digipots for controlling the drive current. So I connected my laptop via USB to my 3D printer and fired up the Makerbot Desktop software and  looked at the digipot settings under Devices -> Device Settings , the setting for digipot A was 118 so I increased this to 122 ,  the maximum is 127. While I was there I changed the setting for channel B to 122 as well just in case its stepper drive had the same problem. I tried driving the filament again but nothing changed click , click , clicking Hmmm! I then pressed the reset button and this time when I drove the filament stepper there was no clicking ,  result! It appears that any changes made to the Device settings are only read in on boot so even if you change something the old value is still used until you press the system reset button whereby the settings are read in from the eeprom.
WARNING! modifications to your machine may damage it or cause a FIRE! you have been warned. Be CAREFUL with Hot things like your printer!

Friday, 5 August 2016

Makerbot on OS X Stuck in Fullscreen Mode!

I have had trouble with OS X El Capitan Version 10.11.6  and Makerbot Version 3.9.1.1143. Once you have entered fullscreen on Makerbot you will not be able to go back to the windowed version using any of the standard key combinations like esc and the ctrl + cmd + F key , it will just plain not work. To fix this from the terminal , first create a copy of /Users/your_username/.config/MakerBot/MakerWare.ini something like MakerWare.ini.orig , then edit the MakerWare.ini file using vim and look for  the WindowGeometry="..........." entry. If you remove the data after the = including the quotes " and replace it with default ( it should look like this WindowGeometry=default). Then save it , when you start Makerbot it should start back in windowed mode - hooray!!! I took ages to find out how to fix this , even forums acknowledged it was a problem but gave no solution , the fix worked , go me!

File resolv.conf changed on reboot

The file /etc/resolv.conf was being reset and losing the correct nameserver on my Raspberry Pi after a reboot. The unfriendly way of fixing ...