With the addition of the Raspberry Pi to my rebuilt Up Plus 3D printer I now have three power supplies connected to the machine. The heated bed is using the original 19V power supply that came with the Up, the RAMPS 1.4 and hot-end are using the 12V supply from my old Prusa and the Raspberry Pi is using an old 5V phone charger. This is a lot to connect to start the printer.
I want to simplify things by just using the 19V supply and fit the machine with two step down voltage regulators. I would need one regulator to step the 19V down to 12V and a second to step down again from 12V to 5V. The 5V is easy as the Raspberry Pi Zero W only draws 250mW max so any USB power supply will work. I settled with a dual USB 15W switch mode supply that can handle 6V – 40V input. The larger supply and dual ouput would be handy if I add a WiFi camera later.
The 19V to 12V supply needs to supply the RAMPS 1.4, Arduino, stepper motors and the hotend. I calculated the peak power draw to be 30W (2.5A). I chose a 50W Power Supply Module that included an LCD display that shows the current draw and voltage. The Ebay listing shows that the unit can supply 35W constant without cooling and 50W with the supplied heatsink. I also added a cooling fan.
The first test run had the 12V supply showing peak current draw of under 2.5A so less than 30W but the heatsink was getting too hot to touch even with a fan on it. 10 minutes into the print the printer stopped with the 19V supply shutting down due to short circuit protection. The second MOSFET on the 12V supply had failed short circuit. I contacted the Ebay seller wh didn’t respond to any e-mails. Swindled.
With a doubtful attitude to Ebay sellers I decided to replace the 50W supply with a 200W supply. This new supply doesn’t have a fancy LCD but it shouldn’t burn up during basic use. I kept the cooling fan just to make sure and the power supply is cool during use.
Now with only one power cable this printer is almost looking finished.
Last weekend was the 2019 Australian Feather-Weight Nationals and Daniel decided the enter Prowler. Prowler has been fairly unchanged since last year except for swapping the friction saw blade with an all purpose demolition saw blade. The controls were also divided between Daniel driving the robot and Andrew controling the weapon. This is the first time with both of us controlling the same robot and was hoped to remove some stress from Daniel while trying to drive and operate the weapon at the same time. Oh, and a new paint job.
The competion was held over 2 days with 2 qualifying rounds held the first day. Prowlers first match was against a lifter called Pooper Scooper. Going into the fight we were concerned about Prowler being turned over but Pooper Scooper’s weapon failed early in the fight. The new saw blade worked well on the mild steel and UHMW Polyethelyne top on Pooper Scooper creating several cuts in the top. A nice win to start the weekend.
The second fight was against Bob who is a viscious looking horizontal spinner. The concern here was that the blade whould hit the spikes on the front of prowler and bounce up into the saw arm. Daniel decided to drive aggresivly to prevent Bobs weapon from getting up to speed. During one attempt at sawing into Bob, Prowler drove Bob into the arena wall and Bob bounce up into the saw causing the saws bearings to pop out. After this Bobs weapon also failed and it became a pushing match. Fortunatly Prowler was able to out-wedge Bob and the arm could also clamp Bob to help drive Bob into the walls. During all this driving and attempted clamping Daniel realised that one of Prowlers drives would cut out while the arm was being raised or lowered. Fortunatly Prowler still won the fight.
Upon returning to the pits I refitted the weapon axle and replaced the bearings and checked that the saw was running true. The drive problem while the arm was being moved was determind the be a low voltage cut-out of one of the drive ESCs. To test this the ESCs were swapped with Berserkers ESCs (because Beserker just happened to be in the car) and Prowler worked ok. Prowler would keep Berserkers ESCs for the second day.
The next day the 2 wins had allowed prowler to qualify for the top 16 finals. The first match up was against The Undertaker which is a under-cutter spinner with a 4kg weapon. Fortunately for us the weapon was not working as The Undertaker had burnt out all its weapon motors the day before. This left The Undertaker fighting as a wedge with extra AR450 plates added to its top for extra armour. While Prowler could not cut into the heavily armoured top of The Undertaker we still won by judge’s decision. Now in the top 8.
Unfortunately the 4th fight was against Abomination, an extremely powerful and well built vertical spinner. Daniels idea was not to box rush but to move to the centre of the arena and hope that Abomination would not want to attack Prowler head on but try to circle around us. Being such a powerfull vertical spinner Abomination would have trouble turning to maneuver around Prowler and Prowler could attack the side of Abomination while it was struggling to turn. Despite Daniels over thinking, Abominations builder Michael just drove head first into Prowler and out wedged us. Prowler was thrown onto its back but self righted quickly. Abomination continued to attack and hit the side of Prowler immediately and the shock caused the liner actuators cast aluminium gearbox to shatter and the saw dropped to the floor. Daniel continued to attack and Prowler was thrown into the air a couple of times before landing on its front with the 2 spikes and the saw touching the ground. With the linear actuator broken Prowler couldn’t right itself and was counted out.
So Prowler went 3 – 1 and ended in the top 8 which is pretty good. Abomination went on to win the competition with straight KOs so we lost to the best. No major problems to try and fix between fights and if we had a spare linear actuator Prowler could have been ready to go again in a few minutes. Quite a successful weekend.
Now that I have my 3D printer running reliably and the RAMPS 1.4 mounted I want to disconnect it from my laptop. At the moment every time I want to print something I need to connect my laptop and leave it connected for the duration of the print. There is an option to add an SD card reader to the RAMPS but that would also require adding a control panel to the printer. It is cheaper to add a Raspberry Pi.
I have been using OctoPrint software on my laptop which also has a pre-made Raspberry Pi ROM called OctoPi that can be loaded directly onto a Pi. OctoPi is designed for a Raspberry Pi 2B or 3B and offers camera support out of the box. Since I am on a budget I decided to just use a Raspberry Pi Zero W. There is several reports of OctoPi not running on a Zero W mostly because the single core processor can’t support running the server and the camera streamer simultaneously. Since I don’t even have a suitable camera I don’t think this is a problem.
After loading OctoPi and running through the setup the printer worked first time exactly as it did from my laptop. The next problem is that I wan’t to print directly from my phone. OctoPi has an option of adding a slicer plugin on the Pi and while looking through the options I came across AstroPrint. AstroPrint is a cloud-based 3D printing system that includes a selection of slicers. Files are uploaded to AstroPrint, sliced in the cloud and then sent to OctoPi via a plugin.
For quick prints of simple models AstroPrint works well enough but if the model needs some fancy slicing then it is better to use a desktop slicer. AstroPrint also does not include many options to control the printer so I still need to use the OctoPi web interface or an android app.
The next problem created by adding the Raspberry Pi is that it needs a seperate 5V power supply as the RAMPS cannot supply enough current for the Raspberry Pi and the Arduino. Now I have 3 power supplies plugged into the printer, a 19V, 12V and now 5V.
Go into the competition at 10:30 while Connie and Alice stay in the hotel. Plan is just to chat with people and watch some fights.
I noticed all the eliminated chinese robots are moved to different benches, but the builders and their equipment are gone. Leslie tells me that the robots are paid for by KOB and must be left behind. The builders took all the spare parts and leave the empty chassis. The international teams are oblivious to this since they don’t really chat to the chinese teams.
Brian Nave is getting bored and is challenging people to a fight. We don’t know when the intruder robots will final be introduced into the competition and the teams are tired of sitting around and doing nothing. I accept his challenge to test his new robot and are told we can have the arena during lunch. But it will take 5 -6 hours to repair Huntsman as I haven’t touched it since it was eliminated and I left my batteries and radio in the hotel. Directors say it is ok and we can fight tomorrow.
Pull everything back out of the crate and start fixing. Requires 3 people to bend the side of the chassis into shape. I had Robert Nani from team Monster and a random chinese fella who was walking past stand on one side of the robot while I used Cat King’s giant wrench to pry the damaged side. Wish I took photos of that. Actually Robert was with me for the entire repair, trying to learn how I designed and built the robot. Severely underestimated that pink beater.
Robot almost ready for testing at 6pm, just requires some soldering for motor plugs. I was correct in the 6 hour estimation for the repair time.
Competition fights finally start, but apparently are only “practice matches” so that the celebrities can learn about the robots on their leagues. The builders don’t want to damage their robots in fights that won’t count and decide to not use their weapons. This results in some boring fights. Some Chinese men from the audience come to see my robot and are rather impressed. Would rather talk to me rather than watch the fights. The directors start complaining that the builders will win money for each win they get, so they should be trying to win, but the builders ignore them. I doubt the fights would get aired.
Catch a taxi for the hotel at 8pm rather than watch the fights and wait for the bus. Turns out the bus left at 1am.
Head in at 11:30 to finish getting the robot ready. Just need to solder some plugs onto a new weapon motor and put in the batteries.
Told we can have the arena in the afternoon, but that didn’t happen. They were filming team meetings and didn’t want too much noise.
Put Huntsman in the test arena. Everything works fine. Drew a nice crowd.
KOB people still asking if I want to fight Shredderator. They seem to think it is a bad idea and I’ll just get destroyed. I just laugh.
Competition fights happen at night, 3 fights scheduled between two leagues. One league wins the first 2 fights, so final fight cancelled.
Told we can borrow the arena at 9:30pm
Huntsman been prepared all day, feel confident.
Put it in the arena. Word gets around and a large crowd forms, including Emma Dumont. I feel extra nervous as I can finally fight in front of a celebrity and show what they missed out on. The arena lights have been turned off and “need to rest”, so we have to find portable lights. Go to turn on the robot and sparks arc up from the screw driver on the drive side. Decide to dismiss it. When doing the prefight checks the robot fails to move. Go back in to check the robot and find the drive power is off. Try to turn it on, more sparks, power light comes on and then dies. I get asked if I can fix it in the arena, but I worry it is a battery short and decide that it will be safer to take it back to the bench for a complete check rather than risk a battery fire.
While getting the robot out I hear Emma making rude jokes about my robot. So annoyed and hate her. Other builders tell her to be quiet.
Bench check shows that batteries are fine and the power lines running from the left to the right side of the robot had been pinched between the frame and the weapon motor. Riding on the trolley over the bumps to the arena must have rubbed through the wire. Every time the screw driver touched the switch and the lid the robot would turn on. The sparks are the capacitors charging. Once the screw driver was removed the robot would switch off. The power light would stay on while the capacitors discharged. If I turned the power screw 2 more turns the robot would have turned on fine, but risked a short as the chassis was grounded.
Shredderator continues to drive in the big arena for practice. Fight postponed as their batteries were flat and the work crew wanted to prepare the arena for tomorrow’s filming.
Go back to the hotel. Not happy.
Alice and Connie not feeling well, so I decide to stay in the hotel during the day. Send a message to Brian to say I still want to fight and he can call me if we get the arena.
New stroller arrives, so test it out by walking up to the big shopping centre for dinner. $35, bargain.
While eating dinner I watch a mother hold a small child while it went to the toilet in a rubbish bin. And then a few minutes later I watch a man search through the bin for a water bottle. I’ll never forget that sight.
While at the shops we get a message from Brian Nave that we have the arena for a fight. Quickly find a taxi and Leslie to head in. Connie and Alice stay behind at the hotel.
Fix the broken wire with an empty coke bottle to protect it from abrasion. Do 3 bench tests.
Head into the arena. Only a quarter of the crowd of the previous night. But that gives it a more underground feel, just like when I first started. Feel more relaxed.
Fight went to plan. Finally drove calmly. Drive slowly to keep the spinner in front of me. Use the armour to box Shredderator into a corner. One of the impacts breaks Shredderators shell and causes it to lose balance and affects its control. I tried to hit it with the axe, but it was in the far corner and the poor lighting made it hard to judge distance, so I missed. So bugger it, I’ll just keep ramming and not worry about being out manovoured. Get Shredderator into a corner and go in with the axe even though I can’t see. The robot bounces into the centre of the arena, but has lost drive. I hear the Shredderator team yelling about a fire and that it was dead too. Double KO.
Lost drive because the battery unplugged and weapon from a bent motor (again).
The KOB arena crew and Blanka Botz (only guys watching) give me the win. Claim victory. Head back to hotel. Only at competition for less than 1 hour.
Go back to the hotel and hear that Shredderator lost its shell and drive base.
Slept very well.
Go down to breakfast. Hear teams at other tables talking about me and the fight. Several teams come to congratulate me.
Walk over to the convenience store before going into the event. Bump into John Reid who congratulates me on the fight. Almost cried. Last time I tried to chat to him was in 2005 when I asked on a forum about kinetic energy calculations for electric hammers. All my robots use the calculations from the ideas he gave me. No longer care about the previous 2 weeks.
Catch the 11:30am bus.
Spend the day slowly fixing the robot.
Several robots ask for a fight. Feels like builders have finally realised that I’m not a noob. Organise fights with Orby, Medusa and Ground Dragon.
Watch a few fights. No idea what stage of the competition we are up to. If I go back I’m going to take a white board to keep track of things.
Go back to hotel on the first bus.
Hear on WeChat that the next day will be interesting with a strange fight format, but unsure if we’ll go in. Maybe have a relaxing day.
So now I have my rebuilt Up Plus 2 3D printer working I need to tidy up the electronics. To do this I downloaded a RAMPS 1.4 case off of Thingiverse and set to printing.
The first problem I had was bed adhesion. The buld plates that came with the printer are similar to a prototyping PCB perf-board with hundreds of tiny holes in it. The PETG filament I am using sticks to the board well enough but all the holes make for a really rough bottom layer. After a little Googling I found that the Up software slicer uses a raft for bed adhesion so I will try that. It took some adjusting to get the first layer height offset correct but it is working.
The next problem was that the prints are warping badly. I had not wired up the bed heater yet as I still needed to change the thermistor. The Ups original 100 ohm thermistor doesn’t work with the RAMPS controller so I replaced it with a 100k ohm thermistor. With the RAMPS power supply set to 13.5V the bed could only reach 65 degrees celsius and even then took 45 minutes to get there. The recommended bed temperature for PETG is 70 degrees so the best I could manage was still 5 degrees too low.
While I had changed the thermistor I didn’t change the heater cartridge in the Ups bed which was designed to work with a 19V power supply. The RAMPS 1.4 has a seperate power input for the heated bed but a look at the schematic shows that the MFR1100 11A PTC resettable fuse is only rated for 16V. A look at how these PTC fuses work and at the datasheet for this particular fuse I see that the critical part is not the voltage but rather the power consumption as the fuses rely on heating of the internal elements for them to work. If more than 16V is applied to the fuse while it is failing then the extra power consumed by the fuse while the internal resistance rises can cause the fuse to fail in a non-resettable way. But since this is what fuses usually do I am willing to risk using the standard PTC fuse at 19V.
I wired up the original Up 19V supply to the 11A input and left the 13.5V supply on the 5A input of the RAMPS and gave it a go. Now it reaches the target 70 degrees in under 15 minutes and has no trouble maintaining that temp.
I had started printing the case for the RAMPS before fixing the bed heater and the case had warped and the print failed when it seperated from the raft 3/4 of the way through. Since it took 14 hours to print as much as I did I didn’t want to start again. I cut the part that printed successfully of the bottom of the model in Cura to finish the print with the bed heater active and then glued the top to my failed print. The pieces don’t quite match due to warping but I now have a momento of how the printer worked before the improvements.
Arrive at venue and told that I am allowed on tv beside Connie. The next stage may involve running and they are afraid to let Connie run. Pregnant ladies are not allowed to do a lot of things in China. Lucky I had the red shirt.
Next stage involved all the contestants in the losers lining up and waiting. Each team captain was given a remote button to press. There was a count down and being first to push a button allowed you to chose another robot to fight. The remaining teams then ask to challenge the robot that managed to push the button first by running onto one of 6 platforms on the stage. The first team would chose from these 6 teams who they wanted to fight. The production crew thought we would all think slowly and then walk to the platforms. But we all knew who we wanted to fight and everyone wanted to run to be the first to the stage. The back row of competitors had no chance to making it to the podiums and it was an unfair situation. After the first two selections they decided that it looked too bad for tv with all the pushing and shoving.
So they re-ran the setup, but this time just made us stick up our hands to ask to fight. Technically I didn’t need to help Connie as putting up your hand was safe for a pregnant lady, but they already filmed me for the introductions, so I was in. Or they forgot I was there.
We already found 6 easy robots and 6 difficult robots. We decided to not press the button and wait to see who the selected robot was. If it was easy, we would challenge, if it was hard, we would wait for the rumble. In hindsight this was a bad idea, but we had no idea how this format was going to work. Unfortunately all the easy robots got selected first. The walker, Barbie, Frog all got selected in the first 4 groups. BBQ, Hippo and several other strong robots were still in the selection group. Didn’t look good for the rumbles.
While the first 4 fights were happening we decided to press the button and found the robots we would select. Better to not wait for the rumble.
In the second round we tried to press the button but weren’t fast enough. However Snake and BBQ got selected and so were the robots I wanted to fight, Doctor, Silver Scorpion and ICEwave. We stuck our hands up, but no one wanted to fight us. We were going into the rumbles with the middle range robots.
They gave us the rumble list while we were watching the fights. We drew the girly vertical spinner, pink beater and a wedge lifter from the college team who were next to us in the pits. The two spinners did not seem reliable.
Connie spoke with the college team and the vertical spinner and found that they wanted to all attack the beater first. First the spinner would hit the beater and then the wedge would hold them while I came in with the axe. Sounded perfect as I could wait for the first 15 – 30 seconds and let the spinners kill themselves. But best not to make plans.
We were told that our fight would be the next morning and to go and get some sleep.
Depart for venue at 9:30. Not enough sleep.
Contemplate testing the robot. Not sure when the fight starts so decide I might not have time after the test to charge the batteries.
Called to line up for the fight at 10:15. I was the first to be ready, as usual. I was told that I could control the weapon while Connie drove the robot.
Our fight was up second. The first fight is delayed due to workers fixing the lighting inside the arena, and then delayed due to robots not powering up. I wish the other teams would do more testing.
Checking out other robots in the line up behind the stage. The vertical spinner was having weapon trouble and the wedge was still unknown. Decided the beater was dangerous and needed to be attacked. Couldn’t trust the other drivers.
Finally in the arena at 11:30. There is no audience, commentators, walk in introductions or interviews for our rumble. Feeling like it won’t even go to air.
Fight delayed as some directors still weren’t told that I could be near the arena or help control the robot. The communication skills of these people are terrible. The TV production directors wanted me to stand with Connie and help control the robot, and the KOB production directors wanted me away from the arena. I didn’t know what to do to make them happy. Eventually a TV director pushed me in the back toward the arena and yelled to start the fight.
Fight finally starts 10 days after the robot was first charged and ready. And after watching 58 out of 60 robots get their turn in the arena. A couple of the robots even had 3 fights before we had our chance.
Robot dead after 15 second. Only swung the axe twice. I moved cautously as I wasn’t sure how the other robots would behave. I could see the beater was really moving fast and seemed more dangerous than I remembered. I tried to have a swing at it. Clipped the beater on the first swing and got flipped. Self-righted fine. Went in for a second attack but the axe swung slowly. The base mounts on weapon motors had bent during all the testing. The extra stress during the fight caused the motor to bend forward and jammed the sprockets together and derail the chain. The axe stopped in mid-swing. The slow swing allowed the beater into the side of the robot, which hit the chassis just in front of the wheel. This is the only spot on the robot without 10mm plate. The chassis supports bent, which caused the first stage gear alignment to get ruined. I then lost a tyre when the robot came down from the hit and then got pushed into the arena drum spinner. Luckily after all these hits the robot landed the correct way up. With the axe jammed forward and the loss of the right wheel there was no weight on the left wheel and the robot was immobile. The beater robot got stuck in the arena saws a few second later and the vertical got flipped by the arena. The wedge won.
Went back to pits to pull apart robot and prepare for another fight, only to be told that there were no rumbles or exhibitions for the robots eliminated at this stage. 30 robots go home this day followed by a 3 day break.
Sad, angry and disappointed all at the same time.
Watched the celebrities chose their teams. Didn’t see the celebrities view our fights. I feel they never saw my robot.
Watched the American gold fish driver get really angry and destroy his radio with a hammer. But he got 2 fights, 1 win and a loss, which was more than we had.
Contemplate packing the robot, but too drained.
Started organising earlier plane tickets home.
Gave a set of the used drive batteries to the nice Chinese guy who owned Silver Scorpion. He seemed rather shocked that I would be that nice.
Lots of Chinese guys came for photos with me or Alice. We seemed popular and everyone says they wished they saw me fight.
Asked to reassemble the robot for a group photo. Impossible to replace the tyre in the 30 seconds I was given.
But still had to wait 30 minutes for the photo to be taken, so could have got the tyre on.
Couldn’t smile for the photo, held Alice in front of me instead.
Told we were needed for a meeting. As usual the directors hang around us, but seem to refuse to look at us and then walk away. No meeting.
Went back to the hotel and then out to dinner.
Couldn’t sleep. Worse than the previous night.
Woke at 3am to check the contract. We miss out on all the promised prize money.
Woke again at 8am, bus leaves at 12:30pm to take people for interviews. Connie won’t be interviewed. Decided to go pack the robot and tools and finish with the whole competition.
Arrive at venue. Most people are just the builders who are eliminated and packing equipment.
Only takes 30 minutes to put everything in the crate. Catch taxi back to the hotel.
Start drawing a new robot and go to dinner. Started drawing a double spinner since the celebrities only liked robots with spinners.
Find out it will cost $450 each to go home early. Cheaper to stay in China.
Rest day. Feeling better.
Go the aquarium with Connie, Alice and Leslie. Alice goes insane over seeing fish.
Head to shopping centre next to Aquarium. Alice has a 2 year-old melt down. Turns out Leslie is allergic to mango. Decide to go back to the hotel. Taxi driver got lost.
Find out Catherine got fired because we weren’t in the competition anymore. I feel really guilty.
Connie tries to find a way to visit her family in Hong Kong for a week. Discover Alice would need her birth certificate for a travel pass. Idea abandoned.
Be lazy in the morning.
Go into the city during the afternoon with Leslie and Catherine.
Visit the M&M and Lego shop. Alice goes insane again.
Nice dinner in a fancy hotel, but still cheap. As a thank you and apology to Catherine.
Visit the Bund at 8pm. Way too many people. Feels like the population of the Gold Coast in one place.
Go back to the hotel. Decide to go back to the competition tomorrow.
With the mechanical repairs done to the old Up Plus 2 I was given I can start on replacing the controller board. The old board had a faulty Y stepper motor driver and wasn’t compatible with the thermistor in my new hot end so I am fitting the printer with the controller from my old printer.
There are several guides on the internet about how to setup and commision a RAMPS 1.4 board in a new 3D printer and I don’t feel like writing my own so I will go over the basic steps here. If you need a more comprehensive guide I would suggest starting here.
Load the latest Marlin firmware onto the Arduino and load OctoPrint onto my laptop and verify that the two can connect to each other so I can use OctoPrint to control the printer.
Connect the endstops to the RAMPS and use the M119 Endstop Status command in the OctoPrint terminal to verify that the endstops work. The Z endstop was connected to the Upper Z Endstop port and the Z probe connected to the Lower Z Endstop.
Connect the motors (while powered off) and check motor direction is correct. I manually moved to carriages to their centers by hand and then jogged the motors 10mm using the OctoPrint controls to check the direction. Since the Z axis is belt driven and falls under its own weight if the motor is off I had to hold it in my hand before driving it. The directions were corrected in the Marlin firmware configuration.h file before reflashing the firmware and trying again.
Check the motors home correctly. This was done with the Ups original magnetically attached Z probe stuck onto the X carriage bracket. I had my hand on the power switch before triggering the home button so I could power off the machine if the motors started homing in the wrong direction. Only the Z axis was wrong and this was corrected in the configuration.h file.
Check each axis Steps/mm setting is correct by measuring starting distance of each axis’s carriage in relation to the printers fame and then using OctoPrint to move the axis 50mm and measuring the real world movement. I found that the Marlins default 80 steps/mm matched the X and Y perfectly and didn’t need adjusting so I set the Z axis to the same 80 steps/mm.
Added the dimensions of the bed into the firmware.
Set Z-probe pin to be the same as the Z endstop and measured and entered the Z probe offset from the nozzle. I also enabled Safe_Z_Homing at the center of the bed as the Z probe was not homing over the bed. Verified with G28 command.
Set Auto_Bed_leveling_Linear in the firmware using 3 points per axis.Verified with G29.
After running G28-G29 I used OctoPrint controls to move to the center of the bed and lowered the nozzle close enough to the bed surface so that a piece of paper could barely fit between the nozzle and the bed. Then I used M114 to read the current position and calculate the correct Z-Probe Z offset and updated the firmware. I like to keep the firmware up to date rather than using EEPROM commands as this means I have a backup of the configuration and if the controller blows up I can reflash a new controller and skip most of these steps.
Connect the extruder drive and verify the drives direction and feed rate with the hotend removed. The rate is checked by feeding a few cm of filament through the extruder and wrapping some tape around the filament where it exits the extruder. I then use OctoPrint to extrude 50mm and measure how much was really extruded using the tape as a reference. I then calculate the error as a percentage and adjust the steps/mm in the firmware by this error. I then repeat the test until the error is as low as possible.
I refitted the hotend and switched it on to check that it heats up. I no longer have an IR thermometer to verify if the thermistor table is correct as the kids wrecked it thinking it was a hammer so I have to presume that the reported temp is accurate. Next I ran M303 C5 E0 S200 to auto tune the PID values and updated them in the firmware.
I waited and watched the selections and fights
all day with not much to do.
Connie locked up inside the filming pits, but
allowed out during the later part of the day. She over heard the celebrities
say they are only wanting spinners.
All rounds of the selections were done. Connie
was not talked to by any of the celebrities until after they had filled their 3
spots. The American and Old Soccer Guy came to talk to ask her about Huntsman
and were surprised that she spoke perfect English, answered every question confidently
and mentioned that we’ve been competing for 16 years. Once they found out how
experienced we were they were disappointed that they didn’t talk to us earlier.
12 of the 48 robots didn’t get selected to fight
in the first round. Earth Mover was selected to join a team without having to
fight, so the remaining 11 become losers without fighting. Doesn’t seem fair.
We could have at least had a practice or demonstration fight.
Connie kept practicing driving. Got a lot better
and drove all around the pits. Started getting in other peoples way, but was
doing perfect flick-turns.
TV Production crew feeling sorry for us. Might
find a way for me to be more involved, including possibly controlling the
Finally got the robot back from the holding area after 3 days. Batteries fine. Tightened a weapon chain as it had be worrying me.
Finally allowed back to the hotel at 1am.
Day 9 Continued
Woke up at 10:30. Told we weren’t needed for the day as the winners and international teams would be fighting.
WeChat blew up about a bad judge call between ******* and *******. Seems that the judge is using his own rules and not the standard international set of rules. None of the teams seem to understand how he is coming to come conclusions. I wish I was there to watch.
Caught a taxi to a big shopping centre. Brought a red shirt that matched Connie’s just in case I was allowed to help her.
While organising dinner got a call that the international fights were finishing and that we were needed for rehearsal. Seems that they can do 12 international fights in the same time it takes to run 5 Chinese fights.
Caught taxi at 8:30pm for the venue. Catherine stayed at the hotel with Alice.
Found that 4 international teams lost. 8 won. But it seems that everyone wants decision on the ****** fight to be reversed.
While Connie had rehearsal Chinese teams started asking a lot of questions. They are getting less afraid of me. Silver Scorpion wants to build a copy of Shunt and is asking how to copy my axe mechanism, but it seems a bit is getting lost in translation.
Medusa is made by a team of students and teachers. They have also entered Thunder. We checked the calculations for the battery capacity of Medusa and found that the batteries are undersize for the weapon, which is why it dies toward the end of its fights. But the rest of the robot looks nice.
Connie came back with instructions of the next phase of the competition. Very confusing and involves running to be selected to fight, so they are letting me substitute for Connie as they are afraid of letting a pregnant woman run. They seem to be afraid of letting Connie do anything, which is why she was given fancy dust masks and an extra fancy chair in the pits. So I guess I can be her stunt man during filming.
I have had to pause work on my robots as I have not been able to get any reliable prints out of my old Prusa Mendel 3D printer. The frame of the printer had twisted again making auto bed leveling impossible while the extruder drive was failing. After moaning to my brother about the troubles he gave me a “new” printer. The “new” printer being an old Up Plus 2 that had previously been written off and stripped for parts.
The first thing I did when it arrived was pull all the covers off to see how bad it was. The mechanical faults seemed to be limited to a broken Y belt clamp and a destroyed hotend. The Y belt clamp had been broken when the printer was pushed against a wall while opperating and there may be an accompanying electrical fault that I can’t assess without first fixing the mechanical issues. So first I designed and printed a new belt clamp using the old printer. Fortunately it worked the first try.
Next I needed to replace the hotend. The only hotend I had available was the E3D V6 on my current printer. So I downloaded some drawings of the E3D V6 and measured the Ups hotend and extruder and made a new mount for the hotend. The trick was to try and get the nozzle of the new hotend to be in the same position as the original nozzle. Since the E3D hotend is much higher than the Up hotend the new mount needed to raise the extruder a fair way. This new mount was the last print ever done on the old Prusa Mendel as I pulled the hotend out after it was finished.
With the mechanicals sorted I could test the electronics. I downloaded the Up software and connected the printer to my laptop. The first problem came when homing the motors. The X and Z axis worked fine but the Y axis whould crash into the front after homing to the rear. It seemed that the Y stepper driver IC was damaged and was stepping a different distance when moving one way than the other. That was very strange but not worth looking into after finding out about the thermistor problem.
The E3D V6 comes with a very common 100k ohm thermistor. A 100k thermistor is used on just about all 3D printers everywhere, except for the Up. The Up uses a much more uncommon 100 ohm thermistor. The different thermistors require different pull up resistors on the control electronics for them to work. Because of this the Up software would report a hotend temperature of over 300 degrees and refuse to run. To fix this I would need to replace the pull up resistor and then work on the Y stepper driver fault. Or replace the control board with my own. So I pulled the RAMPS 1.4 board out of my old printer to replace the Ups damaged controller.
The next step was to completly re-wire the printer and setup the firmware from scratch.
Delayed at check-in by Connie’s passports. Chinese airline doesn’t understand Hong Kong passports.
Delayed at security by batteries. Got through without losing anything. Removed the labels from the weapon batteries to help convince the security that the batteries were undersized. It worked.
Flight at 10:10 am on China Southern from Brisbane to Guangzhou
Flight not too bad. Food was decent. Alice watched Spider-man 3 times.
Landed on time in Guangzhou
Flight to Shanghai delayed 40 mins, so extra transit time. Delayed by Connie’s passports again.
Lost weapon batteries at Guangzhou security. Taken because they had no labels. Plan to fool security in Brisbane back-fired. $400 worth of batteries gone.
2 hour flight from Guangzhou to Shanghai.
Met our assistants at the airport. Leslie and Catherine. They are interns for the Production Company and stay in the same hotel as us.
Got to the hotel at 10pm local time. 18 hours travel time.
Hotel wanted passports. Couldn’t understand Connie’s Hong Kong passport, again.
Went down to breakfast. No other western teams had arrived. Just a few Chinese teams that I remember seeing from the previous season.
Told the bus to leave for the venue left at 11:20, so we went for a walk around the local area while we waited. Was able to buy power-boards as even though China uses the same wall sockets as Australia, Australian plugs don’t have earth pins, the wall sockets locks them out.
Leslie took me on the bus to the venue. Connie stayed in the hotel with Alice and Catherine to try and organise phones and internet.
Bus ride was about 15 minutes. Venue looks like a disused stainless steel processing plant. Bloody huge. At least 1km long.
Arena and pits are in the corner of the factory. Disused conveyors and equipment outside the area.
Didn’t see the arena or filming area, could still hear construction.
The pits were still being set up. Only half the tables put out. Crates were scattered around the tables, making it hard to walk around.
Team Orby seem to have been there earlier as they already found their crate and claimed a table.
We were told to claim a table and that we couldn’t change once we selected it. I quickly found the crate and claimed the table next to it.
Robot and stuff was easy to get on the table. But wire mesh was welded across the table legs, so can’t store stuff under the table. Annoying.
Had lunch supplied by the event. I was the only westerner, so I was given a different meal. Three chicken wings and some green leaves. Everyone else had pork knuckles and other things. Their food looked nicer. This happened for the rest of the competition. I ate a lot of fried chicken.
Found that my spare drive batteries didn’t fit in the weapon battery bay. (I already knew and dreaded this). Leslie spent a few hours trying to buy new batteries online for me. Prince, the international team director, tried to ask the other teams if they could lend some batteries to me. Team Orby was the only team to respond, but they use longer batteries. Nice guy. Hobbyking won’t ship batteries to China from the Hong Kong warehouse. Aliexpress was useless. Leslie found a few batteries on Taobao, took a while to find ones that fit, were in stock, and were cheap. Then needed to figure out how to pay for them. Took about three hours to organise. Leslie was very helpful. Cost $200.
I walked around and looked at the other teams that were setting up. Orby is way too nice to go into combat. Only recognised one other robot, Mr Hippo. Next to my pit table is a robot that seems to be trying to copy Dead Metal, but also seems to be a first time builder, so really dodgy. Also next to us is a pneumatic flipper that looks like a block. Also 4 full body spinners, an ICEwave clone, 4 other flippers, 3 or 4 horizontal spinners and some drum and vertical spinners. Nothing really outstanding, but only half the robots had turned up so far.
Talked to Prince. Asked if I could take photos and got a big NO!! Also asked who the celebrities were, and he said it was still a secret, even to the builders. But he did say one was American. No idea why it was a secret.
We were asked if we wanted to test the robot as we were the only team not painting or building. But without batteries it was useless.
So caught the next bus back to the hotel. This time was a minibus with a lunatic for a driver. So only a 10 minute trip this time.
Connie was bored at the hotel, so we went for another walk. Found Maccas and a convenience store.
Organisers supply dinner, so we went back to the hotel to wait. Was another takeaway box. They must order a couple of hundred for each meal. We got the western menu again and Connie complained. So we got extra Chinese boxes too.
Americans started arriving during the night.
The batteries don’t arrive today, so we got told
to stay in the hotel. Boring day.
Met the Cat King guy during breakfast. Nice guy
Went for a walk again. Bought Chinese snacks and
tried Starbucks. Tried fish cheese.
Connie and Alice had long naps. I was bored and
started writing this.
Went out to find dinner rather than eat the
takeaway boxes. AU$3.5 noodles.
When we came back a bus full of English builders
Had breakfast and went to find stuff to wash clothes.
Batteries arrive before we left for the venue at 11:30.
Was told that we would be taking green screen photos of the robot at 12:40.
Connie had to get photos taken, but they decided that her makeup was not good enough, so they had to give her new makeup and take the photos again.
Finally got to take the green screen photos of the robot at 4:00. Process took 30 minutes. Had a good chat with Warrior and Steel Barbie. I doubt Steel Barbie guys built their robot.
Tested the robot. The axe got stuck in the wall in the arena corner. Suffered radio problems on the drive side. Power switch for weapon VESC fell out.
Fixed radio by moving the receiver. Removed VESC switch.
Weigh in. 97kg
Went back to the hotel at 8:30pm
Received late night message saying that I was not allowed in the filming area and that Connie had to drive the robot. WTF.
Told that the buses leave at 9:30am
Arrived at venue with not much to do.
Tested the robot with Connie driving. Didn’t go well. She had never driven any robots before and kept getting stuck against the walls and over correcting the steering. Typical first time driver.
Sat around doing nothing.
Argued with directors about me not being allowed to drive. Found another Chinese team that had an American guy and Chinese girl. The American guy was allowed to drive and be filmed. Was told that he was allowed different rules because they had planned a back story. We were told to stop complaining and go away.
Sat around sulking and doing nothing. 8 years of designing, 6 months of building and 3 unpaid weeks off work only to be told I would be disqualified if I went near the arena. Not happy.
At 7:30pm rehearsals started. I was told that only Connie was allowed to be involved and I couldn’t watch.
Alice needed to pee. Couldn’t find a toilet with a light fast enough, she wet her pants. I cleaned her up. 15 minutes later she wanted more pee. Still couldn’t find a toilet, Alice wet herself and me. Had to catch a taxi back to the hotel to have a shower.
Connie still at rehearsals.
Not a good day.
Bus left at 9am. Filming starts today.
Directors mentioned that there was a special children’s toilet at the other end of the building. Would have been nice if they told me yesterday.
Bolted up the robot and had it ready for a fight and moved it to the filming pits.
Connie got makeup and told that she needed black jeans, as that was what was in her photo. I was sent back to the hotel to collect black pants for Connie.
Lots of waiting until 5pm when filming finally started.
Began with an exhibition fight between Shredderator and Xiake, to show the celebrities what fighting robots is. Shredderator won easily.
Team selection process for the Chinese robots. All 48 robots placed on display and each celebrity had to pick one. The selected robot would then fight each other in 1 vs 1 fights. The winner would gain a place on the celebrities team, the loser would move to the “pending group”. Each celebrity had a maximum of 3 places on their teams. Connie missed out on the first round, no celebrities wanted to talk to her.
Next two fights between the chosen robots took an hour each. Lots of repeated walk in’s and poses.
Third fight was to contain 2BBQ and Xiake, but the driver wanted more time to prepare his second robot after the damage sustained in the demo fight.
Second round of selections took a long time to start. Connie still not selected and no conversations. No time for any more fights.
Back to hotel at 12am.
Told to catch the bus at 8am. Connie got the bus, I waited with Alice and caught a taxi with Leslie.
Got some breakfast on the way.
Connie and other team captains had to do a little bit of filming for the show intro. They were locked up most of the day.
I did nothing but wait all day.
Tried to find a practice robot to buy on the internet. Nothing suitable.
The fights from the previous night’s selections were run first. Started about 1pm, once the celebrities arrived.
Found a beetle-weight robot from the white tiger team for Connie to practice with. Had to make some modifications to get it to work as one wheel was broken and the speedos had no BEC. Set up the weight distribution so that it drove like Huntsman.
Third round of selections. No-one talked to Connie. Started to realise that there were too many robot and not enough slots on the teams.
Watched the footy scores on Connie’s phone. Suns lost by 1.
Connie started practicing with the beetle.
Final fights run and the missing fight from the previous day.
Getting worried that the robot has been sitting in the set, loaded with batteries and ready to fight, for 36 hours, but I’m not allowed to check that it is fine.
The day finished at 9pm.
Connie drove the beetle in the hotel. Starting to get the hang of driving. Feel like I might be fine with letting her drive if we get selected.