Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Update: The high-temp extruder is installed on the Wanhou and the first PC-Max print is half done. After following the Polymaker instructions to the letter, the print stuck to the bed perfectly and what I can see of the surface finish looks as good or better than what I expect with PLA.
I am really not a fan of rafts, so th next print will go straight on the bed - as long as it has plenty of contact area, I think it will stick just fine. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sun Mar 19, 2017 2:12 pm
evil_steve
Joined: 06 Sep 2015
Posts: 304
Location: Adelaide, SA
Awesome, can't wait to see the result! My printer is actually having the print bed repaired under warranty at the moment as it stopped heating up at all - once I get it back I'll try the polycarbonate again. PC Plus is supposed to print on the Robox without buildtak using a hotter bed.
Sun Mar 19, 2017 3:35 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Now that the part is finished, I can see it warped slightly at the base - probably due to the 100% in-fill. The raft stuck to the Buildtak quite well but not as much as PLA, which almost needs to be hammered off! The next time I will try using a smaller separation distance between the raft and the part to see if the warping can be tamed. I used the middle of the range printing temp, so upping that a bit might help bed adhesion.
The Polymaker instructions mention that parts can be annealed for an hour at 100 C to 'remove stress and strengthen the part' so maybe that is a possible bed temperature - if the filament sticks, perhaps it will stay too hot to warp. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sun Mar 19, 2017 4:25 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Warping fixed:
I turned the bed up to 100C and reduced the recommended gap between the raft & part down from 0.4mm to 0.2mm - the raft sticks to the Buildtak almost better than the Buildtak sticks to the platform and the part now has almost zero warp. Its still there but you need a ruler to detect it . Next time I will try 90 C for the bed to preserve the Buildtak - that stuff doesn't grow on trees, y'know. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sun Mar 19, 2017 9:06 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Printed wheels:
The first test of Ninjaflex wheels is looking plausible - not perfect but worth more testing. With a 15mm thick by 32mm wide test block, there is a reasonable amount of deflection under Mr Mangle's wheel:
The pad has five surface layers and a 25% infill and there is some extra weight on the bot to simulate the metal frame and missing parts. For the next test I will do a lower in-fill and a thicker pad so see if I can get a little more deflection. The main problem with this idea is that Ninjaflex has a shore hardness of 90A and is not particularly grippy. The solution could be to paint the wheel in a softer urethane to give it more grip. The other problem is the low printing speed; just the small test pad took four hours and a full wheel is predicted to take over 20 hours.
CNC enclosure:
I got back to work on the enclosure and the final four sections are welded in:
Now the hard part, standing the frame up. If its holds off raining tomorrow, I will get a bunch of timber and start cutting out the roof beams before hooking up the chain hoist and attempting to get the frame upright. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Mon Mar 20, 2017 6:18 pm
miles&Jules Experienced Roboteer
Joined: 19 May 2010
Posts: 3973
Location: ipswich QLD
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
At the moment it effectively takes up a third of the workshop and its a real PITA to get around it! Once it is standing up and pushed against a wall, it will be much more reasonable. It was surprisingly easy to weld it all together but now I'm wondering if would have been easier to weld the frame in the vertical position - standing the frame up is going to be a nightmare! _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Tue Mar 21, 2017 7:31 am
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Robot Wars:
Mr Mangle (or any other Featherweights) won't be going to RW this year - after all the work put in to the upgrade, the feather division was cancelled. I am really gutted but things have to move on; there may be a Robochallenge Championship in late August as part on the Insomnia 61 gaming event. Robot gods; if you are listening, please make that happen!
Wheels:
I decided to skip small scale testing and print a complete wheel:
It was printed at a slightly higher speed (15mm / sec) than the other test parts and that was a huge mistake:
The wheel has major stringing and bonding problems, making it noticeably weaker. The next version is printing at 8mm / sec and looks perfect - but its taking 26 hours
. The dodgy print will still be fine for fitting a hub and glue adhesion tests. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Thu Mar 23, 2017 2:24 pm
Cpnwolfe
Joined: 29 May 2012
Posts: 454
Location: Rockhampton/qld
26hrs holy but hey still cheaper the RMP! _________________ Creative Instigation - Build Something Awesome!
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
They are very light as well as they are mostly air. The first attempt only weighs 48 grams. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Thu Mar 23, 2017 6:01 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
CNC Enclosure
What trickery is this - is it witchcraft or a multi-axis attachment for the enclosure?
The temporary wheels allowed the enclosure to be centred under a roof beam and helped save the floor from scratches while it was being lifted.
The chain hoist made lifting the enclosure easy, except I had to stand inside the metalwork to use it.
And the enclosure is finally standing up :
There is still a heap of work to do: finish the welds that couldn't be reached before, sand and paint the frame, add the plywood skin, the list seems endless. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Fri Mar 24, 2017 12:17 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
Looking good man _________________ Mechanical engineers build weapons, civil engineers build targets
Fri Mar 24, 2017 1:13 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Not looking so good:
The print came out perfect, the Buildtak sheet, not so much - it was only a week old too _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Fri Mar 24, 2017 3:14 pm
Ellis
Joined: 21 Jul 2012
Posts: 129
Location: Shopshire, England
That's a bit crap! Might be able to get some compensation from the company? _________________ Online store - www.ranglebox.com
Pulsar and friends.
Sat Mar 25, 2017 12:06 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Not likely - the Buildtak was a freebie with a roll of Polymaker filament. I have a spare sheet but they are a HUGE pain in the ass to peel off - which just shows how well Ninjaflex sticks to the bed! I can try changing the settings for the first layer to make it stick less - maybe more speed or less extrusion. There is enough space left on the bed to get it right before I replace it with a new sheet. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
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