BfB Logo Challenge
Hi Folks,
It's the school holidays and I don't have access to the school's Rapman at the moment :'( so I've been getting a bit bored!!
I came across a site with stl files for rapid protoyping machines (sorry can't remember which one) and found a file for an object very much like the BfB logo. I've edited it a bit to change its orientation and converted it into an ascii format as the original was binary. (see attached)
It's very unlikely to be able to be printed without support, and I know that it's all a bit experimental at the moment. So here's the challenge..... who can print this object!!!!... Sorry no prizes (unless BfB want to offer something???) just the good feeling that you would get if you post a picture of a successful print :)
Dave
First of all apologies I had uploaded the stl file that was scaled in inches rather than mm (oops). I have removed the original stl file and replaced it in this message with a new one where the object is approx 80mm in diameter.
Mr Seeker....As for the overhangs... Yep, that's why the "challenge".... I've tried printing a couple of my student's designs that have failed due to overhangs (it seems that Rapman can cope with approx 45 degrees in my limited experience). I have noticed that some people have been experimenting with support materials and so I was wondering how other people get on with this.
So the challenge still stands..... (still haven't heard if the boys from BfB will be willing to put up some incentive/prize)
Dave
PS see new attachement for stl file (please feel free to rescale, modify, etc if necessary)
| Attachment | Size |
|---|---|
| bfblogo80mm.stl | 991.06 KB |
is glueing allowed? :)
Aha, I wondered how long it would be until someone wanted to bend the rules. :o
errr, What rules??? ;)
I suppose "anything goes" at the moment as long as it's documented as to how you have cheated oops I mean managed to overcome the difficulties. But it would be fantastic if someone manages to produce it in a single part/print.
Dave
Just tidying up my computer and found in my IE8 History the page where I got the original file for this challenge from. I thought it would be a good idea to acknowledge the guy that created the shape. The original designer was none other than Leonardo da Vinci (I don't suppose he would be too bothered if I didn't acknowledge him) and the person who did the stl file is George Hart. He's really into polyhedra... it's worth seeing his website http://www.georgehart.com/virtual-polyhedra/leonardo.html.
He also seems to be into Rapid prototyping using commercial machines. There are some very impressive polyhedra on this page http://www.georgehart.com/rp/rp.html unfortunately I think most of these are beyond the capabilities of RapMan.....at the moment.
... but if you fancy a go then the stl files are available for download.
Dave.
PS.... anyone made any progress yet?
the default support that skeinforge generates for this object is massive ... I gave it a go and stopped a print after ~10 layers .. it was just a big solid chunk of plastic...
Hi Bogdan,
Thought that you wouldn't be able to resist giving it a go :)
When generating the support did you use skeinforge settings to print support "everywhere" or just "external" ? would adjusting the support minimum angle help? .... and any idea what the support cross hatch setting does in "raft" (this does not appear to be documented)? was wondering if it does anything like "infill pattern" in fill.
would it be feasible if scaled down further? (assuming you used the 80mm version).
Dave
PS. Iain now knows about the challenge and will discuss it with Ian.... so watch this space ;)
I used the original file (the bigger one) ... and default skeinforge settings (support everywhere) just to see what will happen ... and the result was, as expected, terrible :D .... must finish some chores today so no time to test it, but I believe I will make another attempt tomorrow with tweaked settings :D and maybe with some alterations to the g-code of my own
the cross hatch I knew what that is but - forgot :( ..
..... Just ran skeinforge with and without the cross hatch to see what happens and if it might be useful. From what i can see in the skeinforge viewer all that it does is make each layer of the support material print at right angles to each other.
Yes the support material does look very dense.... I wonder if Enrique has ever thought of doing support material in a hexagon/honeycomb like one of the options in fill? might be worth posting a question.
Dave
I tried it too, but I think to make this, you need a ZCorp. Its impossible to do it with a reprap. I checked it, but was only getting problems.
mr-seeker, I did say it would be a "challenge". Thanks for trying. What sort of problems did you have? perhaps others silly oops, brave enough to try might be able to learn from you.
"It always seems impossible until its done".
Nelson Mandela
Dave
Yes happy to put up a prize, just trying to think what! It is quite a challenge, lets say £100.00 voucher worth of stuff from BfB. But only one rule maximum 1 glue line.
P.S what do I get if I do it first ;D (of course what we all get a better RapMan :))
Ian, I know why you made that rule ;)
[move][glow=red,2,300]Fantastic News!!!![/glow][/move]
A huge thank you to Ian and Iain, as you will see above they have put up a £100 prize!... cool!
Putting that in perspective that's a couple of rolls of polymer, or a new extruder kit or (with a cash top up) another electronics kit!!!
The stakes have just got serious!!!!
Just to clarify the challenge then. The prize goes to the person who prints the most successful BfB logo (3D) based on the supplied stl file. (Ian and Iain have the final say in this and no correspondance will be entered into).
To be considered for the prize you need to post a photograph of your efforts into this discussion together with the stl file (if you have modified it) AND your G-Code file.
RapMan machines only.
Don't forget... Only one glue line permitted.
No "Closing Date" as yet... just the first person to make a successful print in the judges opinion.
So, lets go for it and get printing :)
Dave
PS. In the spirit of the open source nature of RapMan and RepRap please share your experiences with photos and comments on this forum.... that way this challenge also becomes a learning experience and maybe helps in the development of RapMan
| Attachment | Size |
|---|---|
| bfblogo80mm.stl | 991.06 KB |
What I found as problem is the overhang... If I try to print a 50mm high ball, the overhang is so great that it doesnt work...
It would not be a challenge if it was easy, and I can testament that it is not easy :(
Overhangs can be worked around but the actual features are on the thin side and break even mid printing...
Having seen springwald's success at printing with support http://www.bitsfrombytes.com/fora/user/index.php?topic=199.msg1238#msg1238 I'm suprised no one has regained an interest in the BfB logo challenge ;)
Dave
Don't forget BfB's kind offer of a prize :)
The major problem is that you have to print with "support everywhere" and this is bit heavy with the current version of skeinforge (bit too slow, too much filament go out ...) and the support is impossible to remove as it is inside the object but visible.
The original object also have too thin sides that just cannot hold on....
The "one glue line" rule is not that bad, one can print 2 half's of the object and then glue them together, this will allow you to remove the support from the inside, but the "thin sides" are still a problem so I personally wait for a day off so I can design a new object with slightly stronger sides so they can be printed ...
Yes I tried too with support. Hell of a lot of support is generated and it is very hard to remove from this object because the actual features are way too thin. I had some of them fail mid printing, the rest broke while trying to remove some of the support. My best bet would be at hand modeled supports. To improve things I tried only half of the model printed like a dome.
So yes, its a tough challenge and I will try again somewhere in the future but not now.
Bogdan & Unfold,
Good comments/ideas chaps, and glad to hear that the problem is still niggling away at the back of your brains :)
Some other thoughts/comments.... Yes, perhaps designing support as part of the object and not relying on the skeinforge support options may produce a result... sounds like a good plan!
As the struts that make up the design are very slender it may be acceptable to 1. scale the design so that they are reletively thicker or 2. to tweak the design (re-draw it?) so that the overall size is the same but the struts are thicker....or maybe both? I think that as long as the final print stays within the spirit of "fair competition" and that any redesign does not deviate too far from the original stl file then the judges (Ian and Iain) might be able to be convinced.... but their decision is final!
... and building in 2 halves sounds good (so that it has a flat base and internal support can be removed).... nice!
And to anyone else out there with a BfB machine and fancies a crack at the challenge... read through this discussion and maybe give it a go... £100 voucher for BfB parts/materials is still up for grabs!!!... so Good Luck.
Dave
How should it look :-)
I don't want to lie, it's printed on Dimension uPrint :-) I've managed the local reseller to print it as benchmark object :-) I'm going to visit them in few weeks and reverse engineer some of their technologies, muhaha :-D
Go prusajr 8)
Great to see the BfB logo in 3D (even if it is made on a "non-rapman" machine). :o
Unfortunately it doesn't qualify for the prize , so the competition remains open :D
The way things are going and the developments that are happening at BfB and elsewhere it wouldn't surprise me if someone cracks this soon (maybe Netfabb will provide an answer??)
Anyway, thanks for showing the renewed interest.... and to everyone else out there in RapMan Land, THE CHALLENGE STILL STANDS.
Dave
Does it count if I mill it out of a block of wood using a RepMan? ;)
I can do that even without support-material in Skeinforge already. ;)
Not certain on that one????
Drop an e-mail to Ian at BfB to check the "rules".... when the challenge was set milling was very much a "one day in the future" thought. But having done all the development work on milling that you have documented on the forum BfB might consider it "legal" even if the challenge at the time was to "PRINT" with a maximum of one glue line.
even milling it's still probably quite difficult, i can't visualise how you would hollow the shape out. would be interested to see your attempts whether Ian decides if it is "legal" or not.
Good luck
dave
hehe I've never thought that I can win with it :-) It was just for fun :-) Working on dual extruder right now, unfortuantely for mendel which is way moore hackable :-) So we'll se it rpinted soonish :-P
Hi all,
i don't know if the challange is still "valid", but i managed to print the Bfb Logo! :-) However, i had to make use of the "one glue line" rule, which Ian defined earlier in this thread.
I used:
- Netfabb Studio Basic for RapMan[/*:m]
- PLA natural[/*:m]
- Cutter, for to cleaning the prints[/*:m]
- superglue[/*:m]
- Digital camera[/*:m]
Print settings in Netfabb:
- Quality: Medium[/*:m]
- Raft: Standard for first halve[/*:m]
- Temperatures: 200°C raft; 220°C object[/*:m]
- Cooling: yes[/*:m]
My approach:
First i used Netfabb to cut the logo into two halves. I didn't rescale anything so i generated the g-code files within netfabb
Then i started printing the first piece with a raft, which was really not neccessary and i had a lot of trouble removing the whole thing from my bed (now i have some craters in it from the pillars). The second halve was printed without raft. The whole printing process took about 1h for each halve. After a lot of cleaning (the inside of the halves contained a lot of fine strings - looked like candy floss) i glued the halves together. Finished!
On the pictures you see the cleaned halves. The other pictures show the glued logo from different angles. The glue is only recognized if someone takes a closer look.
A couple of days later my brother dropped it while playing with it and two vertical bars broke - but i managed to glue them back in place (Luckily this accident happened after i took the pictures)
Regards
Nordom
Very cool! Congratulations.
Congratulations!
That means you took the prize, nordom :) ... enjoy it, your deserve it ;)
Congrats, great print :)
Well done - looks like a good print as well.
My PLA has just arrived so hopefully I will be playing this weekend.
I can try, but I am sure there will be some overhangs.
Also changed the scale to fit in my reprap.
Will try.