3D Printer Blog resurrection proper!

Ok, I have not posted on this blog for around 10 months as I have been busy with my electric car conversion build (See previous post) but I am now tasked with building a Mendel90 derivative for a good friend who wants to get into 3D printing.

So this blog will now be getting more than a few posts over the next couple of months as I am going to use it to track the progress of this build.

We have already decided that it will be a Mendel 90 with a build volume of 400mm cubed.
Seeing as I have been out of the 3D printer RepRap community for a while and I have never attempted a build of a Mendel 90, I initially had some difficulties getting the OpenScad to build on my PC, after trying on my work PC then my home PC, I finally got it to work on my Home laptop, so now at least I am able to build the source files and potentially customize the Mendel 90 to our preferred specifications.

So it won’t be long before I am printing parts for it, Have not started buying bits for it proper yet I am still working out the best way forward but I am actually really looking forward to building it now.
Also now my EV battery charger build is finished in terms of soldering and such my bench is clear to begin the next project i.e. the next 3D printer.
Looks like I will be pushing the envelope with the size of this beast as well but it should be simple compared to the charger and I have high expectations for it, I will be using 10mm induction hardened smooth rods for the axis as I used 8mm induction hardened smooth rods for mine and they have not a mark on them compared to the z axis (where I did not) and these have score marks from the bearings on them already!

So induction hardened rods are definitely the way to go, I will also be using the J-head hot-end as this seems to be the defacto standard these days.
I may use the sanguinololu electronics set as I have some experience here and there is a lot of support for this set (Firmware etc)
I hope to do the chassis in 3-5mm Ali (as we have some already) and this should give it some serious strength when we start pumping up the print speed.
Will probably fit a quick change x carriage as we will probably want to print extra heads (Bowden style possibly) and this even gives the possibility of multiple print heads, (I am not 100% on the sanguinololu yet as this may limit a triple head upgrade which I definitely want on mine)
I will investigate triple heads again as last time I looked this was still in development, people have done it but there was no definite upgrade path that had been settled on when I last looked (that was a year ago now however and I am sure things have moved on now) Update:- surprisingly there does not seem to have been much development of triple head/extruders over the last year, so I will probably leave this for a future upgrade for now and concentrate on the build.
Triple head give the possibility of 3 colours simultaneously or even 3 types of feed thermoplastic, this would definitely be an additional upgrade (to come later) as triple head hotends are not available off the shelf as yet, but we could cobble together 3 single hotends currently this require 3 motors/drivers etc and pushes the cost up considerably.
This was one reason I wanted a milling CNC machine so I could make my own custom hotends out of brass etc when I am going to find the time however is anyone guess, but hey I have no form of social life so I am sure I can squeeze it in somewhere, anyway as I said I want triple head printing myself so it is definitely on the cards.
In fact I may well build two of these Large Mendel 90’s at the same time 1 for my friend (Steve) and one for me.
Watch this space for rapid updates as the build progresses.

Long time no post!

As I have been very busy with my other pet project, an Electric Vehicle conversion
http://electrobeatev.blogspot.co.uk/
The 3D printer blog has been neglected somewhat.
However as you can see on that blog I am now using it proper to develop and print my own parts for my Electric car conversion.
(well at least the charger side of it anyhow as this is the only part I am really getting my hands dirty on until we get to the wiring stage, any day now)
So the printer itself is getting used and for exactly what I built it for too, a lot of 3D printer builders/users are only interested in 3D printing for “3D printing’s” sake, and therefore you see a lot of trashy plastic crap being uploaded to thingiverse all the time, however that is not to say that there aren’t a lot of great thing designers out there and lots of them do post on thingiverse it is just a shame that they get lost in the background noise of plastic crap that swamps this great site.
Still that is the way of the web I guess 75% crap 25% diamonds! Moan over.
One diamond I found recently was the “J1772 inlet by erroneus” obviously only relevant to Electric car builders but if you are building an EV and search eBay for a j1772 charge socket they cost around £100, and a J1772 – J1772 cable is around £270!
This is just legalized extortion and is exactly why 3D printers are so cool.
Erroneus covers his arse (and fairly enough!) by stating that “I don't think it is a good idea to actually charge a car with this printed connector” but after speaking with an EV expert/friend Steve (7 years+ experience) he and I both agree that if this was printed in 100% ABS at high quality and correctly fitted with bullet plug contacts of the correct type for the J1772 standard that there is no reason why this socket would not be perfectly capable of charging an Electric Car.
In fact I am going to test this theory as I am just completing an open source 12-15KW battery charger from “EmotorWerks” and will be charging my 10KW Lithium polymer pack with it shortly.
Once I have proven the charger works properly I am going to try charging it through one of these connector sockets.
However I will need to convince Erroneus to model me up an J1772 plug as well or find someone who is a lot better at CAD than I am ;-)

Printing parts for friends

As my printer has remained idle for a while now whilst I am concentrating on my other projects (EV build & House build) I was asked by a friend at work who is building a Quadra Copter for an Arduino UNO mount plate I printed this one http://www.thingiverse.com/thing:33327 on his first request but as it turned out this one was going to be fiddly to mount due to the placing of the mount points, so he found  another http://www.thingiverse.com/thing:45053 This one suited the Quadra Copter frame much better and only requires 4 holes to be drilled into his Ali copter center plate.
My friend (Kyle) wanted to pay me for the plastic used but once I had calculated the cost it came in at around 20 pence (GBP) so I told him not to bother with any cash unless he wanted a whole copter frame (hint hint) which I am sure he will once he has trashed the new one he has just bought (he is on his second frame already and I haven’t even seen it fly yet), still it is a pretty impressive beast (Photo’s coming soon) he is currently reworking it to be controlled from a PS3 Bluetooth controller (nice one Kyle)
Photos coming soon.

PCB Milling Part 1

I tested my PCB milling capability the other day by pulling apart one of the kids felt tip pens and putting just the felt nib into the chuck of the drill on the Darwin.

Ran up the “old” Darwin software and setup the Z axis so that the bed was fully up (normally fully down for plastic printing) even then I had to put an extra block of wood on the deck to get the felt nib to touch the A4 sheet of paper that I had taped to the block of wood.

Loaded an example PCB layout and printed it using Pronterface after a little fiddling with the profile setup for Milling.

It worked surprisingly well other than my Z axis did not appear to move at all in fact I could hear the stepper stalling when it was supposed to be lifting the drill up and moving to the next mill point.

I remember that I had these sorts of problems with the Z-axis before when I was trying to print plastic and I solved it by setting the “Limit” to 1mm I tried this on the new milling profile but alas it did not work, this got me to thinking that there is no reason not to upgrade the firmware on my old G3 set now as if I am not printing plastic then I won’t need the extruder at all and this was the key reason I could not upgrade to marlin firmware before, because it does not support RS485 driven Darwin style extruders at all, if I want to print plastic using this G3 set I will have to bodge a G3+ adapter together so that I can drive the additional extruder stepper directly from the motherboard.

As yet I have not tried this I will attempt to change the firmware to Marlin and see if this cures the Z axis stalling problem without the need to use limit  function in SFACT.

If all goes well I may be milling PCB’s sooner rather than later, although I have read online that Darwins are not stable enough to do any sort of milling, I am still going to try and set it up for just PCB milling, if it does not work at all it may well sound the death-knell for the Darwin.

Multiple extruders required!

I have been investigating the best electronics/firmware combo for multiple extruders, I really need 3 extruders minimum to do the experiments that I am interested in, on closer examination of the electronics comparison table

http://reprap.org/wiki/Comparison_of_Electronics

it looks like we have a new contender that is for the first time quoting that it supports 3 extruders! Phoenix

Great, so off I went to join the TVRRUG (Thames Valley Rep Rap User Group) so that I could post on their forum and investigate how true these claims are.

I have the feeling that although the cool looking electronics set they have developed may well support 3 extruders in principle, unless they have already recoded the Marlin firmware then it is unlikely to directly support the additional (3^rd) extruder (I think Marlin supports 2 natively although I am not sure on this)

Anyway I had a very nice response from one of their moderators asking why I was interested in their group considering my (relatively distant) location, after explaining my reasons for interest in their electronics set I am now awaiting final confirmation of my account so that I can get posting on their forum.

A fair few electronics sets can support 2 extruders but not since the old days of using the RepRap Host (remember that!) did the host program natively support multiple (more than 2) extruder configurations, I really also need to experiment with some different software configurations rather than just staying safely where everything just works (i.e. with Pronterface and SFACT)

Maybe I could use RepRap Host now I have the firmware issues sorted (i.e. I am using Sanguinololu with Marlin FW) although I think development of this software set stopped some time ago.

There are several other configurations of electronics and software that I need to investigate, I noticed recently that there is a new PRO electronics set available (not cheaply though) R2C2 electronics this set although not cheap can print at extremely high speeds.

And I need to play with a Ramps set as this seems to be extremely popular and is quoted as being feature rich, I also think I could mill the boards for this set.

I have been asked to build a couple of 3D printers for a friend so I may get a chance to investigate more on this front depending on which electronics sets they choose.

The Pheonix Set has some great build instructions on their website also which should aid the construction process significantly.

Darwin Upgrades Part 2

OK, seeing as most of my cash is being eaten up by the new EV project and I can’t stretch to get a stepper motor for the Darwin so that it could print plastic once again, and seeing as I already have the Prusa printing plastic, I thought I would use this as an opportunity to try my hand at designing a part from scratch (1^st time ever).
I used Open SCAD to design a part that fits the Quick fit X carriage that will secure a mini chuck drill to the Darwin so that I can mill PCB’s.
Picture of part
My first Open SCAD designed from scratch part comes of the printer!
I am seriously impressed with this, not the part that's just a very basic part to fit the quick fit x carriage and dock a basic chuck mini drill (dremel style) to my Darwin printer.
But I am seriously impressed by just how quickly you can go from a need to an idea to a CAD design to a physical part in your hand, a matter of a few hours (this will get shorter as I get better at CAD).
The part I designed and printed mates a basic mini drill to the Darwin, I have been investigating the tool chain for taking a PCB layout say in Eagle and using PCB-GCode plugin to produce a G-Code file for sending to the printer (using yet more 3^rd party software) this should allow the direct milling of PCB’s on the now unused Darwin.
I hope to be milling a Gen7 electronics set and a Hot Bed (both on thingiverse) I even found a gen7 set that uses discrete alternatives to pololu stepper drivers. http://cnc.maket-city.ru/index.php/cnc/gen7tm

Rostock build

I have begun printing the parts for a Rostock printer, I tried printing the rods in both PLA and ABS to see if either were suitable, ABS warped horribly and the rod turned out more like a banana, the PLA one did come out straight once cooled but was far too flexible in my opinion to be useful, so I will probably take the alternative option for the rods and use a stiff rod of some sort and just print the ends and glue them on, I have a long length of glass fiber rod (in the days before carbon fiber this was the best stiffest rod you could get)  if I can find it I will use this for the rods.