[IDEA: Quad Extruder possible? Yes, with a new Design...]

Daid is quite right, with retraction it would have loads of backlash. Also these drives are high speed low torque,

to get any sort of rigidity you need a large cable...then its huge mass anyway.

If you want to do this I would use a sliding spline driveshaft from an Radio Control Car. You can get

really nice carbon filled plastic components for those things. Super light.

Something a bit like this, which is from a Tayma RC truck...1/14 scale.

http://i1233.photobucket.com/albums/ff3 ... MG1721.jpg

Could work, question is by the time you add all that stuff on...will it be light !

[IDEA: Quad Extruder possible? Yes, with a new Design...]

Sorry but to be honest I have absolutely no idea what you mean. A flexible shaft pretty much IS a PTFE tube !

I think you need to upload a sketch, or rephrase your text.

C.

[Throw away your short belts - direct drive.]

Mmm well it wasnt expensive at all to be honest. Here is pretty much what I paid.

Flexible couplers 5Euro each (I bought a whole load because I liked them so much)

8mmm h6 shafts 6Euro each

COUPLERS>

http://www.ebay.co.uk/itm/130707094693? ... 388wt_1139

500mm shafts, cut down to APPROX 370mm>

http://www.conrad.de/ce/de/product/2372 ... Detail=005

I spent alot because I bought quite a few couplers, and also bought some shafts which sucked and then had

to re-order etc.

so all in..

I suppose 40 euros for both axis by the time you pay tax+delivery.

Well worth it I think. I just did the X axis tonight (pics taken on 1st print ! after ditching the X belt!) so will try

another print later this weekend after both axis are done. I am anticipating a noticable improvement in

layer alignment as well as the possibility to increase speeds in future.

I wont send you the STL of the bracket because its rubbish, I need to modify it so it prints with no support.

Once I do a rev 2 bracket tomorrow morning I will happily email anyone the STL. The bracket uses just two

of the standard holes. So no frame mods required !

I was expecting the couplers to be a bit rubbish (from China etc), but for this application they are more than

adequate. If I was building a machine for Siemens or somthing ok I would be paying 100euro a coupler...but Im not..

and these are perfectly functional for these loads and speeds. It did take 4 weeks for the couplers to arrive though...which was maddening.

C.

[Throw away your short belts - direct drive.]

Hi,

Although the standard motor position is simple, easy, compact and visually neat....from a strictly performance

perspective it leaves alot to be desired.

So I thought....why have short belts between stepper and shaft...why not put the motor...ON the shaft.

Thus eliminating both short belts, two pulleys, and the compounded positional error of two rubber belts in

series.

So it just uses 2x flexible shaft couplers (5mm/8mm, with nice clamping bolts instead of horrid grub screws...YUK !)

I use one of the standard motor wooden spacers as a thermal barrier to the PLA motor bracket. The PLA mount made in thickness exactly so that an M3x16mm bolt with a washer is the perfect length to get complete thread engagement into the motor case (standard is 2 threads.....very very bad).

The shaft is 8mm (h6 tolerance) silver steel, bought in 500mm length and chopped down. Needs to be a bit longer

than the standard ones.

I dont realy have any comparative data on accuracy, but I sleep much better knowing that the two short belts are in the bin.

Further data available to interested parties.

Calum Douglas

[Ultimaker reliability/consistency]

I would say that if you are used to dealing with commercial RPT machines, an ultimaker kit is probably not going to be the thing for you.

There are all kinds of little issues to go through:

1) The standard machine "works", in the same way that getting to the bottom of the stairs by falling works.

If you want it to be reliable you will need to replace the extruder with the Bertho system, and fit proper cooling

to the steppers, probably fit forced cooling to the printhead (personally I think its a good idea regardless of which printhead you have), fit belt tensioners that work and so on. It took me 1 month of evenings after I bought mine to get it really running smoothly (and I am a professional mechanical engineer).

2) None of the currently available software packages will do everything you want. CURA cannot handle big STL files

(well not for me!), unless you want to make cookie cutters Skinforge takes far too long to slice, NetFabb doesnt

have retraction working....and so on.

I bought an Ultimaker 3D printer to learn about 3D printing (and also to make prototypes at home).

So I would say that if you are interested to learn a bit, and fit some upgrades youself, and to be happy to

spend a while messing around with software settings...then you can be very happy with an Ultimaker.

If you want something that works out the box, has full software support and is supplied with everything configured

to print properly....you either need a commercial printer or a different kit. I do not know what the standard

of the MAKERBOT machine is so cannot comment on it.

Regards

[maximum stl filesize in Mb]

Yes this has also been a problem for me with CURA, and is why I had to switch to NetFabb in the end. I have

very large complex shapes and when loaded into CURA it shows you the shape for about 1 second then

the display goes to garbage and shows a load of distorted triangle shapes, trying to slice results in a crash.

The same models load straight into NetFabb with no problem at all.

So CURA is, as far as I can see - not currently a great choice for dealing with large complex STLs. Perhaps there will

be some progress on that soon with Ultimaker announcing that its going to shift to CURA officially....

[Cura calibration do not work]

Check the switch with a multi-meter, also I took about 5 attempts to get CURA to "see" the switches going. For me it certainly was not a case of quickly clicking each switch and being done in 15 seconds, sometimes when it asked for the X LH endstop I would have to sit there clicking it for half a minuite before CURA reacted.

[v3 hotend!]

I will keep an eye on this ! Looks interesting.

I would still say that a non-metallic insulator is nice, otherwise the hotend cooler will be extracting a great

deal of heat, which will end up in the hotend drawing more Amps to keep hot.

http://www.technicalglass.de/pdf/macor_ ... ramics.pdf

Perhaps this might be more suitable than PEEK.

Thermal conductivities for reference.

PEEK = 0.25 W/mK

Macor (machinable ceramic) 1.5

Stainless Steel 16

Brass 110

Aluminium 237

[Straighten the Bowden Tube]

You mean one of these ?

Sorry pics are rubbish, but couldnt upload WMV vid, so had to screenshot the vid...

I reduced the Bowden length by 55%, and its now almost straight, by having a super high tech (rubber bands)

extruder mounting system its can move around alot. Having the extruded fixed in the XY doesnt work well

(my 1st try had the extruder mounted on a vertically sliding rod in linerar bearings, and was rubbish :oops: )

So far it works very well indeed, and when combined with Bertho extruder and fan cooled hot end has

resulted in a 100% mechanically reliable machine. No plugs, no jams, no grinding, no overheating.

Happy to discuss further.

However I did this about 3 weeks after getting the ultimaker, so I do not have any data to back up my

design as being in any way worthwhile....other than that it appeals to me. Of course the standard

position for reel and extruder is FAR neater, and nicer to look at.

Regards

Calum Douglas

[Error on running "Could not load LUA"]

Ok everyone: News from Netfabb finally (thanks )

FYI...Ultimaker Engine does NOT WORK if you have windows XP64.

Only Studio Professional works also under XP64.

C.

[Error on running "Could not load LUA"]

haha,

well it seems you cannot get support until you submit a "ticket" on the Netfabb website...which is really

brilliant, because when the program crashes it gives you a nice info window from Netfabb...which says:

"please email support on...xxx.com" and mentions NOTHING about going to the website and submitting a ticket.

Great, 8 days later and nothing.

Way to go guys with the error window message, seriously.

C.

[Belt Wear]

You can help your belts to live longer by giving all your pulley wheels a proper deburring before building the

machine (yes I know sorry not very useful advice once its all together). The standard pulleys have two pressed on

discs at each side to stop the belt slipping off. Because these are obviously made with cost as the #1 priority, these discs are not deburred at all (a burr is a sharp edge caused from manufacturing). So if you dont remove all these edges from the belt alignment discs, they will sit and happily chew away at the edges of your belts. This will become much worse if you have any belt misalignment as then the belt will really be pushed against the sharp edges of the discs on the side of each pulley.

So buy a proper deburring tool set, or just use the edge of a blade to remove all sharp edges from your pulley guide discs. This will help a great deal.

Regards

Calum

[essential hacks]

STL file is available to anyone who wants it.

PM me, did 7 hour print through the night last night..not a single cough, glitch, complaint or sign of any issue.

This was also using retration which brings on the plug issue even faster in my (limited) experience.

Calum

[essential hacks]

Hi,

I would say if we are just talking ESSENTIALS here and not "nice to have but can live without"...

1) Bertho extruder mod

2) Nylock nuts on everything possible

3) Fan cooled hotend/bowden junction (see attached image for my design)

I have had completely trouble free printing since cooling the hotend. Not once plug, jam, leak..nothing.

Not saying dont buy a V2 nozzle, but IMHO they fixed the problem in their own way....and I fixed in mine.

One cost me an 8Euro fan, and some PLA...the other costs....anway I should probably add that I have only

been running my hotend cooler for 10days. So perhaps another couple of months before I can start patting myself

on the back. Perhaps it will jam tomorrow morning (but I dont think so). The Aluminium plate is now so cool

that it is barely warm during printing. I can also leave it on after the machine is off, thus preventing heatsoak, which

was also IMHO at least 50% of the problem with V1 Hotend (which I still have installed).

Regards

Calum Douglas

[Thermocouple destroyed during V2 upgrade]

I cannot help you with this problem, but for anyone reading (and for when you re-assemble) I would

recommend the following.

1) The thermocouple body is probably stainless steel (or it certainly OUGHT to be), so will expand less

than the aluminium block. Try to remove the thermocouple when the assembly is hot.

2) When installing, (as well as a bit of aluminium foil if you have a rattley problem), I would put on

a tiny dab of Copper grease. This will smoke and generally smell a bit for the first while of use, but

is designed as a high temperature grease specifically with the property that it will prevent things

fusing together when locked together for long periods. When it gets hot the soap carrier agent will

slowly evaporate, leaving basically just copper powder in your joint. This will prevent anything from

becoming locked together over time, and also ought not to provide any problems with thermal conductivity.

However I expect that the presence of the grease carrier agent could initially slightly behave as a bit of a

thermal barrier, so until its evapourated your readings might be a fraction off.

The usual trade name for this would be COPASLIP

Anyway thats what Id do !

C.

[Error on running "Could not load LUA"]

So....6 days and nothing from NetFabb.

Not even a "sorry you had a problem, we will get back to you later with an answer"

In the end Ultimaker have very kindly agreed to email them for me, to accellerate the process....but

so far I have to say that considering the expenditure and I less than impressed with this service from

Netfabb.

If you are reading this Netfabb people, right now you are off the Christmas Present list.

[Nozzle tip scraping last layer on transverse]

Hi,

I have recently found some problems with the printhead nozzle tip scraping across the

last printed layer. I thought initially I just had the table too high, but it often happens after the

first layer...but if it does it on the 20th layer then surely its not the initial bed height....

I use CURA at the moment, is this a common issue ? Can you make the head jump up (well ok the table

jump down) during moves to cure this?

I dont think I am extruding too much plastic as the prints look pretty much ok and dont have that

bulging look. Also I dont think anything mechanical is slipping because overall the prints look fine.

This is at 0,2mm layer height with PLA filament at 230 deg C head temp, 50mm/s printspeed, 150mm/s transverse.

Thoughts ?

Calum Douglas

[Error on running "Could not load LUA"]

So when I try to run NetFabb it says:

COULD NOT LOAD LUA

Then I click ignore, when running there is a big red warning triangle on the screen next to the model and I cannot

see any icons for machine calibration or settings ?

Have emailed support at NetFabb but Im not hanging around if they takes ages to come back to me.

Running Windows XP64 Pro

Ideas ?

Calum Douglas

[Ulticontroller Documentation]

Yes I would like to re-ignite this discussion about documentation for the Ulticontroller.

Its very nice, and I use it for little things - but seriously is there not a .pdf somewhere just

at least saying what the units are for each varible, what they do etc?

For example fan speed ? what unit - radians per month ...what? Its definetly not in RPM !!

Extrusion amount, cura set to 900, ulticontroller says something like +250..what does that mean? :?

 

Its a lovely bit of kit, but without documentation its all just shooting in the dark.

Regards

Calum Douglas

[A meeting of German ultimaker users ? Sharing is Caring :-)]

Hi,

I am actually scottish...but I do have 2 good qualifications.

1) Live in Cologne

2) Have an ultimaker

If you have not aready done so I am interested, although I dont think my german

langauge skills will stretch to discussing 3D printing in much detail.

Regards

Calum Douglas

[Gap between infill and outer wall]

Ok thanks guys,

I have printed tensioners on the x-axis, (the wave type) but cannot fit them to the Y-axis because

they foul the rod-blocks and also rub on the inside face of the top panel. So still working out what

to do about that one.

I will check the infill overlap parameter when I get home from work, but I think I did stick that up a bit.

So looks like belt tension.

But why does this only occur on bottom couple of layers ? Once it gets into it a bit, the infill merges very

well with the outer wall...? Hmmm

[Gap between infill and outer wall]

Hi,

Been printing for 2 weeks since building the machine, printing a bracket with 100% infill.

Two questions....

1) I turned on raft (using PLA) because the print seems to not extrude enough plastic for the first

say 100 mm travel, so by using a raft it comes out nice and even by the time the main object appears.

Is there a better way to deal with that ?

2) On the bottom couple of layers (so above the raft, I`m talking about the actual part here), there is a gap

between the infill and inside edge of the outer wall. Ideas on how to fix that ?

Picture attached.

Thanks

Calum Douglas

[X and Y motor mount screws specified too short]

Hi ,

You are quite correct, the specified bolts are far too short and on my machine only had 2 threads

of engagmement when using M3x20s

I replaced them temporarily with M3x30s and a washer stack.

I think the pefect thread length is something like 24mm. So probably M3x25mm plus a fat washer

is about right, or also M3x22 plus no washer also not too bad.

To be honest I am staggered by this, certainly I would be fired at work if I stood up in a meeting

and said that I didnt know that threads must engage by 1.5x diameter.

I suppose the only reason there are not dozens of people with Nemas having stripped threads is that

the wood will compress alot before that happens. But its still exceptionally poor engineering design.

Calum Douglas

Cologne

Germany