Ultimaker suitability question

[etchedpixels 0]

I'm looking at the Ultimaker and a couple of the other printers. I've been digging in the obvious places for info but I've got a few open questions.

The first is on object overall precision - Im currently using Shapeways and mixing 3D printed objects with brass overlays for the detail, fine thin parts etc. This works beautifully, but it takes ages to turn anything around even when Shapeways aren't losing models, being down or trying to charge me twice for the vat. What primarily matters is overall precision - in other words if its 42mm long it ends up being 42mm long ± a small tolerance and that tolerance is basically constant (ie jitter isn't a worry). What sort of tools are needed to calibrate the machine accurately. I know people are printing very fine layers but how much work did that entail and how often are they recalibrating to achieve it ?

Secondly is on supporting material. A lot of the shapes I have curve outwards and I'm not clear if that will need support. Some bits stick straight out so clearly will, other bits I can see how to print as multiple parts easily enough. How much work is usually needed to clean up the support to a good standard ?

Thirdly is overall smoothness. Currently I'm using Shapeways to print some small stuff in FUD (which I don't expect the ultimaker to match - but do hope I can prototype by printing them several times bigger), and bigger stuff which is using WSF with polishing. Their polished WSF is just about acceptable for what I am doing. How does the finer printing with the Ultimaker compare and have people got any good fast ways to polish it (I was wondering if dipping PLA into a water/PVA/washing up liquid mix or similar would smooth it down ?)

Assembling it doesn't bother me too much, most stuff I assemble is a few cm long and involves soldering. Software I'm fine with and my reaction to some of the problem reports is to get the profiling tools out. My software tools currently output fairly horrible openscad code and then use openscad to build the object so the STL is nice and clean and its an apparently known to work path.

Fourth question is on fumes. I assume it needs good ventilation and/or extraction ideally ?

Finally I notice the rival product 8) is offering dual extruders - are we likely to see a dual extruder add on for the Ultimakers using something like wax or pva for support ? Or for that matter a polishing head on the same frame that can print and then follow up with a polish ? I'm slightly puzzled by the lack of combined CNC/3D print devices in the universe, it seems an obvious combo ?

For prototyping the unit seems to be a slam-dunk, and to pass every 'cool' test in the book, but if I was to set it printing 50 of something in batches of 5 (which will fit the bed) then print time is one concern (but a minor one as it can print while I do other stuff) and clean up time a bigger one (because sadly I can't sleep or drink beer down the pub while doing that).

Alan

[joergen 2]

The first is on object overall precision - Im currently using Shapeways and mixing 3D printed objects with brass overlays for the detail, fine thin parts etc. This works beautifully, but it takes ages to turn anything around even when Shapeways aren't losing models, being down or trying to charge me twice for the vat. What primarily matters is overall precision - in other words if its 42mm long it ends up being 42mm long ± a small tolerance and that tolerance is basically constant (ie jitter isn't a worry). What sort of tools are needed to calibrate the machine accurately. I know people are printing very fine layers but how much work did that entail and how often are they recalibrating to achieve it ?

Being somehow responsible for that, I can say the precision of the UM is astounding... 42mm are 42mm, and the only error is variations of the extrusion on the outside... something like +-0.1-0.2mm, no calibration necessary... the only thing you need to measure/verify is the E steps per mm setting, and the filament diameter (down to 0.01mm). small holes under 2.75mm will not come out as 2.75, but will be way more filled in... drilling out is the only solution. holes >3mm tend to come out at the right size.

Secondly is on supporting material. A lot of the shapes I have curve outwards and I'm not clear if that will need support. Some bits stick straight out so clearly will, other bits I can see how to print as multiple parts easily enough. How much work is usually needed to clean up the support to a good standard ?

The UM (and any related printer) can't do what shapeways can do, overhangs and diagonals (45 deg) are possible without support material underneath, and I don't print with support at all anymore, it bothers me way too much. sometimes, dedicated manual support strictures help. horizontal holes and arches are also possible, they just need dedicated slow printing and fast cooling.

Thirdly is overall smoothness. Currently I'm using Shapeways to print some small stuff in FUD (which I don't expect the ultimaker to match - but do hope I can prototype by printing them several times bigger), and bigger stuff which is using WSF with polishing. Their polished WSF is just about acceptable for what I am doing. How does the finer printing with the Ultimaker compare and have people got any good fast ways to polish it (I was wondering if dipping PLA into a water/PVA/washing up liquid mix or similar would smooth it down ?)

many UM users print with PLA. If you get a dual-extruder (and the matching software), you can print the support with PVA, and dissolve it in water. PLA itself is far more difficult, and most users seem to not mind little bumps and strings... the surface is really shiny when printed at the right temp... going lower/faster will make the surface duller, due to incomplete melting. a blade can remove some of the bumps/strings, and with some luck you get a perfect surface (needs practice). sanding it works only wet and a fine grit (i.e. 280-600). dry-sanding doesn't work, PLA is an incredible high friction coefficient, and will melt instantly into the sandpaper... it's mostly a leave it as is situation, IMO. no idea how this plays out with ABS or any of the other printable materials.

Fourth question is on fumes. I assume it needs good ventilation and/or extraction ideally ?

PLA is harmless, ABS requires a window and/or ventilation.

Finally I notice the rival product 8) is offering dual extruders - are we likely to see a dual extruder add on for the Ultimakers using something like wax or pva for support ? Or for that matter a polishing head on the same frame that can print and then follow up with a polish ? I'm slightly puzzled by the lack of combined CNC/3D print devices in the universe, it seems an obvious combo ?

I had thought about starch/sugar paste as support material, but I have not explored it further. I can not comment on any plans of dual head units from UM, and afaik, only netfabb supports it so far. no idea about any other software producing dual head extrusion gcode.

For prototyping the unit seems to be a slam-dunk, and to pass every 'cool' test in the book, but if I was to set it printing 50 of something in batches of 5 (which will fit the bed) then print time is one concern (but a minor one as it can print while I do other stuff) and clean up time a bigger one (because sadly I can't sleep or drink beer down the pub while doing that).

it's good for prototyping, and small runs, but production is better handled by places setup for it.

[Daid 306]

Small note on the overhang, 60 deg angles are possible with the Ultimaker in most cases.

Quality is mostly a time tradeoff. For the best quality you want to print on 0.1mm layers (or smaller) at a speed up to 75mm/s. A 40x40x40 print can take multiple hours then.

[etchedpixels 0]

Being somehow responsible for that, I can say the precision of the UM is astounding... 42mm are 42mm, and the only error is variations of the extrusion on the outside... something like +-0.1-0.2mm, no calibration necessary... the only thing you need to measure/verify is the E steps per mm setting, and the filament diameter (down to 0.01mm). small holes under 2.75mm will not come out as 2.75, but will be way more filled in... drilling out is the only solution. holes >3mm tend to come out at the right size.

The holes business goes for Shapeways too who like printing oval holes.

The UM (and any related printer) can't do what shapeways can do, overhangs and diagonals (45 deg) are possible without support material underneath, and I don't print with support at all anymore, it bothers me way too much. sometimes, dedicated manual support strictures help. horizontal holes and arches are also possible, they just need dedicated slow printing and fast cooling.

Ok that's good to know - Most of my overhangs are gradual outward curves nowhere near 45°

PLA is an incredible high friction coefficient, and will melt instantly into the sandpaper... it's mostly a leave it as is situation, IMO. no idea how this plays out with ABS or any of the other printable materials.

Yep - that was why I was wondering about the old PVA/water/washing up liquid dip trick used with other materials outside of 3D printing.

PLA is harmless, ABS requires a window and/or ventilation.

Excellent. Flat ABS I'd need a heated bed and other horrors anyway.

it's good for prototyping, and small runs, but production is better handled by places setup for it.

Fair enough. I shall have to carry on hating Shapeways screwups 8)

Alan

[etchedpixels 0]

Quality is mostly a time tradeoff. For the best quality you want to print on 0.1mm layers (or smaller) at a speed up to 75mm/s. A 40x40x40 print can take multiple hours then.

Can the layer thickness be changed at different points in a print (at least if the software could do it ?)

[Daid 306]

Quality is mostly a time tradeoff. For the best quality you want to print on 0.1mm layers (or smaller) at a speed up to 75mm/s. A 40x40x40 print can take multiple hours then.

Can the layer thickness be changed at different points in a print (at least if the software could do it ?)

The current software cannot (well, maybe Netfabb can, but I do not have experience with Netfabb). You can set the thickness of the first layer, and all the other layers have the same thickness. Then there is the "skin" trick, which prints the outside lines twice at half the thickness, giving the illusion of better quality at only a fraction of the time cost.

In the end, if you are doing production runs, you can always use a batch of ultimakers (especially with the Ultipanel, because then you don't need a PC anymore to print)