Duct limits Y-travel (solved) but still misses Z-spec!

[calinb 11]

My duct was hitting the right table arm in back so I cut the interfering tab off the duct and super-glued it in that corner. Rubberized superglue with "kicker" (superglue / CA accelerator) works best. Superglue alone will not stick well, requiring this bond "promoter." Note the superglue filet in the corner of the duct to glue the hold the corner together after removing the snap tab and increase the corner strength, should it still make light contact.

However, removing the tab still did not provide the needed clearance with the table arm so I used a Dremel tool to elongate the holes in the duct. I've now moved the duct as far as possible toward the front of the printer and away from the right table arm. (The flats of the back nuts are hard up against the inside wall of the duct.) This mod still resulted in very light contact with the table arm (but probably would've run okay) so I used a fine cutting tool on a Dremel tools to shave another few tenths of a millimeter from the outer wall of the duct where it made contact with the table arm.

This photo does not show the shroud in its current position--all the way forward. It is flush with the side of the fan here but actually needs to go as far as possible to the front of the printer (until the flats of the rear nuts make contact with the duct inner wall), where the outer wall of the duct will be slightly "past flush" with the rear edge of the fan.

After tending to this duct problem, my Ultimaker meets spec for travel in X and Y (210.3 mm and 210.3 mm measured at mechanical hard stop). With careful setting of the limit switches, 210 mm should be possible in operation.

However, in its standard configuration and building from the parts ship in factory kit, the Ultimaker is not even close to making 220 mm in Z-travel! My table only travels 204.8 mm before hitting mechanical limits. I could obtain another 2 mm in Z by screwing the table adjusters all the way down but, to achieve the advertised Z-travel spec, I would need to replace the 10 mm thick acrylic plate with a thin build plate (2.5 mm glass?) and rework the table arms to place the Z-axes bearings right down on the bottom floor of the printer frame at max-Z. This would provide barely over 220 mm of Z-travel, but the table modifications would require a significant effort. Additionally, the hot end could be raised to increase Z-travel to a small degree and reduce the magnitude of the modifications to the table, but that would be even more difficult than modifying the table arms or designing and building an entirely new table.

I don't see how this machine can be advertised as a 210 x 210 x 220 printer, except that most people don't care much about Z and never check the printer's actual performance on the Z-axis. To achieve 220 mm of Z-travel requires much more than adjustment of the printer; it requires a redesign of two or more components!

The design, as shipped, is a 210 x 210 x 206 printer (after fixing the fan duct interference and dropping the build acrylic plate nearly all the way down.

[Daid 306]

The bed was changed from 6mm to 11mm, so that's where 5 extra mm went. Not sure where the last 10mm has to come from. The machine I have here measures about 207mm from min to max Z.

[calinb 11]

Thanks, Daid! That's good to know. I screwed my plexiglass down nearly all the way so my printer is around 206-207 mm now too. Given your accounting for 5 mm in the bed design change, the shortage becomes a mysteriously-missing 8mm. I'm not very motivated to find the missing millimeters because, like most users, my Z-travel is adequate for my needs. I mostly wanted people to be aware of the true Z-travel capability of a currently shipping kit.

[Daid 306]

I mostly wanted people to be aware of the true Z-travel capability of a currently shipping kit.

I think someone just made a mistake, because even on the oldest kits have the same amount of Z travel. (I have one of the first 20 machines here in our FabLab, which hardly looks like an Ultimaker)

[Daid 306]

FYI, the 22cm came from the first design which didn't have the spring loaded bed. And a different weaker Z stage design. The text in the shop is changed now, so no more false advertizement, thanks for pointing out the mistake!

[calinb 11]

No problem and the new spec in the shop looks good, Daid! I'd rather have the current bed than the extra 1-1/2 cm! In fact, I like the spring loaded bed so much, I just milled the same style slots in two 2.5 mm glass plates for my new heated build plate. Milling glass is painstakingly slow!

I'm pleased Ultimaker was responsive and changed it promptly. I was a sort of a "specmeister" in my last job and it's my nature to verify specs, I guess!