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jhertzberg last won the day on November 15 2016

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    Ultimaker Original
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  1. I'm glad my musing was helpful. If you hang your filament spool well above the printer, instead of at the rear, you can reduce some of the strain from the twist.
  2. That makes sense, but if I understand you correctly this means that the orientation of your driving wheel will change relative to the column of filament as the shaft sweeps. Might this twisting snap or weaken the filament? Will the entire hot end rotate with the angle change, or will the filament twist again between the driving wheels and the melt zone? (Sorry if this sounds negative. I really like the idea, and I may be overthinking it.)
  3. You would still have the masses of your motors to contend with on just the wrong diagonal moves. With all the stiffness you are building into your XY carriage, perhaps you would be better served by keeping the motors stationary, and for each, running a splined shaft up the side (y axis) and through a bevel gear assembly mounted to the slider block, with a second splined shaft running through the head, to the opposite slider block. The additional weight of the bevel gear assembly is probably more than offset by the lack of moving motors and the simpler head.
  4. You could relocate your material feeder to eliminate this issue. I think it was David Braam who at one point suspended the feeder inverted above the center of the machine, using a tripod and rubber bands.
  5. Mine has always been on a solid table, but in years past, UM has hung running printers from bungee cords at crazy angles for trade shows. If the worry is that your printer might walk off the table, try putting it on a rubber mat or some cork. That will reduce noise transfer too.
  6. I use a four year old Ultimaker Original, and have made several mods over the years. Quick rundown: Heated Bed - OMG, why did I wait so long! Virtually no minuses. Big pluses for bed adhesion and smooooth bottoms. Direct drive - It works fine, but I don't know how much improvement in print quality it really gave me. I probably could done as well just slowing my jerk settings. The plus is that I have fewer pulleys to worry about. The minus is that I'm always smacking into the protruding motors when fiddling with the feeder. Twister blocks - Do this instead of reptar blocks. They make working on your printhead less of a pain. Z endstop adjuster - If you change nozzles regularly, it's a must. It's a lot easier to twist a thumbscrew than to dig out your 3mm driver to fuss with the switch height. I can't find the model of the one I use, but this should do. Endcaps - Replace the x/y rod endcaps with some that are adjustable for keeping the rods better in place with little friction. Fan cowl - Of course. There are so many. Experiment, or do the excellent dual fan upgrade stickied to the top of the hacks forum. Printhead bowden clamp - I got tired of the grip on the bowden getting weak, or little blue rings going missing when I did atomic pulls. Sound damping - Even before you install the silentstepsticks (I have an installed set too) use some flexible filament to print a feeder standoff and some printer feet. Stick some adhesive backed padding in the bottom of t feet for even more isolation. Various extra bits - Spool spinners, belt tensioners, nozzle holders, etc.
  7. Yes, is the same as shell thickness. It's called wall thickness in Cura. If you are using the new version of Cura, use the advanced settings Gradual Infill Steps and Gradual Infill Step Height along with your setting for Infill Density. You can add these to your UI by clicking the gear icon next to the Infill Category and checking the boxes on the resultant dialog. With this at your disposal, you can set, for example, Infill Density to 20%, Gradual Infill Steps to 2, and Gradual Infill Step Height to 2mm. The result will be an object filled at 5%, until 4mm before the top of the infill area, whereupon the infill will switch to 10%, then at 2mm before the top of the infill area the infill will switch to 20%.
  8. That depends on the object that you are printing. For print quality, if what you mean by that is the best surface representation of the model, the infill percent only has to be high enough so that all features are supported sufficiently and top layers will close and not sag. Simple designs that taper slowly to a point don't require infill at all. For most everything else, an infill of 20% is usually ample if you are using the usual number of top layers. With Cura 2.3 and higher, you can even save material by setting infill to 20%, then setting Gradual Infill Steps to a 1 or 2 so that the 20% is phased in from 5% or 10% as the printing approaches your top layers. Once again, it depends. You have to look at what kind of stresses your part will be subjected to. Is it tension, compression, shearing, or some combination? Greater infill can be useful if it is compression, but increasing your wall thickness is generally more useful otherwise.
  9. Only to a limited extent, since often the optimal settings for a different brand, or even a different color of the same brand, will vary slightly. Some things are obvious, like color inconsistencies, debris, and pocking, but things like underextrusion may be your printer settings. If I am not happy with a print the first time I use a new filament, I'll do some debugging. I'll print a small calibration object ~50mm high, and raise the temperature about 5C every 10mm, starting at 10C below the stated temp for the filament. Or, I might slow the printer down to 50% speed, and increase it by 10% every few mm of layer height to see if/when underextrusion begins. This all assumes that you are inspecting the filament before use. You should check the filament diameter at several spots with digital calipers. A variance much greater than +/- 0.05mm from stated diameter will leave you with overextrusion at the high end and underextrusion at the low end. You should also check that it does not snap too easily when bent. I have received filament that was so brittle that the last quarter of the spool was unusable because the filament continually broke as it went from tightly wound on the spool to straight entering the feeder. Concerning that benchy, it's pretty good, but without seeing the nozzle while it printed I can't be sure why you got that cluster of blobs right above the slight underextrusion, or the unevenness above the door. You should probably remove any obvious material from the outside of your nozzle, perform an atomic pull to clean the inside of the nozzle, and try it again.
  10. Look at the flair of the user you dissed. Look at mine. Look at yours. The etiquette of this board is not like 4chan. The standard here is to comment as if you are face to face. Many of us do meet with each other at conferences and maker faires. I'll give you the benefit of the doubt that you would not say "Never made use of Google in your life?" to someone you were talking to for the first time at a conference. Also, user/ultiarjan 's statement, notwithstanding the existence of combination bearings, is correct. The Ultimaker design uses bushings for XY. Combination bearings instead of bushings would be both overkill and a design problem. Given that the movement rod diameter is 8mm, a bearing outer diameter would be ~15mm, rather than the existing bushing outer diameter of 11mm. This would require a redesign of the slider blocks and more clearance inside the case.
  11. You are new here. We are a supportive forum. Your informative links are very much appreciated. The insulting tone of your comment, not so much.
  12. You also can have access to the rearward holes just forward of the four holes surrounding each of the linear bearings. You would just need to swap in a longer M3 screw.
  13. The Structur3D folks went the syringe and geared extruder route. They even sell a package with the paste extruder integrated with a UM2+. It should be straightforward to adapt their extruder to your toolhead changer. Unfold ~fab uses compressed air and a moineau pump instead of a geared motor, definitely not something for a home use. I ran into the same five issues as you when I built a syringe extruder, but since I'm looking to print clay I'm now thinking about skipping the high viscosity issue entirely, and doing some variant of a powder bed type approach.
  14. It's because the cooling fan would hit a side panel that is flush.
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