burdickjp

All end stops are working according to the systems menu.

If the bed is driven past the bottom of its travel then the Z axis stepper motor stalls and skips steps. The controller thinks it kept moving. The mechanical distance between the bed and nozzle is less than the controller thinks.

If the machine tries to go past the bottom of the Z travel then the head to bed distance is shorter than the controller thinks, and it crashes the nozzle into the bed. The bed is homing correctly during other operations, including print completion and automatic leveling.

I have a UM3E which I've installed some buildtak print sheets on. I've turned off automatic leveling, as the nozzle would melt the print surface. This was behaving correctly for a long time, but recently it's started to misbehave. At print starts it will drive the Z axis down past the end stop. Since it's lost its Z position it will then drive the nozzle into the bed. When I turn on autoleveling and switch to a different bed material the startup sequence is a little different and it behaves normally. I'd like to go back to buildtak sheets. They worked before

I'm having trouble finding what is causing this. I've tried in Cura 4.1 and Cura 4.2. The first layer is over extruding to line widths of over 2 mm when they should be 1.2 mm. I checked my steps per mm by extruding 100 mm of filament. It was within 2%. I corrected it. I switched to a 0.8 mm nozzle and 0.6 mm layers and it seems to be behaving, so I'm thinking there's something buggy in Cura or I'm missing a setting somewhere. UMO_3DBenchy.3mf

Why the heat break?

I am, too! It will be a short while as I am in the middle of a move. I've got some new ideas, but they're not mutually exclusive ideas. I intend to test the hotends in my ultimaker as it is before changing to the DXU.

I'm not necessarily looking at being able to swap between 1.75 mm and 2.85 mm with the same hot end. I'm looking to use the same form factor for both. The same, or mechanically compatible, external dimensions.

Here's my first blog post about the hot ends: https://burdickjp.gitlab.io/2019/05/14/dxu-1.html Verdict: I think I've found an easy way to run 2.85 mm filament.

My parts came in. They look really good! I'll take measurements, put together some solid models, and write up a description sometime this week.

My 1.75 mm parts are on the way from alibaba. I'll report back when I've had a chance to investigate them.

I went looking for a version of the hardware for 2.85 mm filament and had trouble. I'm going to order the 1.75 mm hardware on ali and see what I can make or modify for 2.85 mm filament.

If the short bearings are wearing then something is wrong. The Ultimaker 3 uses a short bearing on the Y axis rod and lasts a long while. Maybe alignment isn't sufficient and it's wearing because of misalignment?

I'm thoroughly interested in doing this. I thought about designing and making the PCB necessary, but couldn't find the correct pogo pins. Care to share?

I am interested in helping with this project. I'd like to design and manufacture the heat break parts to suit both 1.75 and 2.85 mm filament. I should be able to make them compatible with Olsen and 3D Solex blocks.