Midgetmountain published a new build:

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great job

Hey Tweakie,

There is little amount of wobble in the boom (if I move it by hand), but it is surprisingly stiff in fast acceleration. At the moment I have two issues with my design, the build platform mounting (that should be fixed once I can get my hands on a openbuild build platform), and plates mounted on the v-slot moving.

Its still a work in progress.

Midgetmountain, that looks a lot like a design I did earlier this spring. Problem I had was keeping the x axis arm parallel to the y axis. I looked at Bukobot's Bukito design and saw the solution. Their plate that runs up the vertical frame piece and carries the x axis arm has only 3 wheels. Mine had 4 wheels. They had 1 adjuster wheel on one side and the two stationary ones on the opposite side. That creates a triangle wheel design (actually stronger than a 4 sided design). Adjusting the one wheel automatically squares the x axis bar with the y axis, if everything else is square.Your design shows 4 wheels on that vertical axis bar. Try 3.

Here's a picture of my opnbot design.

Hey Keith,

Thanks for the feedback.

There are few problems the current design, that I need to fix. The biggest pain is the plate mounted on the v-slot can slip, making it fun keeping everything aligned. I am going to print a block for the boom to keep it level, and another one for the base to keep it square. Another issue is how I have the build-platform supported (currently used some wooden slates), but when I can get an openbuilds build platform that should fix that up. I am also designing a extruder holder with a force sensor built in, so I can do auto bed levelling.

Below is my first concept, similar to your BldrBot (Which I really like!). I cut this design down so I could keep the parts count down, I was worried that the single 20x20 boom would not be that sturdy, but it surprised me.