I had planned to get the z-axis in place and do up a video of that today, but after our weekly lunch show and tell we got going over the current mechanism and looking for areas that need to be improved.
We've found some variance in the thread widths (not the pitch) on the drive screws, enough that we need to design a simple anti-backlash mechanism in to counter shifting when changing direction. This was something we anticipated, so not a suprise.
The photo is what we drew while talking through the options for how we can fix it, to give you an idea of our process.
At the end of the discussion, we were happy with the general direction, and are going to sleep on it and detail it tomorrow.
It makes noise, it moves, it is at least looking more like something that can print.
So, we have the X and Y axis installed and moving around. This was a busy day full of everything but building the prototype, so I'm happy to have gotten this progress in.
Today was the day that it seemed like everything started to happen at once. We made good progress with the production board setup and configuration, got some more details of the heatbed sorted, and started putting together the current prototype.
So far, it looks pretty amazing. We got as far as having all three axies assembled without the drive rods in place. This allows for seeing what kind of movement we can expect, but can reasonably know it will just get more solid. There were some screws we needed to pick up shorter versions of, so the mechanism will just get more rigid as well. Separately, we were working on the firmware and testing out production electronic boards, so we should have everything ready to start running the prototype representative of the production product. You can see in the video that the movement is smooth and very promising already.
This week was one of those that you just plow through and keep trying until you get the required results.
The parts were accurate, but because we are doing a two sided process, there was some mis-alignment between the two sides which made the parts just off enough that they couldn't be used.
This has been the week that everything is coming together.
First off, we used and abused the new hot end heater, even getting it up to 445C before killing it while putting 30V and over 3A of power through it. It took us three tries to kill it, taking it up over 400C a few times but having soldered connections melt or something similar.
Brutal, just brutal. We had to see what will kill the new flex circuit based hot end, and we found it. 100W of power which resulted in 445C temperature.
We tested out the new flex circuit hot end today for the first time. See the post and video.
This is significant for a few reasons, one is that it will be a less expensive and more efficient hot end. We are testing out the other aspects this week, so will have more to talk about.
We are working on the other parts for the prototype, and will post up more tomorrow.
Things are rockin along here with the team, getting the MakiBox finished and together.
The final designs for the hot end and heat bed were worked out this week, with the table getting a stainless support and the bed itself going stainless. We have a flex circuit coming in on Monday for the final design of that. The CNC fixture is in progress, and we will be able to crank out panels of parts for production using that.
We are shooting for having the parts for this in house this week, so target having the prototype by Wednesday in one form or another. I can’t wait to see this all come together.