Project of the Week is Back!
Happy Wednesday everyone!
We don’t have a ton of results to share this week so we’ll share what we’ve been working on.
New Encoder Connectors:
One issue that we’ve been running into with the Maslow 4s that are out in the wild is that as they get older and dirtier the ethernet connectors to the encoders can become less reliable. We’ve played around with some temporary solutions like dust covers or hot glue and some software fixes to make the firmware more robust to handle interruptions, but a long term solution is needed so we’re testing replacing the ethernet cables with JST connectors.
JST connectors, like those we already use for the DC motors and stepper motors, are a good option because they handle both dust and vibrations very well and we’ve haven’t had any issues with them.
We’re testing with a JST-XH 5 connector which uses two pins for data, two pins for power, and one pin for shielding.
The basics seem to be working, but we will need to test more thoroughly to be sure.
The hardest part has been finding a cable supplier who is willing to work with us on making quality cables in reasonable quantities. The supplier we worked with in the past has a MOQ of 10,000 pcs for this cable which is substantially higher than we would like to order. Hopefully we should be able to find a solution quickly.
We’re working to get a small number of parts made as quickly as possible so that we can get them out to the community for feedback and testing.
Calibration Testing:
Another project that we’ve been working on is dialing in the calibration process. There are a couple of assumptions that Maslow makes about the world in order for the calibration process (and subsequent cuts) to be accurate and we are exampining those assumptions to see if we can improve them.
The first assumption that we make is that the teeth on the belts are spaced exactly 2 mm apart. Nothing in the real world is perfect so while the belt datasheet says they are 2 mm apart, we’ve found in the past that they are actually closer to 1.9988 mm apart and we’re working to see if we can refine that number even further.
This might seem like a very small amount of variation from the correct length, but because the accuracy is per-tooth and there are a lot of teeth, getting that number exactly correct is important.
Unfortunately so far we haven’t found any improvements from changing that number, but we’ll keep digging to be sure.
The second assumption that we’re making is that when the belt is fully retracted, the distance from the center of the hole in the belt end to the center of the router is exactly 153.4 mm. This distance is added to the measured length of the belt to tell the math how far it is from the anchor point to the center of the router bit.
We have also not found any improvement from adjusting that number, but we still have more testing to do.
Overall the rate of change is going down week to week as we’re getting more and more of the low hanging fruit taken care of which means we have less exciting news to report, but we’re still hard at work making things better.
Project of the week is coming back!
Now that we have router bits back in stock we’re bringing back the project of the week!
Every week we are going to have a poll in the forums to pick the coolest project of the week. The winner gets a free router bit, a custom forums award, and bragging rights.
The forums are a great place for support and problem solving, but we also want to encourage more project sharing and collaboration.
Next week we’ll award the top five projects so more folks who posted over the few last months have a chance to win.
Showing us how it's done @Andith posted this very nicely made kitchen helper in the forums this week.
Have a great week everyone!
-Bar and Anna
