Improving the Robotdigg SCARA printer

In the first post in this series I described how I strengthened the bad T-frame of the printer and added adjustable levelling feet. These improvements made it possible to produce prints. The conversion to Duet electronics described in my second post improved print quality and provided faster print speed. However, the large amount of backlash in the distal arm joint drive remained, along with the lesser but still serious backlash in the proximal joint drive. If I was ever to get good prints from this printer, the backlash in both joints would need to be addressed.

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Converting the Robotdigg SCARA printer to Duet electronics

In my previous post I described the Robotdigg SCARA Arm 3D printer in its original form. This post covers the conversion to Duet Ethernet electronics. It may seem odd to use top-of-the range electronics with budget mechanics, and I am not suggesting that it would make sense for other owners of this printer. In my case it made sense because I needed a test bed for testing and maintaining SCARA support in RepRapFirmware, the firmware that runs on the Duets.

Testing the Robotdigg SCARA Arm 3D printer

A colleague spotted this Robotdigg SCARA Arm 3D Printer which sells at just US$280 + shipping and import VAT. As I was working on SCARA printer support in RepRapFirmware, this seemed an ideal low-cost platform to test it on. So we bought one.

In this blog entry, I describe my experiences with this printer as it arrived and what I needed to do before I could try printing with it. A subsequent entry will describe the conversion to Duet Ethernet electronics.

Time to rebuild my large Kossel

It’s more than a year and a half since I published my large Kossel build blog entry.Since then I have upgraded it many times. Several people have built 3D printers based on this design, and some have asked for a more complete bill of materials. So I decided to create a page on this printer as it is now, including yet more upgrades.

More Delta Printer upgrades: WiFi and Silence!

Some of you may already know that I have been working on a new version of the Duet 3D printer electronics. The new board is called the Duet WiFi, and it a joint venture between my own company Escher3D and Think3DPrint3D. The first pre-production board arrived a few days ago. After bench testing it, the time came to install it in a 3D printer. I chose to install it in my delta printer, which is more demanding of the electronics than my Ormerod.

Print bed surface roundup

This time I will discuss the various print surfaces I have used and my experiences with them. Your results may differ.

Upgraded arms for the large delta printer

My large delta printer has been working quite well since the last round of upgrades, but two issues have been bugging me. First, although spiral vase prints were excellent with perfect layer registration, some other prints showed a small misalignment between some of the layers. Second, when I measured the trigger height of the IR sensor at each probe point, I found that the trigger height close to the Z tower was about 0.25mm higher than in most other places. I corrected for this using the H parameter for the probe points affected on the corresponding G30 commands in the bed.g file, so it didn’t affect the delta calibration. But it shouldn’t have been necessary.