So I had to take a break, not for personal reasons but because my Sigma developed a series of issues.
To begin the R16 model I had unfortunately became bent, the gantry holding the x axis stepper bent in. BCN were good about this and actually replaced my entire printer. It took about 6 weeks but they did replace it, and with an R17.
I have had issues with the R17, the same issues many are having – grinding.
On inspection I can see the issue, extruder design, a single knurled wheel and a flat bearing to feed round filament? With retractions it all heats up, the flat side gets compacted and then the filament gets stripped.
This is a very common issue, almost every day somebody on Facebook is talking about it and I believe unless you pretty much remove retractions or print things that don’t need them you’re kind of stuck with this situation.
Options are to go for a Bondtech upgrade, which has 2x round geared wheels that minimise the chances significantly. But there’s a £330 cost.
I’m still getting things back up to uber reliable, but I am getting there. Right now I’d be hard pressed to recommend the Sigma, but if you want / need IDEX for sub £3.5k your options are very limited.