Where am I going wrong? - Under-extrusion

[charles-design 0]

Hi there,

So I made the change to Roberts extruder but after a few test I'm yet to get a decent result out of it.

The green print (Poor Quality Filament) was made using the stock extruder and the clear print was with Roberts.

After this I repeated the test with both higher and lower tension, both of which came out worst.

Am I missing out on a trick to get the tension right?

Is the correct tension in a very small bracket?

Most of the time it's printing the skirt fine but starts under-extruding on the actual print.

Many Thanks,

Charles

 

[donmilne 2]

Well, I'd say it's because you have the spring tension too loose or too tight.

I found it useful to make a small "coin" test print, say 25mm diameter and 2mm thick, .1mm layers, 55mm/s, 100% fill: it takes only a few minutes to print and each layer fill is a decent test of regular extrusion. I also used a loose length of filament say about a meter beyond the feeder, to eliminate spool binding as an influence. I backed off the spring screw to the min force then started off the print, tweaking it clockwise a quarter turn at a time until I got consistent fill.

Once I was happy with the coin I returned to the above extrusion test and got perfect results all the way to the top.

Oh, and it helps to take the time to get the bed levelling spot on. Otherwise that too could be an influence.