Upgrades complete, what to do next

[joelmongeon 39]

After neglecting my UM2 for about 6 months I decided to get back to it and do a bit of upgrading while I was at it. One of the reasons I stopped using my UM2 was because I was having issues with underextrusions. So after installing and a few test prints I think I have some more work to do, just not entirely sure what, and would appreciate some advice.

I first upgraded my feeder to Roberts feeder. I ended up cannibalizing some M3 bolts from my Printrbot metal simple as I've yet to find a good place to buy some without buying in bulk. The nut that holds the bolt and spring is too large for the opening in the printed part, so I can only loosen the tension so much before the bolt falls off. I think I've tightened it too much though as my last print ground the filament and the last few mm air printed.

I then bought an Olsson block, a new Bowden tube, Teflon insulator and I2k insulator. This upgrade went ok. I had to get a new heat sensor as i was not very gentle trying to remove the old one and ended up cutting the wire. I also had to use a spare steel coupler I had lying around as my original had deformed with the nozzle.

I got my new Bowden tube from gr5 and I think I need to reinstall it as it tries to lean into the print bed. I assume twisting the tube so that it wants to curve straight up and down is ideal before installing it on both ends. I found during testing with it leaning over, that my retractions didn't do anything with the default length.

I notice with printing the ultimaker robot that I needed my filament a lot hotter or else I would get underextrusions. I used to be able to print down to 190 C no problem, now I'm having to print at 220 C for a consistent extrusion. I'm guessing the nozzle from the Olsson block needs higher temp as it is way more exposed to the cooling fans with the stock fan shroud. If I print a new shroud that is designed for the Olsson block, I assume I can print much cooler again. 220C really seems to create strings and artifacts on retractions.

I'm also contemplating printing a replacement for the spring that pushes against the Teflon in the extruder, I noticed Labern had one up on youmagine. Am I missing anything obvious to upgrade next? So far on my to do list is, loosen tension on my feeder, reinstall my Bowden tube, print a new fan shroud to better work with the Olsson block, and possibly print a replacement for the spring in the extruder.

[Labern 774]

The Olsson block normally require less heat at it has a longer heat zone. But the fans do cool the tip as you state. You can try this extension and see if your temp settings come back to normal. If not you may have a bad pt-100 temp sensor.

[Labern 774]

You can also print a low friction spool holder. Both Robert and I have one on youmagine that mounts like the original one. Or there are heaps of other styles to choose from.

I like to replace the rear fan with sunon MC25060V2-A99 just to make it nice and quiet. There are ducts to help with cooling for that fan 2 like this one.

There isn't much evidence on most mods to prove one is better than another or even helps at all so some comes down to what you believe is best.

[Dim3nsioneer 557]

If you ever had black particles lying on the x and y stepper motor, coming from the belts, it might be a hint of friction between belts and pulleys due to not ideal length of the black spacers between bearing and pulley of the x and y axes. A good upgrade then might be to print your own spacers better adjusted to your individual printer.

[joelmongeon 39]

Thanks for the replies guys. Sorry for taking so long to reply, my little one has had a cold and I've not had much time for 3d printing.

So I think I just had some bad filament. It was some grey colorfabb pla that I used last year. I stored it in a watertight Tupperware with rechargeable desiccant packs so I thought it would be ok. I switched to a spool of black colorfabb pla and everything printed too hot. So I'm not printing back at a normal 190C without problems.

Labern, thanks for the links, I've just ordered that fan. I've got some colorfabb xt showing up tomorrow so I'll print out the cooling duct. I have used Roberts spool holder and Braddocks but ended up remixing my own so that it would fit into a small container with desiccant packs to help keep moisture out. I'm in Seattle and in the rainy season (now till April) temps hover around 5C-10C and humidity is usually 100%, so I try to make sure my filament stays dry as much as possible.

Dim3nsioneer, I do see some black particles on my X and Y steppers. Looking at the rods on the back on my printer I see they stick out about 1mm. Is this normal or should I loosen something up and push them in?

I've got a project in mind that will need my machine to be in excellent shape. I'm hoping I can get this kind of quality again after tuning and upgrades are done.

[joelmongeon 39]

Ok I must be tired... I was putting my nozzle in Roberts nozzle clip when I noticed I have my .6mm nozzle on my UM2 instead of my .4mm nozzle. I'm guessing my extrusion problems have something to do with that

I'll switch them out tomorrow and run some more tests. I'm guessing replacing the nozzle at temp (around 210C) is the way to go?

Edited November 18, 2015 by Guest

[joelmongeon 39]

Just a quick thanks to everyone who replied. I'm back up and printing and things are looking fantastic!

Here is my first test with a .25mm nozzle on my Olsson block. I added the cooling duct but have yet to actually solder the new fan into place. My UM2 is in the garage so noise isn't really an issue. I've got it as a backup for now.

[skinny-kid 65]

Glad to hear you got it sorted and your machine is running smoothly again!