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Converting to 1.75mm

Posted: May 17th, 2016, 2:07 pm
by danilius
Is it possible to convert a UM2 with an Olsson block to 1.75mm filament? Does it need a different block?

Re: Converting to 1.75mm

Posted: May 17th, 2016, 3:18 pm
by Neotko
Indeed. I use that.

Bowden 6-2mm it's the best, and most reliable. Hard to find, but I can post you some sources.
It needs a new block. China sellers use a 4-2 ptfe that goes up to the nozzle, can work? yes, but no if you want to keep the quality and print temperature.
Also, need nozzles.

So...
- New bowden, or a 2-3mm inside the 3-6mm ultimaker with ptfe glue (the only one that it's reliable to glue and that can survive it's loctite 401 with 770 primer (quite expensive).
- New olsson
- New nozzles

And I'll highly recommend to change to a mk7 since the knurdted diamond shaped bolt of um2 it's designed for 3mm and 1.75 filament needs quite less force to push it, and also it's easier to grind it.

Basically I used the 1.75 modded parts of my umo, and installed a um2 hotend buying the key parts to swordriff (3dsolex).
https://ultimaker.com/en/resources/2055 ... conversion

Oh also.. Advantages
- Less retraction distance = more retracts posible without grinding
- Less temperature to print at high speeds
- It's easier to keep high retracts since it need to push more material to print the same area, so the filament physically moves more.
- Easier to print at slooow speeds, since the feeder must move more. Quite handy for me since I print a lot simulating 0.30-0.34 nozzles with my 0.4's

Downside
- The feeder pushes more filament, so it might translate to more vibrations (I never tested 3mm vs 1.75 but makes sense).
- On summer it's easier to bend the filament from heat of the motor (that just happened today since the print room went to 27C after 7h print and the sun started to hit hard in spain this week).

Re: Converting to 1.75mm

Posted: May 17th, 2016, 5:12 pm
by danilius
Brilliant answer. Thanks so much.

Re: Converting to 1.75mm

Posted: May 17th, 2016, 5:15 pm
by reibuehl
I would be interested in the sources for the 2-6mm bowden.

Re: Converting to 1.75mm

Posted: May 17th, 2016, 6:00 pm
by Neotko
reibuehl wrote:I would be interested in the sources for the 2-6mm bowden.
Sure.

http://www.charlies3dt.com
This one ptfe never failed so far

https://reprapworld.com/?products_detai ... ts_id/438/
Once I got 2m from them that has the outter dia 5.9ish, and it slipped way too much even with taller clips it was problematic. But they have a very nice customer service and I bet they can caliper it before delivering. They sell a very very good mk7

And from china, I found this one, and it was quite ok, good center, and 6.0-6.1 outter dia. But this shop sells CRAP items, like very very very crappy. Don't even think about getting their cheap couplers/barrels, I bough some from them and it's just trash

http://aliexpress.com/item/3D-Printers- ... 82980.html

But this 6-2mm bowden now only it's cheap but it also works.

And that''s all I found in a year of searching :D

Oh also....

You could just use a 4-2mm ptfe, much easier to source, and drill the ptfecoupler just a bit with a 4mm bit to mark the bowden. Then it would be just a matter of using a smaller clip like the ones e3d sells. I never tested this but it should work.

Re: Converting to 1.75mm

Posted: May 29th, 2016, 12:39 pm
by Dim3nsioneer
Ok, hardware ist about ready. I have now the standard 2.85mm on the first extruder (with a bondtech) and the 1.75mm on the second extruder (with a modified Robert-feeder). Next step: Adjusting firmware. Any recommendations on which firmware basis to start?
Dual extrusion is no problem with any Marlin version in question. But what about having different feeders (=different e-steps)? What about individual PID-settings per hotend?

Re: Converting to 1.75mm

Posted: May 29th, 2016, 12:45 pm
by Neotko
Different PID. I know than tinkergnome pulled that from a rc long ago. But I have no idea where he explained it. Oficial firmware doesn't allow 2 pid for hotends.

Two esteps. Same think.

The only fast way I know it's using different gcode headers so you change esteps/pid for a job with one or the second. On S3D you could make a macro to set a gcode if tool 0 or 1 it's used.

Anyway, you might need to google/dig ultimaker to find where tinkergnome explained how to use that dual pid.

Re: Converting to 1.75mm

Posted: May 29th, 2016, 1:16 pm
by Dim3nsioneer
Ah, silly me. I didn't think of putting the information into gcode. It's probably the easiest and fastest way. Thanks!

Re: Converting to 1.75mm

Posted: June 4th, 2016, 1:41 pm
by Dim3nsioneer
Made my first 1.75mm prints today. Worked flawless.
Used equipement:
- Robert-feeder mirrored (as it is feeder two) with 1.75mm filament guide and adjusted body (what's the best way to put this on Youmagine - is there a 'submit derived' function?)
- standard knurled bolt
- 3mm/2mm PTFE tube inside standard Bowden (had to cut it to 3 pieces as friction didn't allow to push it in a one piece)
- 1.75mm TFT coupler
- Anders' spring replacement
- 1.75mm Olsson Block
- 0.4mm nozzle for 1.75mm filament

Edit 06.06.2016: Modified Body of Robert's feeder

Re: Converting to 1.75mm

Posted: June 4th, 2016, 2:02 pm
by Neotko
Test a 10k retract on 1-2h and you might get filament chew. Basic um2 bolt works, but it has it's problems on long term.

Re: Converting to 1.75mm

Posted: June 5th, 2016, 2:24 am
by Dim3nsioneer
MK7 is ready to be mounted... ;-) Just needs a different filament guide

Re: Converting to 1.75mm

Posted: June 5th, 2016, 3:31 am
by Neotko

Re: Converting to 1.75mm

Posted: June 5th, 2016, 5:45 am
by Dim3nsioneer
Yes, but for 1.75mm filament.

Re: Converting to 1.75mm

Posted: June 5th, 2016, 8:40 am
by Neotko
Works for me. Ahh you want to make the hole smaller. Makes sense. I never had a problem with that and 1.75mm

I would reprint it in a slippery material like pla-tec. In fact that's a great idea.

Btw since 1.75 heats faster I modded a bit the feeders for the summer with some heatsinks sticked with alutape and its handling quite nice the 30C that we have here on spain. I had an incident two weeks ago when the heat arrived but so far 70h print on each machine and no problems.