Revo Micro installation on my Mini+  

RE: Revo Micro installation on my Mini+

I went with 300mm and that seemed like the perfect length.

Posted by: @singlefin

Thank you for quick reply.   Total length of Bowden on my Mini+ now is one continuous tube of 320.3mm (the 275mm that's visible between extruder and top of hot end + 35.3mm inside the Bondtech heat break + 10mm inside the Bondtech extruder just after the extruding gears to brass fitting). 

So am I correct to assume that the PTFE tube in the stock or Bondtech heat break should be subtracted? since the Revo Micro with the integrated heat break. 

New total length should be 285mm (275mm visible + 10mm inside the extruder)?  Sorry I just need to have someone else check to make sure my logic is ok.

Thanks

RE: Revo Micro installation on my Mini+

So far I'm extremely disappointed. First I did a number of short (5 minute) test prints to get the live Z right and had no issues. Then on my first real print the filament clogged and the extruder started clicking after 5 minutes. I couldn't purge but I could unload. The display read 220C. I disconnected the bowden tube at the hotend and did a cold pull. Looked inside the hotend and saw nothing unusual. Restarted the print and it seemed to do fine for 1.5 hours until it got near the end. The top layer looks awful. Not the entire top layer just a few spots. Huge blobs of filament that ruined the print.

I contacted E3D support and waiting for their reply. But I have this feeling I'll be reinstalling the old hotend and going back to dealing with the shrinking hotend PTFE tube every 2 months.

If you're considering the Revo Micro you might want to consider holding off until they get the bugs worked out.

RE: Revo Micro installation on my Mini+

Unfortunately I have to agree, my first revo worked great for a week then the thermistor died. This second one had some kind of loose connection causing the hotend temp to be much higher than reported, I redid the connectors myself and it seems okish now but I have next to no faith left in this thing.

RE: Revo Micro installation on my Mini+

Posted by: @tracy

So far I'm extremely disappointed. First I did a number of short (5 minute) test prints to get the live Z right and had no issues. Then on my first real print the filament clogged and the extruder started clicking after 5 minutes. I couldn't purge but I could unload. The display read 220C. I disconnected the bowden tube at the hotend and did a cold pull. Looked inside the hotend and saw nothing unusual. Restarted the print and it seemed to do fine for 1.5 hours until it got near the end. The top layer looks awful. Not the entire top layer just a few spots. Huge blobs of filament that ruined the print.

I contacted E3D support and waiting for their reply. But I have this feeling I'll be reinstalling the old hotend and going back to dealing with the shrinking hotend PTFE tube every 2 months.

If you're considering the Revo Micro you might want to consider holding off until they get the bugs worked out.

What filament and nozzle size were you using?

I found that PLA, on 0.4mm nozzle, at anything less than 0.2mm layer height experience bad heat creep.

However, 0.6mm nozzle was OK. Also 0.6mm and 0.4mm nozzles with PETG, and ABS were also OK.

RE: Revo Micro installation on my Mini+

0.4mm nozzle, PLA and 0.2mm layer height.

Posted by: @pickworthi

 

Posted by: @tracy

So far I'm extremely disappointed. First I did a number of short (5 minute) test prints to get the live Z right and had no issues. Then on my first real print the filament clogged and the extruder started clicking after 5 minutes. I couldn't purge but I could unload. The display read 220C. I disconnected the bowden tube at the hotend and did a cold pull. Looked inside the hotend and saw nothing unusual. Restarted the print and it seemed to do fine for 1.5 hours until it got near the end. The top layer looks awful. Not the entire top layer just a few spots. Huge blobs of filament that ruined the print.

I contacted E3D support and waiting for their reply. But I have this feeling I'll be reinstalling the old hotend and going back to dealing with the shrinking hotend PTFE tube every 2 months.

If you're considering the Revo Micro you might want to consider holding off until they get the bugs worked out.

What filament and nozzle size were you using?

I found that PLA, on 0.4mm nozzle, at anything less than 0.2mm layer height experience bad heat creep.

However, 0.6mm nozzle was OK. Also 0.6mm and 0.4mm nozzles with PETG, and ABS were also OK.

RE: Revo Micro installation on my Mini+

Posted by: @joestinman

 

Posted by: @paulb

I think it might be these, but more reasonable with £4.95 delivery

https://uk.rs-online.com/web/p/brass-pipe-fittings/2936721

 

Even for me delivery with Pneuparts was 12 euros. I ordered them from RS. I still have enough spare PTFE to see if I can find the best length necessary.

I can confirm that the olives from RS are the right ones.

Also, after a mention on Reddit I checked the upgrade documentation on the E3D support site. They now mention that the Bowden tube should be made longer and now also recommend doing PID tuning. I am pretty sure that wasn't there before.

RE: Revo Micro installation on my Mini+

It definitely was not, if they are changing install instructions they should really alert people.

The one thing is clear to me though is when revo micro is working for me it enables a step change in the quality of the prints coming off my mini. I'm now off to do some input shaper tuning and see how fast I can really make this thing go.

RE: Revo Micro installation on my Mini+

It doesn't recommend PID tuning, just says 'If you feel the need to PID tune your Mini '.

They still say 'Prusa recommends not to PID tune the Min'. 

Good to hear they are the right olives, i will order some, as now I have used both my spares up. I did also end up with a 300,mm bowden tube, I have a Bondtech extruder and that seems to work fine.

What I'm not sorted on yet is start and end gcode to unload/reload filament to enable easy replacement of the nozzles. I started using the suggested gcode from the start of this thread, but that needs tuning for the different nozzle sizes.

Any suggestions are welcomed.

RE: Revo Micro installation on my Mini+

"Recommend" is quite an exaggeration.

If you find that the tube is a little short, you can get a new piece of Bowden tube, about 20 to 25mm longer than the existing tube, (300mm total) and add a new brass olive from your spares bag to one end.

If you feel the need to PID tune your Mini you can use pronterface and then add your generated PID values to the start G-code of your slicer.

They don't recommend anything like that. They have just listed the options so people know they don't prohibit these modifications.

RE: Revo Micro installation on my Mini+

Posted by: @joestinman

 

Posted by: @joestinman

 

Posted by: @paulb

I think it might be these, but more reasonable with £4.95 delivery

https://uk.rs-online.com/web/p/brass-pipe-fittings/2936721

 

Even for me delivery with Pneuparts was 12 euros. I ordered them from RS. I still have enough spare PTFE to see if I can find the best length necessary.

I can confirm that the olives from RS are the right ones.

Also, after a mention on Reddit I checked the upgrade documentation on the E3D support site. They now mention that the Bowden tube should be made longer and now also recommend doing PID tuning. I am pretty sure that wasn't there before.

The actual wording change is:

If you find that the tube is a little short, you can get a new piece of Bowden tube, about 20 to 25mm longer than the existing tube, (300mm total) and add a new brass olive from your spares bag to one end.

and:

Prusa recommends not to PID tune the Mini (Source here) and the auto PID tune command that is present on the MK3 is not available. Without custom firmware, you are also unable to save to EEPROM.
If you feel the need to PID tune your Mini you can use pronterface and then add your generated PID values to the start G-code of your slicer.

That reads like suggestions rather than recommendations to me.

I can see no need to PID tune on my mini - previously posted Octoprint track shows a solid temperature control at the set value.

I have had a look at Mini PID tuning before, and for me the tuned values were always worse than the Prusa algorithm.

I've printed several parts now, including 5 hour plus prints, using the .6mm nozzle. results are very good indeed. The only issue I have is with PLA and the .4mm nozzle, which appears to suffer from heat creep (i.e. the PLA forms a heat-break diameter plug while printing, which you can see when you retract the filament). This only happens with PLA on the .4mm nozzle - PETG and ABS print fine. The cause is beyond me at the momen.

RE: Revo Micro installation on my Mini+

That reads like suggestions rather than recommendations to me.

You and Lichtjaeger are right. They 'recommend'. I am not sure on the PID tuning necessity (I did do it) but making a longer Bowden tube should be a 'requirement' in my opinion.

For the ones suffering from heat creep; could it be that the cooling speed needs customisation? Maybe increase hot-end fan speed? Just taking a wild stab.

RE: Revo Micro installation on my Mini+

Unless i'm mistaken, I think the fan speed is fixed. Apparently they are looking at a three-cable fan option in the future.

RE: Revo Micro installation on my Mini+

To change the cooling fan speed you'd have to modify the prusa firmware as it's locked to only be at 50% power, llama is a good custom if you want to stay on marlin but I've made the jump to klipper and typically have that fan on 75%.

RE: Revo Micro installation on my Mini+

so one of the things i ended up doing was make the prime line height .5 as opposed to .2 in my starting g-code and that helped with the clogging issue. However, I still haven't figured out the heat creep issues. 

Posted by: @tracy

So far I'm extremely disappointed. First I did a number of short (5 minute) test prints to get the live Z right and had no issues. Then on my first real print the filament clogged and the extruder started clicking after 5 minutes. I couldn't purge but I could unload. The display read 220C. I disconnected the bowden tube at the hotend and did a cold pull. Looked inside the hotend and saw nothing unusual. Restarted the print and it seemed to do fine for 1.5 hours until it got near the end. The top layer looks awful. Not the entire top layer just a few spots. Huge blobs of filament that ruined the print.

I contacted E3D support and waiting for their reply. But I have this feeling I'll be reinstalling the old hotend and going back to dealing with the shrinking hotend PTFE tube every 2 months.

If you're considering the Revo Micro you might want to consider holding off until they get the bugs worked out.

RE: Revo Micro installation on my Mini+

I have changed my Bowden tube to one of 300mm length, and as others have reported this gives a nice stress free filament load and purge.

To remove the old Bowden tube I basically had to destroy it, it was in the hot end real tight. I inspected the inside, and there are four downward pointing retaining "clips", these grip the tube tightly if it is pulled upwards.

I thus have a question - what trick am I missing to get the Bowden tube out without a huge amount of force?

RE:

You remove the clip and press down on the connector at the top of the revo, it slides out nicely then.

If you've ripped it out the way you describe I hope you have made sure to remove any ptfe tube particles with a hover from the hotend.

RE: Revo Micro installation on my Mini+

Posted by: @sp4rkr4t

You remove the clip and press down on the connector at the top of the revo, it slides out nicely then.

 

If you've ripped it out the way you describe I hope you have made sure to remove any ptfe tube particles with a hover from the hotend.

Thanks. Obvious when pointed out 🙁 Could be in the documentation I guess.

Compressed air rather than hoover, but yes, cleaned before fitting.

RE: Revo Micro installation on my Mini+

Installed it, not happy with my wrapping job.  The issue is the hot end fan.  When I start or reset the Mini, the fan spins- but when I call for heat on the hot end it will start to heat up, but it won’t start the fan???? If I blow through the fan flick it with my finger, it will start to turn and keep turing until the hot end temp goes <50C?????

Hot end temp seems right, it heats up fast- so it seems the heater and the thermister are working- but the hotend fan won’t start spinning during a call for fan due to heat- but like I said, it will during a start-up…

Polarity seems fine- why would it spin on start-up, but not for when the hotend passes 50C?

Checked all the cables, like I said they all seem to work, the fan will spin, but not start…..

RE:

I don't believe the fan spins at 100% with most prints for the first few layers, as opposed to startup... Sounds like the fan won't spin up at lower voltages. You could always try plugging in the original fan and seeing if the behavior continues.

P.S. I am using Lichtjaeger's mod that uses the stock fan, another option for you.

RE: Revo Micro installation on my Mini+

This is a long shot, but you might check the routing of the wires as they come out of the fan casing. The illustrations in the instructions, which are mostly very well-done, don't show these wires or routing, nor describe how they should be placed. In my case, rather than route them around the outside of the mounting bracket, I turned them around 180 degrees immediately as they come out of the fan casing and follow the 90 degree dihedral angle in the bracket. I was a little uncomfortable that they might get pinched there and almost used a razor saw to cut a small groove  for the wires to lay in. Ultimately, I found it easier to  attach the hotend to the bracket first, THEN attach that assembly to the carriage. That seemed to result in less bending force on the hotend structure, and I could see that the wires were not pinched. If the wires are pinched between the bracket and the fan casing, or there is some other unremoved material on the bracket, that may result in a minute warping of the fan casing, that may cause enough friction on the fan rotor that it will not start, but will continue to turn if given a starting "boost". You might test this by loosening the nut that holds the hotend in the bracket  enough to allow some movement between the two. This could allow any warping of the fan casing to "relax". If that results in correct fan operation, you'll have to figure out where the binding is occurring, correct it and retighten the nut. Good luck and let us know how you make out.