What is the difference between bondtech BMG vs the stock i3 mk3s extruder  

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

No diameter reduction in the hot end may lessen jams.

I would not worry about it unless clogs are a problem.

From what I have read, the upgrade from the MK3S is not worth the cost otherwise.

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

@robert-rmm200

Slightly late to the post but hopefully next visitors will read the comment.

I would argue that quite substantially. The reduction in weight mean less artifacts such as ringing or significantly higher speed can be achieved, the 3:1 ratio means higher resolution of extruding, the surface finish is significantly better. But you can either believe someone who hasn't got proof, or look at actual differences yourself: 

https://amp.reddit.com/r/prusa3d/comments/axrzgv/just_installed_the_bondtech_extruder_can_you/

(Different title but image shows stock vs bondtech vs 0.9 stepper) https://www.google.com/amp/s/amp.reddit.com/r/3Dprinting/comments/byoo9y/more_tinkering_with_the_mk3s_adding_9_moons_on_x/   

So, yeah, depending on quality you want to achieve, I would say that bondtech is definitely worth it.

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

Prusa prints  very good so a update is not needed.

If you do maintenance on your printer, it will keep printing good quality.

Al, updates do nothing or only a little , just like the bear update, possible you could get a little more speed from the bear upgrade, but for home use it is not needed. A lot of people like thickening with the printer.

And also updates from prusa do not work anymore.

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

@peter-m26

Literally couldn't agree more. For basic use, yeah, you wont need any updates. The prusa mk3s by default prints phenomenally, but if you're a hobbyist or have a print farm, or need the prints to be as precise as possible. There are many upgrades that help with this. By default mk3s has a few minor issues such as issue 602 on gihub. There are upgrades that are worth the money and there are some that aren't. The bondtech extruder is that £100 but it's worth it. It provides faster print since its lighter, more power so less heatcreap, higher ratio so better accuracy and reduction of the issue 602. There are others such as moons motors on x and y, which are also about £100 but the quality isnt worth £100, so in my opinion I would skip that unless you have too much money. Why don't you print the cube and compare it to the links I sent ? 0.9 steppers, again, they are cheap but you need to edit alot of the code which I personally dont like, but for other who understand coding, it's a huge upgrade (link 2) See if there is a difference between your "maintained" printer and bmg ? So No, the updates dont do "little" they make a huge difference if you know how to do them right. 

Also, bmg is still supported by prusa updates. You just need to send 1 extra command to change steps... or download it from bondtech website who have done that already for us.

Its your own opinion that it's not worth it which I value but I'm sorry, I strongly disagree, bmg provides the best upgrade for your money by far. If it didnt, they wouldn't be making extruders for every printer avaiable and people wouldn't be buying them. 

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

@peter-m26

Literally couldn't agree more. For basic use, yeah, you wont need any updates. The prusa mk3s by default prints phenomenally, but if you're a hobbyist or have a print farm, or need the prints to be as precise as possible. There are many upgrades that help with this. By default mk3s has a few minor issues such as issue 602 on gihub. There are upgrades that are worth the money and there are some that aren't. The bondtech extruder is that £100 but it's worth it. It provides faster print since its lighter, more power so less heatcreap, higher ratio so better accuracy and reduction of the issue 602. There are others such as moons motors on x and y, which are also about £100 but the quality isnt worth £100, so in my opinion I would skip that unless you have too much money. Why don't you print the cube and compare it to the links I sent ? 0.9 steppers, again, they are cheap but you need to edit alot of the code which I personally dont like, but for other who understand coding, it's a huge upgrade (link 2) See if there is a difference between your "maintained" printer and bmg ? So No, the updates dont do "little" they make a huge difference if you know how to do them right. 

Also, bmg is still supported by prusa updates. You just need to send 1 extra command to change steps... or download it from bondtech website who have done that already for us.

Its your own opinion that it's not worth it which I value but I'm sorry, I strongly disagree, bmg provides the best upgrade for your money by far. If it didnt, they wouldn't be making extruders for every printer avaiable and people wouldn't be buying them. 

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

I am totally at my wits end.   I wanted a faster printing solution so upgraded to BMG/Mosquito.   (£££££)

Since then my prints have been absolutely rubbish.   I have dismantled/reassembled several times and cannot find the cause of the problem.   First layer calibration has been repeated at least 10 times. 

The issue is underextrusion and skipping/clicking.  It is really difficult to get a decent first layer unless I turn the speed right down (25%).   If I then up the speed to anything over 50% I get the underextrusion issue.   

I am using PETG (which I have used successfully ever since I got my Prusa) and have experimented with different PrusaSlicer settings with no improvement.   I am now using default Prusament settings which always worked previously.

Yes,  I did use the Bondtech Einsy firmware  to get the correct stepper settings.

Looking at the extruder,  I have tried every possible gear tension setting.  The filament feeds through nicely into the Hotend and the gears are aligned correctly.  The nozzle is clean and I have tried swapping nozzles (including 0.4 and 0.6mm).   I tried with a brand new unopened reel of filament.   

Nothing makes any difference.   I attach a photo of the sort of problem I get.   When it is printing,  there is random clicking and although the motor appears to be turning it is not feeding.

I am so fed up with this that I am on the verge of going back to my original Prusa extruder.   I paid all this money out to get a better and more reliable experience but it has been a very expensive disaster.

Has anyone got any suggestions for anything I may have overlooked?

Peter

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

@drpeej

I would walk back slowly through the installation process step by step and make sure you did everything 100% based on the instructions. Also like part by part and make sure there are no kinks of problems with the tubing.  PTFE tubing not being long enough or too long can creat an issue.  

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

@cwbullet

Thanks for the advice but I've already done that!  Dismantled right back to the gear installation.    I've taken this thing apart and reassembled it again about 5-6 times.  The PTFE tubing isn't the problem as it comes pre-cut with the Mosquito hotend kit.  The filament can be pushed smoothly right down into the hotend with the gear door open.  

Peter

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

Maybe the gcode that sets the extruder current in Prusaslicer is interfering with your extruder motor? Just spitballing here.

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

@drpeej

Can you send us a video showing whats happening. Send us

-extruder motor moving freely so we can rule out broken gears / wiring/ motor skipping steps (Load or unload filament) 

- preheat nozzle to 250, unscrew gear tensioning, push filament with your hand and see if its comming out freely. Pla should come out like water at 250 without any resistance. 

- fan cooling, are you sure there isn't any heatcreep ?

- could your thermistor be displaying wrong temperature and its too cold to extrude ? Can you try pid calibration? Check cables are plugged in fully? Check sensor cables are damaged ? 

- are you sure that you have installed the mosquito bondtech firmware ? There is many bondtech firmwares. 

Sorry for some questions being patronising or stupid but I have to rule out all the basic things. Send us videos or an update with all the points and ill see what else I can recommend. I'm using the bondtech upgrades and I've never had any of the issues so I know its not the design issue. 

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

Thanks for the detailed reply.  The one thing I havent done is PID calibration.  It would certainly make sense if the heatblock temperature was wrong.   It's a new thermistor (the HT version) and I have just noticed that I am using the FW391-Build4017-Bondtech-MK3S-16-EINSy10a-SliceE_HT-Mosquito_Magnum.hex firmware.  I presume I shouldnt be using a magnum version.

It's certainly something to explore before I resort to Hex screwdrivers again.

Peter

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

I think I have narrowed down where the problem is.

I updated the firmware and ran PID calibration but it made no difference.

I then discovered that the clicking is coming from the gearing between the motor shaft and the large plastic gear on the main shaft.

I found this out by running the extruder motor while pressing the extruder gear which is fixed on the main shaft with my finger through the flap at the side.   With very little pressure on this gear,  the clicking occurs and the main shaft does not rotate although the motor shaft continues to rotate.   There is very little torque before the clicking occurs   Clearly something is happening with the gear which is not meshing properly with the motor shaft.   

I took special care to make sure that the gear was properly inserted,  following the instructions,   but I will have to take it all apart to check the gear again 🙁 

Peter

RE: What is the difference between bondtech BMG vs the stock i3 mk3s extruder

Thanks for the advice I received on here about this problem.   As a result,  I am glad to report that this problem is now fixed.   

The cause was mechanical and related to the large plastic gear that was not meshing properly with the small gear on the motor shaft.

After yet another disassembly I discovered that the gear drive shaft was not seating properly in its socket.   

It is now running like a dream so I am happy.

Peter