Migbot Prusa i3 Unofficial Support Thread

agree E3DV6 is a very good hotend and no pain in ass. i would say MK8 type i have no issue on it, no blockage after i come up the way of using of course it troublesome to keep cleaning the throat with ABS but i will never say it's not good, I would say all hotend have good and bad and the only issue is how you use, that's all.

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evetanlm
agree E3DV6 is a very good hotend and no pain in ass. i would say MK8 type i have no issue on it, no blockage after i come up the way of using of course it troublesome to keep cleaning the throat with ABS but i will never say it's not good, I would say all hotend have good and bad and the only issue is how you use, that's all.

It's been proven several time that the MK8 is flawed, they are very prone to heat creep, which is why you get a lot of blockages with them, sure they work, but you'll never be free of that heat creep issue causing blockages. Sure the Lite6 isn't totally ideal as you need to make sure the PTFE is butted up firmly with the nozzle and the radiator is stainless steel which doesn't have as good thermal dissipation properties as Aluminium, but it stands head and shoulders over the MK8, for print quality, heat dissipation and heat creep. The Lite6 (what I would recommend for a Migbot as you're not really going to be printing fast), is not an all metal hot end, it uses standard Bowden tubing as a PTFE liner which butts up against the nozzle, hence why it is cheaper than a full blown v6. There's really no excuse to not upgrade it, you don't even have to design a mount as my one is up on Thingiverse.

1)Buy Lite6
2) Print Mount
3) Install
4)???
5) Profit.

I may be coming over heavy, but you're talking to someone who has been through it all and has had 4 Migbots running at once. Ultimately, it's your choice, and I don't disrespect that, I'm just trying to save the you the pain that I had with it.

I was able to kill my MK8 (all metal) heat creep doing the following.

(1) insulate hot end..
wrap it in insulation, then kapton that very well. make sure the tape is smooth on print side or you'll pickup filament.
this will require you to calibrate the PID again, or at least you definitely should.

(2) force cooling fan through drive system.
got to be creative with the kapton here. carefully folding it to create seals around moving parts, etc. I sealed all the way around the fan, heatsink, to the moving arm and back to the stepper.
The intent was to force all of the air through the hole in the heat sink. I enlarged mine a little as well as cut the fins to have a taper away from the hole. This puts a fair amount of direct airflow into the drive.
You cannot have airflow without an exhaust path. I chose to drill a two holes (1/8"-3mm) next to the threaded shaft feeding the hotend. Followed this up with slot cut into the metal bracket that allowed me to bend the bracket unto the drilled holes to create a diverter or duct for the exhaust air. This directed it airflow across the threaded shaft at the heat choke to help while keeping the airflow from pointing at the hotend or print area.

(3) I drilled through the MK8 and swapped the threaded shaft to allow a single piece of ptfe tubing from drive to tip.(drill for a press and then freeze the tubing to allow it to slide in) Pretty sure the threaded shaft stops the tube just before it would exit. Be sure to get a threaded shaft that has the reduced, or necked down, heat choke. (Heat transfer is very much a function of cross sectional area) Of course the tubing did not really want to behave, so I used a sharp razor to create a sort of thread-like scoring. Did this in such a way that it work one way. Like a fish hook, or one of those christmas tree plastic things that snap in holes. So it will slide towards the hotend but not back into the drive during retracts. Slide the tube all the way in and then trim to match your drive and idler. Ohh, and use that sharp razor to make sure the tube is clean where you cut it, or even give it a very slight bell or bevel.


While working with the heatsink I changed the mounting to allow me to only have one bolt holding the heatsink on. The second bolt holds only the stepper, while the first is a slot. This way I can loosen one bolt and slide the heatsink and fan off as an assembly. I also decided that the heatsink needs to have thermal paste in the area where it is actually in contact with the drive mount.

If I was to swap to the V6, I would very much want to one with the tube holder embedded into the body (not a separate fitting). This would allow the same full length tube, top to bottom, and also better control it without needing my nonsense retention method. I do have everything needed to swap now, but have several hundred hours printing without issue after doing the above while waiting for parts. I am able to run with far less tension on the mk8 spring as well. Running at 225 was risky, and 230 would fail after about an hour every time. Now I print at 238-242 and never have issue, although my longest print time has only been 18hrs.

Anyway, hope that helps someone.
Side note.. I've found it is often cheaper to by a knockoff v6 or lite to get the stainless threaded tube vs buying only the tube. Pretty sure a crappy V6 is better than none, so next time the machine stops it's getting the swap. .

Ax, im sorry which you love Migbot so much, frankly i didn't find that one is a good piece as from time after time it will have problem which i have notice, as for the MK 8 extruder which come with it, i didn't have jam and use on daily base, this is the truth, E3D V6 i do have it and i also have the replica one, i really found no much different in them, for replica one you just need to do some work to make it better, I believe you have 4 migbot but i also have quite a number of different prusa from different company, which i'm testing on them, as for migbot if you use it for long you will see the acrylic frame slowly bend as it using is a recycle type of acrylic and also when you printing ABS, the heat bed holder will bend, i'm not a designer but i just a product tester, i have 5 prusa from different company, and some other type which i'm doing testing, my experience is not only on one type. this forum is not going to be rude to anyone, it's to share experience with everyone, in order to help each other grow in knowledge that's all. we can't force anyone to use what product, we only suggest and see whether the knowledge you share will help them a not. that's all and not pin point anyone. Hope for your kind understanding in the forum.

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evetanlm
Ax, im sorry which you love Migbot so much, frankly i didn't find that one is a good piece as from time after time it will have problem which i have notice, as for the MK 8 extruder which come with it, i didn't have jam and use on daily base, this is the truth, E3D V6 i do have it and i also have the replica one, i really found no much different in them, for replica one you just need to do some work to make it better, I believe you have 4 migbot but i also have quite a number of different prusa from different company, which i'm testing on them, as for migbot if you use it for long you will see the acrylic frame slowly bend as it using is a recycle type of acrylic and also when you printing ABS, the heat bed holder will bend, i'm not a designer but i just a product tester, i have 5 prusa from different company, and some other type which i'm doing testing, my experience is not only on one type. this forum is not going to be rude to anyone, it's to share experience with everyone, in order to help each other grow in knowledge that's all. we can't force anyone to use what product, we only suggest and see whether the knowledge you share will help them a not. that's all and not pin point anyone. Hope for your kind understanding in the forum.

I didn't mean to make it sound like I was having a go nor actually be rude to you, this is just my experience, and one I feel passionately about. All I'm trying to do here is to help those that have a Migbot and help them bypass my frustrations with them, which a lot of people have had. I reference my firmware version and recommending the Lite6 upgrade, here. After sorting the firmware properly, (the stock is horrendous, who the hell thinks an acrylic framed printer can run 3000mm/min accelleration) and adding a Lite6, they're an OK, printer, but nothing like my FB2020 CoreXY Design. I'm fully aware that the acrylic frame can warp and bend, and a mount for an E3D, if printed in the correct plastic, like PETG or ABS, shouldn't warp. I'll soon be offering an aluminium frame upgrade kit, which will stiffen the whole thing up. The 4 Migbots I have probably have a combined usage of 10,000 hours, being used to print commercially, I know them inside and out. All I'm trying to do here is actually reduce peoples frustrations so they can just get on and print.

Not sure while the levels got turned up here.. We can all just click the next link and move on (this rule does not apply to ax as he has been far to helpful to too many). Seriously though, why get wound up, read it, use it or discard it.
I've found the migbot to do a fine job if speed turned down to a creep and replace most of the parts. Loctite or nyloc everything, and spend tons of time tweaking firmware and slicer settings... It's a great printer and working very well at printing out its replacement right now. Obviously the cost is reflected in the quality, and for the $$ you get a lot.

Now, ax, how about a link to the corexy info!

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gotswrv
Not sure while the levels got turned up here.. We can all just click the next link and move on (this rule does not apply to ax as he has been far to helpful to too many). Seriously though, why get wound up, read it, use it or discard it.
I've found the migbot to do a fine job if speed turned down to a creep and replace most of the parts. Loctite or nyloc everything, and spend tons of time tweaking firmware and slicer settings... It's a great printer and working very well at printing out its replacement right now. Obviously the cost is reflected in the quality, and for the $$ you get a lot.

Now, ax, how about a link to the corexy info!

Things do need dropping a notch, each time I did say use the info or not, but not one for arguments, so look *points * FB2020 CoreXY info!

AX, I'm having a problem loading your new RC6 firmware to my machine, Im using the standard bed auto leveling enabled version. When I try to compile the firmware I get the following error message...

exit status 1
'min_software_endstops' was not declared in this scope

Which then directs me to the Marlin_main.cpp tab with

if (min_software_endstops) {

Highlighted. Any advice? Thanks.

NVM I found the problem #define min_software_endstops was commented out.

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GouldShaw
NVM I found the problem #define min_software_endstops was commented out.

derp, I'll get that fixed, should be set to false..

::Edit - Clarification::
min_software_endstops should be set to false for auto levelling only. This allows for the setting of the probe offset.

Edited 1 time(s). Last edit at 06/02/2016 07:26AM by Ax.

Im looking into a 300x200 bed upgrade using the BQ hephestos bed upgrade kit as a template. Just a quick question. What size smooth rods and threaded rods do our machines have?

Edited 1 time(s). Last edit at 06/10/2016 04:01AM by veaceonee.

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veaceonee
Im looking into a 300x200 bed upgrade using the BQ hephestos bed upgrade kit as a template. Just a quick question. What size smooth rods and threaded rods do our machines have?

8mm Diameter smooth rods, M8 Threaded, both 400mm long. Personally, looking at this now, I'd be looking at upgrading both to 10mm diameter to stop any torsional twisting.

If Im going to upgrade to 10mm diameter, then I should just buy this kit. It comes with everything needed. Then, just go on Amazon and get a heated bed for it, done. that makes it even easier (but not cheaper).

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veaceonee
If Im going to upgrade to 10mm diameter, then I should just buy this kit. It comes with everything needed. Then, just go on Amazon and get a heated bed for it, done. that makes it even easier (but not cheaper).

True, but it's probably better to try and hunt down parts separately if you want to save money. Also be aware that you'l need to modify the acrylic parts to fit the 10mm rods. As a note, unless you're going for a silicone heater, the standard MK2B that comes with the Migbot will work for the larger bed, after all, it's what the large bed version uses, admittedly, it's not ideal though.

This may have been covered before but I have just had a weird thing happen.
When saving a new .gcode file to my SD card and installing it in the printer to print it would be listed as the top file easy to find and always listed by most recent file. Now whenever I save a file to the SD card it lists totally random on the printer making it frustrating to find the most recent file now having to search through the whole list until I can find it. It doesn't seem to be in any order at all.
I have no idea why this is so and hoping someone here might know a fix. If I have changed anything I don't know what it was.

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IBaz
This may have been covered before but I have just had a weird thing happen.
When saving a new .gcode file to my SD card and installing it in the printer to print it would be listed as the top file easy to find and always listed by most recent file. Now whenever I save a file to the SD card it lists totally random on the printer making it frustrating to find the most recent file now having to search through the whole list until I can find it. It doesn't seem to be in any order at all.
I have no idea why this is so and hoping someone here might know a fix. If I have changed anything I don't know what it was.

Did you change or upload new firmware? That's the only way that that can happen.

I am running a version of your firmware but have been for ages, long before this problem started. I have not changed any settings that I know of, seems a very strange thing indeed.

Speaking of extruders, I got a new all metal mk8... Doesn't fit right out of the box. Is there already a known solution to mount the thing on, or do I need to just mod it to fit on the carriage?

I had the original one on previously, and this is the common all metal version found on eBay

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pRO84
Speaking of extruders, I got a new all metal mk8... Doesn't fit right out of the box. Is there already a known solution to mount the thing on, or do I need to just mod it to fit on the carriage?

I had the original one on previously, and this is the common all metal version found on eBay

Most probably the latter...

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IBaz
I am running a version of your firmware but have been for ages, long before this problem started. I have not changed any settings that I know of, seems a very strange thing indeed.

Strange, note down yer settings and grab the 1.1 RC6 version. See if that helps..

My printer has been printing things mirrored on the Y axis. I can flip it in Cura, but would rather fix it on the firmware. I tried inverting the stepper direction, but now the stepper just isn’t moving. Is there another setting I need to change? I also changed the end stop from min to max, and back with no movement.

Every time I change filaments recently, it jams in the throat. What am I doing wrong? How do you guys change out filaments?

I have found a few different steel frames for the Prusa i3, thinking of converting my Migbot to steel. Has anyone else done this? If so, have a link? I have yet to find one that includes a space for the LCD panel.

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AccidentalWisdom
I have found a few different steel frames for the Prusa i3, thinking of converting my Migbot to steel. Has anyone else done this? If so, have a link? I have yet to find one that includes a space for the LCD panel.

I was looking at doing something like this, but you're probably better off looking at building an entirely different printer. Core XY is the flavor of the month at the moment. And that way you have a backup if you need to print/reprint something. If you do buy a frame, I wouldn't worry about the display not having a cut out, just print up an enclosure for it - there's about a million variations on Thingiverse.

Thanks, buddy! I have sort of come to the same conclusion since posting. I like the Core XY style, another member on here is designing one and it looks great. I will probably mess about with this Migbot for a bit longer, learn more and then grab one of those.

[www.openbuilds.com]

I'm looking at building a C-Bot, I like the idea of the belts not crossing and there is a triple screw variant for the z axis which makes me happy. Cantilever and opposite side screws don't seem that stable to me.

Still, printing a few upgrades and bolting it to a solid base helps a lot with stability and print quality. I'm looking at you adjustable axis tension.

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InsaneCheese
[www.openbuilds.com]

I'm looking at building a C-Bot, I like the idea of the belts not crossing and there is a triple screw variant for the z axis which makes me happy. Cantilever and opposite side screws don't seem that stable to me.

Still, printing a few upgrades and bolting it to a solid base helps a lot with stability and print quality. I'm looking at you adjustable axis tension.

Cantilever's fine, take my FB2020 - 12mm Z rods solid as a rock, no Z wobble.

Hi fellas,

I recently got the SN04-N proximity sensor, shown below:

[www.amazon.com]

The cable contains a black, a blue and a brown wire. I have a 3-pin JST XH connector to solder these into to connect into the Z- slot (or Z+, maybe, if my firmware is configured that way), but I don't know the order that these wires should be oriented on the board (MKS Base V1.2). So, if I am looking a the board mounted on the Migbot, with the power-from-PSU slot in the top-left corner, in what order should these black, blue and brown wires be in the Z-/+ slot from top to bottom?

One more question - I have two 40mm fans mounted on ducts for cooling the nozzle/filament. Each has a very high gauge pair of wires (black/red, probably at least 28AWG). Would it be ok to take the red wires from both fans and solder them into a single red wire which then runs to the "Fan" slot on the board (and the same for the black wires)? And if that is ok, should I use a lower gauge of wire for the single wire the fans will be soldered in to, like 20AWG, just to ensure that enough current is carried through to power both?

Blue = common
Brown = positive
Black = signal

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gotswrv
Blue = common
Brown = positive
Black = signal

Thank you, gotswrv. Is this just a description of each wire's function, or do you also mean that in order from top to bottom on the board the wires should be Blue = Top / Brown = Middle / Black = Bottom?

Edited 1 time(s). Last edit at 08/02/2016 01:02PM by AccidentalWisdom.

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AccidentalWisdom
Hi fellas,

I recently got the SN04-N proximity sensor, shown below:

[www.amazon.com]

The cable contains a black, a blue and a brown wire. I have a 3-pin JST XH connector to solder these into to connect into the Z- slot (or Z+, maybe, if my firmware is configured that way), but I don't know the order that these wires should be oriented on the board (MKS Base V1.2). So, if I am looking a the board mounted on the Migbot, with the power-from-PSU slot in the top-left corner, in what order should these black, blue and brown wires be in the Z-/+ slot from top to bottom?

One more question - I have two 40mm fans mounted on ducts for cooling the nozzle/filament. Each has a very high gauge pair of wires (black/red, probably at least 28AWG). Would it be ok to take the red wires from both fans and solder them into a single red wire which then runs to the "Fan" slot on the board (and the same for the black wires)? And if that is ok, should I use a lower gauge of wire for the single wire the fans will be soldered in to, like 20AWG, just to ensure that enough current is carried through to power both?

I received a solid answer on this outside the forum. The order of the SN04-N wires on the MKS Base v1.2 board from top to bottom should be Black, Blue, Brown. The sensor is wired in this way on my Migbot and the sensor is running correctly (though still working on getting the position right!).

In answer to my other question about running the four wires of two 40mm fans into a single red and single black wire, this is also fine. I was told it isn't necessary to up the wire gauge, but since I had only 20 and 24 AWG, I went with the 24 AWG.

Hope this helps others.