The Mighty UM2go

[Labern 774]

Hey.

 

It's uses 2.85 but the default feeder is very weak. If the PTFE coupler is old then it won't feed properly and may need replacing. 

 

You should be able to edit and create material profiles on the printer menu or downloading the material data onto the sd card then editing the text file. 

 

There are heat bed kits on eBay that look quite good. Like the UM2+ pcb ones. But I haven't tried one. 

 

I laser cut my own front door and haven't made a top enclosure for it though.

 

No problem using flex plate. Look on eBay as there are a few UM2go things on there. Quality can vary but as UM didn't sell huge numbers of the UM2go it's hard to find proper stores with parts for them. 

[medicalmodeller 5]

Thanks

 

I suspect this is a dumb question but what would happen if you created the Gcode with the U2 profile in Cura and then used the gcode on the U2Go?

 

I have a friend with a laser cutter.    Any chance you can share the dxf for the front door?

[Labern 774]

It will crash in the corner of the printer as the x y coordinates will be off. 

 

Sure I will share them this weekend some time. 

[medicalmodeller 5]

Why does the upgrade kit come with new rods as they seem the same diameter as the existing ones

 

MM

Edited August 23, 2020 by medicalmodeller

[tinkergnome 927]

2 hours ago, medicalmodeller said:

Why does the upgrade kit come with new rods

 

Point 5. on this page is the same explanation that i heard of ("just in case..."):

https://fbrc8.com/products/um2-extrusion-train-upgrade-kit

 

I think you can keep using the old ones if they are still in a good shape.

 

[medicalmodeller 5]

 

 

MM

Quote

 

 

Edited August 23, 2020 by medicalmodeller
Accidental duplicate

[medicalmodeller 5]

Thanks

 

1) Can I ask about the wires for the feeder stepper motor.   The upgrade kit comes with a new stepper motor for the feeder.  Since this is designed for the new feeder, do the wires need reversing?   If they do, which wires do I reverse out of the 4?   I have a 4 pin JST male and female so can create a new plug

 

2) The new feeder is wider than the original.   As a result the mounting plate and the feeder abuts the side panel which stops them lying flat against the back surface.   What is the best way around this?  I cannot put a spacer under the mounting plate as the stepper cog would then not engage with the cog in the feeder.   One option is to cut a way a section of side panel??? However the metal plate would sit over the two screws at the top which would prevent the metal plate lying perfectly flat.   Would this cause wear of the cogs?

Alternatively I could drill new holes to move the feeder 6mm towards the middle and down to avoid the back plate screws??

 

Thanks

 

MM

Edited August 24, 2020 by medicalmodeller
Another 2 questions

[Labern 774]

Yes the wires still need swapping as when you install the kit on an UM2 ultimaker tell you to install the UM2+ firmware. In this firmware the direction is reversed. Swapping the wires allows you to reverse it without firmware change.

 

Not sure about motor size difference. I'm sure when I j stalled the kit on my um2 it was the same size as the old one.

 

I would stick to the original um2go feeder then. It will also give your feeder better resolution.

[medicalmodeller 5]

There are 4 wires (2 pairs) to the stepper motor.  Which ones do I swap?

 

The stepper motor is not bigger, it is the feeder itself.  The feeder is the same as the one on my U2+ and U3 and much beefier than the one that came with the U2Go.  I think I will move the feeder by drilling new holes in the back plate.  No one will see once it's in place.

 

Thanks

 

MM

[Labern 774]

Ahh yes now I remember. The model I designed rotates the feeder around a bit so it would fit. Drilling 2 holes is probably the best option.

 

Swap the 2 outer wires. 

[medicalmodeller 5]

Now back so continuing the upgrade.

I bought a 22mm hole cutter to make the bigger hole for the stepper motor.  Printed a drill guide to go into the metal backing plate to centre the pilot hole for the hole cutter.  I drilled 4 x 3.5mm holes for the retaining screws that go into the motor and used them to hold the metal backing plate.     Hopeless!   The hole cutter would not stay located even with the pilot hole.

 

So I used the backing plate as a guide and used a Dremel to cut away to make the 22mm hole.  After some fine tuning, new stepper and new feeder now installed on the back of the U2Go

 

Now to swap wires.

 

Do I need new firmware or not?

 

Thanks

 

 

[medicalmodeller 5]

Help!

I installed the new feeder motor.   I cut off the original JST connector and swapped the outer wires.   I do not have a crimper for JST so used surgical clip to squeeze the crimp

So the wires were originally Black, Green, Red Blue - shown in photo with connector off the board.    Now they are Blue Green Red Black as shown with connector on the board

 

When I test with the change material command, the motor does not spin.

If I connect the original motor JST  it does spin with the remove material step

 

Can I double check that I have reversed the wires correctly? Of course it could my poor quality crimp but before doing again I wish to know that the order is correct

 

Thanks

[tinkergnome 927]

The goal is to swap the current in one set of coils. I think that one has to swap the wires of exactly one twisted pair (but not sure).

black <-> green  or  red <-> blue - but not both.

 

Or use the methods from this article to find a pair:

https://reprap.org/wiki/Stepper_wiring

 

[medicalmodeller 5]

Good link.   It says..........................................

 

To get the motor moving in the right direction, is actually does matter which coil is which and what the polarity of the coils are. However, if they're wrong, the motor just turns the wrong way, it's easy to fix that by swapping wires. Pick one of the following in order to reverse the stepper's direction:

1. Switching the polarity of either (one) coil, like changing ABCD to BACD or ABCD to ABDC.
2. Swapping the coils, like changing ABCD to CDAB.

 

So back to re-do the wiring.  Probably best to invest in a crimping tool

 

TM

[Smithy 1,144]

When you install the Tinkergnome FW you can also reverse the direction there, so no need to swap the wires.

[gr5 2,170]

You don't need a crimping tool.  I can pop out these wires and slide them back in within seconds.

 

You need a small screwdriver or needle - a jewelers screwdriver - flat head - works well.

 

You push down on the metal thing in the hole and then you can slide the metal part out from the plastic part.  Then you can just slide it into a different hole until it snaps in.

 

[gr5 2,170]

Note that you can reverse servo direction in firmware as well.  If that's your goal.  I have 3 um2go printers and they all have the tinkerGnome version of the um2 software:

https://github.com/TinkerGnome/Ultimaker2Marlin/releases

 

To clarify: reversing direction in the default UM2go firmware requires changing data in Resources.h and rebuilding the firmware.  Doing it in tinkerMarlin you can do it easily in the menu right on the printer.

[medicalmodeller 5]

Bloody hell!.   I reversed just one pair of the wires.   Now the motor works but in the wrong direction.  When I set it to unload it pulls filament up.   When it tries to feed the new filament, it pushes it out.   

 

So finally wired the JST back to how it was originally and the motor seems to work correctly.   It spits out filament when unloading and pulls it in when loading.    

 

So how come I was advised to reverse the motor.  Is there something else I do not know?

 

TM

Edited September 15, 2020 by medicalmodeller
More info

[Torgeir 242]

Hi medicalmodeller,

 

Somehow, -something went wrong.. Try to swap it again!

This change of feeder, will mechanical change direction, -so your wire swap -somehow failed..

Just do it again, -and it will work..  🙂

 

Thanks

Regards

Torgeir

 

 

 

 

 

 

[medicalmodeller 5]

If you have three U2Go+ do all have heated beds?  If they do, which one have you fitted?

 

Do you have a printer profile for Cura of the modified U2Go+?

 

Finally, I have successfully printed a calibration cube.  One thing I found that when loading the filament, the fast travel got the end only about 1/2 way along the Bowden tube.  If I load tinkerMarlin, can I make it go to the print head as it should?

 

Many Thanks

 

MM

Edited September 16, 2020 by medicalmodeller

[gr5 2,170]

5 hours ago, medicalmodeller said:

One thing I found that when loading the filament, the fast travel got the end only about 1/2 way along the Bowden tube.

That's a bad sign.  Your steps/mm is probably off by exactly 2X.  The most common steppers are either 100 or 200 steps per rotation.  You may have the 100 steps per rotation type of stepper.

 

If the above issue (1/2 way down bowden) is the *only* issue then that is difficult to fix.  But if your steps are off by 2X then that is easy to fix in tinkerMarlin as you can set the steps/mm for each axis separately in the menus.

[gr5 2,170]

All 3 of my um2go's have a heated bed, and olsson block.  The Olsson block lets you change nozzles.

 

2 of my um2gos have the Meduza and iRoberti combination feeder upgrade (as it is almost free and I'm cheap).  My 3rd um2go has the original black feeder.

 

I sell heated beds for um2go but don't normally ship to Europe (but will make an exception for you if you want).  I'd prefer you buy um2go heated beds from 3dsolex if they have any left (I believe he stopped buying them so not many left).

 

[medicalmodeller 5]

Duh!   The Bowden tube that comes with the Ultimaker upgrade kit is intended for an Ultimaker 2 and not an Ultimaker2Go.   So its almost twice as long!  So I need to put the original tube in place and accept that the wires will be too long and not neat

 

I will try and buy a heated bed from https://thegr5store.com/store/index.php/ as apparently his one does not smell!

 

Getting there.

 

Thanks

 

MM

[gr5 2,170]

The bowden is pretty easy to cut to length.  The bowden is not symmetrical.  One end has a conical inside reamed out to guide the filament into the bowden at the feeder end.  UM used to mark that end with a piece of tape.  You can tell which is which by looking into both ends and looking at the inside diameter.

 

When cutting the bowden, cut the other end far from the feeder.  Make it the same length as the original bowden that came with the printer.  If you are off by a few cm it's fine.

[medicalmodeller 5]

If I update the firmware to the tinkerGnome firmware for UM2, will the firmware expect the Bowden tube to be the length of the tube on an U2?  

 

For now, I can simply use the shorter Bowden tube that came with the U2Go.   Good to know that its not the same at both ends

 

Thanks

 

Boyd