Heated bed on UM2GO and in general

[2go 6]

Hello,

I've been printing for a few months on Printinz Zebra plate using Faberdashery PLA. Prints stick good, sometimes too good :)When the adhesion is too strong I have to remove the plate and twist it to release the print. Recently it got really annoying because once the plate is warped, I have to straighten it and recalibrate the bed.

So I am contemplating purchasing heated bed for UM2GO from 3dsolex. Two questions:

1. Anyone use it? Have good or bad experiences to share?

2. This is about printing on heated bed in general not necessarily on UM2GO. Is it reasonable to expect regular PLA to stick well to heated glass without using hairspray/glue stick/ etc? Maybe just wiping the glass with isopropyl alcohol before print? I really don't want things to get sticky and messy.

Thanks.

edit: typos

Edited March 23, 2016 by Guest

[Labern 737]

I use it and it's great. You will have longer start times as you have to wait for the heat bed to heat up first. Also due to the nature of the heat bed you need to set I higher then the standard um2 heat bed.

Yes you can print without glue but you need to make sure it's leveled well and don't have fans come on 2 quickly. I use gluestick and it lasts over 1 month and is not messy. The reason I use it as I also print with nGen. That's the best thing about the heated bed. You can print with more materials.

The kit comes with a 35w heater which is another great upgrade. I actually installed a 50w in mine instead which makes the start up times super fast but this is not required.

As I own a UM2 then converting the UM2GO was a must.

[2go 6]

Thanks @Labern for reassurance. Will definitely order one.

Does the heated bed warm up before the nozzle and not at the same time? How long does it take? If a minute or two, then no problems.

At this point I am only interested in printing PLA. Do the printed parts separate easily from the glass once it cools down or will I have to pry/use force? That is my main problem with printing on Zebra plate. Sometimes it just does not want to let go

Final thing: are heated bed options controlled via UM2GO interface (custom firmware) or CURA? I could not find anything related to heated bed in CURA besides a single check-box to turn it on/off. Thanks.

[Labern 737]

the bed heats up then the nozzle. Even on the other UM2's the bead heats up before the nozzle so the nozzle doesnt sit there oozing and emptying the chamber while its waiting for the bed. But seeing that the UM2go has a small power supply then it was made to heat seperate to protect the power supply. It will seem weird at first but it works well.

It takes about 3mins for it to heat up for PLA and a bit longer for ABS temps.

When cooled down the parts lift off like they are just sitting on the glass. If its still warm (even 45deg) then it will be stuck hard.

The bed is controlled on the machine by custom firmware that you get from the Gr5 Store. There are 2 versions. standard and Tinkerware. I recommend the Tinkerware version. the version can be a bit behind the original Tinkerware versions. so it would be nice if Tinkergnome started including it in his releases so it keeps up to date.

[2go 6]

Great, that's all I needed to know Thanks!

[tinkergnome 764]

it would be nice if Tinkergnome started including it in his releases so it keeps up to date.

It needs a test, are you interested?

Tinker V16.03

Choose the variant

"Tinker-MarlinUltimaker2go-HBK-16.03.hex"

[Labern 737]

it would be nice if Tinkergnome started including it in his releases so it keeps up to date.

It needs a test, are you interested?

Tinker V16.03

Choose the variant

"Tinker-MarlinUltimaker2go-HBK-16.03.hex"

Awesome, I will try it out today.

Thanks

[meduza 189]

Could we also get a UM2+ Dual firmware for us with special printers?

[tinkergnome 764]

Could we also get a UM2+ Dual firmware for us with special printers?

 

No - that's off topic...

The question is: which rotation direction of the second feeder? AFAIK the plus feeder cannot be mirrored (at least not as easy as the old one). You're using a mirrored "Robert" on your special printer if i'm right? I can compile a variant for you, but this is indeed very "special".

We will have a firmware with switchable axis directions someday...if anyone finds some time...

[2go 6]

Hello @Labern

I will be installing my heated bed later today. Could you help me out a bit? Please see the picture attached. Am I right assuming that thicker white cables from the heated bed go here (circled in red)? Also, the bed came with new heater. Do I need to change PID values after installing it? Thanks!

Edited April 20, 2016 by Guest

[Labern 737]

Yes you are correct in the wire placement.

The printer will work if you don't change the PID values but I did an auto tune using the tinkergnome firmware. I increased the auto tune temp to 200 as that's close to the print temp and it now works great.

It might alarm on the auto tune due to over shooting. If you reset and start auto tune again while still hot you can get it to work.

Once complete you can do it again from cold and it won't alarm.

[2go 6]

Thanks @Labern for your help. Took a few hours dealing with cables but finally got Olsson block and heated bed installed. Installed new 40w heater, did not touch PID yet, nozzle temp seems fine as it is. Well, for now.

Doing second print now and encountered strange thing. Set heated bed temp to 75 degrees. However it gradually drops in the first five minutes to 62 degrees and stabilizes there. Is it a problem or expected behavior? (never had a heated bed so not sure how it is supposed to work) @tinkergnome maybe something firmware related? Using Tinker-MarlinUltimaker2go-HBK-16.03.1.hex

Thanks!

[Labern 737]

This will probably due to you PID settings

Because the power supply is small and to save it from tripping. The heat bed heats separate to the nozzle. The nozzle has priority over the heat bed. So with fans on high it cools the heat bed and if the nozzle is still requiring a lot of heat then the bed drops in temp.

If you tune the pid for the nozzle it should fix this problem.

[2go 6]

Really appreciate your input. I have autotuned PID of the heater. Now it stays perfectly at the required temperature without any drifting whatsoever. However it does not seem to affect temperature of heated bed, it still drops. I print slow and cool so the nozzle should not require a lot of heat and steal it from the bed. I have not turned on PID for heated bed, only the nozzle, as I read there is not much point doing that, or is there?

So while my nozzle stays perfectly at 195 at my heated bed starts at set 75 degrees for the first layer, as soon as the fans are turned on bed temperature decreases to 62 within five layers or so.

@Labern do you not have this thing going at all? Maybe you print with fans off? I've tried turning fans off mid-print and the temp climbed back to 75, turned fans on again and back to 62. I had a brief e-mail discussion with @swordriff about this and he says that it is normal and expected behavior.

@gr5 has a heated bed installation guide here http://gr5.org/hb/ where it says 'use 75C for PLA and 125C for ABS (equivalent to 60C and 100C on um2) because of the location of the temp sensor'. What I think it means is that glass will be 15 degrees cooler than said heat sensor is measuring but I fail to understand why the bed does not keep up to heat to 75 in the place where sensor is attached. Unless the power supply is really on the verge of tripping.

Lastly, I'm getting really awesome prints. Mirror smooth bottom and prints stick like crazy on bare glass without any tape/glue/whatsoever. It's like having a new and way better printer compared to printing without heated bed. So no problems at all, I'm just trying to figure out why it behaves as it does

[Labern 737]

Mine used to drop as you explain but that was because I wasn't given a more powerful heater and was using the stock UM one.

After I changed my heater I have no problems. It may drop about 5 degrees when the fans turn on but it slowly recovers without an issue.

What fan shroud are you using? I have my design and set to be on full at about 2mm.

[Labern 737]

I guess if you auto tuned the bed you would want the fans blowing on it so it would tune in a more real life environment.

[2go 6]

The marking on my new heater indicates 40w. At the moment I use stock metal fan shroud but looking for a replacement. I might as well print yours first I only have (and only ever used) PLA. Do I need some other material for the shroud?

As for tuning bed, not sure if using PID on bed is even worth it as it heats and cools so slow. But will try when I will have more time, couldn't hurt.

[Labern 737]

Yeah I don't know if PID tuning the bed works but maybe worth a shot.

Yes you will need a more high temp filament unless you can get someone else in your area to print one for you. If you did want to try a more high temp one I would recommend nGen from colorfabb. The finish is really nice and it's not hard to learn how to get nice results unlike XT and others. I print it slightly hotter then PLA ( 220 - 230 ) and fans on 30%

[gr5 1,370]

Hi guys!  I didn't see this thread.  It should *not* drop to 62C.  Maybe it drops when the nozzle first comes on but once the nozzle is up to temp the bed should rapidly (within 30 seconds) reach back to 75C.  I've printed ABS with the bed at 100C no problem.  My nozzle heater is 40W.

I think the problem is the firmware you got from tinkerGnome probably has some bug in it.  I wrote the firmware for the um2go hbk and it was tricky code.  tinkerGnome doesn't really have a need or a way to easily test it.  So I urge you to get the firmware here - the "tinker 16.02" version with my special updates:

http://gr5.org/hb/

It's possible that there are no bugs in tinkerGnome's version but that's the most likely thing right now as I can keep my bed above 100C easily.  I've printed ABS with my um2go many times - in fact that's my main ABS printing machine as it heats up so much faster than the UM2.

[gr5 1,370]

Oh - also - don't mess with the heated bed pid. It's fine as is. The problem you are having is that for some reason the heated bed is not getting the power it needs.

[tinkergnome 764]

tinkerGnome doesn't really have a need or a way to easily test it.

 

Both...

 

So I urge you to get the firmware here - the "tinker 16.02" version with my special updates:

http://gr5.org/hb/

 

...i second this!

[gr5 1,370]

There's another possibility - maybe the nozzle is touching the fan shroud - a common problem with olsson blocks. In this case, once the fans come on, the nozzle needs almost 100% of the power and there is very little left over for the bed. Make sure the nozzle is as high as possible - to do this remove only the front left thumb screw to get access to the round nut, heat the nozzle to 150C, remove the bowden and then using a thin screw driver rotate the nut until the nozzle is as high as possible. Maybe also remove the fan shroud and add some kapton tape between the block and the fan shroud.

[2go 6]

@gr5 thanks for your ideas. I can confirm that firmware has nothing to do with it. Installed one from your site. Still drops to sixty something degrees when fans are 100%.

The heated bed and Olsson block was installed at the same time and I have never used Olsson block before so nozzle touching fan shroud is indeed a possibility. Another thing to test

Also, the heated bed works just fine for my purposes as it is As I only use PLA, 75 for first few layers and 62 for the rest is exactly the way I intended to use it in the first place. But it never hurts to learn to solve little problems.

[gr5 1,370]

Well keep in mind that when the heated bed is at 75C the glass is at 60C. I did most of the testing for this kit even though 3dsolex developed the hardware portion. I compared it to a UM2 side by side using a cheap infrared thermometer.

A big difference between the UM2 and UM2go is that the UM2go has a steel plate and the UM2 has an aluminum plate. Aluminum conducts heat much better.

The firmware that I wrote for the um2go gives the nozzle priority. So if the bed is getting cooler than desired that means the nozzle is working hard to keep the nozzle at temperature.

Again, I have a 39W nozzle heater and can easily print with the bed at 75C and it never goes below 74C. No covers on the printer. I very often print ABS and keep the bed above 100C (with ABS I cover the printer top and front so the air is about 40C inside the um2go).

With the old 25W nozzle I could also keep the bed around 75C but just barely. It would often dip to 70C because the nozzle heater was on more -- so the bed was turned off more.

[2go 6]

My nozzle heater was marked 24v40w I think. So it must be 40w heater which is good I guess. My current metal fan shroud is pretty bent out of shape currently so it really might be touching Olsson block somewhere. Will search for a hub that could print me a new shroud out of something more heat resistant than PLA. Will see then.

Kinda related -- could anyone tell me what are the specs for 4 small screws that attach fan shroud to the print head? The ones that were factory installed seem to be made of cheese or some other soft material