heated platform not responding

[dan]

I installed the heated platform from Hive76 but am not able to get
either a temp reading or a response from the MSOFET. I updated the
motherboard firmware to 1.6 and the extruder board to 1.8, so I am
able to select the heated build platform driver and do see the control
panel entries for the build platform temps.

The temp reads at 112, regardless of whether the thermistor is plugged
in or not. I checked the polarity of the pins (since there is an
electrolytic cap) and they are correct. I checked the resistance of
the thermistor and (once the cap settles) it is 100K. The voltage
across the two outside pins is about 0.5 V, which I imagine is part of
the problem. Should it be 5V?

The MOSFET does not turn on regardless of the set temp that I enter.

Suggestions?

[Jordan Miller]

I would check the solder connections on the connector carefully.
sometimes they can get jostled and short across each other. there's
not a lot of room but do you see three well separated pins? do the cap
and resistor each look well attached/soldered? you may need to fix
with a soldering iron.

jordan

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[Eberhard Rensch]

Hi,
as far as I know, the current Firmware v1.8 (coming with RepG 12 and 13) is built with the heated build platform code switched off. You want to download the source code for FW1.8 directly from the GITHub archive (http://github.com/makerbot/G3Firmware) and build & install it with Arduino 0017 (after switching HAS_HEATED_BUILD_PLATFORM to 1 in Configuration.h, of course).

I try to change the firmware as soon as possible, so it'll be possible to switch on heated build platform support via Replicator G.

Cheers,
Eberhard (MakerBot #127)
Blog: http://pleasantsoftware.com/developer/3d/

[Ethan Dicks]

On 2/17/10, dan <spaces...@gmail.com> wrote:
> I installed the heated platform from Hive76 but am not able to get
> either a temp reading or a response from the MSOFET. I updated the
> motherboard firmware to 1.6 and the extruder board to 1.8, so I am
> able to select the heated build platform driver and do see the control
> panel entries for the build platform temps.

Good start.

> The temp reads at 112, regardless of whether the thermistor is plugged
> in or not.

Not good. Just to be sure, you _did_ plug it into A6, not A7, right?
(A7 is closer to the blue trimpot, A6 is to the right of A7).

The firmware is monitoring A6.

> I checked the polarity of the pins (since there is an
> electrolytic cap) and they are correct.

The cap should go between GND and A6 (with the correct polarity, of
course). Is that what you have?

> I checked the resistance of
> the thermistor and (once the cap settles) it is 100K.

You should probably check the resistance of the thermistor at the
connector without the cap - I don't know how you physically
constructed it, so it might not be easy to do so.

Check the thermistor resistance, then breathe on the thermistor. The
resistance should change visibly between room temp and "body temp".

> The voltage
> across the two outside pins is about 0.5 V, which I imagine is part of
> the problem. Should it be 5V?

The pins are (top down)

GND
Vcc
A6

The 4.7K pullup is between the middle pin and bottom pin (Vcc and A6).
The cap is across from the top pin to the bottom pin (GND and A6).
The thermistor is also across from the top pin to the bottom pin (GND
and A6). Other arrangements of the components are likely to lead to
unsatisfactory results. Missing components or poor solder joints are
also likely to lead to unsatisfactory results.

For mine, I wired the thermistor to a three-position 0.1" cable
directly, then put the resistor and the cap (semi-)permanently on the
back of the board. I did this for ease of assembly and
front-clearance to the edge of the top plate of the Makerbot. I also
have a bucket of recycled 2-by and 3-by pin connectors from dead PCs,
so there was no expense involved once I picked up a spare thermistor
and extra nichrome (I rolled my own, I didn't get a kit).

So... check your wiring. You should be able to see the temp fluctuate.

Also, if you want to test your bed, you can use the "C" MOSFET
connector pairs and turn the "fan" checkbox on and off. You won't get
any feedback and thermal control, but you can ensure your bed heats
up.

-ethan

[dan]

good points, but I checked them carefully and also am getting
reasonable resistance measurements from the connector side of the
joints, so I think they are OK

On Feb 17, 12:43 pm, Jordan Miller <jrdn...@gmail.com> wrote:
> I would check the solder connections on the connector carefully.  
> sometimes they can get jostled and short across each other. there's  
> not a lot of room but do you see three well separated pins? do the cap  
> and resistor each look well attached/soldered? you may need to fix  
> with a soldering iron.
>
> jordan
>

[dan]

Is that true for the Windows version? I just downloaded and
installed, didn't compile it.

[dan]

Great idea! I used the C MOSFETs and the fan control to heat up the
platform and was able to monitor the drop in thermistor resistance
from 100K down to 70K as it heated up. So I know that the wiring is
OK.

The pins on the board seem fine too, as there is Vcc from the top pin
to the middle pin and about +0.5 V at A6.

It seems that the problem is that the software is not monitoring A6,
since putting a resistor bridge of 100K between GND and A6 with the
4.7K resistor between Vcc and A6 produces no change in the control
panel reading of 112.

Also, entering a value above 112 into the platform target temp in
control panel does not turn on the A MOSFET.

Eberhard (above) said that the heated build platform code is turned
off by default and that would certainly answer the problem, however, I
was able to select the heated build platform driver in ReplicatorG, so
it seems that the code should be on. I am running the Windows version
of ReplicatorG

Thanks for the help!

On Feb 17, 2:12 pm, Ethan Dicks <ethan.di...@gmail.com> wrote:

[dan]

More data-- Vcc is 7.75 V and there is 7.2 V on A6 when the build
platform is at room temperature and rises to 7.3 V fairly quickly when
the platform is heated with the C MOSFETs. That is consistent with
what I expect as the thermistor resistance decreases with rising
temperature. So that is further evidence that the problem is with
monitoring A6, not the thermistor or platform wiring.

[bre pettis]

Yup, that's a good hack, just plug it into the fan, turn it on in the control panel. Wait at least 5 minutes and print.

Bre

MakerBot Industries
http://makerbot.com

[Jordan Miller]

This is the exact commit of the source code I used in testing... try building and uploading the ArduinoSlaveExtruder.pde firmware manually with the Arduino IDE. You will have to rename Configuration.h.dist to Configuration.h and may have to clean up a few other errors that come up during compile/upload to board:

http://github.com/makerbot/G3Firmware/zipball/HeatedBuildPlatformFirmwareVerifiedToWork_JordanMiller

jordan

[Andrew Plumb]

Dan, there could be something wrong with the 7805 regulator circuit on your board.

Zach, shouldn't Vcc be 5VDC?

Andrew.

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[dan]

It's OK to just let it run open loop continuously? It won't overheat?

On Feb 17, 4:16 pm, bre pettis <brepet...@gmail.com> wrote:
> Yup, that's a good hack, just plug it into the fan, turn it on in the
> control panel. Wait at least 5 minutes and print.
>
> Bre
>

> MakerBot Industrieshttp://makerbot.com

> > makerbot+u...@googlegroups.com<makerbot%2Bunsu...@googlegroups.com>

[dan]

That voltage seemed odd to me too, but the board is working fine
except for this particular problem. It monitors the extruder
temperature and controls it correctly and drive the motor OK too.

> > For more options, visit this group athttp://groups.google.com/group/makerbot?hl=en.

[dan]

Umm, OK, if I have to modify and recompile the code, I'll do that, but
it seems that many folks are getting this to work just using the
downloaded code directly, no? If not, then this needs to be added to
the install instructions on the wiki:

http://wiki.makerbot.com/makerbot-hotness-v1

On Feb 17, 4:18 pm, Jordan Miller <jrdn...@gmail.com> wrote:
> This is the exact commit of the source code I used in testing... try building and uploading the ArduinoSlaveExtruder.pde firmware manually with the Arduino IDE. You will have to rename Configuration.h.dist to Configuration.h and may have to clean up a few other errors that come up during compile/upload to board:
>

> http://github.com/makerbot/G3Firmware/zipball/HeatedBuildPlatformFirm...

[Jordan Miller]

Hi Dan,

I dunno, I haven't heard of problems or successes. At one point the v1.7 extruder firmware was built-in and was working (RepG 0011), but it looks like that version has been taken out of ReplicatorG and replaced with v1.8 which may not be working?

So i posted the tagged version (yay github) of the firmware that I knew was originally working.

If you have RepG 0011 you might still have v1.7 extruder firmware, which I think also works.

I've asked Adam to comment on this thread as he is the main maintainer of the G3Firmware and RepG source code. Hopefully we'll get this straightened out soon.

jordan

[Jordan Miller]

here's all versions of RepG:
http://code.google.com/p/replicatorg/downloads/list?can=1&q=&colspec=Filename+Summary+Uploaded+Size+DownloadCount

I just checked and v0011 does still have v1.7 extruder firmware inside and available to upload to your board. For simplicity, that's where I would start.

jordan

[dan]

I've been using ReplicatorG v0013, motherboard firmware 1.6 and
extruder firmware 1.8, so perhaps that is the problem.

Just to be clear, ReplicatorG v0011, motherboard firmware 1.6, and
extruder firmware 1.7 are known to work?

On Feb 17, 4:51 pm, Jordan Miller <jrdn...@gmail.com> wrote:
> here's all versions of RepG:http://code.google.com/p/replicatorg/downloads/list?can=1&q=&colspec=...

[Jordan Miller]

Hi Dan,

yep, those are versions known to work. i've also updated the wiki to require these versions to help simplify things for now.

please let us know if that fixes things for you!

also, after you change the extruder firmware to v1.7 and you verify that it works for you, you *should* be able to use RepG 0013 without any more problems.

jordan

[dan]

No joy. With ReplicatorG 0011, motherboard version 1.6, extruder
version 1.7, get essentially the same result. The only difference is
that the platform temp is fixed at 105 instead of 112. Tried it on 2
different Windows machines (Vista and Win7), no difference.

[TeamTeamUSA]

That's the deprecated repository. The current one, from which 0013 was
built, is here: http://github.com/makerbot/ReplicatorG

Go!

=ml=

On Feb 17, 1:51 pm, Jordan Miller <jrdn...@gmail.com> wrote:
> here's all versions of RepG:http://code.google.com/p/replicatorg/downloads/list?can=1&q=&colspec=...

[Jordan Miller]

did you check all the solder joints in the connector for good mechanical connections? are there any solder shorts across the pins?

[dan]

Adam's latest firmware version that is now part of ReplicatorG 0013
works great.
Just download the latest 0013 and upgrade the extruder firmware. You
will see an option for heated platform support.
Problem solved.
Thanks Adam!