Replicator MightyBoard Protection

[Gary Crowell]

Coming soon to a Thing near you.  As soon as I make a few more tweaks and finish the documentation.

This is a small PCB, 2" x 0.75" that provides three protection features for the MIghtyBoard:

1. A 1k resistor is added in series with the 5V that is supplied to each endstop cable.  A short can still occur in the cable, but without the 'hard' 5V, all it will do is cause the endstop function to fail.  The endstops will function normally, but the endstop LED's will be dimmer.  (actually, I couldn't see a difference)
2. The MightyBoard 5V linear regulator is replaced with a switching regulator module.  When the existing 5V regulator fails, it apparently applies 24V to the 5V rail, which destroys most of the components on the board, making it unfeasible to repair.  Hopefully if a short occurs on the board, the switching regulator will shutdown gracefully, without propagating damage elsewhere.
3. ESD prevention diodes are added to the microcontroller endstop inputs.  These might aid in preventing ESD damage to the Replicator, but it's difficult to judge whether they would be effective.

It's also pretty easy to install:  Unplug the three endstop cables.  Plug the board into the six endstop connectors.  Plug the cables into the board.  Solder one wire to get 24V in.  Solder one wire to provide an ESD ground.  And, clip the legs off the original regulator.

Total parts cost for a one-off is about $15.

The switching regulator is pretty nice too.  Fully potted; 500ma max out; 7805 pinout.  With 24Vin, it draws 50ma, delivering 200ma at 5V.  Thats 1.2W in for 1W out.  The LM1084 takes 200ma in to do the same; 4.8W for 1W.

The first picture shows it on the bench, with a couple of extra wires added to check the output.  The second shows it installed on the MightyBoard.  This certainly doesn't cover all of the suspected failure modes of the MightyBoard, but it should help a bit.  

Gary  

--
----------------------------------------------
Gary A. Crowell Sr., P.E., CID+

Linkedin  Elance  KE7FIZ

[Bottleworks]

Excellent!

[Gary Crowell]

LCD Protection board (this is the mate to the Endstop Protection board I posted earlier):

This is a small PCB, 1" x 1.5" that provides four protection/enhancement features for the MightyBoard LCD:

1. Adds a 3.3V regulator near the LCD/SD board, where it's likely to supply a much cleaner regulation to the SD card (as opposed to the regulator being 15 inches away across a board and poorly configured cable).
2. Adds bulk and bypass capacitance to the 5V rail at the LCD board (it currently has none at all that I've seen).
3. Adds ESD diodes to all of the signal lines.
4. Adds better level translation and buffers to the SD signal lines (including some termination that I'll have to fiddle with to see if it's effective).

The board installs on the back of the LCD board by plugging into the ribbon cable connector.  The ribbon cable then plugs into this board.  Pic shows it on the LCD board as installed in a Replicator Front Panel Thing.

I can't really say it's effective for fixing SD card reader problems, 'cause I've never experienced any of those problems... but I think there's a good chance...

This too will be a Thing when I get it written up.

[Gary Crowell]

I've published the second Thing in the series of mods for protecting the Replicator MightyBoard.  Part 3 will be posted in a week or so.  Parts and boards are on order for building a small run of the add-on boards.

Replicator MightyBoard Protection: Part 1 - EndStop Board

Replicator MightyBoard Protection: Part 2 - ESD Protection

Gary

[Bottleworks]

That's fantastic.  Is there a place to pre-order the kits? 

[Zach]

And approximate cost?

[Gary Crowell]

At the moment I'm thinking the two boards, EndStop and LCD, would be no more than $40 for the pair, but I'm still pricing thing out and trying to get it lower.

Gary

And approximate cost?

--
You received this message because you are subscribed to the Google Groups "MakerBot Operators" group.
To unsubscribe from this group and stop receiving emails from it, send an email to makerbot+u...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
 
 

--

[Bradley Pearce]

$40 is a great deal. I would be more then willing to buy at $40.

On 5/20/13, Gary Crowell <garyacr...@gmail.com> wrote:
> At the moment I'm thinking the two boards, EndStop and LCD, would be no
> more than $40 for the pair, but I'm still pricing thing out and trying to
> get it lower.
>
> Gary
>
> On Mon, May 20, 2013 at 3:46 PM, Zach <gur...@gmail.com> wrote:
>
>> And approximate cost?
>>
>>
>> On Monday, May 20, 2013 10:56:36 AM UTC-5, Bottleworks wrote:
>>>
>>> That's fantastic. Is there a place to pre-order the kits?
>>>
>>> On Monday, May 20, 2013 11:50:34 AM UTC-4, Gary wrote:
>>>>
>>>> I've published the second Thing in the series of mods for protecting
>>>> the
>>>> Replicator MightyBoard. Part 3 will be posted in a week or so. Parts
>>>> and
>>>> boards are on order for building a small run of the add-on boards.
>>>>

>>>> *Replicator MightyBoard Protection: Part
>>>> 1<http://www.thingiverse.com/thing:78598>
>>>> * - EndStop Board
>>>> *Replicator MightyBoard Protection: Part
>>>> 2<http://www.thingiverse.com/thing:88888>
>>>> * - ESD Protection
>>>>
>>>> Gary
>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------**----------------

>>>> Gary A. Crowell Sr., P.E., CID+

>>>> Linkedin <http://www.linkedin.com/in/garyacrowellsr>
>>>> Elance<http://www.linkedin.com/redirect?url=http%3A%2F%2Fgaryacrowellsr%2Eelance%2Ecom&urlhash=kJm9>
>>>> KE7FIZ <http://www.arrl.org>

>>>>
>>>> --
>> You received this message because you are subscribed to the Google Groups
>> "MakerBot Operators" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to makerbot+u...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>>
>>
>
>
>
> --
> ----------------------------------------------
> Gary A. Crowell Sr., P.E., CID+

> Linkedin <http://www.linkedin.com/in/garyacrowellsr>
> Elance<http://www.linkedin.com/redirect?url=http%3A%2F%2Fgaryacrowellsr%2Eelance%2Ecom&urlhash=kJm9>
> KE7FIZ <http://www.arrl.org>
>
> --
> You received this message because you are subscribed to a topic in the

> Google Groups "MakerBot Operators" group.

> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/makerbot/QYQHnwryU3c/unsubscribe?hl=en-US.
> To unsubscribe from this group and all its topics, send an email to

[AdanA]

Absolutely, me too. Thanks for doing all this, Gary. 

I'm just a week away from having had my Rep1 for a year. Here's hoping with care and attention.... and your precautionary upgrades.... I'll get at least another year out of her before needing to upgrade to whatever whizbang crazysweet printer 2014 will have to offer.

Adan

[MBuser]

Does this apply to the 2x also?

[Jetguy]

Yes and no. 2X has a different board that has a different onboard
regulator. Other than one person getting a DOA bot, there have been no
reported failures of the 5 Volt section, which is the primary fix.

Because the boards are different, so is the 20 pin interface ribbon
cable and likely, that ESD interface protector board doesn't work
either. Because the Replicator 2 and 2X are closed source, even if
Gary or anyone wanted to, we cannot effectivle create fixes or mods to
the Replicator 2 and 2X machines without reverse engineering and that
requires owning one, something I refuse to do even someone gave me
one.

It's one thing to help the group. It's another thing to have to buy a
bot just to reverse engineer the problems so a person can fix them
because Makerbot refuses to release any even basic schematics.
Stupid on thier part, they hurt themselves by hurting you the loyal
customer.

[Gary Crowell]

Yeah, I think the 2 and 2X are good.  They've got ESD protection everywhere, and moved the 3.3V regulator to the LCD board.  The 5V switcher isn't likely to blow up either, and there's an input fuse.  The only thing they don't have are the resistors in series with the hard 5V to the endstops, but I'm sure they don't use that odd cable that promoted shorts in the first place.  I don't know about signal integrity and level translation to the SD card, but my guess is that they improved that too.

Gary

--
You received this message because you are subscribed to the Google Groups "MakerBot Operators" group.
To unsubscribe from this group and stop receiving emails from it, send an email to makerbot+u...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[Warren Delarme]

I'm in for 3 for my rep 1's when they are ready!

[Terence Ang]

sorry for digging up old thread.

is the boards for the mod still available?

[BTHOON]

I've got 5 extra EndStop PCBs.  The first one I built up works, so I can assume the rest are good.  They were all e tested at least.

Happy to send one each to anyone willing to send me $2 for shipping (that includes the bubble package cost and such), and who will take full responsibility if anything doesn't work/they blow up their bot.

[Terence Ang]

Hi BTHOON,

Thanks for the offer, I am not located in the US, will you ship it to Singapore?

If not I will fab it in China and send the spare PCB to other as well.

Did you make the LCD PCB as well?

Regards,

Terence

[Terence Ang]

I ordered the PCB for both the End stop and LCD protectors. I have 3 sets, I am giving away the spares boards (you pay shipping) after I am done with the mods.

I am not located in the US, so unless you are located in Singapore, or some where near Singapore, it might just be cheaper and to order from OSH rather paying for shipping from me.

I can sell you an assembled board for cost + shipping and a small fee, don't know how much yet. 

Only 2 sets of PCB board available, let me know if you are interested, first come, first served.

Regards,

Terence

[Terence Ang]

Oh and thanks to Gary for the design.

On Thursday, 18 April 2013 22:57:44 UTC+8, Gary wrote:

[oldmaker]

Hi Gary, is this board still available ? thanks

[Federico Boldori]

Not a really in-topic question, but someone knows the pinout of the new LCD board into rep2 / rep2x?

The signal are the same btw? the lcd is driven with a serial shifter in 4 bit mode?

Just curious

[Federico Boldori]

Great things, congratulation for your skill !

[Jetguy]

I know the pinout is different than mightyboard rev E for the interface connector.

 

You might get a better answer in the Jetty/ Sailfish forum.

The reason is, that they know the difference in the LCD code if any and could tell you if it was still being driven SPI (I' think it is but have no way to verify myself).

 

So this is just what I know but I think the major changes are no more 3.3 volt pins, the regulator is now moved to the LCD board. This means all 5 volt logic between the boards? More grounds?

Pretty sure again it's stil SPI aka shift register with the odd bit order out ( or just different from the Adafruit SPI backpack), the 5 buttons for control are still basically there, not multiplexed or anything, just straight lines, and that the SD card is level translated before it goes across the wire.

[Federico Boldori]

Thank you Jetguy.

i will try.

[Dan Newman]

On 06/02/2014, 8:03 AM, Jetguy wrote:
> I know the pinout is different than mightyboard rev E for the interface
> connector.
>
> You might get a better answer in the Jetty/ Sailfish forum.
> The reason is, that they know the difference in the LCD code if any and
> could tell you if it was still being driven SPI (I' think it is but have no
> way to verify myself).

Actually, there's no code difference. When I looked, the difference is
entirely electrical. Since the 3v3 regulator was moved to the LCD/button/SD
module in the Rep 2, there's no longer two wires dedicated to 3v3 lines.
Instead, those wires were made, I believe, additional ground wires.

> So this is just what I know but I think the major changes are no more 3.3
> volt pins, the regulator is now moved to the LCD board. This means all 5
> volt logic between the boards? More grounds?

That was my assessment when I looked.

> Pretty sure again it's stil SPI aka shift register with the odd bit order
> out ( or just different from the Adafruit SPI backpack), the 5 buttons for
> control are still basically there, not multiplexed or anything, just
> straight lines, and that the SD card is level translated before it goes
> across the wire.

That's still all the same. There is a slight difference in the firmware
but it is because they tied these signals to different 1280 I/O pins between
the Rep 1 and Rep 2. Nothing that matters to the module itself.

Dan

[Scott Goldthwaite]

I read through this discussion and it's not clear to me which models this works with.  One post said it didn't work on the Rep2X (or at least couldn't determine if it worked on the 2X).  I'm assuming it works on the Rep 1. What about the Rep 2?

[Jetguy]

Only Replicator 1 AKA mightyboard Rev E.

 

Replicator 2 and 2X have a totally different pinout in the connector and require a completely different safety board that was never created because they (2 and 2X are NOT open source for even the most basic of schematics).

Because of that, the community is highly unlikely to develop much of anything beyond the mechanical upgrades that are out now.