Multiple hour print lifts from ABP. How to fix?

[E. Smith]

I have been trying to print part 1 of the Printable Unicorn Pen
Plotter (http://www.thingiverse.com/thing:4200) and each time a little
over halfway through (~1:30) the part detached from the ABP. Which
then causes the extruder head to crash into it and the print needing
to be aborted. On my second try, I tried taping down the raft to the
ABP's belt, but that didn't help. I finally ended up putting some
Kapton tape directly on the belt and printing on that. That worked
better and it printed further along, but there was enough slack in the
belt that the part lifted up causing the same problem.

Had anyone else had this problem? I was thinking of removing the ABP
belt and putting some Kapton tape directly on the aluminum heat
spreader, will this work? Any suggestions are appreciated!

[Ross Mosshart]

Prints with a large base reeaaaaalllly dont like the ABP, I've put probably fourty hours of print time on mine, and it seems like I put a new belt on every ten hours, or else the belt will warp with the prints, regardless of PLA or ABS.

Your best bet is to keep an HBP or acrylic build platform on hand for large area/really long prints. Not saying that you can't use the ABP for it, just that it will be somewhat picky on parts

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[Paul De Bra]

When you just tape over the heat spreader you effectively end up with
the Heated Build Platform.
I have been contemplating doing the same. No matter how tight the ABP
belt is, with enough force the belt can be lifted up enough (on the
sides) to cause the problem you mention. The problem is most visible
when you have a small footprint and a tall object.
The plastic bag handle http://www.thingiverse.com/thing:3230 gave me
this problem.

[Stan Seibert]

I seem to recall seeing nycdesigner at Botacon 0 showing off a nice
mechanism for quick-swapping build platforms using DB9 connectors to
handle the wiring interface between the extruder controller/relay
board and the platform itself. I've been meaning to do something like
this for a while so I can swap easily between the HBP and ABP,
depending on the needs of the print. (Both platforms are awesome in
their own way.)

On Mar 6, 1:29 pm, Ross Mosshart <ross.mossh...@gmail.com> wrote:
> Prints with a large base reeaaaaalllly dont like the ABP, I've put probably
> fourty hours of print time on mine, and it seems like I put a new belt on
> every ten hours, or else the belt will warp with the prints, regardless of
> PLA or ABS.
>
> Your best bet is to keep an HBP or acrylic build platform on hand for large
> area/really long prints. Not saying that you can't use the ABP for it, just
> that it will be somewhat picky on parts
>

[nycdesigner]

http://www.thingiverse.com/thing:4602

[Jordan Miller]

dunno but yes the ABP material is a HUGE disappointment. it is not marketed as a disposable product; this is disingenuous in the least and false advertising at the worst. indeed I have seldom had it working for several successive prints. e.g. I could print two prusa plates before the belt was ruined and prints started completely failing due to belt warp; you still have to babysit your prints so I don't get where the "-o-matic" part comes in at all. we ordered a bunch of extra belts but we don't use them-- the new super tight tolerances on the ToM kerf means it is harder to put together and take apart without shattering a piece, the acrylic doesn't meet lifetime needs here either and of course the acrylic replacement parts are not available as far as I know. the acrylic and wood kerf tolerances are different because apparently they do not take into account material property differences, so our parts required a lot of sanding to put together. it's completely without logic.

given the higher price of everything on the ToM we have really been nonplussed by the whole thing and our next purchase will be a RepRap Mendel (getting the parts together right now). :-(

we reeeeeaaaally tried to love the ToM, but it leaves a sour taste in the mouth, especially given it's high high price. you can build two mendels for that price with 8x the build volume (each mendel had 4x the build volume). there's simply no contest.

it's soooooo heartbreaking.

jordan

[Paul De Bra]

I find only the pre-made belts to be really disappointing as they are
too tight and you might break things trying to fit them.
I quickly gave up and used the provided material (plastic + kaptop
tape) to make my own belt which is tight but not to the point of
breaking things. Next thing I did was change the time the motor runs
so that the belt makes a full rotation (my experience is that the
object does not stick well to the kapton tape, probably because of
temperature difference), so my object is never on the tape.
I'm running the ToM with ABP without problems except for the issue
with narrow tall objects.

[Matt G]

For longer duration, denser prints I've really been liking the heated
build platform over the Automated Build Platform -- though I will say
that I've printed enough smaller objects on an ABP in the BotCave to
have a lot of o-matic in my life. ;-)

It would definitely be worth examining the model and the skeinforge
settings to see if you can make some adjustments to help yourself out.
If you make the part slightly less dense it might not pull away from
the belt as actively (really solid fill can experience more dramatic
shrinking while cooling, making the base less sturdy). Also, you might
add some tabs to the base to help widen the surface area for better
adherence in general -- you can snap them away and clean up the
finished part pretty easily. (Here's an example:
http://blog.makerbot.com/2011/02/25/mouse-ears-defeat-corner-curling-monster/
)

I will warn you that the printable unicorn is not quite as cool as it
looks -- a few folks have printed them and discovered they were really
missing the self-lubricating slider assembly from the MakerBot kit.
Some folks look at the parts list and skip over that part, but that is
the most costly part of the kit and has a lot to do with how well the
unicorns plotters work. Definitely plan on spending lots of time
working on your printed slider to make sure it doesn't bind during pen
lifts and drops.

Good luck -- and keep us posted as to how printing the part works out!

Matt
MakerBot Customer Service

[James McCracken]

I had to clean up my printed slider slightly. Basically used a
triangular needle file to clean out the slots and make sure there were
no little bumps to catch on.

Other than the fact that it's mounted at a slight slant, been working
great ever since.

I did write an arduino program to break it in however. The thing did
2,000 lifts in a little under an hour and then I was satisfied...

[natko]

Not sure if this helps

Actually still on first belt ( repaired with kapton tape repeatedely
with only one 90x100 zone left) but.

Clean with ascetate, run hot for first 2 layers at 140-145 degC then
back to normal 120-125degC alot of it depends on ambient since MB
electronics does not sence ambient.

Also helps if run first layer thin .. me atm its 0.18, wouldnt suggest
this without Z stop setup.

I can do large prints without nopeheads walls with about 0.5mm
deformation on raised walls vertical up to 10mm high from print bed
(belt) but belt relaxes so base will ward (no matter what u do)

Max print size for me ABP done so far is 90x100x75

Hope this helps, running hot for first 2 layers means manually
changing Gcode, my layer (rough work is 0.4mm with stepper extruder
not MBI but mk3)

[Jwo]

How do you change the temperate of the ABP mid-print? Are you manually
adding the gcode?

- Jwo

On Mar 10, 1:03 pm, natko <na...@btinternet.com> wrote:
> Not sure if this helps
>
> Actually still on first belt ( repaired with kapton tape repeatedely
> with only one 90x100 zone left) but.
>
> Clean with ascetate, run hot for first 2 layers at 140-145 degC then
> back to normal 120-125degC alot of it depends on ambient since MB
> electronics does not sence ambient.
>
> Also helps if run first layer thin .. me atm its 0.18, wouldnt suggest
> this without Z stop setup.
>
> I can do large prints without nopeheads walls with about 0.5mm
> deformation on raised walls vertical up to 10mm high from print bed
> (belt) but belt relaxes so base will ward (no matter what u do)
>

> Max print size for meABPdone so far is 90x100x75

[Ben Jackson]

If you raise the initial M109 platform temp in start.gcode you can add
another below the M6 T0 (wait for temp) that sets something lower:

(...)
M109 S140 T0
(...)
M6 T0 (wait for temp, now platform is 140)
M109 S120 T0 (now allow platform to coast down to 120 while first
layers print)
(...)