Gen 4 electronics

[pandelume]

I'm thinking about ordering gen 4 pcbs from someplace like
http://www.expresspcb.com/ and having a go at putting them together
myself. However I'm not sure it's a good idea, so I'd appreciate
opinions. I understand some of the early cupcake batches had DIY
electronics kits instead of preassembled boards, so presumably it's
not completely crazy. I figure that doing it this way will probably
save money, but more importantly will save time since I have no idea
when the Makerbot Inc. gen 4 kits will become available. Anyone have
any experience with something like this?

Assuming that it's not a terrible idea, is anyone else interested in
ordering pcbs? The cost of each board decreases as quantity
increases, so for something like the motherboard or extruder
controller if probably only makes sense if four or five people are
going to order.

[doug metzler]

are the gen 4 boards different than what Makerbot is currently offering?

http://store.makerbot.com/extruder-controller-assembled-v2-2.html
http://store.makerbot.com/reprap-motherboard-v1-2.html
etc.

Generally it's a good idea to get the boards and build them up yourself just for the experience and skillbuilding, but from a purely practical standpoint you won't save much money and it'll take a lot of time.

DougM

[Chris Gray]

it'd be fun,  I dont think it's a terrible idea :-)

I doubt you'll save money, even if you discount your time $0/hr.  Somehow there will be hidden costs (do you have the right kind of solder, do you have the proper tip on your iron, gotta nice magnifying glass, tweezers, what about a solder wick). and dont forget that one 2cent resistor you'll forget to order (or drop on the floor) that will result in a second $8 shipping and handling fee.  

all that being said, my *only* resistance would be thinking it will cost less. It may, but I kind of doubt it.  If you've got access to a stocked lab you're in a better position to reduce the costs. 

The greatest part about the makerbot is that it brings together so many disciplines.  I'm assuming since you're asking questions about soldering a board you're somewhat new to it?  so I say go for it!   the community is awesome and will help you if you get stuck 

as for projects, like you said, this board isnt a super tough board, it's relatively high-tech so what you learn applies to all kinds of other high end electronics.  It's also low tech enough that you can see the parts, dont have to worry about very fast clocks, and there isnt a BGA (ball grid array,  where the pins are under the chip) part in sight.  

should be fun

On Mon, Dec 13, 2010 at 2:14 PM, pandelume <pand...@gmail.com> wrote:

[Matthew Wilson]

I'd order a set and wait. You might get them faster, but it will cost
more (possibly a lot more) and you'll do a lot more work figuring out
what to order and then assembling them.

On Mon, Dec 13, 2010 at 2:14 PM, pandelume <pand...@gmail.com> wrote:

[pandelume]

@doug, the current electronics for sale at Makerbot are gen 3 - in
other words the current cupcake electronics. The thing-o-matic comes
with the gen 4 boards, as explained here: http://wiki.makerbot.com/thingomatic

I already have an SMT toolkit, which I purchased with just this sort
of thing in mind - but I don't have much experience. With respect to
cost, I crunched some numbers for the gen 4 stepper and mechanical
endstop (which would be on the same pcb to save money - they would be
cut apart after delivery) and it looks like the sweet spot for the
whole shebang is about 16-20 boards, or 4-5 orders of 4 boards each -
cost ~$50.3 - $49.5 apiece, not including all shipping. For
comparison, the gen 3 assembled board and opto endstop kit from
Makerbot is $40 (35 for the controller, 5 for the endstop kit) plus
shipping. So definitely more expensive than what you could order
today, even before counting labor. I have no idea what the gen 4 sets
will sell for, but I imagine it'll be more expensive than the gen 3.
What I'm mostly concerned about is that the thing-o-matics will ship
out without many electronics left over, so that they either won't be
for sale at all, or will be snapped up in about 10 minutes.

The numbers also suggest that it probably doesn't make much sense to
do this for the motherboard or extruder controller if you can buy them
direct, since you'd need 16 orders of one apiece instead of 4 orders
of 4 before you'd reach the sweet spot on the expresspcb curve.
Here's hoping they are for sale at Makerbot soon.

Having said all that, I'm still tempted to do it for the steppers/
endstops if nothing else - assuming I can find 3 other people that are
interested. Any takers?

Paul

On Dec 13, 2:39 pm, Matthew Wilson <unrepentantg...@gmail.com> wrote:
> I'd order a set and wait.  You might get them faster, but it will cost
> more (possibly a lot more) and you'll do a lot more work figuring out
> what to order and then assembling them.
>
>
>
>
>
>
>
> On Mon, Dec 13, 2010 at 2:14 PM, pandelume <pandel...@gmail.com> wrote:
> > I'm thinking about ordering gen 4 pcbs from someplace like

> >http://www.expresspcb.com/and having a go at putting them together

[doug metzler]

I can do the SMT stuff, I'd even be willing to help out anyone who can't.

Can you send me a link to the Gen 4 electronics?  I'm having a hard time differentiating between generations and revision numbers :-)

Thanks,

DougM

[pandelume]

No problem, the eagle files are here:

Motherboard: http://www.thingiverse.com/thing:4968
Extruder Controller: http://www.thingiverse.com/thing:4969
Stepper Driver: http://www.thingiverse.com/thing:4970
Endstop: http://www.thingiverse.com/thing:4971

Paul

> > > >http://www.expresspcb.com/andhaving a go at putting them together

[doug metzler]

Ok, just for fun I loaded the extruder controller into BatchPCB and they came back with $21.  The only downside to this is the turnaround time could be up to a month, but lately it's been hovering around 2 weeks.  My last order was on 12/1 and shipped today, so that's just over 2 weeks.

Given this I think we should pool up our order for parts, but get the boards made independently (or we could pool that too if people want to).  If we order soon we could easily have both parts and boards in-house for the January 29 meeting.  Some ambitious person could even have the boards stuffed and running.

So I'm in for the motherboard and the extruder controller, but out for the stepper driver and the endstop since I have my own designs for both of those.

I guess I better order an Arduino Mega...  Do you know if the Mega is pin-compatible with the Mega2560?  I'd rather get the 2560...

Thanks,

DougM

[pandelume]

@Doug, I think the mega 2560 is compatible with most mega shields, but
it might be worth asking the makerbot folks to be sure.

I tried uploading the extruder controller to batchpcb, but it gave me
a failure error due to violating the minimum trace width
requirements. Did you edit the board so that it would pass?

I also uploaded the other boards, with the following price results:

Motherboard: $42.04
Stepper controller: $12.32
endstop: $2.85
Thing-o-matic heater board: $55.89

For comparison, if ordered from expresspcb.com you'd have to order 6
combined stepper controller and endstop boards (to be cut apart after
delivery) to beat the batchpcb price per board - not counting handling
charges or shipping. The expresspcb boards would also not be nearly
as nice, having no soldermask or silkscreen and needing to be cut
apart prior to use. On the other hand, you'd only need 2 expresspcb
motherboards to beat the batchpcb price - although with no solder mask
I don't know that the motherboard as designed would be easy to
assemble.

Speaking of which, I noticed that there was a lot more copper in the
top and bottom layers after cam processing than there appeared to be
on the board layout alone. Did I do something wrong in the
processing, or is it a ground plane or something? At the moment I'm
afraid to use these because I don't know if I did it right.

Paul

> > > > > >http://www.expresspcb.com/andhavinga go at putting them together

[doug metzler]

I noticed that too - I was going to drop a note to the BatchPCB guy and see if he thought it was a real problem or a phantom problem.  It looked like maybe it was just the one pad for the USB chip and I have an alternate pad for that so I might ditz with it when I have time.

I'd like soldermask :-)

On the question about more copper, which board?

How many people have expressed interest thus far?

Thanks,

DougM

[Paul Connor]

So far as I know, you're the only person who's expressed any interest
in building gen 4 electronics. Hopefully some others will turn up
soon.

I'd say that batchpcb is the only way to go - if only I'd known about
it, I'd have suggested it from the start :) Regarding the seemingly
excess copper, I noticed it on the motherboard and stepper controller,
but if may be on the others as well and I didn't notice it. I've
attached the top copper files for the motherboard and stepper in case
you'd like to take a look. I don't know all that much about eagle or
electronics design software, so these were generated using the cam
tool and instructions here: http://www.sparkfun.com/tutorials/109 I
downloaded the board files, opened them in eagle, and ran the cam
process from sparkfun. I suspect the "extra" copper is supposed to be
there, but I admit to being confused why it appears in some
representations of the board but not in others.

Thanks for the help,

Paul

[doug metzler]

great news, I got a reply from the BatchPCB guy - he said:

Yeah this pcb design was fine, just glitches in the bot.  I passed it.

So I have the passed rev of that one board ready to order.  We'll probably have to get him to manually pass the other designs as well if we want to get those made.

what next?

DougM

[Paul Connor]

I uploaded all the others including the heater board - the only one
that failed was the extruder controller, so I think we're good to go
assuming that I generated the gerber files correctly.

I looked at the component lists for the stepper controller and endstop
on thingiverse and all the parts missing suppliers were available from
digikey - I assume that'll be the case for the other boards, but I
haven't finished going through them yet. I'll attach a spreadsheet
with the supplier part numbers and quantities when I finish.

Paul

[doug metzler]

Send me the list when you get it done - I probably already have most of the passives in stock so it's a matter of the connectors and the actives.

Should I go ahead and order 2 Extruder Controllers and you order one each of everything you want, and an extra motherboard for me?  Then I'd owe you about $20, so maybe I'll make the digikey order for both of us if it works out right.

DougM

[dave/lenore plassman]

Has anyone done anything with fabber systems not based on belt drives?  Most of my interests are really around prototyping rather than production per se.  Speed therefore is not too critical.  I'm looking at a 3 dimensional lead screw driven system.   What are thoughts anybody might have?  Dave
 

---

Date: Mon, 20 Dec 2010 19:53:36 -0800
Subject: Re: Gen 4 electronics
From: doug.m...@gmail.com
To: seattle...@googlegroups.com

[pandelume]

@Doug, sounds like a plan - I'll send the list as soon as I finish.
I just want to confirm that the files I generated look ok to you (per
a previous post). I attached top copper files for the stepper and
motherboard, so if you would be kind enough to compare them with your
own files I'd really appreciate it. With respect to the components, I
don't mind doing it either way. I suppose it makes sense to order
everything together to save on shipping, but I don't think we'll be
ordering enough to get much in the way of volume discounts. But we
can order separately if you prefer.

@dave/lenore, this might be better as a new thread, but there's
nothing wrong with using screw drive on all axes - in fact the cupcake
and thing-o-matic have a screw-driven Z-stages (cupcake is M8 threaded
rod and thing-o-matic is something like 1/4"-16 acme screw). I also
don't think that a 3-axis lead screw setup needs to be very slow,
particularly in this application since there are no cutting forces to
deal with, so you can gear your steppers for fast travel if you like.
Lots of steppers can be driven fairly fast anyway, so you could just
check your motor specs and do direct drive. But really the only
reason to switch to lead screws is for increased load capacity - they
can theoretically be more accurate, but I don't think you need it for
FDM in the Makerbot/reprap style. The specs for the thing-o-matic
are .0008" in x and y and .0002" in z. Even if you round everything
to say +/-.001", so long as your layer registration is good (no z-
wobble), the build quality is influenced far more by the toolpath
quality and the extruded filament width than the xyz positioning.
Having said that, backlash due to poorly tensioned belts would be bad
for quality, but I think that's more a maintenance issue. What
exactly did you have in mind and why would you prefer leadscrews?
Maybe a hybrid machine with standard milling and FDM capability?

Paul

On Dec 20, 10:05 pm, dave/lenore plassman <plassmand...@hotmail.com>
wrote:

> Has anyone done anything with fabber systems not based on belt drives?  Most of my interests are really around prototyping rather than production per se.  Speed therefore is not too critical.  I'm looking at a 3 dimensional lead screw driven system.   What are thoughts anybody might have?  Dave
>

> Date: Mon, 20 Dec 2010 19:53:36 -0800
> Subject: Re: Gen 4 electronics

> From: doug.metz...@gmail.com

> To: seattle...@googlegroups.com
>
> Send me the list when you get it done - I probably already have most of the passives in stock so it's a matter of the connectors and the actives.
>
> Should I go ahead and order 2 Extruder Controllers and you order one each of everything you want, and an extra motherboard for me?  Then I'd owe you about $20, so maybe I'll make the digikey order for both of us if it works out right.
>
> DougM
>

> On Mon, Dec 20, 2010 at 11:48 AM, Paul Connor <pandel...@gmail.com> wrote:
>
> I uploaded all the others including the heater board - the only one
> that failed was the extruder controller, so I think we're good to go
> assuming that I generated the gerber files correctly.
>
> I looked at the component lists for the stepper controller and endstop
> on thingiverse and all the parts missing suppliers were available from
> digikey - I assume that'll be the case for the other boards, but I
> haven't finished going through them yet.  I'll attach a spreadsheet
> with the supplier part numbers and quantities when I finish.
>
> Paul
>
>
>
>
>
>
>
> On Mon, Dec 20, 2010 at 9:46 AM, doug metzler <doug.metz...@gmail.com> wrote:
> > great news, I got a reply from the BatchPCB guy - he said:
>
> > Yeah this pcb design was fine, just glitches in the bot.  I passed it.
>
> > So I have the passed rev of that one board ready to order.  We'll probably
> > have to get him to manually pass the other designs as well if we want to get
> > those made.
>
> > what next?
>
> > DougM
>

> > On Fri, Dec 17, 2010 at 6:50 PM, Paul Connor <pandel...@gmail.com> wrote:
>
> >> So far as I know, you're the only person who's expressed any interest
> >> in building gen 4 electronics.  Hopefully some others will turn up
> >> soon.
>
> >> I'd say that batchpcb is the only way to go - if only I'd known about
> >> it, I'd have suggested it from the start :)  Regarding the seemingly
> >> excess copper, I noticed it on the motherboard and stepper controller,
> >> but if may be on the others as well and I didn't notice it.  I've
> >> attached the top copper files for the motherboard and stepper in case
> >> you'd like to take a look.  I don't know all that much about eagle or
> >> electronics design software, so these were generated using the cam
> >> tool and instructions here:http://www.sparkfun.com/tutorials/109 I
> >> downloaded the board files, opened them in eagle, and ran the cam
> >> process from sparkfun.  I suspect the "extra" copper is supposed to be
> >> there, but I admit to being confused why it appears in some
> >> representations of the board but not in others.
>
> >> Thanks for the help,
>
> >> Paul
>

> >> On Fri, Dec 17, 2010 at 5:22 PM, doug metzler <doug.metz...@gmail.com>

> >> wrote:
> >> > I noticed that too - I was going to drop a note to the BatchPCB guy and
> >> > see
> >> > if he thought it was a real problem or a phantom problem.  It looked
> >> > like
> >> > maybe it was just the one pad for the USB chip and I have an alternate
> >> > pad
> >> > for that so I might ditz with it when I have time.
>
> >> > I'd like soldermask :-)
>
> >> > On the question about more copper, which board?
>
> >> > How many people have expressed interest thus far?
>
> >> > Thanks,
>
> >> > DougM
>

> ...
>
> read more »

[pandelume]

Apparently these strings are divided after all, since my reply to dave/
lenore didn't seem to come through to this email conversation. In any
case, my reply to Doug is reproduced here:

@Doug, sounds like a plan - I'll send the list as soon as I finish.
I just want to confirm that the files I generated look ok to you (per
a previous post). I attached top copper files for the stepper and
motherboard, so if you would be kind enough to compare them with your
own files I'd really appreciate it. With respect to the components,
I
don't mind doing it either way. I suppose it makes sense to order
everything together to save on shipping, but I don't think we'll be
ordering enough to get much in the way of volume discounts. But we
can order separately if you prefer.

Paul

On Dec 20, 7:53 pm, doug metzler <doug.metz...@gmail.com> wrote:
> Send me the list when you get it done - I probably already have most of the
> passives in stock so it's a matter of the connectors and the actives.
>
> Should I go ahead and order 2 Extruder Controllers and you order one each of
> everything you want, and an extra motherboard for me?  Then I'd owe you
> about $20, so maybe I'll make the digikey order for both of us if it works
> out right.
>
> DougM
>
>
>
>
>
>
>
> On Mon, Dec 20, 2010 at 11:48 AM, Paul Connor <pandel...@gmail.com> wrote:
> > I uploaded all the others including the heater board - the only one
> > that failed was the extruder controller, so I think we're good to go
> > assuming that I generated the gerber files correctly.
>
> > I looked at the component lists for the stepper controller and endstop
> > on thingiverse and all the parts missing suppliers were available from
> > digikey - I assume that'll be the case for the other boards, but I
> > haven't finished going through them yet.  I'll attach a spreadsheet
> > with the supplier part numbers and quantities when I finish.
>
> > Paul
>

> > On Mon, Dec 20, 2010 at 9:46 AM, doug metzler <doug.metz...@gmail.com>

> > wrote:
> > > great news, I got a reply from the BatchPCB guy - he said:
>
> > > Yeah this pcb design was fine, just glitches in the bot.  I passed it.
>
> > > So I have the passed rev of that one board ready to order.  We'll
> > probably
> > > have to get him to manually pass the other designs as well if we want to
> > get
> > > those made.
>
> > > what next?
>
> > > DougM
>

> > > On Fri, Dec 17, 2010 at 6:50 PM, Paul Connor <pandel...@gmail.com>

> > wrote:
>
> > >> So far as I know, you're the only person who's expressed any interest
> > >> in building gen 4 electronics.  Hopefully some others will turn up
> > >> soon.
>
> > >> I'd say that batchpcb is the only way to go - if only I'd known about
> > >> it, I'd have suggested it from the start :)  Regarding the seemingly
> > >> excess copper, I noticed it on the motherboard and stepper controller,
> > >> but if may be on the others as well and I didn't notice it.  I've
> > >> attached the top copper files for the motherboard and stepper in case
> > >> you'd like to take a look.  I don't know all that much about eagle or
> > >> electronics design software, so these were generated using the cam
> > >> tool and instructions here:http://www.sparkfun.com/tutorials/109 I
> > >> downloaded the board files, opened them in eagle, and ran the cam
> > >> process from sparkfun.  I suspect the "extra" copper is supposed to be
> > >> there, but I admit to being confused why it appears in some
> > >> representations of the board but not in others.
>
> > >> Thanks for the help,
>
> > >> Paul
>

> > >> On Fri, Dec 17, 2010 at 5:22 PM, doug metzler <doug.metz...@gmail.com>

> > >> wrote:
> > >> > I noticed that too - I was going to drop a note to the BatchPCB guy
> > and
> > >> > see
> > >> > if he thought it was a real problem or a phantom problem.  It looked
> > >> > like
> > >> > maybe it was just the one pad for the USB chip and I have an alternate
> > >> > pad
> > >> > for that so I might ditz with it when I have time.
>
> > >> > I'd like soldermask :-)
>
> > >> > On the question about more copper, which board?
>
> > >> > How many people have expressed interest thus far?
>
> > >> > Thanks,
>
> > >> > DougM
>

> > >> > On Fri, Dec 17, 2010 at 2:19 PM, pandelume <pandel...@gmail.com>

> ...
>
> read more »

[dave/lenore plassman]

I find tensioning belts and adjusting pulleys to be kind of a pain and it would be nice to just couple the motors to the shafts and go from there.
 
> Date: Tue, 21 Dec 2010 15:19:07 -0800
> Subject: Re: New Topic
> From: pand...@gmail.com
> To: seattle...@googlegroups.com

[doug metzler]

@paul, I think you're fine - the top layer is copper fill, which I think is what's throwing you off.

Attached is a collage of all the layers I got when I put it through.  If yours looks like mine then everything is good.

If you're still nervous, though, I have attached the zip of the files that I uploaded to BatchPCB.

Let's order parts separately - the savings in shipping isn't significant and it keeps the bookkeeping time to a minimum.

Do you still want me to order your extruder board or do you want to submit your own?  I'm good either way.  If you submit your own you'll need to email sup...@batchpcb.com when it fails and ask him to manually approve it.  He's really good, though, probably 1/2 day turnaround.

Thanks,

DougM

[Gene Buckle]

On Wed, 22 Dec 2010, dave/lenore plassman wrote:

>
> I find tensioning belts and adjusting pulleys to be kind of a pain and
> it would be nice to just couple the motors to the shafts and go from
> there.

Isn't the reason for the belt system is the speed at which they can move
the print head?

g.

--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
http://www.simpits.org/geneb - The Me-109F/X Project

ScarletDME - The red hot Data Management Environment
A Multi-Value database for the masses, not the classes.
http://www.scarletdme.org - Get it _today_!

Political correctness is a doctrine, fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a turd
by the clean end.

[Paul Connor]

I don't know for sure, and I certainly wouldn't want to speak for the
Makerbot people, but I think at least part of the reason for using
belts is that they're cheap and can be used off the shelf with minimal
modification and low part count. On the cupcake x axis, for example,
you have one drive pulley, one idler pulley, a belt, some lasercut
clamps, and a few nuts and bolts. A lead screw would either be a
relatively expensive off the shelf part (or one that was configurable,
like from misumi) or a custom machined part. In addition you'd need a
coupler, some bearings, anti-backlash nut, and a more complicated
mounting arrangement on the machine body and the x-stage. Which is
not to say that it's particularly hard or all that incrementally
expensive, but when you're shooting for a hobby/DIY price of under
$1000 every little bit adds up, so to speak. Off the top of my head,
I would imagine that lead screws on xyz on the cupcake would have
added at least $200 to the cost of the kit.

But there's no reason not to do it if you want to. Are you thinking
of designing a whole new machine or modifying the thing-o-matic or
cupcake?

[doug metzler]

Does anyone know for sure whether it's a speed issue?  I'm starting to build my machine but I'm building it from scratch (except for the boards obviously) and was planning on building a screw-driven machine.  But if it's too slow that could be a whole lot of misdirected work.  The problem with running the steppers faster is they lose torque as they speed up so you're much more liable to miss steps.

Thanks,

DougM

[andrewn]

You will need to make sure that none of the forces running down the screw from starting and stopping are taken along the shaft of the stepper motor, the belt isolates these. You'll need some form of slip coupling when joining the screw in line with the motor.

If you change the pitch of the thread on the screw then you not only change the speed at with the platform moves but also the resolution of the steps along the screw for each of the motor steps.

Something else to consider. Cheers.

--
Andrew Nicholson    and...@lesto.com

[doug metzler]

Here is what I find amazing

at Grainger, acme threaded rod (1/2-10) 3' is $8  But the corresponding nut is $38.
at McMaster, acme threaded rod (1/2-10) 3' is $61  But the corresponding nut is $5.57.

I guess I'll be making 2 orders.

I've seen this in components as well - Digikey vs. Mouser, but nothing as dramatic as the above.

Thanks for the advice Andrew - I'll have bearing blocks that carry the linear load on the screws and will probably use spider couplings for the connection, at least for the first rev.

I'm figuring that if I use the above 1/2-10 acme I'll still be able to get respectable speed vs. say, 1/2-24 threaded rod from Lowes.

DougM