Makerbots can make Mendels, right?

1.5 to 2 lb to print a mendel

60 hours for a perfect, no raft print.

Prints tend to last 2-3 hours before you fill your board, or need to recenter for saftey sake.

So 20-30 set ups, in a perfect world.

Even Rapman, which is known to be one of the more reliable printers out there has never managed a full sheet print of menel, that would be a 12+ hour print, and 1 stepper skip kills it all.

Considering you are talking about 100k plus steps in that 12 hour period, and 1 step kills it. Our reliablility is high, but not that high.

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repraplogphase.blogspot.com

I regularly do 8 hour prints on my Rapman with no problems. That presumes that the relative humidity is above 50%, mind.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

What it sounds like to me is that if you buy a Rapman and get it working as well as Forrest's, there's not reason why you couldn't cut up a mendel into ~8 hour long prints, then sell the finished kit at $300 now or (hypothetically) $150 down the line. If you did, a single kit of mendel would pay for 30 or 15 lbs of ABS, respectively (based on makerbot price for natural ABS, while consuming only about 2 lbs. I'm not saying you could make a living off of your rapman or anything, but even if we up the time spacexula has quoted by 33% for slop room, to 80 hours.. If you set up a 8 hour print before you leave for work or school every weekday, then every two weeks you've produced a set of printed mendel parts, which cost you ~$20 in plastic. That's $130 - $280 over cost of materials. The electricity cost is going to depend on where you live, obviously, but I'm thinking it isn't going to be anything excessive. Bitsfrombytes sells the rapman with a 60 watt power supply. If that's what it takes to run the machine while printing, then you're talking about 4.8 kilowatt hours per print. Portland General electric lists $.08 per kilowatt hour - that might not be the up to the minute price and your mileage may vary, but as an estimate, that's $.384 - less than 50 cents of electricity. That means one mendel print will likely pay for all the electricity you will ever use with your machine - it's a pretty negligible cost.

It sure sounds to me like a Rapman could easily be made to pay for itself, even when the price of mendel parts drops. Even for $100 or less, IF your machine is reliable enough to run an 8 hour print unattended, you can make a rapman pay for itself, its power consumption, and its feedstock by making and selling mendel parts.

I said I regularly do 8 hour prints with my Rapman. I work out of my home. I'd never leave it for 8 hours unattended. It's a very good, solid machine. Occasionally, however, it goes south. A few weeks ago, for example, I went next door to help my sister set up a new printer. When I came back 45 minutes later I discovered that my Rapman had partially reset leaving the xy positioning still and the extruder happily extruding. The extruder barrel was buried in about 10 cubic centimeters of molten ABS. The experience left me with an extruder barrel that would have to be completely rebuilt {I had a spare} and a small pit in my acrylic sheet print surface. I replaced the barrel, recalibrated the z-axis settings for the new barrel and was printing again within 30 minutes.

Another thing that regularly happens with Rapman is that the xy positioning system moves so fast that it shakes the frame. Because the bolted acrylic connectors in Rapman aren't secured with lock washers {you really can't tighten the bolts and nuts too tightly for fear of cracking the acrylic sheet parts} this shaking causes the Rapman to shed M3 and M5 nuts quite regularly. You will hear a clatter and find a nut on the floor and then you have to figure out which of the hundreds of bolts it could have been secured to that it must be reconnected to. Mind, Rapman is so overdesigned that you can lose dozens of nuts without having the frame integrity threatened. It is disconcerting, however. I keep a little bowl for loose nuts and then, from time to time, go over my Rapman between prints and thread them back on.


That's the sort of thing that can happen to you even with a Rapman.

Edited 2 time(s). Last edit at 02/23/2010 08:47PM by Forrest Higgs.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Tomyuen, when I get this thing operational, I'll see to it you get a set of printed parts. As for other stuff, try makerbot.com for electronics and extruder.

In my experience, the cost of labor dwarfs any other costs of making stuff with a RepRap. You can't just say "if your machine is reliable enough" because no one has managed to make a super reliable machine without investing hundreds of hours of their own time learning about RepRaps and making lots of adjustments to a machine to make it reliable. You then have to account for that upfront labor cost.

You could amortize that learning time by building 3 or 4 RepRaps. At that point you have sunk $2000+ in materials and $2000+ in learning time and assembly. Now when you try to earn that money back you run a risk of using up the demand. I'm sure you could sell 5 or 6, but it seems quite risky to assume you can sell the dozens you need to make up your sunk costs.

Any way you slice it up, labor kills you.

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Darwin clone, Gen 2 electronics, Arduino Duemilanove w/ AtMega328, 5D Firmware, Pinchwheel extruder
[www.codeerrors.com]

Also must Remember Forrest is one of the premier RepRap users in the world.

Hey Forrest, tell your wife that, I am sure the will quiver.

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repraplogphase.blogspot.com

spacexula Wrote:
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> Also must Remember Forrest is one of the premier
> RepRap users in the world.
>
> Hey Forrest, tell your wife that, I am sure the
> will quiver.

Beg pardon? What are you talking about?

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Sorry, it was a joke, obviously a bad one.

If any person can calibrate a Rapman it's you, considering some of the work you have done, and how active you are over at the BfB forum.

I would say you are one of the more well known people in the community, therefore the "premier RepRap user" statement.

Wives always seem to downplay a husbands acompleshments to their face (at least in my experence, even when they brack behind your back about you).

Basically it was a completament, completely FUBARed.

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repraplogphase.blogspot.com

spacexula: Mostly, I was confused. I've been divorced since 1993.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

1 vote for makerbot.... even if its too late!

Mine has now produced 2 and a bit mendels.

Yes, its a LOT of work to get it to the point where its not going to drive you mad. But with a heated build platform (which is easy on the makerbot, and already supported in the firmware... don't know if thats true for Rapman) you can cure the warping problem. (mostly, some parts are just too big. I'm going to have to design my own alternative parts that are a bit more sutible for reprap!)

I'm printing parts seperatly, not least of all because I don't have the blender skills to do it the sheet way. (Plus I'm using slightly different skeinforge settings for some parts).

TheRuttmeister Wrote:
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>
> Yes, its a LOT of work to get it to the point
> where its not going to drive you mad.
>
LOL! First generation equipment is always like that.
>
> But with a
> heated build platform (which is easy on the
> makerbot, and already supported in the firmware...
> don't know if thats true for Rapman) you can cure
> the warping problem. (mostly, some parts are just
> too big.
>
I know of several people who are beginning to use heated print surfaces with Rapman. They don't require firmware changes since Skeinforge already has settings for that.
>
> I'm going to have to design my own
> alternative parts that are a bit more sutible for
> reprap!)
>
The mendel parts could certainly use a redesign for ease of printing. Several of the bigger parts seem to me to be unnecessarily nasty. That's not a criticism of Ed, mind. The first cut of any new equipment design is like that. :-)

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

I uploaded my production sheets to Thingiverse

Cuts Mendel down to 24 prints. Just search production mendel

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repraplogphase.blogspot.com

hmmm ... would it make sense to have that up in the wiki?

spacexula Wrote:
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> I uploaded my production sheets to Thingiverse
>
> Cuts Mendel down to 24 prints. Just search
> production mendel


BTW, you officially PWN.

Forrest Higgs Wrote:
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> TheRuttmeister Wrote:
> --------------------------------------------------
> -----
> >
> > Yes, its a LOT of work to get it to the point
> > where its not going to drive you mad.
> >
> LOL! First generation equipment is always like
> that.
> >
> > But with a
> > heated build platform (which is easy on the
> > makerbot, and already supported in the
> firmware...
> > don't know if thats true for Rapman) you can
> cure
> > the warping problem. (mostly, some parts are
> just
> > too big.
> >
> I know of several people who are beginning to use
> heated print surfaces with Rapman. They don't
> require firmware changes since Skeinforge already
> has settings for that.
> >
> > I'm going to have to design my own
> > alternative parts that are a bit more sutible
> for
> > reprap!)
> >
> The mendel parts could certainly use a redesign
> for ease of printing. Several of the bigger parts
> seem to me to be unnecessarily nasty. That's not
> a criticism of Ed, mind. The first cut of any new
> equipment design is like that. :-)

Yeah, its very good for a second gen machine... but I don't agree with some of the design choices they made, plus the whole warping thing.

And how are they driving their heated beds? Does the rapman have the extra capacity to do it in a similar way to Makerbots extra mosfets? (because the only skeinforge difference is the raftless tool, )

TheRuttmeister Wrote:
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>
>
> And how are they driving their heated beds? Does
> the rapman have the extra capacity to do it in a
> similar way to Makerbots extra mosfets? (because
> the only skeinforge difference is the raftless
> tool, )
>
If you're talking about Rapman, individuals are simply adding heated beds to their printers. To the best of my knowledge BitsFromBytes is not currently planning to make a heated bed an intrinsic part of any of their printers.

I don't find that surprising. It's not clear what the best heated bed technology is at the moment or even if heated beds are a clearly good idea.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison